Mianserin as a discriminative stimulus in rats: asymmetrical cross-generalization with scopolamine.
The present study was conducted to determine if the tetracyclic antidepressant mianserin could be established as a discriminative stimulus in rats. One group of rats was trained to discriminate mianserin (4.0 mg/kg, IP) from saline in a two-lever drug discrimination procedure, and a second group of rats was trained to discriminate the muscarinic cholinergic antagonist scopolamine (0.25 mg/kg, IP) from saline. Generalization testing with the training drugs yielded an ED50 of 0.502 mg/kg for the mianserin-trained rats and an ED50 of 0.048 mg/kg for the scopolamine-trained rats. Asymmetrical cross-generalization between mianserin and scopolamine was observed, because scopolamine produced mianserin-appropriate responding, but mianserin did not produce scopolamine-appropriate responding. This study is the first demonstration that rats can be trained to discriminate mianserin from saline and that antagonism of muscarinic cholinergic receptors is sufficient to produce mianserin-appropriate responding.
Department of Psychology, Virginia Commonwealth University, Richmond 23284-2018, USA.
B M
BM
Kelley
J H
JH
Porter
S A
SA
Varvel
D000818:Animals; D004192:Discrimination, Psychological; D004305:Dose-Response Relationship, Drug; D008297:Male; D008803:Mianserin / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012601:Scopolamine / Q000494:pharmacology*; D012965:Sodium Chloride / Q000494:pharmacology
D008803:Mianserin; D012965:Sodium Chloride; D012601:Scopolamine