Role of nitric oxide in brain regions related to defensive reactions

Autor(es)

Guimarães, F. S. ^[1] ; Moreira, F. A. ; Aguiar, D. C. ; De Lucca, A. C. B. ; Beijamini, V.

Afiliação do(s) autor(es)

^[1] Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto. Departamento de Farmacologia - Brasil

• Tipo de documento: Artigo Científico
• Fonte: NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS; v. 29, n. 8, p. 1313-1322, 2005.
• Área do conhecimento: Ciências Biológicas - Farmacologia
• Assunto(s): Ansiedade Pânico GABA Serotonina

Resumo

Nitric oxide synthase (NOS) positive neurons are located in most brain areas related to defensive reactions, including the dorsolateral periaqueductal grey (dlPAG). NOS inhibitors injected into this structure induce anxiolytic-like responses whereas NO donors promote flight reactions. Intra-dlPAG administration of carboxy-PTIO, a NO scavenger, or ODQ, a soluble guanylate cyclase inhibitor, produced anxiolytic-like effects on rats exposed to the elevated plus-maze (EPM). A double-staining experiment using NADPHd histochemistry and c-Fos immunohistochemistry in rats exposed to a cat or to the EPM showed increased activation of NO producing neurons in the dlPAG, paraventricular and lateral nuclei of hypothalamus and dorsal raphe nucleus. Cat exposure also increased activation of NOS neurons in the medial amygdala, dorsal pre-mammillary nucleus and bed nucleus of stria terminalis. Local infusion into the dlPAG of a glutamate NMDA-receptor antagonist (AP7) or a benzodiazepine agonist (midazolam) completely prevented the flight reactions induced by intra-dlPAG administration of SIN-1, a NO donor. The responses were also inhibited by the 5-HT2A/C agonist DOI but not by a 5-HT1A agonist. These results suggest a modulatory role for NO on brain areas related to defensive reactions, probably by interacting with glutamate, serotonin and/or GABA-mediated neurotransmission. (AU)

• Processo FAPESP: 02/13197-2 - Participação do glutamato e óxido nítrico na fisiopatogenia de distúrbios neuropsiquiátricos
• Beneficiário: Francisco Silveira Guimaraes
• Modalidade de apoio: Auxílio à Pesquisa - Temático