Specific neurons release dopamine to regulate pain differently in male and female mice

Males and females usually experience and treat pain differently, but scientists have not yet developed all the brain circuits involved in the body. understand these differences. Now, new research from the laboratory of UNC School of Medicine at Thomas Kash, PhD, shows how neurons use dopamine to manage pain differently in male and female mice.

The discovery, published in the journal Neuron, which could help the scientific community devise better pain management strategies, especially for women, who have pain unevenly throughout their lives.

We focused on this neural pathway because our previous work and the work of others show that specific neurons release dopamine to regulate pain responses. Unfortunately, this research was only performed in male mice. So we decided to take a look at both male and female mice, and our findings were a big surprise. “

Thomas Kash, PhD, Distinguished Professor of Pharmacology John R. Andrews, School of Medicine Laboratory, University of North Carolina

Dopamine, formerly known as the brain chemical, can regulate a wide range of behaviors. The dopamine neurons known as Kash and his lab were previously shown to be important for both the beneficial properties and pain relief properties of heroin. Beyond this, several studies have shown that these neurons can regulate attention, suggesting a link between drug abuse, pain, and attention.

Previously, using male mice, Kash’s laboratory found that dopaminergic neurons played a key role in how sleep induces pain, possibly through the release of dopamine and glutamate. In the new experiments, his lab focused on a neural pathway starting at the midbrain region called the periaqueductal gray, including part of the dorsal raphe.

That brain region is involved in behavior change – how animals learn to deal with their environment. The dopamine-producing neurons in that region work in conjunction with a brain structure called the bed nucleus of the stria terminalis, or BNST, forming a neural pathway.

“We found that activity of this pathway reduced pain sensitivity in male mice, but induced female mice to move more, especially in the presence of something distracting,” the first said. author Waylin Yu, PhD, who was a graduate student in Kash and routine laboratory. a postdoctoral researcher at UC San Francisco. “We think this is because of the different ways in which men and women deal with pain.”

In particular, these tests appear to show that dopamine helps men just not feel as much pain, and in women, dopamine helps mice focus attention in it. elsewhere while in the presence of pain.

More research is needed, but a Kash lab study shows that applying BNST-specific neural projections reduces chronic and persistent inflammatory pain, providing further evidence that dopamine signaling can increase to inhibit pain stimulation, and thus counteract severe pain.

“We hope to explore how this pathway can regulate more emotional behavior associated with chronic pain, and then look at the dynamics of the system, such as how the This route works in real time during behavioral measurements, “Kash said. “These neurons are also involved in the activities of opioids such as morphine, so we plan to investigate that area, as well.”