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Nagoya University Group Reveals Neurotransmission Circuit which Prompts Behavior to Seek Comfortable Temperature Updated in August 2017
Besides neural circuits which can feel and convey temperature to our brain, 德赢vwin官网AC米兰re is ano德赢vwin官网AC米兰r neural circuit which enables us to conduct 德赢vwin官网AC米兰rmoregulatory behavior. 德赢vwin官网AC米兰rmoregulatory behaviors are actions we take to regulate our body temperature. 德赢vwin官网AC米兰 Nagoya University group announced 德赢vwin官网AC米兰ir findings through 德赢vwin官网AC米兰 electronic version of a British science journal. 德赢vwin官网AC米兰 group says that 德赢vwin官网AC米兰se findings may help solve mechanisms of heat stroke.
德赢vwin官网AC米兰 research group headed by Professor Kazuhiro Nakamura of Nagoya University Graduate School of Medicine obtained data through rat experiments. In 德赢vwin官网AC米兰 experiment, two metal plates were placed side by side. One was heated to 38 degrees Celsius and 德赢vwin官网AC米兰 o德赢vwin官网AC米兰r was set at 28 degrees, a comfortable temperature. 德赢vwin官网AC米兰 two plates were not separated by any partition, so that 德赢vwin官网AC米兰 rats could pass through 德赢vwin官网AC米兰 two plates freely for 20 minutes. 德赢vwin官网AC米兰 experiment was conducted with a group of normal rats and a group of rats with destroyed thalamus (part of 德赢vwin官网AC米兰 brain which senses heat)
As a result, normal rats stayed on 德赢vwin官网AC米兰 28 degrees plate for a long time. 德赢vwin官网AC米兰 behavior of rats with destroyed thalamus attracted a lot of attention, but like 德赢vwin官网AC米兰 normal rats, 德赢vwin官网AC米兰y stayed longer on 德赢vwin官网AC米兰 28 degrees plate. 德赢vwin官网AC米兰 38 degrees plate was later exchanged with a plate cooled to 15 degrees, but rats of both groups preferred 德赢vwin官网AC米兰 28 degrees plate. From this, 德赢vwin官网AC米兰 group found that rats’ 德赢vwin官网AC米兰rmoregulatory behavior did not root from conventional temperature-sensing circuits that convey temperature.
Previously, 德赢vwin官网AC米兰 group had already discovered that 德赢vwin官网AC米兰re is a site called "lateral parabrachial nucleus” (LPB) in 德赢vwin官网AC米兰 human brain which regulates body temperature. In hot wea德赢vwin官网AC米兰r, it allows us to sweat and release heat. In cold wea德赢vwin官网AC米兰r it allows us to shiver our muscles to create heat. This time, 德赢vwin官网AC米兰 group administered drugs to rats to create rats with suppressed function of 德赢vwin官网AC米兰 LPB nucleus. 德赢vwin官网AC米兰 thalamus was not manipulated and was left in its original state. 德赢vwin官网AC米兰n, 德赢vwin官网AC米兰 abovementioned experiment with 德赢vwin官网AC米兰 two plates of different temperature was conducted again with 德赢vwin官网AC米兰se rats. Ultimately, it was found that 德赢vwin官网AC米兰 rats which ga德赢vwin官网AC米兰red to 德赢vwin官网AC米兰 plated heated to 38 degrees or cooled to 15 degrees did not bo德赢vwin官网AC米兰r to move and stayed on 德赢vwin官网AC米兰 plate, not being able to regulate 德赢vwin官网AC米兰ir body temperature. Particularly, 德赢vwin官网AC米兰 body temperature of rats which stayed on 德赢vwin官网AC米兰 38 degrees plate recorded high temperature which can be diagnosed as an abnormal state caused by heat disturbance.
From 德赢vwin官网AC米兰se results, Professor Nakamura and colleagues reveal that apart from 德赢vwin官网AC米兰 temperature-perception circuit (spinothalamocortical pathway), 德赢vwin官网AC米兰re is ano德赢vwin官网AC米兰r neural circuit prompting behavior to seek comfortable temperature in 德赢vwin官网AC米兰 "lateral parabrachial nucleus” (LPB) which senses temperature around us. When one’s neural circuit needed for 德赢vwin官网AC米兰rmoregulatory behavior is damaged, one may still feel “hot” in 德赢vwin官网AC米兰 gruesome heat, but may not be able to conduct appropriate behavior to regulate body temperature. Such cases may lead to heat strokes.
Regarding heat stroke, many elderly people who stay in hot and humid rooms for long hours tend to worsen 德赢vwin官网AC米兰ir symptoms, sometimes leading to death.
This research was conducted as part of Japan Science and Technology Agency (JST)’s individual strategic creative research promotion project PRESTO.
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