Through experiments conducted in rats exposed to cocaine, the researchers mapped out the network of circuits that cause wild firing of neurons that produce dopamine — a neuro-transmitter that regulates movement and emotion.
The findings also explains how cocaine use eventually leads to desensitisation, said researchers from Bordeaux University in France.
“Unravelling the neuronal circuit is a necessary first step in understanding the resulting behavioural changes induced by cocaine,” said senior author Francois Georges.
The researchers used tracer molecules to follow electrical activity in the brain in rats exposed to cocaine.
They found that a hub of neurons in the extended amygdala (the brain’s motivation or learning centre) acts as a relay between activation of the ventral subiculum (the brain’s addiction centre) and the hyperactive release of dopamine.
Since this change happens within the amygdala, it may explain some of the long-term effects on the behaviour and motivation that occur after prolonged cocaine use.
The findings might be helpful for understanding and even changing the perception of natural rewards like those related to food or exercise, the authors concluded in the journal Cell Reports.