Neurons monitor the accumulation of excess weight

We used to think that our senses are only for communicating with the outside world. But in fact, the body ‘eavesdrops’ on itself – and does it much more actively than we used to think.

A new study by scientists from the Weizmann Institute has shown that nerve cells can sense what is going on inside our fat tissue. And it is this internal ‘fat sensing’ that can have a strong influence on metabolism.

Mice in which the ability to sense pressure in fat tissue was switched off were unexpectedly protected from obesity. Even when they ate fatty food and did not move much, their body did not hurry to store excess – on the contrary, it actively burned energy.

It turned out that certain nerve cells, usually associated with skin and muscle, grow into fat tissue. They track mechanical changes – that is, they sense how much the tissue becomes tight or taut. These signals, the scientists suggest, help the body decide whether to store fat or burn it.

At the centre of attention was a special sensor Piezo2 – it’s what allows cells to pick up pressure. When it was switched off, the mice began to behave very differently: blood sugar levels dropped, insulin sensitivity improved and the risk of fatty liver disease disappeared, even though there was plenty of fat in the diet.

It was Piezo2 that turned out to be a kind of metabolic ‘brake’: it suppresses the work of brown fat, which is normally responsible for burning calories. When the brake was removed, the mice’s bodies began to actively expend energy instead of storing it.

It’s important to note that brown and beige fat are not the fats we fear. They’re just the ones that help warm the body and burn excess glucose. The problem is that under normal circumstances, the body often drowns out their activity – and it’s now becoming clear why.

It is also interesting that previously scientists paid almost no attention to the neural connection with fat tissue. All hope was in hormones such as leptin. But the nervous system works much faster – and gives the body a signal almost instantly.