Dopamine modulates the afterhyperpolarization in neostriatal neurones
Por:
Hernández-López S., Bargas J., Reyes A., Galarraga E.
Publicada:
1 ene 1996
Resumen:
Intracellular techniques were used to study the actions of dopaminergic D1 agonists on the afterhyperpolarization (AHP) that follows action potentials in rat neostriatal neurones. Dopamine or Cl-APB (10 ?M), or 1-10 ?M 6-Cl-PB all increased AHP amplitude. This effect was blocked by 1 ?M SCH-23390, a D1 antagonist, but not by 1 ?M sulpiride, a D2 antagonist. Both 500 ?M dibutyryl cAMP and 5 ?M BayK 8644 induced a similar AHP increase. BayK 8644 occluded the effect of agonists. The results suggest that the action of dopamine is mediated via the recently described protein kinase A enhancement of L-type Ca2+ channels. The results partially explain the decrease in firing frequency induced by dopamine and a possible site of antagonism with cholinergic modulation.
Filiaciones:
Hernández-López S.:
Departamento de Neurociencias, Instituto de Fisiología Celular, UNAM, PO Box 70-253, México City, DF 04510, Mexico
Bargas J.:
Departamento de Neurociencias, Instituto de Fisiología Celular, UNAM, PO Box 70-253, México City, DF 04510, Mexico
Reyes A.:
Departamento de Neurociencias, Instituto de Fisiología Celular, UNAM, PO Box 70-253, México City, DF 04510, Mexico
Galarraga E.:
Departamento de Neurociencias, Instituto de Fisiología Celular, UNAM, PO Box 70-253, México City, DF 04510, Mexico
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