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

The blockage of ventromedial hypothalamus CRF type 2 receptors impairs escape responses in the elevated T-maze

Full text
Silva, Mariana S. C. F. ; Souza, Thaissa M. O. ; Pereira, Bruno A. ; Ribeiro, Daniel A. ; Cespedes, Isabel C. ; Bittencourt, Jackson C. ; Viana, Milena B.
Total Authors: 7
Document type: Journal article
Source: Behavioural Brain Research; v. 329, p. 41-50, JUN 30 2017.
Web of Science Citations: 3

In a previous study, the administration of corticotrophin-releasing factor (CRF) into the dorsomedial hypothalamus (DMH), a region that modulates defensive reactions, was shown to facilitate elevated T-maze (ETM) avoidance responses, an anxiogenic-like effect. Intra-DMH administration of the CRF type 1 receptor (CRFR1) antagonist antalarmin induced anxiolytic-like effects and counteracted the anxiogenic effects of CRF. The present study further investigates the role played by CRF receptors of the medial hypothalamus in anxiety. For that, male wistar rats were treated with CRFR1 and CRFR2-modulating drugs in the DMH or VMH, another hypothalamic nucleus implicated with defensive and emotional behavior, and tested in the ETM for inhibitory avoidance and escape measurements. In clinical terms, these responses have been respectively related to generalized anxiety and panic disorder. All animals were tested in an open field, immediately after the ETM, for locomotor activity assessment. The results showed that intra-VMH CRF or antalarmin did not alter ETM avoidance or escape performance. Intra-VMH injection of the CRFR2 preferential antagonist antisauvagine-30 or of the selective CRFR2 antagonist astressin 2-B inhibited escape performance, a panicolytic-like effect, without altering avoidance reactions. The CRFR2 agonist urocortin-2 intra-VMH was by itself without effect but blocked the effects of astressin 2-B. None of the drugs administered into the DMH altered ETM measurements. Additionally, none of the compounds altered locomotor activity measurements. These results suggest that VMH CRFR2 modulate a defensive response associated with panic disorder and are of relevance to the better understanding of the neural mechanisms underlying this pathological condition. (AU)

FAPESP's process: 13/17389-8 - The role played by the dorsal and median raphe nuclei in the modulation of stress and anxiety-related responses
Grantee:Milena de Barros Viana
Support Opportunities: Regular Research Grants