With the global temperature rising, it is crucial for human detecting the temperature and avoiding overheating to regulate the body’s temperature.
However, till now, we know very little about the molecular mechanisms responsible for detecting temperature in the sensory neurons of our skin.
A new research by King’s College published on Nature, reveal that a gene called TRPM2 has been shown to be “too hot” in mice.
TRP channel proteins can sense different degrees of heat
It has been known that some TRP (transient receptor potential) proteins can be activated by a high degree of pain.
Thermally activated channels contain many channel proteins like TRPV2,TRPV1, TRPM3, ANO1, TRPV3,TRPV4, TRPM8 and TRPA1. The absence of these channels has a modest effect on the behavior of mice only in the thermal environment, But the loss of TRPM8 can make the mice have a significant effect on the cool sensation at degree 10 – 25 C.
These proteins can transmit positive ions across the cell membrane, thus changing the internal voltage of the nerve cells. This change in voltage, in turn, triggers nerve activity, thus causing a painful sensation.
TRPM2 can feel the heat of midsummer
Dr. Chun Hsiang and Professor Peter McNaughton in King’s College have discovered an channel called TRPM2, which has not previously been linked to a sense of temperature. They used calcium imaging to identify heat sensitive neurons that do not express known TRP channels, Combined with calcium ion imaging, electrophysiological and RNA sequencing showed that the heat sensitive ion channels in these neurons are TRPM2. After the new sensory channel protein was isolated, they removed the TRPM2 gene in a group of mice and allowed the mice to compare their behavior with normal mice at 33 C or 38 C. The researchers found that normal mice prefer a cool 33 C than 38 C. The deletion of the TRPM2 gene did not distinguish between the two situation.
‘Removal of TRPM2 in these mice eliminated their ability to detect non painful heat, but the ability to use other known receptors to detect pain in the high temperature was not affected，This reveals how we can detect whether the environment is too warm at the sensory level’ said by Dr. Chun Hsiang.