Homovanillic acid in caudate and pre-frontal cortex following neuroleptics.

Homovanillic acid (HVA) was measured in rat caudate and pre-frontal cortex 3 h following a single dose of a variety of neuroleptics. Thioridazine, haloperidol, fluphenazine, and metoclopramide increased HVA levels in caudate more than in pre-frontal cortex; whereas sulpiride and clozapine produced greater increases in HVA in pre-frontal cortex. These results are consistent with the proposal that rat pre-frontal cortex is relatively deficient in dopamine autoreceptors.