Pawlosky, R. J. | Search bioRxiv

bioRxiv2025

Peripheral alcohol metabolism dictates ethanol consumption and drinking microstructure in mice

BackgroundEthanol metabolism is intimately linked with the physiological and behavioral aspects of ethanol consumption. Ethanol is mainly oxidized by alcohol dehydrogenase (ADH) to acetaldehyde and further to acetate via aldehyde dehydrogenases (ALDHs). Understanding how ethanol and its metabolites work together to initiate and drive continued ethanol consumption is crucial for identifying interventions for alcohol use disorder (AUD). Therefore, the goal of our study was to determine how ADH1, which is mainly peripherally-expressed and metabolizes >90% of ingested ethanol, modulates ethanol metabolite distribution and downstream behaviors. MethodsEthanol consumption in drinking-in-the-dark (DID) and two-bottle choice (2BC) drinking paradigms, ethanol metabolite concentrations, and lickometry were assessed after ADH1 inhibition and/or in Adh1-knockout (Adh1 KO) mice. ResultsWe found that Adh1 KO mice of both sexes exhibited decreased ethanol consumption and preference compared to wild-type (WT) mice in DID and 2BC. ADH1 inhibitor fomepizole (4-MP) also significantly decreased normal and sweetened ethanol consumption in DID studies. Measurement of ethanol and its metabolites revealed that ethanol was increased at 1h but not 15 min, peripheral acetaldehyde was slightly decreased at both time points, and ethanol-induced increases in acetate were abolished after ethanol administration in Adh1 KO mice compared to controls. Similarly, ethanol accumulation as a function of consumption was 2-fold higher in Adh1 KO or 4-MP treated mice compared to controls. We then used lickometry to determine how this perturbation in ethanol metabolism affects drinking microstructure. Adh1 KO mice consume most of their ethanol in the first 30 min like WT mice but display altered temporal shifts in drinking behaviors and do not form normal bout structures, resulting in lower ethanol consumption. ConclusionsOur study demonstrates that ADH1-mediated ethanol metabolism is a key determinant of ethanol consumption, highlighting a fundamental knowledge gap around how ethanol and its metabolites drive ethanol consumption.

neuroscience↗

bioRxiv2022

Ketone ester-enriched diet ameliorates motor and dopamine release deficits in MitoPark mice

BackgroundParkinsons disease is a progressive, neurodegenerative disease characterized by motor dysfunction and dopamine deficits. The MitoPark mouse recapitulates several facets of Parkinsons disease, including gradual development of motor deficits, which enables the study of potential therapeutic interventions. One therapeutic strategy involves decreasing the mitochondrial metabolic load by inducing ketosis and providing an alternative energy source for neurons, leading to decreased neuronal oxidative stress. ObjectiveWe assessed whether administration of a ketone ester-enriched diet would improve motor and dopamine release deficits in MitoPark mice. MethodsMotor function (rotarod and open field tests), dopamine release (fast-scan cyclic voltammetry), tissue dopamine levels (GC-MS), and dopamine neurons and axons (immunofluorescence) were assessed in MitoPark and control mice fed either the standard or ketone ester-enriched diets. ResultsWhen started on the ketone diet before motor dysfunction onset, MitoPark mice had preserved motor function relative to standard diet MitoPark mice. While the ketone ester enriched diet did not preserve dopamine neurons or striatal dopamine axons, dopamine release in ketone diet MitoPark mice was greater than standard diet MitoPark mice but less than control mice. In a follow up experiment, we began the ketone diet after motor dysfunction onset and observed a modest preservation of motor function in ketone diet MitoPark mice relative to standard diet MitoPark mice. ConclusionThe improvement in motor dysfunction indicates that a ketone ester enriched diet or ketone supplement may represent a promising adjunct treatment for Parkinsons disease.

neuroscience↗