Snoozing Worms Help Explain Evolution Of Sleep

Washington, Jan 17 (UNI) Researchers have zeroed in on the snoozing worm to resolve the central biological mystery-- why we sleep.

The research seeks not only to explain the reason behind sleeping but would also provide potential drug targets for sleep disorders.

''There is a period of behavioural inactivity during the roundworm C elegans' development called 'lethargus' that has sleep-like properties,'' explained David M Raizen, MD, PhD, Assistant Professor of Neurology, in collaboration with other researchers at the Penn Center for Sleep.

''Just as humans are less responsive during sleep, so is the worm during lethargus,'' pointed out Raizen.

''Just as humans fall asleep faster and sleep deeper following sleep deprivation, so does the worm,'' he added.

By demonstrating that worms sleep, Raizen and colleagues have not only demonstrated the omnipresence of sleep in nature, but also propose a compelling hypothesis for the purpose for sleep, Science Daily reported.

In order for the nervous system to grow and change, there must be down time of active behaviour. Other researchers at Penn have shown that, in mammals, synaptic (the pairing of homologous chromosomes, one from each parent, during early meiosis) changes occur during sleep and that deprivation of sleep results in a disruption of these synaptic changes.

In addition, the research team used C elegans as a model system to identify a gene that regulates sleep. This gene, which encodes a protein kinase and is regulated by a small molecule called cyclic GMP, has been previously studied but not suspected to play a role in sleep regulation.

The findings suggest a potential role for this gene in regulating human sleep and may provide an avenue for developing new drugs for sleep disorders.

''It opens up an entire new line of inquiry into the functions of sleep,'' notes Penn Center for Sleep Director and co-author Allan I.

Pack, MB, Chb, PhD.

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