Are some parts of your body too sensitive?

Now, pick up a paper towel and touch or swipe it with your finger.

But don't think that all parts can be so delicate.

I have to admit that some areas of the body are indeed more sensitive

In the past, neuroscientists used a very intuitive and slightly pleasant model "sensory dwarf" to describe the representation ratio of different areas of the body in the somatosensory and motor cortex

The brain provides a lot of space for processing information from sensory neurons in sensitive skin

The strange thing is that the skin in sensitive areas does not have more neurons than other areas

According to experimental results in mice, in the early stages of development, the mouse's hairless soles are the same as other hairy areas, and the number of neurons in the brain is proportionally characterized

▲Study diagram (picture source: reference [2])

Since the number of sensory neurons is not very different, there must be other mechanisms that help amplify the signals of sensitive skin

▲When the glabrous area (adult) is touched, the neuron signals in certain brain areas will be stronger, which is in sharp contrast with the hairy area (picture source: reference [2])

But the brainstem will also be eccentric, and brainstem neurons will have a stronger connection with sensory neurons in the hairless area, amplifying the signs of sensitive skin

Research suggests that this change in the brain is only related to the type of skin, and will not change according to the number of times you produce touch

In fact, from an evolutionary point of view, this distinction is necessary for mammals, because the appearance of animals has great changes

Note: The original text has been deleted

Reference materials:

[1] Unraveling the mystery of touch.

[2] Brendan P.