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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Rapid Activation of Glucocorticoid Receptors in the Prefrontal Cortex Mediates the Expression of Contextual Conditioned Fear in Rats

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Author(s):
Reis, Fernando M. C. V. [1, 2] ; Almada, Rafael C. [1, 3] ; Fogaca, Manoela V. [1, 3] ; Brandao, Marcus L. [1, 2]
Total Authors: 4
Affiliation:
[1] INeC, Ribeirao Preto, SP - Brazil
[2] Univ Sao Paulo, FFCLRP, Dept Psicol, Ave Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil
[3] Univ Sao Paulo, FMRP, Dept Farmacol, BR-14040901 Ribeirao Preto, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: CEREBRAL CORTEX; v. 26, n. 6, p. 2639-2649, JUN 2016.
Web of Science Citations: 6
Abstract

The aim of the present study was to investigate the role of glucocorticoids in medial prefrontal cortex (mPFC) activity and the expression of contextual conditioned fear (freezing). Rats were pretreated with vehicle or metyrapone, a corticosterone synthesis blocker, and exposed to a context previously paired with footshocks. Freezing and Fos-protein expression in different mPFC regions were assessed. Exposure to the aversive context led to increased freezing and Fos expression in the prelimbic (PrL), anterior cingulate areas 1 and 2 (Cg1/Cg2). Pretreatment with metyrapone decreased freezing and Fos expression in these areas. Administration of spironolactone, an MR antagonist, in the PrL before the test decreased freezing. Pretreatment with RU38486, a glucocorticoid receptor (GR) antagonist, reduced this effect of spironolactone, suggesting that the effects of this MR antagonist may be attributable to a redirection of endogenous corticosterone actions to GRs. Consistent with this result, the decrease in freezing that was induced by intra-PrL injections of corticosterone was attenuated by pretreatment with RU38486 but not spironolactone. These findings indicate that corticosterone release during aversive conditioning influences mPFC activity and the retrieval of conditioned fear memory indicating the importance of balance between MR:GR-mediated effects in this brain region in this process. (AU)

FAPESP's process: 11/00041-3 - Neurobiology of stress: the sensorimotor gating
Grantee:Marcus Lira Brandão
Support Opportunities: Research Projects - Thematic Grants