Effects of continuous exposure to light on behavioral dopaminergic supersensitivity.
Biol Psychiatry
; 45(12): 1622-9, 1999 Jun 15.
Article
en En
| MEDLINE
| ID: mdl-10376124
BACKGROUND: This study examines the effects of long-term continuous exposure to light on dopaminergic supersensitivity induced by repeated treatment with haloperidol in rats. METHODS: Spontaneous general activity in an open-field (SGA) and stereotyped behavior induced by apomorphine (SB-APO) or amphetamine (SB-AMP) were used as experimental parameters. Rats were allocated to four groups in each experiment: saline-treated animals kept under a 12-hour light/dark cycle (LD) or 24-hour light/light cycle (LL), and 2 mg/kg haloperidol-treated animals kept under the above cycles. Plasma corticosterone concentration was also measured by radioimmunoassay in saline-treated rats kept under a LD or LL cycle. RESULTS: All the behavioral parameters used showed the development of central dopaminergic supersensitivity in rats kept under both cycles. Continuous exposure to light enhanced SGA and SB-AMP in both saline- and haloperidol-treated rats, but did not modify SB-APO. Animals kept under the LL cycle presented an increased plasma corticosterone concentration. CONCLUSIONS: Our results suggest that continuous exposure to light leads to an increase in dopaminergic function in both normal and "supersensitive" rats. This effect seems to be mediated by a presynaptic mechanism possibly involving corticosterone actions.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Antipsicóticos
/
Dopaminérgicos
/
Apomorfina
/
Agonistas de Dopamina
/
Trastorno de Movimiento Estereotipado
/
Dextroanfetamina
/
Hipersensibilidad a las Drogas
/
Haloperidol
/
Luz
Límite:
Animals
Idioma:
En
Revista:
Biol Psychiatry
Año:
1999
Tipo del documento:
Article
País de afiliación:
Brasil
Pais de publicación:
Estados Unidos