Apomorphine (5 mg/kg) produces a behavioral syndrome in the rat, consisting of sniffing, chewing and locomotion. Dopamine receptor blockers spiroperidol and pimozide effectively block this syndrome (ED50 for spiroperidol between 0.125 and 0.250 mg/kg and for pimozide 0.5 mg/kg). L-tryptophan (150 mg/kg) given to a pargyline (50 mg/kg) pretreated rat produces a syndrome consisting of tremor, rigidity, forepaw treading and head weaving. This 'serotonergic' syndrome can be blocked by spiroperidol (ED50 0.75 mg/kg), but pimozide in doses as high as 10 mg/kg is ineffective. These data indicate that some dopamine receptor blockers also affect serotonin receptors, whereas others do not.
All Science Journal Classification (ASJC) codes
- Dopamine receptors
- Pargyline-L-tryptophan syndrome
- Serotonin receptors