Fast synaptic vesicle reuse slows the rate of synaptic depression in the CA1 region of hippocampus


Creative Commons License

Ertunc M., Sara Y., Chung C., Atasoy D., Virmani T., Kavalali E. T.

JOURNAL OF NEUROSCIENCE, vol.27, no.2, pp.341-354, 2007 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 27 Issue: 2
  • Publication Date: 2007
  • Doi Number: 10.1523/jneurosci.4051-06.2007
  • Journal Name: JOURNAL OF NEUROSCIENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.341-354
  • Keywords: synaptic vesicle recycling, hippocampal slice, short term synaptic depression, vesicle reacidification, endocytosis, CA1, Schaffer collateral, FROG NEUROMUSCULAR-JUNCTION, READILY RELEASABLE POOL, KISS-AND-RUN, MULTIVESICULAR RELEASE, NERVE-TERMINALS, 2 MODES, SYNAPSES, ENDOCYTOSIS, TRANSMISSION, GLUTAMATE
  • Hacettepe University Affiliated: Yes

Abstract

During short-term synaptic depression, neurotransmission rapidly decreases in response to repetitive action potential firing. Here, by blocking the vacuolar ATPase, alkalinizing the extracellular pH, or exposing hippocampal slices to pH buffers, we impaired neurotransmitter refilling, and electrophysiologically tested the role of vesicle reuse in synaptic depression. Under all conditions, synapses onto hippocampal CA1 pyramidal cells showed faster depression with increasing stimulation frequencies. At 20 Hz, compromising neurotransmitter refilling increased depression within 300 ms reaching completion within 2 s, suggesting a minimal contribution of reserve vesicles to neurotransmission. In contrast, at 1 Hz, depression emerged gradually and became significant within 100 s. Moreover, the depression induced by pH buffers was reversible with a similar frequency dependence, suggesting that the frequency-dependent increase in depression was caused by impairment of rapid synaptic vesicle reuse. These results indicate that synaptic vesicle trafficking impacts the kinetics of short-term synaptic plasticity at an extremely rapid time scale.