Facilitation of 5-HT2A/2C-mediated neurotransmission in the ventromedial hypothalamic nucleus decreases anxiety in the elevated T-maze

Facilitation of 5-HT2A/2C-mediated neurotransmission in the ventromedial hypothalamic nucleus decreases anxiety in the elevated T-maze

Author Silva, E. S. da Autor UNIFESP Google Scholar
Poltronieri, Selma Conceição Google Scholar
Nascimento, Juliana Olivetti Guzman Autor UNIFESP Google Scholar
Zangrossi Junior, Helio Google Scholar
Viana, Milena de Barros Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Ctr Univ Votuporanga UNIFEV
Universidade de São Paulo (USP)
Abstract Previous evidence has shown that facilitation of GABA/benzodiazepine-mediated neurotransmission in the ventromedial hypothalamus (VMH) inhibits both escape and inhibitory avoidance responses generated in the elevated T-maze test of anxiety (ETM). These defensive behaviors have been associated with panic and generalized anxiety, respectively. Aside from GABA/benzodiazepine receptors, the VMH also contains a significant number of serotonin (5-HT) receptors, including 1A, 2A and 2C subtypes. the purpose of the present study was to investigate the effect of the activation of 5-HT1A and 5-HT2A/2C receptors in the VMH on defensive behavioral responses in rats submitted to the ETM. for that, male Wistar rats were treated intra-VMH with the 5-HT1A agonist 8-OH-DPAT, with the 5-HT2A/2C agonist DOI, with the 5-HT2C selective agonist MK-212, or with the 5-HT2A/2C antagonist ketanserin and 10 min after were submitted to the ETM. Results showed that both DOI and MK-212 significantly decreased avoidance measurements, an anxiolytic-like effect, without altering escape. 8-OH-DPAT and ketanserin were without effect, although the last drug attenuated the effects of DOI. None of the drugs altered locomotor activity in an open field. These results suggest that 5-HT2A/2C receptors of the VMH are involved in the regulation of inhibitory avoidance and might be of relevance to the physiopathology of generalized anxiety. (C) 2010 Elsevier B.V. All rights reserved.
Keywords Ventromedial hypothalamus
5-HT1A receptors
5-HT2A/2C receptors
Elevated T-maze
Inhibitory avoidance
Generalized anxiety
Language English
Sponsor Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Grant number FAPESP: 08/58815-1
Date 2011-01-20
Published in Behavioural Brain Research. Amsterdam: Elsevier B.V., v. 216, n. 2, p. 692-698, 2011.
ISSN 0166-4328 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 692-698
Origin https://dx.doi.org/10.1016/j.bbr.2010.09.016
Access rights Closed access
Type Article
Web of Science ID WOS:000285217300029
URI https://repositorio.unifesp.br/handle/11600/33357

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