Synaptic expression of glutamate receptor after encoding of fear memory in the rat amygdala

Shiu Hwa Yeh, Sheng Chun Mao, Hui Ching Lin, Po Wu Gean

Research output: Contribution to journalArticlepeer-review

74 Citations (Scopus)

Abstract

Fear conditioning has been ascribed to presynaptic mechanisms, particularly presynaptic facilitation of transmission at thalamo- and cortico-amygdala synapses. Here, by labeling surface receptors with biotin or using membrane fractionation approaches, we report that fear conditioning resulted in an increase in surface expression of GluR1 subunit of α-amino-3-hydroxy-5- methyl-4-isoxazolepropionic acid receptors in the amygdala, whereas total GluR1 mRNA and protein levels were unchanged. The control group that received conditioned stimulus (CS) and unconditioned stimulus in an unpaired fashion did not present any increase, indicating that GluR1 increase was specific to the learning component of the task. Conditioning-induced increase in surface expression of GluR1 depended on the activation of N-methyl-D-aspartate receptors and protein kinases and required the synthesis of new proteins. CS-alone trials applied 24 h before training attenuated fear-potentiated startle and prevented conditioning-induced increase in surface expression of GluR1. Increase in GluR1 was also observed in the amygdala slices after delivery of tetanic stimulation that elicited long-term potentiation of synaptic transmission. Proteasome inhibitor increased surface expression of GluR1 in a time- and dose-dependent manner. Furthermore, pretraining administration of proteasome inhibitor into the amygdala facilitated the fear-potentiated startle. These results suggest that long-term memory formation is correlated with the change in synaptic expression of GluR1, and trafficking of GluR1 to the synaptic sites contributes at least in part to the expression of fear memory.

Original languageEnglish
Pages (from-to)299-308
Number of pages10
JournalMolecular Pharmacology
Volume69
Issue number1
DOIs
Publication statusPublished - 2006 Jan

All Science Journal Classification (ASJC) codes

  • Molecular Medicine
  • Pharmacology

Fingerprint Dive into the research topics of 'Synaptic expression of glutamate receptor after encoding of fear memory in the rat amygdala'. Together they form a unique fingerprint.

Cite this