7-OH-DPAT has d-amphetamine-like discriminative stimulus properties

BEVINS, R. A., J. E. KLEBAUR AND M. T. BARDO. 7-OH-DPAT has d-amphetaminelike discriminative stimulus properties. PHARMACOL BIOCHEM BEHAV 58(2) 485-490, 1997.--Rats were trained on a d-amphetamine (1 mg/kg) vs. saline discrimination task using food-maintained responding (fixed ratio = 25). In extinction tests, drug-appropriate responding decreased as the dose of amphetamine was substituted for the training dose decreased. The dopamine D2/D3 receptor agonist (+/-)7-hydroxy-N,N-di-n-propyl-2-aminotetralin (7-OH-DPAT) substituted fully for the amphetamine discriminative stimulus at the higher doses examined (0.1, 0.3, 1.0 mg/kg). This substitution was accompanied by a substantial decrease in overall response rates. Eticlopride, a dopamine D2/D3 receptor antagonist, partially blocked 7-OH-DPAT substitution. Thus, at the higher doses, 7-OH-DPAT shared sufficient discriminative stimulus properties with the amphetamine to prompt full substitution. Eticlopride antagonism suggests a role for the D2/D3 dopamine receptor in this substitution. (C) 1997 Elsevier Science inc.