Scientists have recorded a silent "scream" of human skin for the first time

The human body consists of many interacting parts and tissues that need constant information exchange. Communication systems in the organism maintain its vital functions. We instantly remove our hand from a hot surface thanks to the nervous system, and the regulation of heartbeat by electrical signals has allowed the creation of a vital invention - the artificial pacemaker.

For many years, the scientific community held the opinion that only neurons and heart cells use electrical impulses for communication, while epithelial cells, which line our skin, organs, and body cavities, "remain silent," primarily performing the functions of protective barriers capable of absorbing and secreting various substances.

However, a sensational discovery by American researchers has overturned this notion. Scientists found that epithelial cells are also capable of transmitting signals, using a kind of "long and slow scream." This revolutionary discovery could radically change the approach to using electrical medical devices to accelerate wound healing. The study was published in the prestigious scientific journal Proceedings of the National Academy of Sciences.

"Epithelial cells 'scream' to their neighbors when damaged - slowly, persistently, and over long distances. It's similar to a nerve impulse, but a thousand times slower," explains Steve Grenik from the University of Massachusetts in Amherst.

For the experiment, scientists developed an innovative chip connected to an array of 60 electrodes and covered it with a layer of keratinocytes - human epidermal cells. The researchers made a precise damage to this layer using a laser, and then carefully tracked the resulting electrical changes.

The results were astonishing: the signals spread at a speed of about 10 millimeters per second over distances of up to hundreds of micrometers from the site of damage - which is a very significant distance by cellular world standards.

The study showed that cell communication strongly depends on ion channels - tiny pores in cell membranes that serve to transfer calcium ions. Notably, the ion channels of epithelial cells actively respond to mechanical stimuli.

Particularly interesting was the fact that epithelial signals last much longer than neuronal ones - up to five hours. At the same time, the communication goes through phases characteristic of neuron communication. However, scientists still need to figure out what specific signals the cells use and how different types of epithelial cells handle communication in case of damage.