Activation of dopamine D4 receptor inhibits an L-type calcium current in cerebellar granule cells.
Neuroscience
; 68(1): 107-16, 1995 Sep.
Article
en En
| MEDLINE
| ID: mdl-7477916
ABSTRACT
The functions of the D4 receptor, a newly cloned D2-like receptor, as well as the identity of cells expressing it, are still poorly defined. Using quantitative polymerase chain reaction we detected the messenger RNA of the D4, but not other D2-like receptor, in cultured granule cells from neonatal rat cerebellum. In these neurons, dopamine reduced high-voltage-activated calcium current, with a pharmacology corresponding to that of the D4 receptor. The response declined from one to three days, when calcium currents were mostly sensitive to nifedipine, to 15 days, when nifedipine-insensitive calcium currents were also present and D4 receptor messenger RNA had declined. The dopamine response was abolished after pretreatment of the cells by pertussis toxin, was potentiated and made irreversible by infusion of guanosine 5'-O-(3-thiotriphosphate) but persisted in the presence of cyclic AMP and isobutylmethylxanthine. These results indicate the presence in the neonatal cerebellum of a functional D4 receptor inhibiting an L-type calcium current, an action involving a Gi/Go protein but independent from adenylate cyclase inhibition.
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Base de datos:
MEDLINE
Asunto principal:
Bloqueadores de los Canales de Calcio
/
Cerebelo
/
Receptores Dopaminérgicos
/
Receptores de Dopamina D2
/
Agonistas de Dopamina
Idioma:
En
Revista:
Neuroscience
Año:
1995
Tipo del documento:
Article