The internal body temperature in humans and mammals is maintained at 37℃/96℉, unless disrupted by a force like an illness or heat exhaustion. Regulating the body to stay in the normal range is crucial for survival and for enzyme function. Our internal body temperature is constantly being regulated by our hypothalamus, located at the base of our brain. The hypothalamus uses sensors from a mediator known as prostaglandin E which is brought about when an infection is present in the body. After PGE2 is present, it signals for the body to raise its temperature and combat the infection. If temperature levels are abnormal, the enzymes in our body have trouble functioning because they need specific temperature conditions to carry out reactions. Therefore, maintaining homeostasis throughout the body by regulating internal temperature is key to human survival.
A team of researchers at Nagoya University in Japan were inspired by this process and decided to focus on the unknown neurons that make up the receptors of PGE2 and how this regulation process functions. The group of professors and colleagues successfully discovered key neurons that work to regulate the body temperature of mammals. This finding can be highly useful for creating future technology that can artificially fix body temperature related conditions such as hypothermia, heat stroke, and obesity.
By using rats as a subject for their research, they exposed the rats to cold (4°C), room (24°C) and hot (36°C) temperatures to observe the effect of temperature changes on EP3 neuron response. After conducting the experiment, the researchers were able to conclude that exposure to the hot temperature led to an activation of EP3 neurons and the cold temperatures did not. Once they made this conclusion, they dug deeper into the neurons and analyzed the nerve fibers of the neurons to discover where the signal transmission occurs after sensing an infection. The researchers were able to conclude that the neuron fibers are spread out in different areas of the brain, mainly the dosomedial hypothalmus, which works to activate the sympathetic nervous system. Not only did they discover these fibers, but they also discovered the substance that EP3 neurons utilize to send signals to DMH. By observing the structure and chemical makeup, they found that this substance is a neurotransmitter known as gamma-aminobutyric acid (GABA), which inhibits neuron excitation.
Finally, their findings support the idea that EP3 neurons are a major component of regulating internal body temperature and that they send out the GABA substance to signal to DMH neurons for a proper response. Their research proves that intiating a neural response decreases body temperature and inhibiting neurons leads to an increase in body temperature. Furthermore, their strong research in this area can support future development of advanced technology that will be capable of artificially adjusting internal body temperature. The anticipated technology could help prevent hypothermia, treat obesity to keep body temperature slightly higher and initiate fat burning, and be a key method of survival in hot environments.