What’s keeping you up?

SHINNING A LIGHT ON SLEEP It’s a fairly simple concept: Bright light helps keep us awake, while darkness helps us sleep. Now researchers at UCLA have identified the group of neurons that mediates whether or not light arouses us.

The researchers reported that the cells necessary for a light-induced arousal response are located in the hypothalamus, an area of the brain responsible for, among other things, control of the autonomic nervous system, body temperature, hunger, thirst, fatigue, and sleep. These cells release a neurotransmitter called hypocretin. In the current study, researchers examined the behavioural capabilities of mice that had their hypocretin genetically knocked-out” (KO mice) and compared them with the activities of normal, wild-type mice (WT) that still had their hypocretin neurons. The researchers tested the two groups while they performed a variety of tasks during both light and dark phases. Surprisingly, they found that the KO mice were only deficient at working for positive rewards during the light phase. During the dark phase, however, these mice learned at the same rate as their WT littermates and were completely unimpaired in working for the same rewards.The findings suggest that administering hypocretin and boosting the function of hypocretin cells will increase the light- induced arousal response. Conversely, blocking their function by administering hypocrelin receptor blockers will reduce this response and thereby induce sleep.

Leave a Comment

Previous post:

Next post: