Fear conditioning enhances spontaneous AMPA receptor-mediated synaptic transmission in mouse hippocampal CA1 area

Ming Zhou*, Lisa Conboy, Carmen Sandi, Marian Joels, Harm J. Krugers

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

21 Citations (Scopus)

Abstract

AMPA receptor-mediated synaptic modifications in the amygdala have been reported to sustain cued fear conditioning. However, the hippocampal formation is also critically involved in fear learning. Therefore, we examined whether fear conditioning is also accompanied by changes in AMPA receptor-mediated synaptic transmission in the hippocampus. We focused on spontaneous miniature excitatory post-synaptic currents (mEPSCs). Young adult mice were trained using tone/footshock pairings and contextual/cued memories were tested 3-4 h and 1 day later. We found that the mEPSC frequency was significantly enhanced when recorded 3 h, but not 24 h, after fear conditioning training. Fear training induced a slight enhancement in the mEPSC amplitude at 3 h after training. The increased mEPSC frequency and amplitude were absent in animals that were only exposed to footshock or novelty or unpaired tone/footshock training. This implies that learning the association between context, tone and footshock transiently enhances hippocampal CA1 spontaneous synaptic transmission, which may contribute to the encoding of the fearful event.

Original languageEnglish
Pages (from-to)1559-1564
Number of pages6
JournalEuropean Journal of Neuroscience
Volume30
Issue number8
DOIs
Publication statusPublished - Oct-2009
Externally publishedYes

Keywords

  • AMPA
  • CA1
  • fear conditioning
  • hippocampus
  • memory
  • mEPSCs
  • LONG-TERM POTENTIATION
  • TRAFFICKING
  • AMYGDALA
  • MEMORY
  • NEURONS
  • PLASTICITY
  • AMPLITUDE
  • SYNAPSES
  • CURRENTS
  • PATHWAY

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