Role of 5-HT1A receptors in the ventral hippocampus in the regulation of anxiety- and panic-related defensive behaviors in rats

Autor(es)

Hernandes, Paloma Molina ^[1] ; Batistela, Matheus Fitipaldi ^[1] ; Vilela-Costa, Heloisa Helena ^[1] ; Sant `Ana, Ana Beatriz ; Kumpel, Vinicius Dias ^[2] ; Tirapelle, Mariane Cariati ^[2] ; Bom, Ariela de Oliveira Pedro ^[2] ; de Andrade, Telma Goncalves Carneiro Spera ^[2] ; Zangrossi Jr, Helio

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Pharmacol, Ribeirao Preto, SP - Brazil

^[2] Sao Paulo State Univ UNESP, Dept Biol Sci, Assis, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Behavioural Brain Research; v. 408, JUN 25 2021.
• Citações Web of Science: 0

Resumo

Changes in 5-HT1A receptor (5-HT1AR)-mediated neurotransmission in the hippocampus have been associated with anxiety, depression and in the mode of action of antidepressant drugs. It has been commonly accepted that whereas the dorsal pole of the hippocampus (DH) is involved in cognitive processing, the ventral pole (VH) is associated with emotional regulation. However, to date, only a few studies have directly addressed the role played by VH 5-HT1ARs in anxiety and panic processing, and their results are conflicting. Here we report that intra-VH administration of the 5-HT1A receptor agonist 8-OH-DPAT, the endogenous agonist serotonin (5-HT), or the standard anxiolytic benzodiazepine midazolam impaired the acquisition of inhibitory avoidance in the elevated T-maze (ETM) of male Wistar rats, indicating an anxiolytic effect. Conversely, local injection of the 5HT1AR antagonist WAY-100635 caused the opposite effect. These results were equally found in the Vogel conflict test. None of these drugs interfered with locomotor activity in the open-field test, nor did they alter the expression of the escape response in the ETM, a defensive behavior associated with panic. Pre-injection of a subeffective dose of WAY-100635 in the VH blocked the anxiolytic effect of 5-HT or 8-OH-DPAT in the Vogel test, confirming the involvement of 5-HT1AR for this behavioral effect. The effect in this test was anxiety-selective as none of the drugs affected water consumption or nociception. In conclusion, our results suggest that 5-HT1ARs in the VH play a tonic inhibitory role in anxiety processing. These receptors, however, are not involved in the regulation of panic-related escape behavior. (AU)

• Processo FAPESP: 16/16015-5 - Atividade serotonérgica no hipocampo ventral sobre receptores 5-HT2A na regulação de comportamentos defensivos relacionados com a ansiedade generalizada e com o pânico
• Beneficiário: Paloma Molina Hernandes
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 17/18437-7 - Investigação do papel dos receptores 5-HT1A localizados nas asas laterais do núcleo dorsal da rafe no efeito panicolítico promovido pelo tratamento com fluoxetina
• Beneficiário: Heloísa Helena Vilela Costa
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado