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Fear conditioning enhances spontaneous AMPA receptor‐mediated synaptic transmission in mouse hippocampal CA1 area
Author(s) -
Zhou Ming,
Conboy Lisa,
Sandi Carmen,
Joëls Marian,
Krugers Harm J.
Publication year - 2009
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2009.06951.x
Subject(s) - fear conditioning , ampa receptor , neuroscience , hippocampal formation , excitatory postsynaptic potential , neurotransmission , fear processing in the brain , psychology , extinction (optical mineralogy) , hippocampus , amygdala , context (archaeology) , biology , receptor , glutamate receptor , inhibitory postsynaptic potential , paleontology , biochemistry
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.