JW DeMarsh^1,6, AJ Brandner^1,6, GE Homanics^3,4, BK Taylor^2,3,6, SP Farris^2,5,6

Alcohol Use Disorder (AUD) is a chronic, relapsing condition in which pain during withdrawal- collectively termed chronic alcohol withdrawal-induced pain (CAWIP)- contributes to continued alcohol use and relapse. Despite its clinical relevance, the behavioral and neurophysiological mechanisms underlying CAWIP remain poorly understood. This study broadly characterizes CAWIP using complementary behavioral and electrophysiological measures across two mouse models of chronic alcohol exposure. Adult C57BL/6J mice underwent either chronic intermittent ethanol vapor (CIEV) exposure to model dependence or a novel one-bottle access (1BA) voluntary drinking paradigm as a comparison model. Pain-related behaviors were assessed via von Frey testing for cold hypersensitivity, and conditioned place pereference/aversion (CPP/CPA) for spontaneous pain-like behaviors. To investigate underlying neurophysiological changes, excitatory neurons in the parabrachial nucleus were examined for markers of hyperexcitability, spontaneous activity, and membrane resistance. Withdrawal from both CIEV and 1BA exposure produced cold hypersensitivity and mechanical hypersensitivity alongside electrophysiological recordings that confirmed increased neuronal hyperexcitability, spontaneous activity, and altered membrane resistance. Together, these findings suggest that CAWIP involves intrinsic central neuronal changes that may drive sensory hypersensitivity during withdrawal. These results advance our understanding of the multidimensional nature of CAWIP and set the stage for future studies to uncover the central neuronal mechanisms driving this phenomenon and discover more clinically-relevant therapeutic targets.

¹University of Pittsburgh, Center for Neuroscience, Pittsburgh, PA, 15261, USA ²University of Pittsburgh, Department of Anesthesiology & Perioperative Medicine, Pittsburgh, PA, 15261, USA

³University of Pittsburgh, Department of Pharmacology & Chemical Biology, Pittsburgh, PA, 15261, USA

⁴University of Pittsburgh, Department of Neurobiology, Pittsburgh, PA, 15261, USA

⁵University of Pittsburgh, Department of Biomedical Informatics, Pittsburgh, PA, 15261, USA

⁶University of Pittsburgh, Center for Pain Research, Pittsburgh, PA, 15261, USA