Researchers from US and Japan have been able to identify a type of neuron that is responsible for keeping the living beings awake. By tracking the nerve cells in rats, the researchers had found that the identified type of neuron receives inhibitory signals during night that makes them inactive, and hence animals sleep.

These neurons produce a chemical called orexin that keeps the animal awake. Inhibitors of this protein will cause sleepiness, and in human beings, deficiency of this protein may lead to narcolepsy or sleeping sickness.

Scientists of the study feel that how the orexin-producing neurons connect to other neurons, is the fact that will perhaps be able to explain how when a person gets up from sleep, tends to remain awake. By mapping the neurons it will be possible to find out how animals sleep and why.

Brain mapping is a comparatively new technique developed by French scientists and provides new ways of navigating the neural pathways of the brain. This is the first time the technique is used to trace a particular neural pathway.

The study was reported in the April issue of the journal Neuron