演題詳細
Poster
シナプス小胞蛋白SV2Aによる神経伝達物質放出の調節
Synaptic vesicle glycoprotein 2A modulates vesicular release at sympathetic synapses
- P1-035
- 谷藤 章太 / Shota Tanifuji:1 Vogl Christian / Christian Vogl:2 Stephens Gary J. / Gary J. Stephens:2 Mochida Sumiko / Sumiko Mochida:1
- 1:東京医大・細胞生理学 / Dept Physiol., Tokyo Med.Univ. 2:School of Pharmacy, Univ of Reading, Reading, UK / School of Pharmacy, Univ of Reading, Reading, UK
Synaptic vesicle glycoprotein-2A (SV2A) is a transmembrane protein found in secretory vesicles and is known to be critical for regulated exocytosis in central neurons although its mechanism of action remains uncertain. We extend studies of SV2A mechanisms to peripheral sympathetic neurons by investigating a role for SV2A in superior cervical ganglion (SCG) neurons. We show that RNAi-mediated SV2A-knockdown markedly affects presynaptic function, causing attenuation in the size of the readily releasable pool (RRP), increased paired-pulse depression (PPD) and delay in RRP recovery after stimulus-dependent depletion. SV2A-knockdown also reduced voltage-dependent Ca2+ channel (VDCC) current density in isolated SCG neurons. These data show that correct SV2A function is required for transmitter release at sympathetic neurons. Mechanistically, we demonstrate that SV2A acts to direct normal synaptic transmission by maintaining RRP size and formation, has a facilitatory role in recovery from synaptic depression and that SV2A deficits are association with aberrant presynaptic Ca2+ current density. Overall, these results demonstrate that SV2A maintains normal neurotransmission in sympathetic neurons, and that such functions are conserved between peripheral and central neurons.