Differential effects of TRH, amphetamine, naloxone, and fenmetozole on ethanol actions: attenuation of the effects of punishment and impairment of aerial righting reflex.

The effects of four putative ethanol antagonists [thyrotropin releasing hormone (TRH), naloxone, d-amphetamine, and fenmetozole] on two distinct behavioral actions of ethanol were compared. TRH (20-40 mg/kg) reduced ethanol-induced impairment of the aerial righting reflex (ARR) but enhanced the ethanol-induced increase in punished drinking (anticonflict effect). Naloxone antagonized both actions of ethanol but only at high doses (20-60 mg/kg). Amphetamine (1-4 mg/kg) abolished the ethanol effect on punished drinking but did not alter its impairment of the ARR (1-8 mg/kg). Conversely, fenmetozole antagonized the ethanol impairment of the ARR (15-30 mg/kg) but not ethanol's anticonflict action. The inconsistent pattern of "antagonist" interactions of these drugs with the behavioral actions of ethanol suggests that ethanol alters several neurochemical systems to produce its behavioral effects.