Dr. Sho Aoki of Okinawa Institute of Science and Technology has revealed that the flexibility of the head is controlled by specific neurons (nerve cells) in the brain.It has been thought that a special nerve cell called cholinergic interneuron, which is present in only 1 to 2% of the striatum that controls advanced decision making, is related to flexibility, but there is no confirmation. bottom.
First, we trained normal rats and rats with injured cholinergic interneurons to receive sugar as a reward by pressing one of the two left and right levers.By setting the sugar to be available only from the right lever for the first few days, both rats were able to learn the rules without difficulty.Therefore, the levers that receive sugar are switched at random, but the light is turned on on the correct lever.In order to receive a reward, it is necessary to newly capture information called light.Normal rats responded flexibly to light, while the other rat was unable to pay attention to light and continued to behave according to the first rule.
This experiment demonstrated that rats with impaired cholinergic interneurons could not incorporate information that was not needed by the rules once learned, that is, they became stiff.In other words, it was confirmed that this neuron has a role to encourage the search for new rules as the situation changes.Since these nerve cells decline with aging, it may be a hint to explain why the head becomes stiff with aging.
Source:[Okinawa Institute of Science and Technology] Elucidation of the cause of stiff head !?