Activation of 5-HT2 receptors mediates behavioral effects of hallucinogenic drugs. DOI, a hallucinogen, when administered to rodents, induces head shakes referred to as "wet dog" shakes. This test is used to evaluate potential antipsychotics and treatments for Tourette's syndrome.

Pretreatment of ICR mice with the 5-HT2 receptor antagonist ketanserin, the typical antipsychotic haloperidol, and the atypical antispychotics clozapine and olanzapine, significantly decreases the number of headshakes induced by DOI (10 mg/kg) over a period of 10 minutes.