Activation of extrasynaptic NMDARs at individual parallel fiber-molecular layer interneuron synapses in cerebellum

Ben Nahir, Craig E. Jahr

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

NMDA receptors (NMDARs) expressed by cerebellar molecular layer interneurons (MLIs) are not activated by single exocytotic events but can respond to glutamate spillover following coactivation of adjacent parallel fibers (PFs), indicating that NMDARs are perisynaptic. Several types of synaptic plasticity rely on these receptors but whether they are activated at isolated synapses is not known. Using a combination of electrophysiological and optical recording techniques in acute slices of rat cerebellum, along with modeling, we find that repetitive activation of single PF-MLI synapses can activate NMDARs in MLIs. High-frequency stimulation, multivesicular release (MVR), or asynchronous release can each activate NMDARs. Frequency facilitation was found at all PF-MLI synapses but, while some showed robust MVR with increased release probability, most were limited to univesicular release. Together, these results reveal a functional diversity of PF synapses, which use different mechanisms to activate NMDARs.

Original languageEnglish (US)
Pages (from-to)16323-16333
Number of pages11
JournalJournal of Neuroscience
Volume33
Issue number41
DOIs
StatePublished - Oct 14 2013

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ASJC Scopus subject areas

  • Neuroscience(all)

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