Interrelations between dopaminergic and GABA-ergic transmitter mechanisms in apomorphine stereotypy.

The effects of dopamine (DA)-ergic and GABA-ergic pharmacological agents on apomorphine stereotypy upon intraperitoneal administration in male albino rats has been studied. It has been found that: the DA-ergic agonist L-DOPA increases the intensity of apomorphine stereotypy, without influencing its total duration. The DA-ergic antagonist haloperidol inhibits significantly apomorphine stereotypy, with marked dose-effect dependence, shortening its duration. The GABA-ergic antagonist picrotoxin potentiates nearly twice apomorphine stereotypy and increases its duration. The GABA-ergic agonists depakine and aminooxyacetic acid (AOAA) inhibit substantially apomorphine stereotypy and shorten its duration. Participation of DA-ergic and GABA-ergic transmitter mechanisms in apomorphine stereotypy as well as interactions of these two transmitter systems in the nigrostriatum, are assumed.