Dorsomedial hypothalamus serotonin 1A receptors mediate a panic-related response in the elevated T-maze

Dorsomedial hypothalamus serotonin 1A receptors mediate a panic-related response in the elevated T-maze

Author Nascimento, Juliana Olivetti Guzman Autor UNIFESP Google Scholar
Kikuchi, Leticia Sumiko Autor UNIFESP Google Scholar
Bortoli, Valquiria Camin de Google Scholar
Zangrossi, Helio Google Scholar
Viana, Milena de Barros Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Univ Fed Espirito Santo
Universidade de São Paulo (USP)
Abstract The dorsomedial hypothalamus (DMH) has long been associated with the regulation of escape, a panicrelated defensive response. Previous evidence has shown that the activation of serotonin (5-HT) 1A and 2A receptors impairs escape behavior induced by the electrical stimulation of the same region. in this study we further explore the relationship of the DMH with defense by investigating the effects of 5-HT1A activation on escape behavior generated in male Wistar rats by an ethologically based aversive stimuli, exposure to one of the open arms of the elevated T-maze (ETM). Aside from escape, the ETM also allows the measurement of inhibitory avoidance, a defensive response associated with generalized anxiety disorder. To evaluate locomotor activity, after ETM measurements animals were submitted to an open field. Results showed that intra-DMH administration of the 5-HT1A receptor agonist 8-OH-DPAT inhibited escape expression. Local administration of the 5-HT1A antagonist WAY-100635 by its own was ineffective, but blocked the panicolytic-like effect of 8-OH-DPAT. Chronic (21 days) systemic treatment with imipramine potentiated the anti-escape effect of 8-OH-DPAT. No significant effects of treatment with 8-OH-DPAT or imipramine on avoidance latencies or the number of lines crossed in the open field were found: These results indicate that 5-HT1A receptors within the DMH may play a phasic inhibitory role on ETM escape expression. As previously proposed, facilitation of 5-HT1A-mediated neurotransmission in the DMH may be involved in the mechanism of action of anti-panic compounds. (C) 2014 Elsevier Inc. All rights reserved.
Keywords Panic
Escape
Serotonin 1A receptors
Dorsomedial hypothalamus
Elevated T-maze
Language English
Date 2014-10-01
Published in Brain Research Bulletin. Oxford: Pergamon-Elsevier B.V., v. 109, p. 39-45, 2014.
ISSN 0361-9230 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 39-45
Origin https://dx.doi.org/10.1016/j.brainresbull.2014.09.011
Access rights Closed access
Type Article
Web of Science ID WOS:000347596800005
URI https://repositorio.unifesp.br/handle/11600/38282

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