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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

GABA(A) receptor blockade in dorsomedial and ventromedial nuclei of the hypothalamus evokes panic-like elaborated defensive behaviour followed by innate fear-induced antinociception

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Autor(es):
Freitas, Renato Leonardo [1] ; Uribe-Marino, Andres [1] ; Castiblanco-Urbina, Maria Angelica [1] ; Elias-Filho, Daoud Hibraim [1] ; Coimbra, Norberto Cysne [2]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, INeC, BR-14040901 Ribeirao Preto, SP - Brazil
[2] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Farmacol, Lab Neuroanat & Neuropsicobiol, BR-14049900 Ribeirao Preto, SP - Brazil
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Brain Research; v. 1305, p. 118-131, DEC 11 2009.
Citações Web of Science: 32
Resumo

Dysfunction in the hypothalamic GABAergic system has been implicated in panic syndrome in humans. Furthermore, several studies have implicated the hypothalamus in the elaboration of pain modulation. Panic-prone states are able to be experimentally induced in laboratory animals to study this phenomenon. The aim of the present work was to investigate the involvement of medial hypothalamic nuclei in the organization of panic-like behaviour and the innate fear-induced oscillations of nociceptive thresholds. The blockade of GABA(A) receptors in the neuronal substrates of the ventromedial. or dorsomedial hypothalamus was followed by elaborated defensive panic-like reactions. Moreover, innate fear-induced antinociception was consistently elicited after the escape behaviour. The escape responses organized by the dorsomedial and ventromedial hypothalamic nuclei were characteristically more elaborated, and a remarkable exploratory behaviour was recorded during GABA(A) receptor blockade in the medial hypothalamus. The motor characteristic of the elaborated defensive escape behaviour and the patterns of defensive alertness and defensive immobility induced by microinjection of the bicuculline either into the dorsomedial. or into the ventromedial hypothalamus were very similar. This was followed by the same pattern of innate fear-induced antinociceptive response that lasted approximately 40 min after the elaborated defensive escape reaction in both cases. These findings suggest that dysfunction of the GABA-mediated neuronal system in the medial hypothalamus causes panic-like responses in laboratory animals, and that the elaborated escape behaviour organized in both dorsomedial and ventromedial hypothalamic nuclei are followed by significant innate-fear-induced antinociception. Our findings indicate that the GABA(A) receptor of dorsomedial and ventromedial hypothalamic nuclei are critically involved in the modulation of panic-like behaviour. (C) 2009 Elsevier B.V. All rights reserved. (AU)

Processo FAPESP: 09/01153-0 - Envolvimento das redes neurais do locus coeruleus e da neurotransmissão noradrenérgica no núcleo dorsal da rafe em processos antinociceptivos induzidos por reações de fuga orientada evocada pela estimulação química do hipotálamo medial
Beneficiário:Andres Uribe Marino
Linha de fomento: Bolsas no Brasil - Mestrado
Processo FAPESP: 03/05256-1 - Caracterizacao de receptores serotoninergicos na analgesia pos-ictal: envolvimento do nucleo dorsal da rafe.
Beneficiário:Renato Leonardo de Freitas
Linha de fomento: Bolsas no Brasil - Mestrado