For those who are chronically sleep deprived , and those who work in shifts , students and truck drivers , a usual strategy is the recovery of lost hours on weekends .
Thinking logically , recovery sleep rather pay this debt that we owe to the hours lost, without long-term effects . But a new study from the Medical University of Pennsylvania presents some disturbing evidence – that the loss of a chronically sleep can be more serious than we previously thought and can drive to irreversible physical disorders and even loss of brain cells . Article of this study was published in March in The Journal of Neuroscience.
Using a mouse affected by chronic sleep loss , Dr Sigrid Veasey , associate professor of medicine and member of the Centre for Sleep and Circadian Neurobiology at the Perelman School of Medicine , along with collaborators at Peking University, has determined that waking ( insomnia ) is linked to the extended damage and loss of neurons which are essential to the optimal alert and cognition , neurons of the brain called the locus coeruleus ( LC ) .
” In general, we always assumed full cognitive recovery after short periods or long-term insomnia ,” said Veasey . But some studies have shown that among people ‘s attention and other parts of cognition does not return to normal even after three days to recover sleep , raising the issue of persistent brain damage . I wanted to figure out exactly if chronic sleep loss affects neurons , whether the damage is reversible and which neurons are involved . ”
Mice were examined after periods of normal sleep , short and long term insomnia after sleep pattern typical of a shift worker . Veasey ‘s laboratory discovered that in response to short-term sleep loss , LC neurons enhances the production of sirtuin protein type 3 ( SIRT3 ) that is important for energy production and mitochondrial redox responses and protects neurons from metabolic damage .
SIRT3 is essential to the lack of sleep for short periods to maintain metabolic homeostasis , but the insomnia extended,the SIRT3 response is absent. After some days of sleep as sleep pattern typical of a shift worker , LC neurons in mice begin to show low levels of SIRT3 , enhancing cell death and the mice lost 25 % of these neurons.
“This is the first time that sleep loss can lead to neuronal loss ,” notes Veasey . Amazingly, research suggests that mitochondria in neurons in the LC responds to loss of sleep and sleep loss can accommodate short but not prolonged insomnia .
This leaves the possibility that in a particular way to increase the level of SIRT3 by the mitochondria could help rescue neurons and their protection over an extended period of chronic insomnia . The study also shows the importance of sleep to restore metabolic homeostasis among mitochondria in neurons of the LC and possibly in other brain areas to ensure their right functioning during waking hours .
Veasey supports the need for further research to establish the existence of similar phenomena in people and to determine how long the insomnia puts people at risk of developing brain damage . ” Given the role of SIRT3 in the adaptive answer to sleep loss , the extent of neuronal damage can vary among individuals.
In particular, aging , diabetes, high fat diet and a sedentary lifestyle could reduce SIRT3 . If the cells in these individuals , including neurons , and reduced SIRT3 levels due to loss of sleep , these people may be at greater risk of developing nerve cell damage . ”
The next step is to subject the model to a test SIRT3 . ” Now we can overexpress SIRT3 in LC neurons ,” said Veasey . “If we can prove that protect cells and insomnia, when we aim to promise therapies for millions of workers in shifts . ”
Planning team also examine post-mortem shift workers to search for evidence of increased neuronal loss in the LC and signs of neurodegenerative diseases such as Alzheimer ‘s and Parkinson’s , since previous studies in mice have shown that damage or disorders LC neurons may accelerate the progression of these diseases. Not produce direct these diseases, ” damage neurons in the LC due to loss of sleep may facilitate and accelerate neurodegeneration among people who already have the disease ,” said Veasey .
While more studies will be necessary to answer these questions , this study provides further confirmation of a scientific consensus that grows fast: sleep is more important than previously thought . In the past, Veasey adds , “No one believed that our brain can be irreversibly damaged due to loss of sleep .” Now it is as clear as it’s possible.