Signaling pathways affected by IL-1beta during reconsolidation of contextual fear memory and the modulatory effect of alpha-MSH

MACHADO IVANA; GONZALEZ PATRICIA; VILCAES A. ALEJANDRO; ROTH, GERMAN A.; LASAGA MERCEDES; SCIMONELLI TERESA N.

Cancun

Congreso; 24th. Biennial Meeting of the International Society for Neurochemistry (ISN) and American Society for Neurochemistry (ASN).; 2013

ISN - ASN

Interleukin-1beta (IL-1b) is a pro-inflammatory cytokine that orchestrates inflammatory and host defense responses in the body. Apart from this role, IL-1b has also been implicated in cognitive processes. Previous studies of our group have demonstrated that the intrahippocampal administration of IL-1b impaired reconsolidation of contextual fear memory. This effect was reversed by the melanocortin alpha-melanocyte-stimulating hormone (a-MSH), through activation of MC4-R. The mechanisms underlying the effect of IL-1b on memory reconsolidation have not been established yet. Thus, we examine the effect of IL-1b on glutamate release, ERK 2 phosphorylation and zif268 activation during reconsolidation. In this study, we find that IL-1b produces a significant decrease of glutamate release after memory reactivation and also reduces ERK2 phosphorylation and zif268 expression in the hippocampus. The central administration of a-MSH can reverse the decrease of glutamate release and zif268 expression induced by IL-1b. Our results establish for the first time the possible mechanisms involved in the detrimental effect of IL-1b on memory reconsolidation and also that a-MSH may exert a beneficial modulatory role in preventing IL-1b effects.