<i>chrna3</i> Modulates Alcohol Response

Abstract

Alcohol use disorders (AUDs) are complex phenomena governed by genetics, neurophysiology, environment, and societal structures. New methods to understand the underlying neurogenetics are valuable for designing personalized interventional strategies. Here, we used a two-choice self-administration zebrafish assay to isolate the function of nicotinic acetylcholine receptor subunit alpha3 ( chrna3 ) in alcohol response. Juvenile zebrafish, of either sex, prior to complete sex differentiation, were examined in this study. They exhibited a biphasic response when self-administering alcohol that transitioned from attraction to aversion within minutes, suggesting they can regulate exposure to alcohol. This inverted U-shaped self-administration mirrored the effect alcohol has on shoaling behavior. Exposure to low concentration of alcohol reduced anxiety-like behaviors, while sedative effects became prominent at higher concentrations resulting in reduced locomotion and uncoordinated swimming. In contrast, these responses are blunted in chrna3 mutants. They exhibited prolonged alcohol self-administration and increased gregariousness. Transcriptomic analyses suggest that glutamatergic and GABAergic neurotransmission alongside cholinergic signaling is impacted in the mutant brains. Our results thus suggest that chrna3 dysfunction has a systemic change with an increase in alcohol tolerance being one effect. These findings also highlight the use of nonrodent alternatives to understand the neurogenetics of development of AUD.