We have long known how our skin’s nerve endings detect the cold and quickly transmit information to our brain, but we don’t understand exactly how it works. The scientists have now decided to mystery.
Michigan University researchers set out to investigate the way the feeling of pleasant freshness in our skin is transmitted to the brain, from the hypothesis that there could be an unknown “connection route” that transmits the message-a separate way from other sensory signs such as pain, heat and extreme cold.
Although we know that the nerve endings of the skin – TRPM8 Sensors – They were able to detect these pleasant cold temperatures, scientists had not yet discovered how these messages arrived in the brain, without being interrupted by other sensory information of neuronal shots, where they are processed and understood.
According to, now, For the first time, scientists discovered the complete neural circuit of the skin to the brain specifically for the sensory processing of the cold temperature.
In his mouse study, in the journal Nature Communications, the researchers found that this circuit detects pleasant freshness through the skin and amplifies the sign in the spinal cord on the way to the brain.
“The skin is the largest organ the body,” says Bo DuanSenior Author, Associate Professor of Molecular, Mobile and Development Biology at UM. “It helps us detect our environment and separate and distinguish different stimuli.”
“Yet There are many interesting questions About how he does this, but now we have a way to how he feels cold temperatures, ”he added.” This is the first neural circuit to the feeling of temperature at which the complete path of the skin to the brain was clearly identified. “
The cold signal is activated when the skin is exposed to temperatures of about 15 to 25ºC. Then the primary sensory neurons are excited, transmitting this new information to the spinal cord. This is where a unique signal amplification plays a key role in the sensory circuit.
In the rats, the sTRPM8 Skin Sleeping speak softly in response to coldnessthen the current TRHR+ spinal interneurons as a kind of preamplifier that increases this sign of coldness only.
Calcrl+ projection neurons then carry this clean and amplified “cold” signal to the lateral parabrakial nucleus – a cluster of neurons on the upper brain trunk – without any signal interference from other messages that transmit information about things such as pain, itching or heat.
When investigators silenced the “preamplifier” of the spine, the Cold channel got silent.
The team made this discovery through advanced image techniques and electrophysiology To observe how rodents transmitted the feeling of cold skin temperatures to the brain.
“These tools allowed us to previously identify the neural pathways of the chemical itch and the mechanical itch,” said Duan. “Working together, the team identified this via very interesting and very dedicated to the feeling of cold“.
And although the discovery focuses on the way rats feel a pleasant feeling of cold, genetic sequencing shows a parallel with human biologyFrom what scientists hope we also have the same skin of the skin to the brain.
Now, the team expects to examine whether the acute cold pain has its own distinct way and if it can be manipulated to help alleviate medical conditions associated with this most unpleasant sensory experience.
“I think the painful sensations will be more complicated,” said Duan. “When we are in higher risk situations, there may be several ways involved.”
The investigators also stressed that more than 70% of chemotherapy patients They felt pain due to cold temperatures. Thus, a better understanding of these cold and cold roads could potentially provide new ways to block this amplified signaling to the brain.
Teresa Oliveira Campos, Zap //
