Superior colliculus modulates the compulsion in a model of addiction with foot-shock.

Compulsive drug use despite negative consequences is a core addiction feature and key therapeutic target. Animal models utilize footshock to screen for mice exhibiting compulsive-like addiction traits. Following the administration of aversive stimuli, compulsive animals persist in drug-seeking, suggesting that addicted individuals may have impaired innate defensive responses, thereby exacerbating addictive behaviors. However, little is known about the neural mechanisms behind this behavior. The superior colliculus (SC), a multisensory integration hub, plays a crucial regulatory role in innate fear and defense. This study employed an optical intracranial self-stimulation (oICSS) addiction-like model. Using footshock to screen for mice with compulsive-like behavior, fiber photometry recordings revealed significant differences in neuronal activity within the SC. Specifically, SC neurons in compulsive-like mice showed significantly lower responses to footshock stimuli compared to non-compulsive mice. Subsequently, chemogenetic inhibition of SC neuronal activity in non-compulsive mice significantly reduced their resistance to footshock, inducing a compulsive-like state. Conversely, chemogenetic activation of SC neurons in compulsive-like mice significantly decreased their oICSS behavior. These findings indicate that mice exhibiting compulsive-like addiction behavior, identified through footshock, exhibit significant functional abnormalities in SC neurons. The SC is implicated in regulating compulsive addictive behaviors, providing novel insights into the mechanisms of compulsivity and identifying a promising new target for addiction intervention.