Scientists' Surprising Discovery: Compressing the Leg Bone May Help Treat Brain Injury

A new study shows that bone may communicate with the brain through chemical signals in the blood and may help the healing process after injury.

At first glance, it seems strange to go to the leg bone to help the damaged brain. But new research in mice and pigs suggests that bone may communicate with the brain through the blood and, under certain conditions, produce messages that help reduce brain damage.

According to Zomit, in their experiments, Chinese researchers put pressure on the leg bones of animals with a special device in a completely controlled manner. Animals that received this treatment method after brain damage had a higher chance of survival compared to the control group, and their movement abilities and memory were also better restored. This approach also had promising results in rats with stroke.

The idea of study was formed from an old phenomenon in medicine. Doctors have known for years that some patients with severe brain damage have broken bones that heal faster than usual. Sometimes ossification occurs even in the soft tissues of the body, where there should be no bone.

By applying controlled pressure to the tibia of mice and pigs, researchers observed improvements in survival, movement and memory after brain injury.

These observations show that the damaged brain can send messages to the bone. This time, the researchers asked the opposite question: if the brain can affect the bone, can the bone also send a message to the brain to help the healing process?

To test this hypothesis, a device was designed that applied gentle and precise pressure to the leg bone. In each session, the bone was compressed 300 times at a rate of two compressions per second. This work continued five days a week.

Mice that received this treatment after brain damage performed better in motor tests. They also performed better on a spatial memory test; A test in which the animal has to remember the location of a platform hidden in water.

The results were not limited to animal behavior. According to ScienceAlert, in the treated mice, the extent of brain damage was smaller, more nerve cells survived, and chronic brain inflammation was reduced. Evidence of increased formation of new nerve cells was also observed.

There was still an important question. Calf pressing doesn't just affect the bone; Muscles, nerves and blood vessels may also react. So the researchers had to determine that the observed effect was actually coming from the bone itself.

To answer the question, the researchers paid attention to the living cells inside the bone. Contrary to its hard and immobile appearance, bone is a living tissue. The cells inside it can sense pressure and movement and release various chemicals in response.

One of the most important parts of this mechanism is a protein called PIEZO1, which acts as a pressure sensor. When the researchers disabled the activity of PIEZO1 in the bone cells of the mice, compression of the leg bone no longer had the previously protective effect on the brain. This result showed that the bone cells themselves must sense the pressure for the beneficial effect to occur.

The researchers then conducted another experiment. They isolated the blood serum of mice whose leg bones had been compressed and injected it into brain-damaged mice that had not themselves been subjected to bone compression. These mice also lost fewer nerve cells compared to the control group.

Calf pressing doesn't just affect the bone; Muscles, nerves and blood vessels may also react

This experiment gave the researchers an important clue: the beneficial effect was not just the result of mechanical pressure on the foot. It seemed that the bone, after receiving pressure, enters the blood and these substances reach the brain through the blood stream.

After treatment, the amount of several substances in the blood increased, which are associated with the protection of nerve cells, reduction of inflammation and tissue repair. The researchers did not find a specific substance as the main factor. It is likely that a series of chemical messages simultaneously cause this effect.

In order to make it clear that this method does not work only in mice, the researchers also conducted the experiment on four-month-old miniature pigs. The pig brain is larger than the rat brain and is more similar to the human brain in terms of structure and function.

At this stage, the pigs were brain damaged in a controlled manner. Six pigs were subjected to tibial compression and the other six pigs were not treated as a control group.

Treated pigs performed better in behavioral tests and survived longer. The size of the damaged part of their brains was also smaller, more nerve cells remained healthy, and substances related to brain protection and repair were increased in their blood. Four weeks later, the researchers examined the tibia, knee joint and cartilage of the animals and found no obvious signs of damage from this pressure.

However, the study has important limitations. In the experiment on pigs, there were only six animals in each group. All of the mice and pigs were also male, so it's not yet clear whether female animals show the same response. On the other hand, the brain damage of animals was created in a laboratory environment in a precise and controlled manner. In humans, concussions are very diverse and differ greatly in terms of injury location, severity, and complications.

Researchers still don't know how long bone compression should be done after an injury, how long the effect lasts, and exactly which substances in the blood play the biggest role. Therefore, the results of this study do not mean that in case of a head injury, one should press the person's leg. Traumatic brain injury is an emergency situation and should be treated under the supervision of a doctor.

The main importance of the research is in something else: bone is not only the skeleton of the body. This tissue can sense force, react to it, and release chemicals into the bloodstream that may affect other organs, including the brain.

Bone is not just the body's skeleton, but can sense force, react to it, and release chemicals into the bloodstream.

In these experiments, pressing the bone activated its cells. These cells changed the chemical composition of the blood, and the resulting messages likely helped reduce inflammation, preserve nerve cells, and better repair the brain.

If further studies confirm this mechanism in larger samples and eventually in humans, methods for immune stimulation of bone or even drugs based on the protective substances produced by it may be developed in the future. Of course, such applications are currently at the hypothesis and research stage.

The current result is simple but unexpected: the healing process of the damaged brain may not be limited to the brain itself. Leg bones may also be part of the body's response to injury.

The research was published in the journal Nature Neuroscience.