Addiction is a psychological and physical inability to stop consuming a chemical, drug, activity, or substance, even though it is causing psychological and physical harm.
New research has found that the cerebellum, a large part of the human brain that scientists thought was primarily involved in motor control, may play a key role in reward-seeking and social behaviours such as addiction.
The scientists conducted a study on mice using optogenetics to test their hypothesis. By genetically inducing photosensitivity, the researchers could selectively activate the axons of the neurons in the cerebellum, to see how the neurons in the VTA would be affected.
In the first experiment, rodents were free to explore all four corners of a room, but when they reached one specific corner, the researchers stimulated the rodents’ cerebellar neurons using optogenetics.
The scientists hypothesized that, if the stimulation were pleasurable, the rodents would continue to seek the rewarding behavior — that is, they would repeatedly go back to the corner where they received the pleasurable stimulation.
As the team expected, the stimulated rodents opted to return to that same corner more often than the control mice.
Next, to confirm that stimulating the axons of the cerebellar neurons played a role in addiction, the researchers conditioned the mice to receive pleasurable stimulation of these axons in a brightly lit area.
Typically, mice avoid bright lights and tend to feel more comfortable in the dark, where they can avoid predators. But in this final experiment, they chose to go against their usual preference, for the sake of the pleasurable stimulation.
Current treatments of addiction include…..
- behavioral therapy and counseling
- medication and drug-based treatment
- medical devices to treat withdrawal
- treating related psychological factors, such as depression
- ongoing care to reduce the risk of relapse
However addiction treatment is highly personalised and can take a long time. Addiction is a chronic condition with a range of psychological and physical effects. Each substance or behaviour may require different management. This new research provides more knowledge about addiction which could potentially have a beneficial impact on the way in which it is treated
“We propose that this […] pathway may explain, at least in part, the association between the cerebellum and addictive behaviors, and provides a basis for a role for the cerebellum in other motivated and social behaviors.”