Homer-1A, ERK-2, CaMKIIalpha;, and Syntaxin-1 Induction in the Rat Hippocampus During the Consolidation of an Aversive Memory

BEKINSCHTEIN P; IGAZ LM; MEDINA JH

Los Cocos, Cordoba, Argentina

Congreso; XVII NATIONAL MEETING OF THE ARGENTINE SOCIETY FOR NEUROCHEMISTRY; 2002

ARGENTINE SOCIETY FOR NEUROCHEMISTRY

Long term memory (LTM) formation involves a series of neuronal plastic changes. It is widely acceptedthat consolidation ofLTMrequires neuronal gene expression, de novo protein synthesis and remodeling ofsynaptic contacts, whereas short termmemoryformation is independent ofmRNAor protein synthesis.Wehave identified at least two time periods during which administration of transcriptional inhibitors resultsin an amnesic effect: one at the moment of training and another around 4 to 6 h posttraining. Using DNAarray technology, we have been able to identify genes that might be involved in memory consolidation ofa passive avoidance task. Some of these genes could be involved in pre- or postsynaptic changes observedin neuronal plasticity events. In these experiments we have analyzed Homer-1a, ERK 1/2, CaMKIIalpha,and Syntaxin-1 protein levels in the hippocampus of na´ıve, shocked, or trained rats. Significant changesrelated to learning of this task were detected for these proteins 24 h after the training session. However,3 h post training these levels remained equal between trained and shocked animals. Our results suggestthat hippocampal gene expression might be necessary in the late periods of LTM consolidation.