Researchers Identify Key Brain Circuits for Reward-Seeking, Avoidance Behavior

Researchers have identified connections between neurons in brain systems associated with reward, stress and emotion. Conducted in mice, the new study may help untangle multiple psychiatric conditions, including alcohol use disorder, anxiety disorders, insomnia and depression in humans.

“Understanding these intricate brain systems will be critical for developing diagnostic and therapeutic tools for a broad array of conditions,” said Dr. George Koob, director of the National Institute on Alcohol Abuse and Alcoholism, which contributed funding for the study. NIMH also provided major support for the research.

A report of the study, by first author Dr. William Giardino and colleagues at Stanford University, appeared in the August 2018 issue of Nature Neuroscience.

Responding appropriately to aversive or rewarding stimuli is essential for survival. This requires fine-tuned regulation of brain systems that enable rapid responses to changes in the environment, such as those involved in sleep, wakefulness, stress and reward-seeking. These same brain systems are often dysregulated in addiction and other psychiatric conditions.

In the new study, researchers looked at the extended amygdala, a brain region involved in fear, arousal and emotional processing and which plays a significant role in drug and alcohol addiction. They focused on a part of this structure known as the bed nucleus of stria terminalis (BNST), which connects the extended amygdala to the hypothalamus, a brain region that regulates sleep, appetite and body temperature.

The hypothalamus is also thought to promote both negative and positive emotional states. A better understanding of how the BNST and hypothalamus work to coordinate emotion-related behavior could shed light on the emotional processes dysregulated in addiction.