The dopamine D3/D2receptor agonists 7-OH-DPAT, quinpirole, quinelorane, and PD128907, the mixed dopamine agonist apomorphine, the D2agonist bromocriptine, and the D1/D5agonist SKF38393 were examined in models of hypothermia and prepulse inhibition (PPI) in Wistar rats. As dopamine agonist-induced hypothermia has been proposed as a model of D3receptor function, and dopamine agonists are known to disrupt PPI, drug potencies to induce hypothermia were established and compared with doses necessary to disrupt PPI. 7-OH-DPAT, quinpirole, quinelorane, PD128907, and apomorphine, reduced body temperature and disrupted PPI with a similar rank order of potency (quinelorane>quinpirole=7-OHDPAT>PD128907=apomorphine). Bromocriptine and SKF38393 were ineffective in both models. In a separate study, the dopamine reuptake inhibitors cocaine and GBR 12909 had no effect on PPI. In a final set of studies, the D2/D3antagonist raclopride blocked both 7-OH-DPAT-induced hypothermia and 7-OH-DPAT-induced PPI disruption. The 5-HT,A antagonist WAY 100,135, and the peripheral D2-like antagonist domperidone had no effect. These findings suggest that the hypothermia and PPI disruptions seen with some of these dopamine agonists may be mediated by central D3receptors; however, only studies using more selective dopamine receptor ligands can definitively rule out effects at the D2or D4receptors.