New Research on Brain Protein KCC2 Reveals Habit Formation Mechanisms

Researchers at Georgetown University Medical Center have identified a way the brain's learning system can shift depending on the activity of a protein known as KCC2. This research, published in Nature Communications on December 9, emphasizes how variations in KCC2 levels can affect the ability to form reward associations, which is crucial in understanding habit formation and addiction.

Alexey Ostroumov, PhD, assistant professor in the Department of Pharmacology & Physiology, stated that disruptions in the KCC2 protein can interfere with the link between cues and rewarding outcomes, a process that is altered in conditions such as addiction, depression, and schizophrenia.

The study found that when KCC2 levels are reduced, dopamine neurons fire more rapidly, enhancing the formation of new reward associations. In their experiments, researchers monitored the behavior of rats during Pavlovian cue-reward tests, where a sound signaled an impending sugar reward.

Their findings revealed that short bursts of dopamine serve as strong learning signals that help the brain assign value to experiences. Ostroumov explained that this mechanism could explain why certain cues, such as drinking coffee, can trigger cravings in smokers.

The research also looked into how drugs like diazepam affect neuron coordination, noting that diazepam can enhance coordinated firing patterns among neurons, improving their ability to transmit information.

The team utilized various experimental methods, including electrophysiology and behavioral tests, with rats chosen for their reliable performance in complex tasks. The implications of this research extend to developing improved treatments for addiction and other brain disorders by restoring healthy learning mechanisms.

The study was supported by grants from the National Institutes of Health and other organizations, with no reported conflicts of interest from the authors.