Actin-dependent rapid recruitment of reluctant synaptic vesicles into a fast-releasing vesicle pool

• DOI: 10.1073/pnas.1114072109
• Publication Date: 2012-03-06T04:33:43Z
• Authors: Jae Sung Lee; Won-Kyung Ho; Suk-Ho Lee
• Keywords: Recruitment, Neurophysiological; 0303 health sciences; Neuronal Plasticity; Time Factors; Action Potentials; Excitatory Postsynaptic Potentials; Actins; Polymerization; Rats; Rats, Sprague-Dawley; Actin Cytoskeleton; 03 medical and health sciences; Calmodulin; Animals; Calcium; Neurons, Afferent; Synaptic Vesicles

Glutamatergic synaptic terminals harbor reluctant vesicles (SVs) that contribute little to synchronous release during action potentials but are competent when stimulated by sucrose or direct intracellular application of calcium. It has been noted the proximity a release-competent SV calcium source is one primary factors differentiate SVs from fast-releasing ones at calyx Held synapse. not known whether can be converted into ones. Here we show recruited rapidly in an actin-dependent manner become once pool depleted short depolarization. Recovery was accompanied parallel reduction number SVs. Quantitative analysis time course depletion high-frequency stimulation revealed early phase ones, thereby counteracting short-term depression. During late phase, however, after have used up, another process calmodulin-dependent recruitment activated. These results document role plasticity and support hypothesis positional priming, which posits via relocation closer Ca 2+ -channels.