This volume is part of the "Science Briefings" series which reviews and discusses rapidly advancing fields of current research throughout modern biology. In covering such "hot" areas of research, they serve a twofold function: on the one hand, they provide comprehensive summaries of recent advances on the frontiers of science to keep the specialists up to date with the expanding volume of literature in their reseach area; on the other, they are written and organized in a readable way, so that they can inform a broader scientific audience, including graduate students on the latest developments in biology. This book covers all major aspects of synaptic transmission: the topics range from biosynthesis of neurotransmitters through release mechanisms to receptors and signalling. It also includes the most recent work on neurotransmitter release of central synapses where the electrical impulse may stimulate diffusion of only a single synaptic vesicle.