EFFECTS OF THE ENVIRONMENTAL TOXICANT, PARAQUAT, ON BINGE-LIKE ALCOHOL DRINKING AND ALCOHOL-INDUCED LOCOMOTOR SENSITIZATION IN HIGH AND LOW-ALCOHOL-PREFERRING MICE

Parkinson’s Disease (PD) and Alcohol Use Disorder (AUD) are neurodegenerative conditions that involve similar neurobiological pathways and affect motivation and reward dysregulations. This project aims to explore whether PD-related insults affect alcohol-related motivation and reward. We utilized paraquat (PQ) exposure as a neurotoxicant-induced model for PD and mice selectively bred for a differential in alcohol preference as a model for genetic and neurobiological susceptibility for high/low alcohol consumption. In Experiment 1, binge-like alcohol drinking after three weeks of PQ exposure (10 mg/kg, i.p. once per week) or saline was assessed in HAP male and female mice. The four-day Drinking in the Dark (DID) procedure was used to induce binge-like alcohol drinking. Dorsal (DS) and ventral (VS) striatal catecholamines were analyzed after DID. Overall, PQ-treated HAP males had significantly lower alcohol intake than saline-treated males. This effect was absent in female HAP mice. Catecholamine quantification showed lower DOPAC levels in VS of PQ-treated vs. saline-treated HAP male mice. Experiment 2 assessed alcohol-induced locomotor sensitization in adult male and female high (HAP) and low-alcohol-preferring (LAP) mice after PQ exposure. Following the same 3 weeks of PQ or saline exposure, mice received 6 sensitization induction days with either 3 g/kg i.p. EtOH or saline. On test day, an alcohol challenge dose of 2 g/kg in all mice was used to determine the expression of locomotor sensitization. PQ exposure had no significant effect on locomotor activity and sensitization. However, PQ-treated mice showed great variability in their alcohol-induced locomotor activity compared to other groups. These data suggest a sex difference in PQ’s effect on alcohol binge-like drinking. However, PQ’s effect on alcohol-induced locomotor sensitization is not conclusive. This project will elucidate potential mechanisms behind PD-related neuropsychiatric comorbid conditions like AUD. Such findings may assist in early diagnosis and treatment refinement, as these comorbidities precede the motor manifestation of PD by decades and significantly impact the quality of life.