title: The role of neurotrophins in neurotransmitter release.
abstract: The neurotrophins (NTs) have recently been shown to elicit pronounced effects on quantal neurotransmitter release at both central and peripheral nervous system synapses. Due to their activity-dependent release, as well as the subcellular localization of both protein and receptor, NTs are ideally suited to modify the strength of neuronal connections by "fine-tuning" synaptic activity through direct actions at presynaptic terminals. Here, using BDNF as a prototypical example, the authors provide an update of recent evidence demonstrating that NTs enhance quantal neurotransmitter release at synapses through presynaptic mechanisms. The authors further propose that a potential target for NT actions at presynaptic terminals is the mechanism by which terminals retrieve synaptic vesicles after exocytosis. Depending on the temporal demands placed on synapses during high-frequency synaptic transmission, synapses may use two alternative modes of synaptic vesicle retrieval, the conventional slow endosomal recycling or a faster rapid retrieval at the active zone, referred to as "kiss-and-run." By modulating Ca2+ microdomains associated with voltage-gated Ca2+ channels at active zones, NTs may elicit a switch from the slow to the fast mode of endocytosis of vesicles at presynaptic terminals during high-frequency synaptic transmission, allowing more reliable information transfer and neuronal signaling in the central nervous system.
authors.affiliation: Department of Psychology, Civitan International Research Center. University of Alabama at Birmingham, Birmingham, Alabama 35294-0021, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Tyler
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Perrett
authors.forename: Lucas D
authors.initials: LD
authors.lastname: Pozzo-Miller
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D006801:Humans; D009414:Nerve Growth Factors / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D018377:Neurotransmitter Agents