Light-based brain therapy reduces opioid relapse in rats

Researchers examines a computer screen (photo by Ted S. Warren, College of Veterinary Medicine).

Researchers in the US have identified a specific brain circuit in rats that drives relapse following opioid use, with light-based stimulation mimicking this pathway, significantly reducing addictive behaviour. 

Opioid overdose deaths remain a major public health crisis, with relapse posing a significant barrier to long-term recovery.  

The team at Washington State University traced a circuit connecting two brain regions – the prelimbic cortex and the paraventricular thalamus – which becomes active during drug-seeking episodes.  

When the researchers reduced activity in this circuit using optogenetics (a technique in which light delivered through implanted optical fibres alters brain activity), rats showed a marked drop in opioid-seeking behaviour. 

“While this study was done in rats, the same brain pathway exists in humans,” said Giuseppe Giannotti, assistant professor at Washington State University, noting that modern techniques such as deep brain stimulation could one day be harnessed to target drug relapse-related brain circuits in people. 

By isolating and controlling the drivers of craving, this research, published in The Journal of Neuroscience, lays the groundwork for future interventions on opioid-related relapses.