Rats get SAD, but backwards.

Most people are aware that the shorter days of winter lead to less sunlight exposure and can cause depression-like symptoms known as seasonal affective disorder, or SAD, but they probably aren’t aware that this process is reversed in rats.

New research from the University of California, San Diego, has found that actually rats experience increases in depression and anxiety when the days grow longer. Of greatest importance is the discovery that large changes in the day and night cycle cause a new chemical code to be adopted by the rat’s brain cells, allowing an entirely different neurotransmitter to stimulate the same part of the brain.

Read more at University of California San Diego