Control of lipolysis by a population of oxytocinergic sympathetic neurons. (https://www.nature.com/articles/s41586-023-06830-x)

These scientists wanted to understand how a special substance called oxytocin affects our bodies. Oxytocin is a small molecule made in a part of our brain called the hypothalamus and is released by a special part called the posterior pituitary. It is known to have different effects on our body, like helping mothers give birth, helping with breastfeeding, and influencing our social behavior.

Scientists have also been studying if oxytocin can be used as a treatment for conditions like autism and schizophrenia. They have found that when oxytocin is given from outside our body, it can also affect our body weight, the levels of fats in our blood, and how our body controls sugar. This suggests that oxytocin could be helpful in treating diseases related to our metabolism, like obesity or diabetes.

But the scientists wanted to know if the oxytocin that is naturally produced in our body also plays a role in controlling our metabolism. So, they did some experiments using mice and also studied human volunteers. They found that oxytocin is actually very important in regulating how our body breaks down fat stored in a special tissue called adipose tissue. They also found that oxytocin helps other molecules in our body called beta-adrenergic agonists to work better in breaking down fat.

The most surprising discovery was that the oxytocin involved in these metabolic actions comes from a special group of nerve cells that were not known before. These nerve cells are called tyrosine hydroxylase-positive sympathetic neurons. These nerve cells are part of our peripheral nervous system, which is the network of nerves that spread throughout our body.

So, this study shows that oxytocin, which is made in our brain and released by a special part, is an important regulator of how our body handles fat and controls our metabolism. It also shows that oxytocin is produced by a specific group of nerve cells in our peripheral nervous system. This new knowledge can help scientists develop new treatments for metabolic diseases in the future.

Li E., Wang L., Wang D., Chi J., Lin Z., Smith GI., Klein S., Cohen P., Rosen ED. Control of lipolysis by a population of oxytocinergic sympathetic neurons. Nature. 2024 Jan;625(7993):175-180. doi: 10.1038/s41586-023-06830-x. Epub 2023 Dec 13.