A Systematic Approach to Studying Synaptic Function in Vertebrates

Excerpt

Synapses represent the major point of communication between neurons. There are billions of neurons in mammalian brains, each of which on the average forms thousands of synapses. These synapses interconnect neurons into huge networks of large complexity. The properties of these networks are, among others, determined by the characteristics of synaptic communication.

Signal transfer between neurons at a synapse, referred to as synaptic transmission, involves two components: release of neurotransmitters from presynaptic neurons and recognition of neurotransmitters by postsynaptic cells. Both components are highly regulated. Major progress has been made in recent years in the description of the molecular events underlying synaptic transmission, although the precise mechanisms are still unclear. Neurotransmitter release from presynaptic nerve terminals is effected by exocytosis of synaptic vesicles. Synaptic vesicles constitute an abundant secretory organelle of the nerve terminal. They accumulate neurotransmitters by active transport to very high concentrations. The vesicles dock firmly at the...