The atypical antipsychotic blonanserin reverses (+)-PD-128907- and ketamine-induced deficit in executive function in common marmosets
Abstract Antagonism of the dopamine D 3 receptor is considered a promising strategy for the treatment of cognitive impairment associated with schizophrenia. We have previously reported that the atypical antipsychotic blonanserin, a dopamine D 2 /D 3 and serotonin 5-HT 2A receptor antagonist, highly occupies dopamine D 3 receptors at its antipsychotic dose range in rats. In the present study, we evaluated the effects of blonanserin on executive function in common marmosets using the object retrieval with detour (ORD) task. The dopamine D 3 receptor-preferring agonist (+)-PD-128907 at 1 mg/kg decreased success rate in the difficult trial, but not in the easy trial. Since the difference between the two trials is only cognitive demand, our findings indicate that excess activation of dopamine D 3 receptors impairs executive function in common marmosets. Blonanserin at 0.1 mg/kg reversed the decrease in success rate induced by (+)-PD-128907 in the difficult trial. This finding indicates that blonanserin has beneficial effect on executive function deficit induced by activation of the dopamine D 3 receptor in common marmosets. Next, and based on the glutamatergic hypothesis of schizophrenia, the common marmosets were treated with the N-methyl- d- aspartate (NMDA) receptor antagonist ketamine. Ketamine at sub-anesthetic doses decreased success rate in the difficult trial, but not in the easy trial. Blonanserin at 0.1 mg/kg reversed the decrease in success rate induced by ketamine in the difficult trial. The findings of this study suggest that blonanserin might have beneficial effect on executive dysfunction in patients with schizophrenia.