by Richard Liang
The human body is equipped with effective mechanisms that maintain thermal homeostasis. For example, fevers can be induced to provide an optimal environment to fight certain diseases. However, it is vital that fever temperatures are maintained within a particular threshold. They cannot be too low or the energy available for enzyme activity will be too low. They cannot be too high or the enzymes in the body will denature and lose their function. Recently, a study led by Kun Song from the American Association for the Advancement of Science showed that the body’s temperature can be manipulated through TRMP2, an ion channel involved in thermoregulation.
The preoptic area (POA) of the hypothalamus, where these TRMP2 channels are located, serves as the body’s natural thermostat, detecting any changes in ambient temperature. The TRMP2 channels were first identified in the POA through calcium imaging, which showed that this subset of neurons in the POA were sensitive to temperature. After the channels were identified, the TRMP2 channels of mice were manipulated to test their thermoregulation abilities. Vesicular Glutamate Transporter 2 (VGLUT2) was used to excite the channel while glutamate decarboxylase 1 (GAD1) was used to inhibit the channel.
The results suggest that the TRMP2 channels are responsible for controlling the fever response. TRMP2 activation with VGLUT2 caused an average decrease in core temperature by 10°C. TRMP2 inhibition with GAD1 caused an average increase in core temperature by 1.5°C. From these results, it is clear that TRMP2 channels can be manipulated to a certain extent to control body temperature. This could be useful in trying to either induce a fever or limit one before it becomes detrimental to a patient.
- K. Song, et al., The TRPM2 channel is a hypothalamic heat sensor that limits fever and can drive hypothermia. American Association for the Advancement of Science (2016).
- Image retrieved from: Image retrieved from https://pixabay.com/static/uploads/photo/2014/04/03/10/30/fever-310721_960_720.png