Psychiatry research
-
Psychiatry research · Dec 1998
Effects of specific dopamine D1 and D2 receptor antagonists and agonists and neuroleptic drugs on emotional defecation in a rat model of akathisia.
An increase in emotional defecation in rats in a well-habituated environment induced by neuroleptic drugs (NDef) has been proposed as a model for neuroleptic-induced akathisia. We examined the effects of dopamine receptor antagonists and agonists on this model. A selective dopamine D1 antagonist (SCH 23390) and a selective D2 antagonist (raclopride) induced increased defecation at higher doses, and demonstrated a synergistic effect at lower doses. ⋯ The results of our studies suggest that NDef is most probably an effect of central dopamine antagonism that is not specific to D1 or D2 receptors, but that the two receptor subtypes have a synergistic effect. It is unlikely to be due to actions of neuroleptics on 5HT2 or alpha1 receptors as has sometimes been suggested. The results have implications for our understanding of the pathogenesis of akathisia.