In Syrian hamsters, 5-HT fibres within the suprachiasmatic nuclei are necessary for the expression of 8-OH-DPAT induced phase-advance of locomotor activity rhythm.
Neurosci Lett
; 256(1): 33-6, 1998 Oct 30.
Article
em En
| MEDLINE
| ID: mdl-9832210
ABSTRACT
8-Hydroxy-2-[di-n-propylamino]-tetralin) (8-OH-DPAT), a 5-HT1A/7 receptor agonist, has a chronobiological effect on the circadian system. To identify how the 8-OH-DPAT exerts this effect, we specifically destroyed the serotonergic (5-HT) fibres connecting the median raphe nuclei (RN) to the suprachiasmatic nuclei (SCN) of the hypothalamus by using microinjections of a neurotoxin 5,7-dihydroxytryptamine into the SCN. After administration of 8-OH-DPAT (0.1 ml, 5 mg/kg) at circadian time 7, the control and the 'partially-lesioned' animals showed a large phase-advance whereas in the 'well-lesioned' hamsters the phase-advances were significantly reduced or absent. The present study demonstrates that, in the Syrian hamster, the 5-HT fibres connecting the RN to the SCN are essential for the phase-shifting action of peripheral 8-OH-DPAT injections, and that the drug does very probably not exert its chronobiological effect directly onto SCN neurons but through receptors localized on median raphe nucleus neurons.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Núcleo Supraquiasmático
/
Serotonina
/
Ritmo Circadiano
/
8-Hidroxi-2-(di-n-propilamino)tetralina
/
Agonistas do Receptor de Serotonina
/
Atividade Motora
/
Fibras Nervosas
Limite:
Animals
Idioma:
En
Revista:
Neurosci Lett
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
França