Everything You Thought You Knew About Dopamine Is Wrong!

This specific gene therapy method entails the introduction of a genetically altered virus (depicted in the image above) into the brain. The aim is to trigger an increase in dopamine synthesis, addressing its deficiency observed in individuals with alcohol use disorder.

Until now, it was believed that dopamine, the “pleasure molecule,” was primarily involved in the reward circuit associated with positive experiences. A groundbreaking experiment conducted on voluntary patients has challenged this belief.

When you indulge in a piece of high-quality chocolate, the avid cocoa enthusiast in you may experience a surge of pleasure and well-being. As a result, you are inclined to indulge further. Your brain’s production of dopamine, a neurotransmitter involved in mood regulation, movement, and the reward circuit, causes this desire.

This circuit compels us to voluntarily perform actions, more or less essential to our survival, by producing the infamous “pleasure molecule”: eating, drinking, engaging in sexual activities, maintaining a social life, reading, listening to music, etc. It is also implicated in addiction issues. Until now, its role was thought to be in learning through pleasure, but an experiment detailed in a study published on December 1st in Science Advances could disrupt what was previously believed.

The Experiment: A World First

Researchers from Wake Forest University School of Medicine demonstrated that the release of dopamine in the human brain is also involved in the learning process from negative experiences, allowing the brain to adjust and adapt its behavior based on the outcomes of these experiences. To reach this conclusion, scientists inserted a carbon fiber microelectrode into the brains of three voluntary participants who were undergoing brain surgery to treat essential tremors.

These patients were then invited to play a computer game in which their choices were either rewarded or punished with real monetary gains or losses. The game consisted of three stages in which participants learned, through positive or negative feedback, to make choices that maximized rewards and minimized penalties. Dopamine levels were continuously measured every 100 milliseconds during each of the three stages of the game.

Enhancing Understanding of Psychiatric Disorders

We discovered that dopamine not only plays a role in signaling positive and negative experiences in the brain but that its production is optimal when trying to learn from these outcomes,” enthused Professor Kenneth T. Kishida, Associate Professor of Physiology and Pharmacology and neurosurgeon at Wake Forest School of Medicine, in a press release. “What is also interesting is that it appears the dopaminergic system takes different pathways in the brain depending on whether the experience is rewarding or punitive.”

According to the researcher, this experiment—the first to directly measure dopaminergic activity in the human brain—could aid in “better understanding the underlying mechanisms of depression, addiction, and related psychiatric and neurological disorders.”