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Fundamental research

04 - 06 - 2018

The mysteries of sleep

A study in C elegans worms reveals the role of glia cells in sleep-related immobility.


Sleep is an extremely common behaviour and is preserved in animals. It is accompanied by a state of immobility close to paralysis.


Many mechanisms are known to trigger sleep and wake such as the circadian rhythm or adenosine. But we do not know the mechanism that causes and controls the immobility related to sleep. The intervention of glia cells that provide many functions in the brain in relation to neurons is thought to be involved.


To look into the subject, Researchers used the C. elegans worm, as the number and functions of their neurons and glial cells are well known. They created a line of worms devoid of glial cells and observed:

               - in immature worms, earlier and longer lethargy (associated with moults) and prolonged larval development

               - in adults, moments of immobility from a few seconds to a few minutes which is unusual in these animals which evokes narcolepsy in human.

The absence of glial cells therefore seems to increase immobility.


Then the researchers studied in this worm line how the neurons function. They discovered that the suppression of ALA * neurons removed the effects of glial cell suppression. They concluded that glial cells control the effects of ALA neurons.


The involvement of glial cells in sleep-related immobility is now demonstrated in C. elegans. It remains to establish which mediators are involved and then to transfer these discoveries to the human brain to lead to medical applications.




 * neurons that trigger immobility by acting on the neurons that control movement