Alcohol impacts an fMRI marker of neural inhibition in humans and rodents

Acute alcohol consumption leads to cognitive and behavioral disinhibition that increase health and social risks, such as traffic fatalities and violence. Although rodent studies have shown that alcohol affects neural inhibition, its relevance to humans remains largely unexplored. Here, we used the Hurst exponent—an fMRI-based marker of neural inhibition—to examine alcohol’s effects in both rats and humans. In rats, acute alcohol administration significantly reduced the cortical Hurst exponent, suggesting decrease of neural inhibition. This reduction was strongly correlated with the spatial distribution of GABA _A receptor expression, highlighting the key role of these receptors in mediating alcohol’s effects. Similarly, in humans, acute alcohol consumption reduced the cortical Hurst exponent, especially in brain regions with high GABA _A receptor expression. Our findings provide cross-species in vivo evidence that acute alcohol consumption modulates neural inhibition, offering new insights into the neural mechanisms underlying alcohol-induced behavioral modulation.