Blockade of D-1 dopamine receptors by SCH 23390 prevents EEG and behavioral activation induced by L-dopa.
Administration of L-DOPA, a precursor of dopamine, induced EEG activation, arousal and signs of behavioral excitation in the rabbit. The effects were fully prevented by pretreatment with minute doses (0.01 mg/kg i.v.) of the selective D-1 antagonist SCH 23390. Conversely, its S-enantiomer SCH 23388, which has weak actions on D-1 receptors, displayed relatively low inhibition of L-DOPA effects. (-)-Sulpiride (12.5 mg/kg), a selective D-2 antagonist, and haloperidol (0.1-0.3 mg/kg), a neuroleptic that interacts preferentially with D-2 receptors, both inhibited behavioral effects but failed to block EEG activation. The data indicate that D-1 receptors play an essential role in mediating EEG activation induced by L-DOPA.
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001552:Benzazepines / Q000494:pharmacology*; D004569:Electroencephalography; D006220:Haloperidol / Q000494:pharmacology; D007980:Levodopa / Q000494:pharmacology*; D008297:Male; D011817:Rabbits; D011954:Receptors, Dopamine / Q000187:drug effects*; D017447:Receptors, Dopamine D1; D013469:Sulpiride / Q000494:pharmacology
D001552:Benzazepines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D007980:Levodopa; D013469:Sulpiride; D006220:Haloperidol