• Home
  • Search Results
  • 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.

Brain research bulletin (2014-10-08)
Juliana O G Nascimento, Letícia Sumiko Kikuchi, Valquíria Camin de Bortoli, Hélio Zangrossi, Milena B Viana

The dorsomedial hypothalamus (DMH) has long been associated with the regulation of escape, a panic-related 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.

Product Number
Product Description

Imipramine hydrochloride, ≥99% (TLC)
Flunixin Meglumine, Pharmaceutical Secondary Standard; Certified Reference Material
Imipramine hydrochloride, BioXtra, ≥99% (TLC)
Flunixin meglumine, ≥98% (HPLC)
Imipramine hydrochloride, European Pharmacopoeia (EP) Reference Standard
Imipramine for system suitability, European Pharmacopoeia (EP) Reference Standard
Flunixin meglumine, European Pharmacopoeia (EP) Reference Standard
Imipramine hydrochloride, United States Pharmacopeia (USP) Reference Standard

Social Media

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon


Research. Development. Production.

We are a leading supplier to the global Life Science industry with solutions and services for research, biotechnology development and production, and pharmaceutical drug therapy development and production.

© 2021 Merck KGaA, Darmstadt, Germany and/or its affiliates. All Rights Reserved.

Reproduction of any materials from the site is strictly forbidden without permission.