The role of dopaminergic systems in gamma-hydroxybutyrate-induced electrocorticogram hypersynchronization in the rat.
The effects of dopaminergic agonists and antagonists on the duration of hypersynchronization induced in the electrocorticogram (ecog) by gamma-hydroxybutyrate (gamma-HB) were tested in rats. Apomorphine (0-2-8 mg kg-1), piribedil (2-5-10 mg kt-1) and haloperidol (0-5-1 mg kg-1) had no influence on the duration of the hypersynchrony. Amphetamine (1-5-6 mg kg-1) inhibited the hypersynchrony, while (3,4-dihydroxyphenylamino)-2-imidazoline (DPI; 5, but not 1, mg kg-1) prolonged its duration. The lack of effect of the dopamine receptor agonists apomorphine and piribedil, and the dopamine receptor blocker haloperidol, on the gamma-HB-induced hypersynchrony might indicate that the inhibition of the impulse flow in the nigrostriatal dopamine system by gamma-HB is not involved in the generation of the hypersynchrony. DPI is thought to be an agonist at a dopamine receptor not sensitive to apomorphine, and its facilitatory effect on gamam-HB-hypersynchrony can be interpreted in terms of a possible involvement of another dopamine system in the ecog hypersynchrony induced by gamma-HB. The antagonism of gamma-HB by amphetamine is possibly due to an indirect stimulatory effect on noradrenergic receptors.
D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003344:Cortical Synchronization; D003891:Desipramine / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology*; D004569:Electroencephalography; D006220:Haloperidol / Q000494:pharmacology; D006885:Hydroxybutyrates / Q000494:pharmacology*; D008297:Male; D010891:Piribedil / Q000494:pharmacology; D051381:Rats; D011954:Receptors, Dopamine / Q000187:drug effects
D006885:Hydroxybutyrates; D011954:Receptors, Dopamine; D000661:Amphetamine; D010891:Piribedil; D006220:Haloperidol; D003891:Desipramine; D004298:Dopamine