Fast vesicle replenishment and rapid recovery from desensitization at a single synaptic release site

John J. Crowley, Adam G. Carter, Wade G. Regehr

Research output: Contribution to journalArticle


When the synaptic connection between two neurons consists of a small number of release sites, the ability to maintain transmission at high frequencies is limited by vesicle mobilization and by the response of postsynaptic receptors. These two properties were examined at single release sites between granule cells and stellate cells by triggering bursts of quantal events either with α-latrotoxin or with high-frequency trains of presynaptic activity. Bursts and evoked responses consisted of tens to hundreds of events with frequencies of up to hundreds per second. This indicates that single release sites can rapidly supply vesicles from a reserve pool to a release-ready pool. In addition, postsynaptic AMPA receptors recover from desensitization with a time constant of ∼5 ms. Thus, even for synapses composed of a single release site, granule cells can effectively activate stellate cells during sustained high-frequency transmission because of rapid vesicle mobilization and fast recovery of AMPA receptors from desensitization.

Original languageEnglish (US)
Pages (from-to)5448-5460
Number of pages13
JournalJournal of Neuroscience
Issue number20
StatePublished - May 16 2007



  • AMPA
  • Desensitization
  • Latrotoxin
  • Mobilization
  • Reloading
  • Vesicle

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this