It’s been suggested that the amount of sleep needed for optimum health is eight hours. However, it appears that many of us seem to get by perfectly well on much less. This is mainly due to differences in genetics, as has been suggested in recent research published in the latest edition of Current Biology, where scientists identified the two genes responsible.
Helping us to understand the mechanics of sleep
The senior author of the study, Professor Kyunghee Koh of Thomas Jefferson University, admits that there’s still a lot that we don’t understand about sleep, especially in regard to the initiation of the process. During her recent research, Koh and her team were able to uncover the specific area of the brain and the pathway responsible for controlling the amount of time that we sleep. By examining thousands of mutant fly lines, they discovered a mutant that appeared to sleep far less than other flies. Through a series of genetic and biochemical experiments, the scientists were able to track how this mutant protein, Taranis, interacted with other proteins, and found that it attached itself to Cyclin A, which is a known sleep regulator. Together Taranis and Cyclin A combine to form a substance which appears to inactivate Cdk1, which usually suppresses sleep and promotes wakefulness.
Cyclin A has been found to exist in a small number of neurons, including seven neurons on either side of the brain. These areas of the fly brain correspond to the hypothalamus in the human brain, which is one of our known sleep centres. When the Taranis protein was reduced in these neurons the scientists observed a reduction of overall sleep. The scientists believe that this area of the fly’s brain is an arousal centre and that Taranis has the effect of inhibiting this area during sleep.
While the Taranis protein does have a corresponding protein in the human brain, it’s not yet clear whether this works in the same way. However, Dr Koh and her team plan to continue their work by investigating the cues that cause Taranis to be turned on and which proteins are affected when sleep is prevented.