Discriminative stimulus properties of ethanol in the rat: effects of neurosteroids and picrotoxin

Tetrahydrodeoxycorticosterone (5β-THDOC; 1.3–12.0 mg/kg), a neurosteroid enhancing the GABA_A receptor-associated chloride conductance, produced predominantly ethanol-appropriate responding (>80%) in rats trained to discriminate 1.0 g/kg ethanol from saline. However, neither picrotoxin (0.25–1.5 mg/kg), nor dehydroepiandrosterone sulfate (0.01–100.0 mg/kg), a neurosteroid acting as a GABA_A receptor antagonist, attenuated the stimulus effects of ethanol. These results indicate that: (1) at least certain neurosteroids may produce subjective states similar to these induced by ethanol; (2) blockade of the GABA_A receptor-associated channel does not eliminate the ethanol interoceptive cue in rats. ©1997 Elsevier Science B.V. All rights reserved.