Synaptic transmission is triggered when calcium ions enter presynaptic terminals via voltage-gated calcium channels. Calcium influx leads to a series of protein-protein interactions resulting in the release of neurotransmitters from vesicles into the synaptic cleft. Neurotransmitters can interact with postsynaptic receptors or, by feedback, with presynaptic receptors present on nerve terminals. Our group uses patch clamp electrophysiology to investigate presynaptic mechanisms in synaptic transmission. In particular, we are interested in modulation of presynaptic calcium channels and G protein-coupled receptor (GPCR). We are also investigating the molecular determinants in the modulation of ion channels and receptors and in inhibitory synaptic transmission in the mammalian cerebellum, and have extended this work to excitatory transmission in hippocampal brain slices. Our current focus here is on plant derived cannabinoids, which we are investigating using electrophysiological recordings from brain slices. In addition, we investigate ion channel and GPCR modulation in native neurones and recombinant cells.