Professor Hiroki Ueda of the University of Tokyo Graduate School of Medicine and a joint research group of RIKEN have announced that calcium ions play an important role in the mechanism of sleep.It is expected to lead to the development of diagnosis and treatment methods for sleep disorders.This study was published in the online version of "Neuron".
This research group first created a computer model of nerve cells in order to identify the genes required for the formation of special brain waves seen during sleep.Four genes: (4) voltage-gated calcium channel and (XNUMX) NMDA-type glutamate receptor, which changes its function depending on the calcium ion concentration, (XNUMX) calcium-dependent potassium channel, and (XNUMX) calcium pump, which releases calcium ions to the outside of the cell. We predicted that the group was involved in brain wave formation during sleep.
To substantiate this prediction, we generated each gene knockout mouse and measured sleep.As a result, the knockout mice (XNUMX) and (XNUMX) showed a significant decrease in sleep time, and the knockout mice in (XNUMX) showed a dramatic increase in sleep time. Regarding (XNUMX), as a result of pharmacologically inhibiting the action and conducting an analysis, it was confirmed that sleep time was reduced.Observation of the brains of mice with further reduced sleep showed that inhibition of calcium ion influx stimulated nerve cells in the cerebral cortex.From this, it can be said that it became clear this time that calcium ions put the brain to sleep.
In the future, further research on these sleep-disordered mice is expected to contribute to elucidating the causes of diseases associated with sleep disorders such as depression and Alzheimer's disease, and to developing therapeutic agents.
