Factors Influencing Short-term Synaptic Plasticity in the Avian Cochlear Nucleus Magnocellularis

Jason Tait Sanchez*, Karla Quinones, Sebastian Otto-Meyer

*Corresponding author for this work

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

Defined as reduced neural responses during high rates of activity, synaptic depression is a form of short-term plasticity important for the temporal filtering of sound. In the avian cochlear nucleus magnocellularis (NM), an auditory brainstem structure, mechanisms regulating short-term synaptic depression include pre-, post-, and extrasynaptic factors. Using varied paired-pulse stimulus intervals, we found that the time course of synaptic depression lasts up to four seconds at late-developing NM synapses. Synaptic depression was largely reliant on exogenous Ca2+-dependent probability of presynaptic neurotransmitter release, and to a lesser extent, on the desensitization of postsynaptic a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptor (AMPA-R). Interestingly, although extrasynaptic glutamate clearance did not play a significant role in regulating synaptic depression, blocking glutamate clearance at early-developing synapses altered synaptic dynamics, changing responses from depression to facilitation. These results suggest a developmental shift in the relative reliance on pre-, post-, and extrasynaptic factors in regulating short-term synaptic plasticity in NM.

Original languageEnglish (US)
Pages (from-to)11-24
Number of pages14
JournalJournal of Experimental Neuroscience
Volume2015
DOIs
StatePublished - Jan 1 2015

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Keywords

  • AMPA receptors
  • Desensitization
  • Development
  • Glutamate transporters
  • Nucleus magnocellularis
  • short-term synaptic depression

ASJC Scopus subject areas

  • Neuroscience(all)

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