Blockade of amygdala metabotropic glutamate receptor subtype 1 impairs fear extinction

Jeongyeon Kim, Sukwon Lee, Heewoo Park, Beomjong Song, Ingie Hong, Dongho Geum, Kisoon Shin, Sukwoo Choi

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63 Citations (Scopus)

Abstract

The metabotropic glutamate receptor subtype 1 (mGluR1) is thought to be crucial for several forms of memory, but its role in memory extinction has not been determined. Here, we examined a role of mGluR1 in the extinction of conditioned fear using microinjection of an mGluR1 antagonist, CPCCOEt, into the lateral amygdala (LA), a critical structure for fear conditioning and extinction. Intra-LA injection of 3 μg CPCCOEt impaired extinction that was initiated 48 h after the conditioning, but not that initiated 2 h after the conditioning, indicating that the effectiveness of CPCCOEt depends upon the length of time since fear conditioning. The CPCCOEt injection failed to alter an mGluR1-like receptor (mGluR5)-dependent acquisition of fear memory, further supporting the specificity of the injected CPCCOEt on mGluR1. Together, our results suggest that amygdala mGluR1 plays a critical role in the extinction of learned fear, but not in the acquisition of fear memory.

Original languageEnglish
Pages (from-to)188-193
Number of pages6
JournalBiochemical and biophysical research communications
Volume355
Issue number1
DOIs
Publication statusPublished - 2007 Mar 30

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Keywords

  • Amygdala
  • CPCCOEt
  • Conditioning
  • Consolidation
  • Extinction
  • mGluR1

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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