Perineuronal Nets in the Insula Regulate Aversion-Resistant Alcohol Drinking

One of the most pernicious characteristics of alcohol use disorder is the compulsion to drink despite negative consequences. The insular cortex (insula) controls decision-making under conditions of risk or conflict and regulates maladaptive behaviors in the context of addiction. Cortical activity is tightly controlled by fast-spiking inhibitory interneurons that are often enclosed by specialized extracellular matrix structures known as perineuronal nets, which regulate neuronal excitability and plasticity. Using a mouse model of compulsive drinking in which alcohol was adulterated with the bitter tastant quinine, we demonstrate that disrupting perineuronal nets in the insula rendered mice more sensitive to quinine-adulterated alcohol. Activation of the insula, as measured by c-fos expression, occurred during aversion-resistant drinking and was further enhanced by elimination of perineuronal nets. These results provide fundamental insight into neuroanatomical and cellular mechanisms that control compulsive drinking.