Study in rats suggests basis for compulsive behaviours could be inflammation, not 'habit loop'

New Delhi, Jan 2 (PTI) Compulsive behaviours may not involve a "habit loop" that overrides self-control, but may instead involve inflammation in a brain region known to be important for choosing actions, according to a study in rats, challenging long-held views.

Behaviours in which people repeat a set of actions despite being aware of negative consequences -- such as handwashing or gambling -- are thought to stem from "entrenched habits, so it is difficult for people to break free and take back cognitive control," senior author Laura Bradfield, a behavioural neuroscientist at the University of Technology Sydney in Australia, said.

Ordinarily, habits are useful because they allow us to act on autopilot, such as when we brush our teeth or drive a familiar route, so we can think about other things, Bradfield said.

"However, if we are driving and a child steps onto the road, then we suddenly become aware of our surroundings and focus on what we are doing. This involves taking back conscious control, thinking about possible outcomes and adjusting our behaviour," Bradfield said.

The study, published in the journal Neuropsychopharmacology, looked at rats and tested whether inducing inflammation in the striatum -- brain region responsible for motor control, habit forming and motivation -- would increase habitual behaviour.

The researchers found that the rat's behaviour shifted toward more deliberate, effortful decision-making rather than habit.

"Surprisingly, the animals became more goal-directed and continued to adjust their behaviour based on outcomes, even in situations where habits would normally take over," Bradfield said.

The result was attributed to astrocytes -- star-shaped cells in the brain that support neurons. Inflammation caused these cells to multiply and interfere with nearby groups of neurons that control movement and decision-making, the researchers said.

"Results show that striatal neuroinflammation is sufficient to bias action selection toward excessive goal-directed control via dysregulated astrocyte function," the authors wrote.

They suggested that drugs targeting astrocytes and reducing neuroinflammation, as well as broader anti-inflammatory measures such as exercise or getting better sleep, could offer new avenues for treatment. PTI KRS KRS MAH MAH