Regional distribution of Fos-like immunoreactivity in the rat brain after exposure to fear-inducing stimuli.
Braz J Med Biol Res
; 27(4): 1077-81, 1994 Apr.
Article
em En
| MEDLINE
| ID: mdl-8087088
Fos protein immunohistochemistry was used to identify the neural substrate of fear/anxiety. The structures activated by exposure of Long Evans male rats (280-300 g) to the elevated plus-maze, a widely used animal model of anxiety, were compared with those activated by chemical stimulation of two aversive areas of the brain, the dorsal periaqueductal gray matter and the medial hypothalamus. Three different patterns of activation were obtained: Pattern 1 resulted from microinjection of the excitatory amino acid kainate (60 pmol; N = 5) or of the GABA(A) receptor antagonist SR-95531 (16 pmol; N = 3) into the dorsal periaqueductal gray matter and consisted mainly of caudal structures; Pattern 2 was observed after kainate injection (60 pmol; N = 4) into the medial hypothalamus and had a predominantly prosencephalic distribution; Pattern 3 extended from rostral to caudal brain regions and was induced by microinjection of either SR-95531 (16 pmol; N = 1) or kainate (120 pmol; N = 3) into the medial hypothalamus, as well as by 15-min exposure to the plus-maze (N = 3). Control animals were either injected with saline into the MH (N = 3) or the PAG (N = 3) or were exposed for 15 s to the elevated plus maze (N = 3) and exhibited no significant labeling. These results further support the participation of periventricular structures in the regulation of fear and aversion.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Substância Cinzenta Periaquedutal
/
Proteínas Proto-Oncogênicas c-fos
/
Medo
/
Hipotálamo Médio
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Braz J Med Biol Res
Ano de publicação:
1994
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Brasil