Energy levels link sleep control mechanisms
Sleep, or lack of it, can determine level of cognitive performance which is linked with accidents as well as increased risk of serious health problems. Links between cell energy levels, gene transcription and sleep rhythms may uncover answers to sleep disorders and the ill-effects of sleep deprivation.
Timing and quality of sleep is determined by a homeostatic process that compensates for sleeplessness and a circadian cycle to determine the time of day when we should sleep. The effects of even minor misalignments between these two processes, as in jet lag for example, indicate that sleep control is a very relevant feature in cognitive performance and life quality.
Previous studies by the EU-funded 'Redox potential as an interface between sleep homeostasis and circadian rhythms' (Redoxsleepcircadian) project members have suggested that although the two cycles are supposed to operate independently, the two main clock genes work together for homeostatic sleep regulation and generation of circadian rhythms. Not only that, but both CLOCK and NPAS2, the core clock genes, depend on the redox potential in cells suggesting that the two sleep mechanisms are linked through cell metabolism.
The aim of the recently completed project Redoxsleepcircadian was to understand the cell processes that determine our daytime performance and sleep quality. By inducing circadian rhythms in a type of connective tissue cell, fibroblasts, the sleep scientists could determine if there were any accompanying redox changes.
Using redox genetic probes along with a time lapse imaging system, changes in redox potential were recorded in living fibroblasts. Any increases in transcriptional activity in the clock genes Per1 and Per2 during sleep deprivation may indicate energy deficits in prolonged wakefulness. Per 1 and Per 2 are under direct control of CLOCK and NPAS2.
Results indicated that Per2 regulates activity-induced and circadian mechanisms central to regulation of sleep and wake periods. Moreover, molecular feedback underlying circadian rhythm generation was able to regulate the requirements of homeostatic sleep need.
In parallel, the project team also focused on Per2 in mice. This sleep gene has been observed to increase expression after sleep deprivation (SD) in the rodent. The scientists demonstrated that all living mice increased levels of Per2 protein production with different dynamics in the brain. This was particularly so in the cerebral cortex as well as in the liver and the kidney.
Interestingly, extended times without sleep affected Per2 RNA expression through circadian and non-circadian mechanisms always resulting in increased Per2 protein. This suggests that there is no separation between the two cycles.
At the recent close of the project, Redoxsleepcircadian was further investigating the role of the main circadian pacemaker, the suprachiasmatic nucleus (SCN), a miniscule region on the brain's midline. Regulating many neuronal and hormonal activities, the SCN is key player in the relationship between clock genes, sleep and wakefulness.
Ability to control sleep rhythms could mean a welcome reprieve for patients with sleep disorders. Jet lag and disorientation due to shift work for many of the world's labour force could also become things of the past.
Provided by CORDIS
- Phase of clock gene expression in human leukocytes correlates with habitual sleep timing May 01, 2008 | not rated yet | 0
- Researchers observe disruptions of daily rhythms in Alzheimer's patients' brains Apr 27, 2011 | not rated yet | 0
- Hormones tied to elderly sleep problems Apr 12, 2011 | not rated yet | 0
- Night shift nurses more likely to have poor sleep habits Jun 11, 2007 | not rated yet | 0
- Actigraphy is a useful way to assess and manage sleep disorders Apr 23, 2007 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Why is zone 1 in liver more prone to ischemic injury?
17 hours ago Hi, Is it because around central vein, there is only deoxygenated blood from the vein where as in the periphery there is hepatic artery. Also why...
How can there be villous adenoma in colon, if there are no villi there
May 22, 2013 As title suggest. Thanks :smile:
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013 Hello everyone, Ok Stomach's normal epithelium is simple columnar, now in intestinal type of adenocarcinoma of stomach it undergoes "intestinal...
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
- More from Physics Forums - Medical Sciences
More news stories
By discovering the new mechanism by which estrogen suppresses lipid synthesis in the liver, UC Irvine endocrinologists have revealed a potential new approach toward treating certain liver diseases.
Medical research 6 hours ago | not rated yet | 0 |
Aortic arch pulse wave velocity, a measure of arterial stiffness, is a strong independent predictor of disease of the vessels that supply blood to the brain, according to a new study published in the June issue the journal ...
Medical research 6 hours ago | not rated yet | 0
Since the discovery of Prontosil in 1932, sulfonamide antibiotics have been used to combat a wide spectrum of bacterial infections, from acne to chlamydia and pneumonia. However, their side effects can include serious neurological ...
Medical research 8 hours ago | not rated yet | 0 |
Scientists at the National Institutes of Health report they have discovered in mouse studies that a small molecule released in the spinal cord triggers a process that is later experienced in the brain as ...
Medical research 8 hours ago | 5 / 5 (2) | 0 |
Spanish researchers have discovered that the daily clearance of neutrophils from the body stimulates the release of hematopoietic stem cells from the bone marrow into the bloodstream, according to a report published today ...
Medical research 9 hours ago | 5 / 5 (2) | 0
(Medical Xpress)—Regulating the distribution of power in neurons is done by a system that makes the national electric grid look simple by comparison. Each neuron has several thousand mitochondria confined ...
4 hours ago | 4.8 / 5 (5) | 0 |
Teams of highly respected Alzheimer's researchers failed to replicate what appeared to be breakthrough results for the treatment of this brain disease when they were published last year in the journal Science.
8 hours ago | 5 / 5 (1) | 2 |
A brief visual task can predict IQ, according to a new study. This surprisingly simple exercise measures the brain's unconscious ability to filter out visual movement. The study shows that individuals whose ...
10 hours ago | 4.9 / 5 (7) | 0 |
Little is known about why asthma develops, how it constricts the airway or why response to treatments varies between patients. Now, a team of researchers at Weill Cornell Medical College, Columbia University Medical Center ...
8 hours ago | not rated yet | 0 |
Ethnic background plays a surprisingly large role in how diabetes develops on a cellular level, according to two new studies led by researchers at the Stanford University School of Medicine.
6 hours ago | not rated yet | 0 |
Even while being dragged to its destruction inside a cell, a cancer-promoting growth factor receptor fires away, sending signals that thwart the development of tumor-suppressing microRNAs (miRNAs) before it's dissolved, researchers ...
5 hours ago | not rated yet | 0 |