Dorsomedial hypothalamus CRF type 1 receptors selectively modulate inhibitory avoidance responses in the elevated T-maze

Autor(es)

Silva, Mariana S. C. F. ^[1] ; Pereira, Bruno A. ^[1] ; Cespedes, Isabel C. ^[1] ; Nascimento, Juliana O. G. ^[2] ; Bittencourt, Jackson C. ^[3] ; Viana, Milena B. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Dept Biociencias, BR-11060001 Santos, SP - Brazil

^[2] Univ Fed Sao Paulo, Dept Psiquiatria & Psicol Med, BR-04038020 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Inst Ciencias Biomed, Dept Anat, BR-05508000 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Behavioural Brain Research; v. 271, p. 249-257, SEP 1 2014.
• Citações Web of Science: 12

Resumo

Corticotropin-releasing factor (CRF) plays a critical role in the mediation of physiological and behavioral responses to stressors. In the present study, we investigated the role played by the CRF system within the dorsomedial hypothalamus (DMH) in the modulation of anxiety- and panic-related responses. Male Wistar rats were administered into the DMH with CRF (125 and 250 ng/0.2 mu l, experiment 1) or with the CRFR1 antagonist antalarmin (25 ng/0.2 mu l, experiment 2) and 10 min later tested in the elevated T-maze (ETM) for inhibitory avoidance and escape measurements. In clinical terms, these responses have been respectively related to generalized anxiety and panic disorder. To further verify if the anxiogenic effects of CRF were mediated by CRFR1 activation, we also investigated the effects of the combined treatment with CRF (250 ng/0.2 mu l) and antalarmin (25 ng/0.2 mu l) (experiment 3). All animals were tested in an open field, immediately after the ETM, for locomotor activity assessment. Results showed that 250 ng/0.2 mu l of CRF facilitated ETM avoidance, an anxiogenic response. Antalarmin significantly decreased avoidance latencies, an anxiolytic effect, and was able to counteract the anxiogenic effects of CRF. None of the compounds administered altered escape responses or locomotor activity measurements. These results suggest that CRF in the DMH exerts anxiogenic effects by activating type 1 receptors, which might be of relevance to the physiopathology of generalized anxiety disorder. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 11/17471-0 - Efeitos do estresse agudo e crônico sobre respostas comportamentais de defesa
• Beneficiário: Milena de Barros Viana
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/17389-8 - O papel exercido pelos núcleos dorsal e mediano da rafe sobre a modulação de respostas relacionadas ao estresse e à ansiedade
• Beneficiário: Milena de Barros Viana
• Modalidade de apoio: Auxílio à Pesquisa - Regular