Increased hippocampal CREB phosphorylation after retrieval of remote contextual fear memories in Carioca high-conditioned freezing rats.

Autor: Nunes F; Department of Psychology, Pontifical Catholic University of Rio de Janeiro, RJ, Brazil., Lotufo Denucci B; Department of Physiological Sciences, Institute of Biology, State University of Rio de Janeiro, RJ, Brazil., Velho Martins Lages Y; Department of Psychology, Pontifical Catholic University of Rio de Janeiro, RJ, Brazil., Maisonnette S; Department of Psychology, Pontifical Catholic University of Rio de Janeiro, RJ, Brazil., Eichenberg Krahe T; Department of Psychology, Pontifical Catholic University of Rio de Janeiro, RJ, Brazil., Pedro Mello Cruz A; Laboratory of Behavioral Neuroscience, Institute of Psychology, University of Brasilia, Federal District, Brazil., Landeira-Fernandez J; Department of Psychology, Pontifical Catholic University of Rio de Janeiro, RJ, Brazil. Electronic address: landeira@puc-rio.br.
Jazyk: angličtina
Zdroj: Neurobiology of learning and memory [Neurobiol Learn Mem] 2023 Nov; Vol. 205, pp. 107828. Date of Electronic Publication: 2023 Sep 18.
DOI: 10.1016/j.nlm.2023.107828
Abstrakt: The participation of the hippocampal formation in consolidation and reconsolidation of contextual fear memories has been widely recognized and known to be dependent on the activation of the cAMP response element (CRE) binding protein (CREB) pathway. Recent findings have challenged the prevailing view that over time contextual fear memories migrate to neocortical circuits and no longer require the hippocampus for retrieval of remote fearful memories. It has also recently been found that this brain structure is important for the maintenance and recall of remote fear memories associated with aversive events, a common trait in stress-related disorders such as generalized anxiety disorder (GAD), major depression, and post-traumatic stress disorder. In view of these findings, here we examined the putative role of CREB in the hippocampus of an animal model of GAD during the retrieval of remote contextual fear memories. Specifically, we evaluated CREB phosphorylation in the hippocampus of male Carioca High- and Low-conditioned Freezing rats (CHF and CLF, respectively) upon re-exposure of animals to contextual cues associated to footshocks weeks after fear conditioning. Age-matched male rats from a randomized crossbreeding population served as controls (CTL). Adrenal catecholamine levels were also measured as a biological marker of stress response. Seven weeks after contextual fear conditioning, half of the sample of CHF (n = 9), CLF (n = 10) and CTL (n = 10) rats were randomly assigned to return to the same context chamber where footshocks were previously administrated (Context condition), while the remaining animals were individually placed in standard housing cages (Control condition). Western blot results indicated that pCREB levels were significantly increased in the hippocampus of CHF rats for both Context and Control conditions when compared to the other experimental groups. CHF rats in the Context condition also exhibited significant more freezing than that observed for both CLF and CTL rats. Lastly, CHF animals in the Context condition displayed significantly higher adrenal catecholamine levels than those in the Control condition, whereas no differences in catecholamine levels were observed between Context and Control conditions for CLF and CTL rats. These findings are discussed from a perspective in which the hippocampus plays a role in the maintenance and recall of remote contextual fear memories via the CREB pathway.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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