Behavioral desensitization to nicotine is enhanced differentially by ethanol in long-sleep and short-sleep mice

Ethanol enhanced the nicotine-induced behavioral desensitization in both mouse lines; however, this effect was seen at lower ethanol doses and was more pronounced in LS mice, suggesting the ethanol effect probably involves changes in brain sensitivity to nicotine.

Abstract

In order to assess the anticonvulsant potency of ethanol, male and female long-sleep (LS) and short-sleep (SS) mice were pretreated with ethanol 7.5 min prior to challenge with an ED80 dose of nicotine (LS: 4.25 mg/kg; SS: 6.25 mg/kg). LS mice were more sensitive to the anticonvulsant effects of ethanol than were SS mice. In order to assess the effect of ethanol on the nicotine-induced behavioral desensitization to nicotine observed previously in these mice, animals were pretreated with saline, nonanticonvulsant doses of ethanol (0.25 g/kg, 0.75 g/kg or 1.5 g/kg), a subseizure-producing dose of nicotine (2.0 mg/kg) or a combination of these two drugs 15 or 30 min prior to nicotine challenge. Ethanol enhanced the nicotine-induced behavioral desensitization in both mouse lines; however, this effect was seen at lower ethanol doses and was more pronounced in LS mice. Ethanol pretreatment did not affect brain nicotine concentrations; therefore, the ethanol effect probably involves changes in brain sensitivity to nicotine.