title: Role of serotonin 1A receptors in the median raphe nucleus on the behavioral consequences of forced swim stress.
abstract: Despite the intense research on the neurobiology of stress, the role of serotonin (5-HT)1A receptors still remains to be elucidated. In the hippocampus, post-synaptic 5-HT1A receptors activation induces anxiolytic effects in animals previously exposed to stressful situations. However, little is known about somatodendritic 5-HT1A receptors in the median raphe nucleus (MRN). Therefore, the aim of this study was to investigate the role of 5-HT1A receptors located in the MRN in rats exposed to forced swim stress. After recovering from surgery, rats were forced to swim for 15 min in a cylinder. Intra-MRN injections of saline, 8-OH-DPAT (3 nmol/0.2 µL) and/or WAY-100635 (0.3 nmol/0.2 µL) were performed immediately before or after pre-exposure or 24 h later (immediately before test). Non-stressed rats received the same treatment 24 h or 10 min before test. Our data showed that 8-OH-DPAT increased latency to display immobility while decreasing time spent immobile in almost all experimental conditions. These effects were not prevented by previous treatment with WAY-100635. No effects of different treatments were described in non-stressed animals. Taken together, our data suggest that in addition to activation of 5-HT1A, 5-HT7 receptors may also be involved in the behavioural consequences of exposure to swim stress.
authors.affiliation: 1Departamento de Psicologia da Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brasil.
authors.forename: P V G
authors.initials: PV
authors.lastname: Almeida
authors.forename: M C
authors.initials: MC
authors.lastname: Trovo
authors.forename: A M
authors.initials: AM
authors.lastname: Tokumoto
authors.forename: A C
authors.initials: AC
authors.lastname: Pereira
authors.forename: C M
authors.initials: CM
authors.lastname: Padovan
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D004195:Disease Models, Animal; D006624:Hippocampus / Q000378:metabolism; D008297:Male; D010879:Piperazines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D011903:Raphe Nuclei / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D011985:Receptors, Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013315:Stress, Psychological / Q000503:physiopathology*; D013550:Swimming; D013997:Time Factors
chemical_list: D010879:Piperazines; D011725:Pyridines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C104425:serotonin 7 receptor; D044282:Receptor, Serotonin, 5-HT1A; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin
keywords: Serotonin 1A receptors; depression; forced swim stress; median raphe nucleus