Behavioral disinhibition in mice bred for high drinking in the dark (HDID) and HS controls increases following ethanol

Background: Alcohol consumption and behavioral inhibition share some common underlying genetic mechanisms. The current study examined whether lines of mice selected for high blood ethanol concentrations, attained by heavy drinking in the dark period (DID) of the light-dark cycle that models binge drinking, also exhibit higher levels of drug-naïve inhibition. It also examined whether the administration of ethanol would result in higher levels of disinhibition in these selected lines compared to the founder stock (HS). Methods: A Go/No-Go task was used to assess baseline inhibition and the effects of acute ethanol on disinhibition (response to a No-Go cue) in the HS line and in mice selected for high levels of DID (HDID-1 and HDID-2). Results: Lines did not differ in inhibition at baseline and all lines showed increased disinhibition following moderate doses of ethanol. Ethanol decreased responding to Go cues for HDID-2 and HS lines at high doses but not HDID-1 mice. Conclusions: These data corroborate previous work showing ethanol-induced increases in behavioral disinhibition. The selection paradigm did not result in differential sensitivity to the disinhibiting effects of ethanol, but did result in differential sensitivity to the suppressant effects of ethanol on operant behavior between the two HDID lines.