Biphasic ERK1/2 activation in both the hippocampus and amygdala may reveal a system consolidation of contextual fear memory.
Neurobiology of Learning and Memory. 2007-11-01; 88(4): 424-434
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1. Neurobiol Learn Mem. 2007 Nov;88(4):424-34. Epub 2007 Jul 5.
Biphasic ERK1/2 activation in both the hippocampus and amygdala may reveal a
system consolidation of contextual fear memory.
Trifilieff P(1), Calandreau L, Herry C, Mons N, Micheau J.
(1)CNRS UMR 5228, Centre de Neurosciences Intégratives et Cognitives, Avenue des
Facultés, 33405 Talence, France.
There is accumulating evidences to suggest that memory consolidation in some
conditions involves two waves of neuronal plastic change. Using two fear
conditioning procedures in male C57BL/6J mice, we have recently shown that
consolidation of the foreground contextual fear memory required two waves of
ERK1/2 activation in hippocampal CA1, while consolidation of cue conditioning was
only associated with the early phase of activation. The present experiment
further showed that this bi-phasic pattern of ERK1/2 activation was not
restricted to hippocampal CA1, but could also be observed in other fear
memory-related brain areas. The unpaired conditioning procedure (context in
foreground) induced two waves of ERK1/2 activation in hippocampal CA1 and CA3, as
well as in the LA and BLA nuclei of the amygdala. In contrast, the paired
conditioning procedure (context in background) led to a transient early phase
only in hippocampal CA1 and LA. In addition, ERK1/2 phosphorylation in the
hippocampus was found to correlate with that in the amygdala nuclei specifically
after the unpaired procedure. Taken together, our data suggest that the observed
biphasic pattern of neuronal plastic events may reflect the interplay between
hippocampal and amygdala activity-dependent plasticity critical for the system
consolidation of contextual fear memory.
PMID: 17613254 [Indexed for MEDLINE]