Scientists have uncovered a portion of the brain called the nociceptin system that works to decrease effects of stress. The discovery could hold the key to future medicines targeting disorders related to stress and anxiety.

Stress creates changes in the brain on the cellular level, and researchers at The Scripps Research Institute (TSRI), the National Institutes of Health, and Italy’s University of Camerino found nociceptin, the system’s namesake neurotransmitter, has the capability to prevent or reverse those cellular changes.

Nociceptin falls in the opioid category of neurotransmitters and displays both the potential to worsen pain and lessen stress. 

Discovered in the 1990s, researchers first learned about its ability to worsen pain during studies with mice. Upon further study, scientists found it also blocked reward pathways activated with the highly addictive opioids morphine and heroin. In this latest round of studies, researchers collaborated to examine nociceptin’s interaction with the amygdala, a part of the brain integral to processing emotions. Stress signals the amygdala to alert the hypothalamus, another part of the brain that tells the nervous system to activate its fight or flight response.

Researchers at the National Institute on Alcohol Abuse and Alcoholism found that animals placed under stress in a laboratory demonstrated increased activity of genes associated with nociceptin. At TSRI, scientists found that nociceptin reduced activity of a stress hormone. Then, Italian biologist Roberto Ciccocioppo injected nociceptin into rat amygdalas, finding the rats resisted showing stress-induced behaviors.

The international scientists inferred the brain produces nociceptin when under stress to normalize itself. 

Researchers hypothesized that chronic stress alters neurons related to the nociceptin system, impairing its functioning and possibly leading to anxiety disorders.

Pharmaceutical companies are now working on medications that imitate nociceptin, and the pills could soon become ready for human trials. Select early animal trials have already proven successful.

What do you think about scientists’ discovery of a stress-busting neurotransmitter? 

Image by amy leonard via Flickr


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