Can acupuncture change how the body reacts to harm? A study in mice looked for clues.

The team used needles with a weak electric pulse in the back leg. They traced a group of nerve cells deep under the skin.

The signal traveled toward the brain. The vagus nerve helped carry the message. Small glands near the kidneys released chemicals. Two signs of inflammation fell. Inflammation is part of how the body reacts to harm.

Next, the team removed those nerve cells. The needles no longer caused the same changes. These nerves were needed for this response.

In a second test, the team changed the nerve cells so light could switch them on. Light then set off the same chain of events.

This helps explain one effect in mice. It does not show that the treatment works for people with cancer.