Influence of dopamine agonists and an opiate antagonist on agaricus-induced catalepsy, as tested by a new method.

A few drugs affecting the dopaminergic system were tested for cataleptic effects in mice, and compared with an orally administered plant extract, Agaricus Muscarius 30. Haloperidol, Agaricus, and a low dose of apomorphine (0.3 mg/kg) were cataleptic. Paralleling previously reported results with haloperidol, the Agaricus catalepsy was potentiated by the mixed agonist, apomorphine (5 mg/kg), and by the selective D2 agonist, bromocriptine (5 mg/kg) and was reversed by the D1 agonist, SKF 38393. Naloxone also reversed Agaricus catalepsy, suggesting an involvement of opiate as well as dopaminergic mechanisms. All conditions that produced catalepsy also suppressed spontaneous locomotion, except for Agaricus 30 given alone. These experiments also compared cataleptic drugs by the published "pinch" method that involves repeated trials with a new single-trial method. Catalepsy was produced by the same drugs in both tests, but the single-trial method was more sensitive for disclosing the catalepsy induced by weaker cataleptogens.