Researchers report the unexpected presence of a type of neuron in the brains of mice that appears to play a central role in promoting sleep by turning 'off' wake-promoting neurons. The newly identified brain cells, located in a part of the hypothalamus called the zona incerta, they say, could offer novel drug targets to treat sleep disorders, such as insomnia and narcolepsy, caused by the dysfunction of sleep-regulating neurons.
https://www.sciencedaily.com/releases/2017/08/170831091451.htm