Hyperpolarizing and depolarizing actions of dopamine via D-1 and D-2 receptors on nucleus accumbens neurons.
The effect of dopamine (DA) on the nucleus accumbens neurons in guinea-pig brain slices was studied by intracellular recordings. DA caused a hyperpolarization in 28% of the neurons tested, a depolarization in 11%, and a hyperpolarization followed by a depolarization in 53%. The remaining neurons were unaffected. Analyses of the responses revealed that the DA hyperpolarization was produced by activation of the D-1 receptor and associated with an increase in potassium conductance, whereas the DA depolarization was generated by activation of the D-2 receptor and accompanied by a decrease in potassium conductance. DA uptake inhibitors augmented both the hyperpolarizing and depolarizing responses, while cyclic adenosine monophosphate selectively enhanced the former.
D000818:Animals; D004298:Dopamine / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009431:Neural Conduction / Q000187:drug effects; D009714:Nucleus Accumbens / Q000187:drug effects*; D011188:Potassium / Q000502:physiology; D011954:Receptors, Dopamine / Q000187:drug effects*; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D012686:Septal Nuclei / Q000187:drug effects*
D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D011188:Potassium; D004298:Dopamine