Antagonism of the discriminative effects of diazepam by pyrazoloquinolines in rats.
The diazepam-like agonist and diazepam antagonist properties of the pyrazoloquinoline benzodiazepine receptor ligands CGS8216, CGS9895 and CGS9896 were evaluated in rats trained to discriminate between saline and 1.0 mg/kg of diazepam in a two-choice, discrete-trial procedure. None of the three pyrazoloquinolines produced diazepam-like discriminative effects over the dose range of 1.0-30 mg/kg. The effects of 1.0 mg/kg of diazepam were antagonized by CGS8216 and CGS9895, but not by CGS9896. The present results provide behavioral evidence for benzodiazepine receptor heterogeneity.
D000818:Animals; D003975:Diazepam / Q000037:antagonists & inhibitors*; D004193:Discrimination Learning / Q000187:drug effects*; D008297:Male; D011720:Pyrazoles / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D011956:Receptors, Cell Surface / Q000187:drug effects; D011963:Receptors, GABA-A
D011720:Pyrazoles; D011956:Receptors, Cell Surface; D011963:Receptors, GABA-A; C034704:2-(4-chlorophenyl)-2,5-dihydropyrazolo(4,3-c)quinoline-3(3H)-one; C039232:2,5-dihydro-2-(4-methoxyphenyl)-3H-pyrazolo(4,3-c)quinolin-3-one; C033830:2-phenylpyrazolo(4,3-c)quinolin-3(5H)-one; D003975:Diazepam