Sleep is a vitally important process for the brain and the body. The need for sleep ("sleep pressure") increases gradually during the periods that we are awake, as reflected by us feeling tired, and dissipates when we sleep, reaching the lowest levels just before we wake up fresh and rested. Evidence indicates that the brain is among the first targets that are impacted by sleep deprivation. However, despite this extensive knowledge of the importance of sleep, much controversy remains about the biological mechanisms that convey the numerous benefits of sleep.
The predominant idea that sleep plays a "restorative" role fits well with our subjective experience. However, the question remains: what precisely needs to be restored after a period of wakefulness and how do restorative changes occurring at the level of individual cells benefit from a global shut down occurring during sleep?
Vladyslav Vyazovskiy and a team of collaborators have advanced a new hypothesis, recently published in Nature Reviews Neuroscience, that the biological function of sleep is to allow for vital "repair and maintenance" of the neurons in our brains.
"We propose that these repair functions can only occur if the rest periods of individual neurons are aligned precisely at a time scale of seconds or less. The reasoning for this is that we have billions of neurons in our brain, and each of them is connected with thousands of other neurons, all of whom are constantly talking to one another. Therefore, it appears that our neurons cannot rest and repair themselves independently, but must shut down at the same time so that they do not disturb one another and allow each individual cell to obtain the rest it needs. If neurons attempt to obtain rest while we are awake, it is not only much less efficient but also has serious negative effects on our performance. Similar phenomena can be found outside of biology. The London Underground system, for example, can only function properly during the day because it has extensive maintenance every night, during which all trains stop running between the interconnected stations. We suggest that sleep allows a similar period of maintenance for the brain." - A/Prof Vyazovskiy.
In this MRC funded project led by Associate Professor Vyazovskiy's laboratory at DPAG, in collaboration with Professor Kenneth Harris from University College London's Institute of Neurology and Professor Colin Akerman, Professor of Neuroscience at Oxford University's Department of Pharmacology, the team will combine expertise in cutting edge techniques, including electrophysiology, molecular-genetics and pharmacology, and will perform research at several distinct scales - from single cells, to local networks of cells, to the behaviour of the organism.
"It will thus make a major advance in the field of sleep neuroscience and the knowledge obtained will benefit numerous clinical applications that are concerned with the prevention and treatment of sleep disturbances, including improving the management of sleep in shift workers and the prognosis of patients suffering from neurodegenerative disorders, such as Alzheimer's disease." - A/Prof Vyazovskiy.
Vladyslav's team are currently recruiting for the position of Postdoctoral Research Scientist. Further details can be found on the DPAG Vacancies site and the University of Oxford Jobs and Vacancies database.