Synaptic vesicle recycling as a substrate for neural plasticity

Chemical synapses are the principle nodes of communication between neurons and are critical for the processing and storage of information in the brain. They consist of two functionally and structurally distinct compartments: presynaptic terminals and postsynaptic specializations. Presynaptic terminals store and release neurotransmitter substances in membranous organelles named synaptic vesicles, whereas postsynaptic structures contain signaling molecules responsible for generation of neuronal responses to released neurotransmitters. This chapter is primarily devoted to discussion of the cellular mechanisms that can underlie forms of synaptic plasticity that arise from changes in the structure and function of presynaptic terminals. Here, we will discuss prevailing concepts regarding presynaptic forms of plasticity rather than providing an exhaustive review of existing literature. Several recent review papers give an excellent account of the topic and the literature, some of which will not be covered here in detail (Atwood and Karunanithi, 2002; Zucker and Regehr, 2002; Jahn et al., 2003; Murthy and De Camilli, 2003).