Researchers at the University of Technology Sydney report that inducing localized inflammation in a striatal region involved in action selection pushed rats toward more goal-directed, outcome-sensitive behavior rather than automatic habits. The team traced the effect to disrupted astrocyte function, a finding they say could inform future approaches to compulsive disorders such as OCD and addiction.
For years, many researchers have argued that compulsive behaviors—seen in conditions including obsessive-compulsive disorder, substance use disorders and gambling disorder—reflect habits that become overlearned and hard to stop. Habits can be useful in daily life, allowing routine tasks such as brushing teeth or driving familiar routes to proceed with little conscious effort.
Senior author Dr. Laura Bradfield, a behavioral neuroscientist at the University of Technology Sydney (UTS), described this contrast between automatic and deliberate control using a driving example: when an unexpected hazard appears, such as a child stepping onto the road, people typically shift attention and consciously adjust their actions.
In the new rat study, the UTS team focused on neuroinflammation in the striatum, a brain region involved in selecting actions. Bradfield said evidence from neuroimaging studies has frequently linked striatal inflammation with compulsive disorders, prompting the researchers to test whether inducing inflammation in this region would bias behavior toward habits.
Instead, the results ran in the opposite direction. According to the researchers, rats with experimentally induced inflammation in the posterior dorsomedial striatum remained sensitive to outcomes and continued to adjust their responding in situations that would normally favor habit formation.
The work was led by Dr. Arvie Rodriguez Abiero during his PhD research at UTS and published in the journal Neuropsychopharmacology. In the paper, the authors report that the behavioral shift was associated with changes in astrocytes—star-shaped support cells in the brain—after inflammation. They further found that manipulating astrocyte signaling altered the activity of nearby neurons and modulated goal-directed control.
The findings support a broader interpretation that, at least in this animal model, some forms of compulsive-like repetition may reflect excessive or misdirected deliberate control rather than a simple failure of self-control caused by entrenched habits. Bradfield pointed to repeated handwashing driven by fear of germs as an example of behavior that can involve conscious effort rather than “autopilot.”
The researchers said the results raise the possibility that treatments aimed at reducing neuroinflammation or restoring astrocyte function could be worth exploring, alongside broader anti-inflammatory strategies such as regular exercise and improved sleep. The study was conducted at UTS, and the summary of the work was released by the university.
