tag:theconversation.com,2011:/africa/topics/on-the-brain-1563/articlesOn the brain – The Conversation2014-01-15T19:14:39Ztag:theconversation.com,2011:article/178732014-01-15T19:14:39Z2014-01-15T19:14:39ZIt’s electrifying: non-invasive brain stimulation<figure><img src="https://images.theconversation.com/files/38560/original/dn7wc7mb-1389066814.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The scientific evidence for brain stimulation is only in its initial stages.</span> <span class="attribution"><span class="source">Image from shutterstock.com</span></span></figcaption></figure><p>A simple procedure requiring only a nine-volt battery and a few cords strapped to your head is gaining momentum with DIY types eager to improve brain function.</p>
<p>Brain stimulation involves weak electric currents passed into the brain through pads placed on the scalp. The electric current can alter the activity of brain cells and has the potential to improve your ability to learn. </p>
<p>But the evidence for brain stimulation is, so far, thin on the ground. And with no real understanding of the potential dangers of long-term use, the risks of electrical brain stimulation might outweigh the benefits. </p>
<h2>Electrify your brain</h2>
<p>Using a simple device, brain stimulation allows you to alter the activity of brain cells. Early research suggests that this form of brain stimulation, known as transcranial direct current stimulation, may manipulate brain plasticity and improve <a href="http://www.ncbi.nlm.nih.gov/pubmed/21055945">numeracy</a>, <a href="http://www.ncbi.nlm.nih.gov/pubmed/22305346">reading efficiency</a>, <a href="http://www.ncbi.nlm.nih.gov/pubmed/23988131">language learning</a> and <a href="http://www.ncbi.nlm.nih.gov/pubmed/22440856">complex problem solving</a>.</p>
<p>Apart from enhancing the healthy brain, brain stimulation may be able to help people re-learn skills lost through injury or illness. After a stroke, learning to walk again, button a coat or hold a fork can take months of intensive therapy. </p>
<p>If important skills could be re-learnt faster, therapy times would be shorter, people would get better quicker and health-care costs would be reduced. But the scientific evidence for brain stimulation is only in its initial stages. </p>
<h2>All-purpose brain enhancer? Not quite</h2>
<p>There have been many early studies designed to investigate, in principle, whether brain stimulation might work in humans. But most have only a small number of participants, and have experimental designs at high risk of bias, with no control treatment to compare to brain stimulation, investigators who were not blinded (so they knew which group was receiving which intervention), and a lack of random allocation.</p>
<p>We don’t yet have high-quality evidence in the form of randomised controlled trials, which are only just beginning. And although brain stimulation appears safe in the short term (the main risk is the potential for skin burns under the electrodes), long-term safety studies are yet to be completed. </p>
<p>This is not to say that brain stimulation doesn’t work, it’s just that there’s insufficient evidence to tell one way or the other.</p>
<p>But the simplicity of this technology means that early positive findings are enough for those who are keen to try enhancing their brains at home. You can find online instructions about building a brain stimulation unit of your own, and see people using the technique to improve their quiz results on <a href="http://www.youtube.com/watch?v=6V64IXFg9yc">YouTube</a>. But be warned, we still don’t know the potential dangers of such use.</p>
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<figcaption><span class="caption">A DIY brain stimulation enthusiast attempts to stimulate his brain to improve his math skills.</span></figcaption>
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<p>Amidst the growing hype, a <a href="http://www.ncbi.nlm.nih.gov/pubmed/23733050">study published</a> earlier this year highlighted the need for careful policy to ensure public safety while supporting DIY innovation, to avoid driving the practice underground.</p>
<p>The authors advocate “managed technological optimism” that consists of education on the potential benefits and risks of brain stimulation, open communication between DIYers and scientists and active oversight, rather than heavy government regulation.</p>
<h2>The risks</h2>
<p>The effects of brain stimulation depend on a complex range of factors. </p>
<p>The intensity of the electrical current, which part of the brain the electrodes are positioned over (you need to be sending a current to the part of the brain involved in the function you are attempting to improve) and the time that electric current is applied for can all affect results. Some applications of brain stimulation <a href="http://www.ncbi.nlm.nih.gov/pubmed/21495074">may impair</a>, rather than enhance brain function, while <a href="http://www.ncbi.nlm.nih.gov/pubmed/21170277">increasing the application time</a> may give long-lasting effects. </p>
<p>The risk? Inadvertently producing detrimental, long-lasting brain effects that are difficult to reverse.</p>
<p>In people with medical conditions, brain stimulation may impact negatively on other treatments or medications. And the type of brain stimulation needed to give a positive effect may differ depending on the medical condition and a person’s individual brain anatomy. </p>
<p>This means brain stimulation that works for one person may not work for another. A one-size fits all approach to brain enhancement is likely to be impractical and risky.</p>
<p>The ethical implications of brain stimulation are relatively easy to navigate when it’s used for treating disabling medical conditions. But it all gets much more complex when we talk about using brain stimulation in the healthy brain to enhance numeracy, reading, problem solving or learning to kick a football. </p>
<p>Who will have access to this technology? Will it be available in schools, sports training facilities, universities? How will we prevent disadvantaging those whose brains don’t respond? And could this technology simply provide new opportunities for pushy parents to get pushier? </p>
<p>If brain enhancement technology is shown to be effective, these are just a few of the questions we will have to answer.</p><img src="https://counter.theconversation.com/content/17873/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Siobhan Schabrun has received funding from The National Health and Medical Research Council, The International Association for the Study of Pain, Parkinson's QLD Inc and Arthritis Australia.</span></em></p>A simple procedure requiring only a nine-volt battery and a few cords strapped to your head is gaining momentum with DIY types eager to improve brain function. Brain stimulation involves weak electric…Siobhan Schabrun, Research fellow in brain plasticity and rehabilitation, Western Sydney UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/35542011-10-11T03:37:18Z2011-10-11T03:37:18ZSet to fade: is the brain doomed to degenerate?<figure><img src="https://images.theconversation.com/files/4279/original/4264423055_f68e7a1747_o.jpg?ixlib=rb-1.1.0&rect=1%2C38%2C849%2C767&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The brain repairs itself only minimally following damage or disease.</span> <span class="attribution"><span class="source">x-ray delta one</span></span></figcaption></figure><p><em>Welcome to the sixth and final part of _On the Brain</em>, a Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Professor Malcolm Horne, deputy director of the Florey Neuroscience Institutes, and Bradley Turner, Senior Research Officer at Florey, examine why our brains degenerate, and ask whether there is any chance of changing this. Enjoy._</p>
<p>Why does age make the brain so susceptible to degeneration?</p>
<p><a href="http://theconversation.com/victims-of-our-own-success-why-more-of-us-are-facing-dementia-1156">Dementia</a> is a fatal disorder and the third leading cause of death in Australia – it increases markedly with age and approximately one in 100 Australians suffers from it. </p>
<p>Organs such as the liver, gut and blood repair and renovate themselves by regularly replacing damaged or ageing cells. Each of these organs has a <a href="http://www.medterms.com/script/main/art.asp?articlekey=10148">nidus</a> where stem cells manufacture these replacements. But brain and muscle cells endure with very little replacement. </p>
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<img alt="" src="https://images.theconversation.com/files/4264/original/GE_Healthcare.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/4264/original/GE_Healthcare.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=448&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4264/original/GE_Healthcare.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=448&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4264/original/GE_Healthcare.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=448&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4264/original/GE_Healthcare.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=563&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4264/original/GE_Healthcare.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=563&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4264/original/GE_Healthcare.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=563&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Stem cells are only found in a couple of brain regions.</span>
<span class="attribution"><span class="source">GE Healthcare</span></span>
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<p>While the liver can be almost completely repaired, even when as much as 50% is lost through injury or disease, there is only minimal repair of the brain following cell loss through damage or disease.</p>
<p>Animals with simple nervous systems and reptiles have brains that can self-repair but it appears that mammals lost this ability at some point in their evolution. We don’t know when or why this happened. </p>
<h2>Going, gone</h2>
<p>Brain cells can’t store their own energy but depend on being continuously supplied from blood and from their support cells, known as glia, which supply nutrients and other molecules needed for survival, and remove toxins. They act as the nerve cells’ private guardians.</p>
<p>Nerve cells have especially high energy demands, consuming about 20% of the body’s oxygen requirement and 25% of its sugar requirement, and brain cells die only a few minutes after blood supply fails.</p>
<p>Energy is needed to maintain a voltage across the membranes, which is necessary for producing the signals that pass between nerve cells. These connect to each other by long processes called <a href="http://psychology.about.com/od/biopsychology/ss/neuronanat_5.htm">axons</a> or nerve fibres. </p>
<p>It’s worth remembering the axons going from brain to spinal cord or cord to muscle can be more than a metre long. </p>
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<p>In nerve cells, as with all cells in the body, energy is also required for normal cellular functions. Cell <a href="http://learn.genetics.utah.edu/content/begin/cells/insideacell/">organelles</a> must be trafficked, cell parts repaired, renovated or extended, membranes repaired and synthesised. </p>
<p>Such processes demand the manufacture of proteins – <a href="http://www.nobelprize.org/educational/medicine/dna/index.html">DNA and RNA</a>. In carrying out these tasks, molecules “wear out” and must be degraded and removed. </p>
<p>Also, a certain proportion of the newly-synthesised replacement proteins are defective and must be replaced. </p>
<h2>Cleaning up</h2>
<p>Nerve cells can be thought of as miniature factories requiring resources and expending energy for their survival, while producing waste by-products. </p>
<p>They require careful cleaning and maintenance, otherwise there’s the potential for protein to build up as “junk” within the cell, reducing the efficiency of the cell and increasing energy demands. </p>
<p>A common feature of the ageing brain is the appearance of abnormal protein junk piles in nerve cells. Quite often these are harmless, but in some cases they are signatures for degenerative brain disorders such as <a href="http://www.nia.nih.gov/Alzheimers/Publications/adfact.htm">Alzheimer’s disease</a>, <a href="http://www.parkinsons.org.au/about-ps/whatps.html">Parkinson’s disease</a> and <a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Motor_neurone_disease_explained?open">motor neurone disease</a>. </p>
<p>The exact reasons why these sticky protein clumps form in the brain is not well understood but the junk piles most likely reflect waste build up in nerve cells. </p>
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<img alt="" src="https://images.theconversation.com/files/4263/original/800px-Complete_neuron_cell_diagram_en.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/4263/original/800px-Complete_neuron_cell_diagram_en.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=437&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4263/original/800px-Complete_neuron_cell_diagram_en.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=437&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4263/original/800px-Complete_neuron_cell_diagram_en.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=437&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4263/original/800px-Complete_neuron_cell_diagram_en.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=549&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4263/original/800px-Complete_neuron_cell_diagram_en.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=549&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4263/original/800px-Complete_neuron_cell_diagram_en.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=549&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Nerve cells are complex, and can’t be repaired.</span>
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<p>When junk accumulates in cells from other organs, those cells are marked for demolition and replaced. This option is not available for the brain, placing it at increased risk of degeneration with increasing age.</p>
<p>There is a suspicion, but no clear proof, that lifestyles with a focus on exercise, non-smoking, reduced fat and calorie intake, and continuing mental activity may reduce the risk of these degenerations. </p>
<p>There’s also a suspicion that, in some diseases such as Parkinsons, exposure to insecticides, which damage the efficiency of cell transport and disposal systems, may increase the risk of disease.</p>
<p>A key area of research is to better understand how and why these sticky protein clumps form in the brain. </p>
<p>When this is known, there will be a greater chance of designing drugs or lifestyles that prevent or slow the rate of brain decay.</p>
<p>Until then, we must continue to use our heads.</p>
<p><strong>This is the sixth part of our series <em>On the brain</em>. To read the other instalments, follow the links below:</strong>
</p><p><strong>Part One: <a href="http://theconversation.com/picking-your-brains-whats-going-on-inside-your-head-3559">Picking your brains: what’s going on inside your head?</a></strong> <br>
<strong>Part Two: <a href="http://theconversation.com/your-brain-knows-the-moves-you-just-get-in-its-way-3555">Your brain knows the moves (you just get in the way)</a></strong><br>
<strong>Part Three: <a href="http://theconversation.com/brains-addiction-what-makes-heavy-drug-users-different-3556">Brain’s addiction: what makes heavy drug users different?</a></strong><br>
<strong>Part Four: <a href="http://theconversation.com/brains-addiction-is-shooting-up-a-disease-or-a-choice-3560">Brain’s addiction: is shooting up a disease or a choice?</a></strong><br>
<strong>Part Five: <a href="http://theconversation.com/rebuilding-the-damaged-brain-can-stem-cells-be-used-as-repair-kits-3557">Rebuilding the damaged brain: can stem cells be used as repair kits?</a></strong><br></p><img src="https://counter.theconversation.com/content/3554/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Malcolm Horne receives funding from ARC, NHMRC Bethlehem Griffith Foundation, Comercialise Australia.</span></em></p><p class="fine-print"><em><span>Bradley Turner receives funding from NHMRC, Bethlehem Griffiths Research Foundation and Motor Neuron Disease Research Institute of Australia.</span></em></p>Welcome to the sixth and final part of _On the Brain, a Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Professor Malcolm Horne…Malcolm Horne, Honorary (Professorial Fellow) at the Centre for Neuroscience, The University of MelbourneBradley Turner, Senior Research Officer, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/35572011-10-06T23:26:55Z2011-10-06T23:26:55ZRebuilding the damaged brain: can stem cells be used as repair kits?<figure><img src="https://images.theconversation.com/files/4258/original/brain.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">brain</span> </figcaption></figure><p><em>Welcome to part five of _On the brain</em>, a Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Lachlan Thompson, head of the Neurogenesis and Neural Transplantation laboratory at the Florey Neuroscience Institute, explores the brain’s ability to repair itself, with or without medical assistance._</p>
<p>Our brains are finely tuned to perform a remarkable variety of complex tasks. Unfortunately, repairing themselves after injury isn’t one of them. </p>
<p>This means the loss of <a href="http://www.ncbi.nlm.nih.gov/books/NBK11154/">neuronal circuitry</a> that occurs following damage is permanent, as are the functional consequences for the patient. </p>
<p>So can we rebuild the damaged brain? Clinical trials in patients with <a href="http://www.parkinsons.org.au/about-ps/whatps.html">Parkinson’s disease</a> (PD) suggest we can.</p>
<p>In PD there’s a progressive and permanent loss of a group of <a href="http://www.psychologytoday.com/basics/dopamine">dopamine</a>-producing neurons that form an essential pathway in the brain circuitry controlling movement. </p>
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<p>In the late 1970s, <a href="http://www.med.lu.se/expmed/neurobiology/members/anders_bjoerklund">researchers in Sweden</a> found if new dopamine neurons are transplanted into the brain they can survive and restore normal control of movement by essentially replacing the damaged circuitry. Since then, more than 300 PD patients have received dopamine-neuron transplants. </p>
<p>While the results have been astonishingly good for some patients, this therapeutic approach is not without its problems. </p>
<p>The procedure relies on the use of human foetal tissue (acquired from elective abortions) and requires anywhere between two and four foetal donors per patient. Hardly a sustainable or, depending on who you ask, ethical resource. </p>
<p>Also, the overall results have been highly variable and unpredictable between patients. This very likely is also related to the use of foetal tissue, which is virtually impossible to standardise in terms of the number and kinds of cells that are grafted into each patient. </p>
<h2>Where to now, then?</h2>
<p>We know that in principle the therapeutic strategy outlined above has great potential but there’s clearly a need for a better cell source. Enter <a href="http://stemcells.nih.gov/info/basics/">stem cells</a>.</p>
<p>The hype and expectation surrounding stem cells over the last decade has been impossible to ignore. Most of the excitement in this field surrounds the most powerful <em><a href="http://www.explorestemcells.co.uk/pluripotentstemcells.html">pluripotent</a></em> stem cells that have the ability to generate any cell type in the body, including neurons for brain and spinal cord repair. </p>
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<img alt="" src="https://images.theconversation.com/files/4187/original/800px-Stem_cells_diagram.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/4187/original/800px-Stem_cells_diagram.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=548&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4187/original/800px-Stem_cells_diagram.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=548&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4187/original/800px-Stem_cells_diagram.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=548&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4187/original/800px-Stem_cells_diagram.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=689&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4187/original/800px-Stem_cells_diagram.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=689&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4187/original/800px-Stem_cells_diagram.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=689&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Pluripotent, embryonic stem cells originate as inner mass cells within a blastocyst. Thehe stem cells can become any tissue in the body, excluding a placenta.</span>
<span class="attribution"><span class="source">Mike Jones</span></span>
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<p>The most well-studied pluripotent stem cell is the <a href="http://stemcells.nih.gov/info/basics/basics3.asp">embryonic stem (ES) cell</a>. These are cells that exist transiently during embryonic development – after a fertilised egg has grown to reach a cell mass of 100-200 cells. They are essentially the “building blocks” for the whole organism. </p>
<p>Most of the ES cells used in research are “extra” embryos created through <em>in vitro</em> fertilization (<a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/In_vitro_fertilisation">IVF</a>) procedures. These cells can be grown in large numbers in the laboratory and there are now routine procedures for generating a wide variety of neurons relevant to specific neurological conditions, including dopamine neurons for PD. </p>
<p>While the potential of ES cells for brain and spinal cord repair is undeniable, this is offset somewhat by ethical concerns about their use in medical research. Is it OK to use cells with the potential to generate life as a kind of “spare parts” factory for patients with potentially life-threatening brain or spinal cord injuries? Not everyone thinks so. </p>
<p>Recent groundbreaking <a href="http://www.asianscientist.com/features/shinya-yamanka-induced-pluripotent-stem-cell-ips/">work from Japan</a> offers a possible solution. In 2006, a team lead by Professor Yamanaka at Kyoto University discovered a method that converts normal adult cells (e.g. skin cells) into pluripotent stem cells called “<a href="http://stemcells.nih.gov/info/basics/basics10.asp">induced pluripotent stem (iPS) cells</a>”, which essentially have all the properties of ES cells. This is discussed in the video below.</p>
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<p>The method discovered by Yamanaka may lead to therapies in which patients can use their own cells as a “repair-kit” to generate new ones for brain repair. It has also opened an interesting new area in stem cell science where iPS cells can be established from patients to model certain diseases in the laboratory dish.</p>
<h2>Stem cells and you</h2>
<p>Australian scientists are making progress in this area. Recently, researchers at the University of Melbourne – <a href="http://www.cns.unimelb.edu.au/research/Stem%20Cell/">Dr. Mirella Dottori</a> and <a href="http://www.bobim.org/index.php?option=com_content&task=view&id=169&Itemid=1">Dr. Alice Peabay</a> – have established iPS cell lines from patients with <a href="http://www.mda.org.au/Disorders/Peripheral/FA.asp">Freidrich’s Ataxia</a>, providing a valuable new research tool in the fight against this debilitating disease, which affects the heart and central nervous system. </p>
<p>Similarly, <a href="http://www.pnas.org/content/early/2010/08/18/1010209107">scientists in Boston</a> have created dopamine neurons from iPS cells and found they can survive and improve motor function after transplantation in an animal model of Parkinson’s disease. </p>
<p>When will we see stem cell based procedures available for patients? While the stage is now set for the development of stem cell treatments for brain repair, a considerable amount of work still needs to be completed before we see these as safe and effective mainstream therapies. </p>
<p>In the meantime, a worrying consequence of the hype surrounding stem cell research has been the rise of so-called “stem cell tourism”. Patients who have exhausted conventional treatment options are increasingly being attracted by clinics in countries such as China, India, Malaysia and the Philippines to receive stem cell treatments. </p>
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<img alt="" src="https://images.theconversation.com/files/4185/original/4862057915_8d8359b520_o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/4185/original/4862057915_8d8359b520_o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4185/original/4862057915_8d8359b520_o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4185/original/4862057915_8d8359b520_o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4185/original/4862057915_8d8359b520_o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4185/original/4862057915_8d8359b520_o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4185/original/4862057915_8d8359b520_o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">BWJones</span></span>
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</figure>
<p>The procedures are typically expensive and performed in an unregulated environment with little or no scientific basis to suggest a positive outcome. Anecdotally, there have also been a number of examples of patients returning home with acute, and potentially life-threating, complications arising from the treatment. </p>
<p>This phenomenon adds further urgency to the need to develop regulated therapies built on solid scientific evidence.</p>
<p>Much of the pre-clinical research required in this area will focus on understanding exactly how stem cell preparations integrate into damaged circuitry after transplantation and how to standardise the procedures in order to deliver predictable therapeutic outcomes. </p>
<p>There is also an important safety aspect to consider. The powerful nature of stem cells means there’s a risk that, if the wrong cell types are transplanted, they may continue to grow and give rise to tumours. </p>
<p>Such hurdles need to be overcome before we see what has been a very promising period for stem cell biology in the laboratory translated into real outcomes for patients.</p>
<p><strong>This is the fifth part of our series <em>On the brain</em>. To read the other instalments, follow the links below:</strong></p>
<p><strong>Part One: <a href="http://theconversation.com/picking-your-brains-whats-going-on-inside-your-head-3559">Picking your brains: what’s going on inside your head?</a></strong> <br>
<strong>Part Two: <a href="http://theconversation.com/your-brain-knows-the-moves-you-just-get-in-its-way-3555">Your brain knows the moves (you just get in the way)</a></strong><br>
<strong>Part Three: <a href="http://theconversation.com/brains-addiction-what-makes-heavy-drug-users-different-3556">Brain’s addiction: what makes heavy drug users different?</a></strong></p><img src="https://counter.theconversation.com/content/3557/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lachlan Thompson receives funding from the National Health and Medical Research Council and the Motor Neuron Disease Research Institute and is an associate investigator on the Australian Research Council's Stem Cells Australia initiative.</span></em></p>Welcome to part five of _On the brain, a Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Lachlan Thompson, head of the Neurogenesis…Lachlan Thompson, Head of Neural Transplantation, Florey Institute of Neuroscience and Mental HealthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/35602011-10-06T19:46:55Z2011-10-06T19:46:55ZBrain’s addiction: is shooting up a disease or a choice?<figure><img src="https://images.theconversation.com/files/4030/original/3533571619_5fb834267b_o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Addicts have choices, but those choices might be severely constrained.</span> <span class="attribution"><span class="source">davidblume</span></span></figcaption></figure><p><em>Welcome to part four of _On the brain</em>, a Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Neil Levy, Head of Neuroethics at Florey Neuroscience Institutes, considers the role of “choice” and “responsibility” in addictive behaviour. Enjoy._</p>
<p>Public discussions of addiction too often fall into the trap of simplistic slogans. </p>
<p>One side asserts addicts are fully responsible for what they do and can choose to act differently; the other side asserts addiction is a brain disease and that therefore addicts do not choose their behaviour. </p>
<p>Both views are partially true, but each is also very misleading. Addicts do make choices, including the choice to consume the drug to which they are addicted. But the <a href="http://www.minddisorders.com/Kau-Nu/Neuropsychological-testing.html">neuropsychological</a> changes involved in addiction mean their capacity for choice is abnormal enough to mean it would often be unreasonable to expect them to make alternative choices.</p>
<h2>You choose</h2>
<p>What is it to make a choice? Roughly speaking, we choose when we respond to reasons. A reflex is not a choice: when the doctor hits my kneecap, I don’t respond to a reason to jerk my leg. </p>
<p>A behaviour that looks more like a choice – compulsive hand-washing, say – might not be a choice if it is not responsive to reasons.</p>
<p>We test to see whether the behaviour is responsive to reasons by seeing how the person responds to various incentives. If the person is choosing, they will make a different choice given the right incentive. </p>
<p>So the compulsive hand-washer is choosing to wash her hands if she would stop for $100, or because she is hungry (enough), or what have you. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/4037/original/3195481964_d3b5649ae3_z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/4037/original/3195481964_d3b5649ae3_z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4037/original/3195481964_d3b5649ae3_z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4037/original/3195481964_d3b5649ae3_z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4037/original/3195481964_d3b5649ae3_z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4037/original/3195481964_d3b5649ae3_z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4037/original/3195481964_d3b5649ae3_z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Ms. Tina</span></span>
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</figure>
<p>Using this test, it’s immediately apparent that addicts make choices, both to engage in activities (sometimes illegal, of course) to procure their drug, and to consume their drug. </p>
<p>An addict would not shoot up, for instance, were they sitting opposite a police officer. Their behaviour is sensitive to reasons, and therefore is chosen.</p>
<p>But as the example of the compulsive hand-washer illustrates, saying a piece of behaviour is “chosen” is only the beginning of the story. Sufferers from obsessive-compulsive disorders, phobias and so on, make choices, but their choices are pathological in various ways. </p>
<p>We can see this using precisely the same kind of test we used to show they are making choices at all. Take the person who suffers from <a href="http://pages.infinit.net/drnayman/agorapho.htm">agoraphobia</a> – fear of open spaces – and who therefore does not leave their house for months or even years. We can show they are choosing to remain inside by showing they would go out were they presented with a sufficiently large incentive. </p>
<p>By the same token, the fact they would not go out for a smaller incentive shows their choices are severely constrained. An agoraphobic might leave his house if he ran out of food entirely, but not, say, if all he had left was spaghetti, or merely to avoid severe social embarrassment. These facts show his choices are highly abnormal. </p>
<p>And the fact he would not leave the house to avoid a moderate harm, or to gain a moderate benefit (say to get $500) helps us to see it would be unreasonable to expect him to make alternative choices under the circumstances in which he finds himself.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/4029/original/2263289897_5caf9842a0_o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/4029/original/2263289897_5caf9842a0_o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=464&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4029/original/2263289897_5caf9842a0_o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=464&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4029/original/2263289897_5caf9842a0_o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=464&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4029/original/2263289897_5caf9842a0_o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=583&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4029/original/2263289897_5caf9842a0_o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=583&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4029/original/2263289897_5caf9842a0_o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=583&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="attribution"><span class="source">P - A - S</span></span>
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<h2>A great escape</h2>
<p>The evidence with regard to addiction seems to indicate addicts’ choices are similarly constrained. Due to a variety of factors, addicts find it far harder to control some of their actions then most other people. </p>
<p>Neuroadaptations (whereby the brain attempts to compensate for something that influences normal functioning) decrease the control these people have over their actions, and also make drugs and drug-related cues hard to ignore. </p>
<p>Very often this, when added to concurrent mental illness, poverty and hopelessness, makes a drug-facilitated temporary escape very tempting. In other words, they choose, but they find it harder to make alternative choices.</p>
<p>These facts often make it unreasonable for us to expect addicts to make better choices. Whether it’s unreasonable on a particular occasion depends on what the choice is. </p>
<p>We rightly expect people to try harder to avoid seriously immoral actions, such as mugging a stranger, then less serious. The more distant the relationship between the addiction and the action, the less difficult addicts typically find it to exercise control. </p>
<p>So we might reasonably expect addicts to avoid mugging strangers for money to buy heroin, but it might be unreasonable to expect them to refrain from taking the drug when they have it. Again, it will depend on the circumstances. </p>
<p>We might expect more of an addict who becomes a mother (and the evidence suggests parenthood often does provide a sufficient incentive to many addicts to stay clean).</p>
<p>We need to give up simplistic dichotomies such as “chosen” or “responsible”. We need to recognise human action exists on a continuum, on which a great deal of behaviour is chosen but to different degrees. </p>
<p>And we need to develop means of assisting addicts so they can make better choices. </p>
<p>That means adopting a multi-pronged approach in which we address all the circumstances that make their choices difficult.</p>
<p><strong>This is the fourth part of our series <em>On the brain</em>. To read the other instalments, follow the links below:</strong></p>
<p><strong>Part One: <a href="http://theconversation.com/picking-your-brains-whats-going-on-inside-your-head-3559">Picking your brains: what’s going on inside your head?</a></strong> <br>
<strong>Part Two: <a href="http://theconversation.com/your-brain-knows-the-moves-you-just-get-in-its-way-3555">Your brain knows the moves (you just get in the way)</a></strong><br>
<strong>Part Three: <a href="http://theconversation.com/brains-addiction-what-makes-heavy-drug-users-different-3556">Brain’s addiction: what makes heavy drug users different?</a></strong></p><img src="https://counter.theconversation.com/content/3560/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Neil Levy receives funding from the Australian Research Council, the John Templeton Foundation, and the Wellcome Fund</span></em></p>Welcome to part four of _On the brain, a Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Neil Levy, Head of Neuroethics at Florey…Neil Levy, Head of Neuroethics, Florey Institute of Neuroscience and Mental HealthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/35562011-10-05T19:52:32Z2011-10-05T19:52:32ZBrain’s addiction: what makes heavy drug users different?<figure><img src="https://images.theconversation.com/files/4042/original/3582402039_889b57fcac_b.jpg?ixlib=rb-1.1.0&rect=3%2C20%2C815%2C643&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Susceptibility to addiction can be seen as a form of Russian Roulette.</span> <span class="attribution"><span class="source">kriffster</span></span></figcaption></figure><p><em>Welcome to part three of _On the brain</em>, a Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Professor Andrew J. Lawrence, the Florey Neuroscience Institute’s head of behavioural neuroscience, and head of the addiction neuroscience laboratory, investigates the brain’s role in drug-seeking, drug-taking and drug-induced neural adaption. Enjoy._</p>
<p>One of the reasons there’s considerable polarisation whenever the subject of addiction is raised is the stereotyped associations of addicts with illegality. </p>
<p>In reality, this is the thin end of the wedge; by far the most harm and mortality is related to alcohol and tobacco use, both of which are legal. </p>
<p>While one can question the motivations driving people to experiment with drugs/alcohol in the first instance, addiction, once developed, can be regarded as a chronic, relapsing disorder. </p>
<p>Most people know somebody who has repeatedly tried, but failed, to stop smoking with periods of abstinence in-between relapses – that’s addiction in a nutshell. Despite this, only a relatively small number of people who ever use a drug actually become addicted to it. Why? </p>
<p>This is a difficult question to answer, but pieces of the puzzle are gradually coming together. </p>
<p>Some genes have been implicated in addiction; but, unlike other disorders (<a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Huntingtons_disease_explained">Huntington’s disease</a>, for example), there’s no single causative gene that can be labelled as an addiction gene. It’s most unlikely there ever will be. </p>
<p>Also, many addicts are what is known as “<a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Dual_diagnosis">dual diagnosis</a>” patients with co-morbid (co-existent) psychiatric problems that add a further layer of complexity. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/4039/original/4097561067_16cf6986ec.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/4039/original/4097561067_16cf6986ec.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=463&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4039/original/4097561067_16cf6986ec.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=463&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4039/original/4097561067_16cf6986ec.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=463&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4039/original/4097561067_16cf6986ec.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=581&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4039/original/4097561067_16cf6986ec.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=581&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4039/original/4097561067_16cf6986ec.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=581&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Ms. Tina</span></span>
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<p>Nevertheless, an individual with one or more alterations in specific genes may be more vulnerable to developing addiction after experimenting with drug use. </p>
<p>In that regard, drug use could be viewed as a form of Russian Roulette – if we don’t know the combined genetic vulnerability, we are playing a dangerous game. </p>
<p>At another level, there is increasing evidence that drugs/alcohol can drive changes in the expression of genes via what are called <a href="http://theconversation.com/think-you-can-think-yourself-better-think-again-558">epigenetic mechanisms</a>. </p>
<p>Again, these adaptations can dramatically alter the way the brain functions.</p>
<p>If we consider function, recent studies provide strong evidence there’s a subset of individuals who are more prone to long-lasting drug-induced alterations in brain function. </p>
<p>Again, before drug use occurs we do not know who all of these vulnerable individuals are, reinforcing the notion of Russian Roulette. </p>
<p>While drugs of abuse alter brain function in all people, for many this is a temporary situation. But after repeated drug use, some people will experience enduring alterations in the way certain brain pathways work. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/4040/original/5706323954_40187bbdb9_b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/4040/original/5706323954_40187bbdb9_b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/4040/original/5706323954_40187bbdb9_b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/4040/original/5706323954_40187bbdb9_b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/4040/original/5706323954_40187bbdb9_b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/4040/original/5706323954_40187bbdb9_b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/4040/original/5706323954_40187bbdb9_b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
<span class="attribution"><span class="source">bleu man</span></span>
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<p>Critically, these pathways are implicated in decision making, behavioural regulation and link past experiences to actions (such as an environmental cue associated with drug use). </p>
<p>So while continued drug use and relapses can be seen as poor choices, these decisions are made by a system that has effectively been hijacked by prior drug use. Understanding the mechanisms behind this phenomenon are therefore a pressing question in addiction research.</p>
<p>Can the affected brain pathways recover? For the majority of people, this seems to be the case, since they only experience a temporary change in brain function and do not become addicted. </p>
<p>Studying the mechanisms of functional recovery in non-addicts that use drugs/alcohol episodically could therefore shed light on what is dysfunctional in addicts. To do this, we need robust model systems that recapitulate the human experience. </p>
<p>Fortunately, animal models are progressing to the stage where questions of this nature are becoming easier to deal with than ever. Nevertheless, while the question may seem straightforward, getting an answer will likely be more complicated!</p>
<p>While choice is a significant component in continued drug use, this reflects the working of a somewhat dysfunctional brain. What seems rational to one person may be an impossible task for another. </p>
<p>Exploring how we can address the problem of a dysfunctional (addicted) brain, from all possible angles (neurobiological, psychological, sociological etc), should be a matter of urgency.</p>
<p><strong>This is the third part of our series <em>On the brain</em>. To read the other instalments, follow the links below:</strong></p>
<p><strong>Part One: <a href="http://theconversation.com/picking-your-brains-whats-going-on-inside-your-head-3559">Picking your brains: what’s going on inside your head?</a></strong> <br>
<strong>Part Two: <a href="http://theconversation.com/your-brain-knows-the-moves-you-just-get-in-its-way-3555">Your brain knows the moves (you just get in the way)</a></strong><br>
<strong>Part Four: <a>Brain’s addiction: is shooting up a disease or a choice?</a></strong></p><img src="https://counter.theconversation.com/content/3556/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew J. Lawrence does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Welcome to part three of _On the brain, a Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Professor Andrew J. Lawrence, the…Andrew J. Lawrence, Head of behavioural neuroscience, Florey Institute of Neuroscience and Mental HealthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/35552011-10-04T01:15:41Z2011-10-04T01:15:41ZYour brain knows the moves (you just get in its way)<figure><img src="https://images.theconversation.com/files/4022/original/2918918286_f692265f25_o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Everything from playing sport to speaking a foreign language is better when done automatically.</span> <span class="attribution"><span class="source">pfv</span></span></figcaption></figure><p><em>Welcome to part two of _On the brain</em>, a Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Malcolm Horne,
deputy director of the Florey Neuroscience Institutes, explores the brain’s role in our capacity to move and, through our understanding of this, the way we might treat brain disorders._</p>
<p>The 2003 Rugby World Cup final between Australia and England was a tense match with scores level through each team scoring penalty goals. </p>
<p>Under the scrutiny of a 100,000 strong crowd and the millions around the world watching on TV, the players had to step up and strike the kick accurately to keep their team in the game. </p>
<p>Kicking (well) is a highly learned and practiced skill but one that easily disappears under cognitive pressure. </p>
<p>It also exemplifies the way human movement differs from that of other animals by showing the capacity of humans to learn and modify their movement to achieve specific outcomes.</p>
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<p>The capacity to move so as to capture food or engage in reproduction was a very early step in human evolutionary history. Traces of this ancient history are reflected in the structure and workings of the human spinal cord, which controls movement in the same way as almost all other animals including reptiles. </p>
<p>With time, the mammalian brain has evolved extra neural equipment, layered over these basic spinal reflex paths, to achieve more complex control of the spinal systems. </p>
<p>These neural systems coordinate the four limbs and trunk with information from the eyes, ears and balance system: this function is well exemplified in the silky movements of the cat. </p>
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<p>Our understanding of how these systems work has advanced to the degree that active research is directed at tapping into and recording from these brain structures to control prosthesis for aiding people with brain injury in standing, walking and grasping objects.</p>
<p>Although cats and other animals move gracefully and are perfectly adapted to survive and function in their natural habitat, humans more than any other animal can learn or modify movements, adapting them to carry out new tasks. </p>
<p>No other animal has the capacity to learn the piano, to play tennis, putt in golf, drive a car or kick goals in rugby. </p>
<p>This capacity results from frontal lobes (see below) forming a further layer of control of the older movement systems. The frontal lobes lie behind the frontal bones and above the eyes, and have expanded greatly in humans. </p>
<p>Their growth is a major reason for the increased brain size of <a href="http://humanorigins.si.edu/evidence/human-fossils/species/homo-sapiens">homo sapiens</a> and importantly, for their capacity to reason.</p>
<figure><a title='By Polygon data were generated by Life Science Databases(LSDB). (Polygon data are from BodyParts3D.[11]) [CC-BY-SA-2.1-jp (www.creativecommons.org/licenses/by-sa/2.1/jp/deed.en)], via Wikimedia Commons' href='http://upload.wikimedia.org/wikipedia/commons/9/99/Four_lobes_animation_small2.gif'><img width='440' alt='Frontal lobe animation' src='//upload.wikimedia.org/wikipedia/commons/5/54/Frontal_lobe_animation.gif'/>
</a></figure>
<p>Understanding how conscious, goal-directed behavior drives skilled movement is a major goal. The issues can be exemplified by reflecting on learning to drive. </p>
<p>The young driver initially devotes all of his or her attention on coordinating gears, clutch, steering wheel, brakes and accelerator, with almost no capacity for attending to pedestrians or other traffic. </p>
<p>Slowly the basic skills are learned and are carried out almost effortlessly and, in effect, subconsciously, so attention can be directed at negotiating traffic and talking to passengers. This process is a fundamental action of the frontal lobes.</p>
<p>By using a mechanism called “<a href="http://www.gemmlearning.com/working_memory_definition.php">working memory</a>” the frontal lobes can attend to a handful of items: one example might be remembering a telephone number for long enough to dial it. </p>
<p>Depending on the complexity of the task, most people can hold five or so items in their attention. </p>
<p>When learning to drive, working memory/attention is fully engaged in coordinating the mechanics of driving. At the same time, the frontal lobes, including a structure called the <a href="http://webspace.ship.edu/cgboer/basalganglia.html">basal ganglia</a>, is busy “learning” the components of driving, such as changing gears. </p>
<image id="4026" align="left">
<p>These components are referred to as “chunks” and, when used in a particular sequence, they can produce a more complex goal-directed movement. </p>
<p>Importantly, with learning, attention is no longer directed at producing the chunk of movement but in attending to the goal of the complex movement. </p>
<p>A single note of music can be produced on the piano, even by a novice, and producing them in order, and with suitable timing, produces a tune. Learning to play the piano means the chunks of movement required to make sequences of notes is done automatically so that attention can be directed at making music rather than the mechanics of playing the piano. </p>
<p>Learning to drive entails turning the motor tasks into skilled chunks so that attention can be directed at traffic and safety. </p>
<p>Paradoxically, turning attention back on to performing the chunks can degrade their production. Kicking for goal in rugby or putting in golf is best achieved when the frontal lobes produce the movements automatically.</p>
<p>One of the aims of sports psychology is to ensure that, even though the world is watching, the movements are performed automatically.</p>
<p>Understanding how these skilled, goal-directed movements are made will influence the way people are taught and trained to develop complex motor skills. </p>
<h2>Diseases of movement</h2>
<p>This knowledge is vitally important to diseases of movement. <a href="http://www.parkinsons.org.au/about-ps/whatps.html">Parkinson’s disease</a> affects the brain regions and chemicals required to produce skilled movements. As a result, goal-directed movement is lost. </p>
<p>On the other hand, disorders such as <a href="http://tourette13.tripod.com/">Tourette’s</a> syndrome may reflect the irrelevant, inappropriate and unwanted production of fragments of movements called tics. </p>
<p>It’s becoming apparent that closely related regions in the frontal lobes use a similar process to control many forms of learned and skilled behaviour, including language acquisition, behavioural habits and even falling in love. </p>
<p>Thus discovering how chunks of movement are learned and then used to make goal-directed behaviours might not only help in elite sport, but in many other facets of human behaviour.</p>
<h2>Impulse control</h2>
<p>Struggling to speak “schoolboy” German in Berlin is analogous to learning to drive: we are still struggling with the mechanics of language production rather than using it for the goal of communication. </p>
<p>Fluent speakers effortlessly respond to questions and comments and, while some of these responses are thoughtful and considered, many are more habitual and stereotyped, reflecting current language fashions. </p>
<p>Many morning greeting rituals are a form of word tennis with two or three brief exchanges about the weather and how we are all well, thank you. </p>
<p>The impulsive response can result in that experience of having said something and then wishing the words back could be taken back. </p>
<p>The reflexive or impulsive production of movement, whether it be language, sport or music, is efficient and produces highly levels of motor performance. </p>
<p>But it also leads to impulsive behaviour that’s not always appropriate. </p>
<p>One key role of the frontal lobes is to arbitrate between the times when the response to the impulse should be suppressed and when it can be allowed. </p>
<p>The effectiveness of this regulation may be what results in a number of impulsive behaviours or disorders.</p>
<p>The brain is a sophisticated motor that, when trained, will produce sublime musicians and great goal-kickers – but, as with any sophisticated instrument, minor changes in function can have serious consequences. </p>
<p><strong>This is the second part of our series <em>On the brain</em>. To read the other instalments, follow the links below:</strong></p>
<p><strong>Part One: <a href="http://theconversation.com/picking-your-brains-whats-going-on-inside-your-head-3559">Picking your brains: what’s going on inside your head?</a></strong> <br>
<strong>Part Three: <a href="http://theconversation.com/brains-addiction-what-makes-heavy-drug-users-different-3556">Brain’s addiction: what makes heavy drug users different?</a></strong><br>
<strong>Part Four: <a href="https://theconversation.com/brains-addiction-is-shooting-up-a-disease-or-a-choice-3560">Brain’s addiction: is shooting up a disease or a choice?</a></strong></p></iframe></div></figure><img src="https://counter.theconversation.com/content/3555/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Malcolm Horne receives funding from ARC, NHMRC Bethlehem Griffith Foundation, Comercialise Australia.”
</span></em></p>Welcome to part two of _On the brain, a Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Malcolm Horne, deputy director of the…Malcolm Horne, Honorary (Professorial Fellow) at the Centre for Neuroscience, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/35592011-10-02T19:30:06Z2011-10-02T19:30:06ZPicking your brains: what’s going on inside your head?<figure><img src="https://images.theconversation.com/files/3972/original/4667287296_9930258a94_b_1_.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Neuroscience has made great gains but the best is yet to come.</span> <span class="attribution"><span class="source">Jenn and Tony Bot</span></span></figcaption></figure><p><em>Welcome to</em> On the brain, <em>a new Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Professor Geoffrey Donnan, a world-renowned stroke researcher and director of the Florey Neuroscience Institute, summarises major highlights in brain diagnoses and ponders the future of treatments for brain disease. Enjoy.</em></p>
<p>The past 30 years have seen the most remarkable advances in the study of the brain. And the past ten have seen more advances in our understanding than all the other years combined. </p>
<p>These range from the most fundamental changes within cells right through to how the brain interconnects and functions.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/3986/original/Computed_tomography_of_human_brain_-_large.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/3986/original/Computed_tomography_of_human_brain_-_large.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=428&fit=crop&dpr=1 600w, https://images.theconversation.com/files/3986/original/Computed_tomography_of_human_brain_-_large.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=428&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/3986/original/Computed_tomography_of_human_brain_-_large.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=428&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/3986/original/Computed_tomography_of_human_brain_-_large.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=538&fit=crop&dpr=1 754w, https://images.theconversation.com/files/3986/original/Computed_tomography_of_human_brain_-_large.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=538&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/3986/original/Computed_tomography_of_human_brain_-_large.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=538&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">X-ray computed tomography.</span>
</figcaption>
</figure>
<p>Enormous strides were made in brain research during the 19th century and consolidated during the latter half of the 20th century. But then, while our knowledge of brain disease plateaued, significant advances were being made in unravelling our understanding of disease processes in accessible organs such as the heart, liver, kidney and blood. </p>
<p>So much so that exciting new treatments were developed for diseases of these organs. </p>
<p>Meanwhile, progress in neuroscience research remained frustratingly slow as the brain remained in its lofty and boney chamber, isolated, often ravaged by disease and largely untreated. </p>
<p>Up until the mid-1970s, the only way to really access the brain was either during surgical operations or, less fortunately, at autopsy. There were some incredibly crude imaging techniques that offered limited and indirect insight into brain structure – and which were, frankly, dangerous. </p>
<p>The most invasive procedure involved injecting air into the <a href="http://www.medterms.com/script/main/art.asp?articlekey=9168">ventricles</a> of the brain via the lumbar spinal region. This took advantage of the continuity of the ventricles with the fluid spaces surrounding the spinal cord. </p>
<p>Interestingly, the technique was an extension of a serendipitous finding by clinicians during the First World War. They found that, when penetrating injuries to the brain allowed air entry to the ventricles, plain X-rays would clearly outline the ventricular contours in sharp relief. </p>
<p>In Melbourne, we had the world expert in research into the interpretation on these images, <a href="http://adb.anu.edu.au/biography/robertson-edward-graeme-11541">Dr E Graeme Robertson</a>. This did not diminish the discomfort felt by most patients who were subjected to the procedure: most were left with quite a headache.</p>
<p>Fortunately, the imaging revolution was not far away. During a remarkable decade from the mid-1970s to the mid-1980s, <a href="http://serc.carleton.edu/research_education/geochemsheets/techniques/CT.html">X-ray computed tomography</a> (CT) took us all to another level. </p>
<p>For the first time, neurologists could actually see brain pathologies such as <a href="http://www.strokecenter.org/patients/ich.htm">intracerebral haemorrhage</a> – when a blood vessel bursts within the brain – with startling clarity. </p>
<p>The technological advance of computing had allowed a <a href="http://www.thefreedictionary.com/stereotaxic">stereotaxic</a> computation of multiple X-ray images accrued by rotating gantry (see below) to be displayed as a simple image. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/pnAkPexEdk0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>As if this was not enough, almost overnight, in the 1970s, along came another even more sophisticated technique: <a href="http://www.howstuffworks.com/mri.htm">magnetic resonance imaging</a> (MRI). Here, scientists had taken advantage of the differing response of atomic structures, particularly <a href="http://whatis.techtarget.com/definition/0,,sid9_gci214458,00.html">protons</a>, to perturbations by radio frequency waves within a magnetic field. </p>
<p>In practice, this meant high-powered computing could generate maps of these protons. Even better, brain blood vessel flow and brain function could be studied.</p>
<p>At about the same time, another technique, <a href="http://www.webmd.com/a-to-z-guides/positron-emission-tomography">Positron Emission Tomography</a> (PET), a nuclear imaging technique, was developed which allowed the distribution of chemical reactions within the brain to be mapped. The sky seemed the limit. </p>
<p>Even the location of human emotions could be mapped to specific locations. If there was ever any doubt the brain ruled the body, this was being dispelled almost weekly as we learned how brain function interpreted the senses and drove motor function. </p>
<p>While these extraordinary advances were occurring in imaging the entire brain and its function, similar developments were occurring in imaging individual cells and their function. </p>
<p></p><figure><a title="Dwayne Reed at en.wikipedia [CC-BY-SA-3.0 (www.creativecommons.org/licenses/by-sa/3.0) or GFDL (www.gnu.org/copyleft/fdl.html)], from Wikimedia Commons" href="http://commons.wikimedia.org/wiki/File:Structural.gif"><img width="440" alt="Structural" src="//upload.wikimedia.org/wikipedia/commons/d/db/Structural.gif"><p></p>
<p></p><figcaption>An animation of MRI head scans.</figcaption></a><p></p>
<p>In much the same way astronomers were seeing new objects in space and, as a consequence, determining new theories about the universe, scientists were seeing the inner workings of the cell in wonderful and colourful detail to make similar inferences about its mechanism of action. </p>
<p>These days, critical compounds for cell survival such as calcium can now be imaged as it is pumped in and out of cells. By genetically modifying cells to carry <a href="http://en.wikipedia.org/wiki/Channelrhodopsin">light-sensitive rhodopsin</a>, they may be switched on and off from the distance. </p>
<p>Then groups and systems of cells can be studied so the means by which they interact can be better understood. Suddenly the very working of the brain can be observed at a cellular systems level and scientists have insight into how whole brain components have a functional output. </p>
<p>For example, it should be possible to observe how the brain stem systems work in controlling blood pressure and breathing.</p>
<h2>The avant-garde</h2>
<p>When considering the drivers of the tremendous advances in neuroscience in this fairly brief period of time, imaging is an absolute standout. The other two critical components have been the unravelling of cellular biology generally and the revolution that has occurred in the <a href="http://theconversation.com/revealed-57-pieces-of-the-ms-puzzle-2807">genetics of disease</a>. </p>
<p>Cellular biology involves the study of cellular structure and function in all its facets – how it acts as a minute factory with inputs, outputs and energy sources. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/3996/original/531px-PET-image.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/3996/original/531px-PET-image.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=678&fit=crop&dpr=1 600w, https://images.theconversation.com/files/3996/original/531px-PET-image.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=678&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/3996/original/531px-PET-image.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=678&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/3996/original/531px-PET-image.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=852&fit=crop&dpr=1 754w, https://images.theconversation.com/files/3996/original/531px-PET-image.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=852&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/3996/original/531px-PET-image.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=852&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A PET image of the brain.</span>
</figcaption>
</figure>
<p>The third factor associated with this revolution in neuroscience, the genetics of disease, is equally intriguing. The adventure was really launched with the plan to map the <a href="http://www.ncbi.nlm.nih.gov/genome/guide/human/">human genome</a> in the late 1980s. </p>
<p>It was thought to be such a massive task that it would take more than 20 years. Because of the remarkable advances in technology, not least the harnessing of unexpected increases in computing technology, the genome was cracked in just 13 years, <a href="http://www.ornl.gov/sci/techresources/Human_Genome/home.shtml">culminating in 2003</a>. </p>
<p>Here in Melbourne we had our own wins with <a href="http://www.brain.org.au/epilepsyresearch/staff/profiles/s_berkovic.html">Professor Sam Berkovic</a> and his team of collaborators discovering the <a href="http://uninews.unimelb.edu.au/news/2915/">first genes responsible for epilepsy</a>. </p>
<p>By tracing the function of these genes, Berkovic and his team were able to establish that the cause of many of the epilepsies involves a disorder of pumps on the surface of cells which keep the ionic concentrations stable within cells. </p>
<p>A failure of these pumps alters the excitability of the cells and allows them to discharge their impulses to neighbouring cells and promote seizures more broadly in the brain. </p>
<p>The next step is to design new medications which might stabilise these cellular pumps. </p>
<h2>Gains </h2>
<p>So what therapeutic advances have occurred as result of all this frenetic scientific activity? Numerous therapies are now part of the neurologist’s toolkit, whereas in earlier years his or her role was to diagnose and prognosticate with virtually no therapies to offer. </p>
<p>Now a neurologist must be familiar with:</p>
<ul>
<li>four categories of intervention to be of proven benefit immediately after the onset of stroke</li>
<li>seven forms of intervention to prevent recurrent stroke</li>
<li>four categories of therapy for multiple sclerosis </li>
<li>new categories of therapies for movement disorders such as Parkinson’s disease and dementias such as Alzheimer’s disease.<br></li>
</ul>
<p>Where will it end? My view is that we’re at the beginning of an even more wonderful period of the flowering of the neurosciences. </p>
<p>If I were a young clinician or scientist wondering which area of research to enter there would be no hesitation – the mysteries of our most complex organ and the seat of the soul await.</p>
<p><strong>This is the first part of our series <em>On the brain</em>. To read the other instalments, follow the links below:</strong></p>
<p><strong>Part Two: <a href="http://theconversation.com/your-brain-knows-the-moves-you-just-get-in-its-way-3555">Your brain knows the moves (you just get in its way)</a></strong> <br>
<strong>Part Three: <a href="http://theconversation.com/brains-addiction-what-makes-heavy-drug-users-different-3556">Brain’s addiction: what makes heavy drug users different?</a></strong><br>
<strong>Part Four: <a>Brain’s addiction: is shooting up a disease or a choice?</a></strong></p></figure><img src="https://counter.theconversation.com/content/3559/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Geoffrey Donnan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Welcome to On the brain, a new Conversation series by people whose job it is to know as much as there is to know about the body’s most complex organ. Here, Professor Geoffrey Donnan, a world-renowned stroke…Geoffrey Donnan, Director, Florey Institute of Neuroscience and Mental HealthLicensed as Creative Commons – attribution, no derivatives.