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Sleep Deprivation Disrupts Brain-Cell Communication, Study Finds (npr.org)

A new study published in the journal Nature Medicine found that sleep deprivation causes the bursts of electrical activity that brain cells use to communicate to become slower and weaker. "The finding could help explain why a lack of sleep impairs a range of mental functions, says Dr. Itzhak Fried, an author of the study and a professor of neurosurgery at the University of California, Los Angeles," reports NPR. From the report: The finding comes from an unusual study of patients being evaluated for surgery to correct severe epilepsy. As part of the evaluation, doctors place wires in the brain to find out where a patient's seizures are starting. That allows Fried and a team of scientists to monitor hundreds of individual brain cells, often for days. And because patients with epilepsy are frequently kept awake in order to provoke a seizure, the scientists had an ideal way to study the effects of sleep deprivation. In the study, all the patients agreed to categorize images of faces, places and animals. Each image caused cells in areas of the brain involved in perception to produce distinctive patterns of electrical activity. Then, four of the patients stayed up all night before looking at more images. And in these patients, "the neurons are responding slower," Fried says. "The responses are diminished, and they are smeared over longer periods of time." These changes impair the cells' ability to communicate, Fried says. And that leads to mental lapses that can affect not only perception but memory.

3 of 87 comments (clear)

  1. Re:Good news by Anonymous Coward · · Score: 1, Informative

    America is not a democracy you moron, and it never was.

    Officially it is a constitutional republic; it uses a democratic process to select its representatives but that doesn't make it a democracy.

    Unofficially, it functions as a plutocracy, which means all the important decisions are made by a group of un-elected wealthy elites. Most of our democratic process is just smoke-and-mirrors to make the lower classes feel involved.

    Denmark is no perpetual utopia. No system of government is immune to corruption. Denmark will fall too, eventually, as all governments eventually do.

  2. Study characterizes effect by Okian+Warrior · · Score: 2, Informative

    and constant lack of sleep may make it a long lasting effect

    no shit, how much did that grant cost me

    The importance of the study is that it characterizes the effect in a way that can be replicated, and then used for further study. For example, the effect drugs have on the subject, or different types of sleep.

    It might also help in validating or invalidating specific hypotheses.

    For example, there is a hypothesis that neurotransmitters evolved from nutrient sources. The theory goes that when simple organisms ate something there was a wash of nutrients (such as glucose) throughout the system. Evolution then gave the organisms sensors that would associate particular inputs with the wash of nutrients they receive from eating, and trigger the "swallow" action (probably invagination at that level). Then the organism evolved to separate the swallow signal from the sensor signal by using a modified nutrient as the signal, and when the organism fed successfully it would convert some of the nutrient into the signal to "feed" the sensor cells.

    Fast forward and we have a complex system of cells that use various neurotransmitters as "food" to represent information. The neurotransmitters are sent cell-to-cell, but also scavenged and reused, and the scavenging process is not 100% efficient so the extra neurotransmitters act as growth factors - a cell can grow more dendrites to scavenge more of the "food" neurotransmitters in the areas where they are most often generated, leading to Hebbian theory and all that.

    Back to the study...

    It seems reasonable that wakefulness uses one or more neurotransmitters so often that the scavenging process can't keep up, and the sleep phase is needed for the scavenging to catch up. This is by design, because the unscavenged neurotransmitters also act as growth factors to encourage dendrite growth among correlated neurons.

    If the study is right, it might be possible to measure the neurotransmitter levels as the patient gets sleepy, correlate it with the distinctive neural patterns, and thus identify the neurotransmitters that get depleted during wakefulness. (The study has identified the distinctive patterns we need to look for.)

    And that would have all sorts of applications.

    (Also, I don't know how much that grant cost you, but it was probably worth it.)

  3. No laughing matter by DaMattster · · Score: 3, Informative

    Seriously, sleep deprivation can cause all kinds of health problems. Sleep is the time when your body heals and repairs damage during the day. Depriving yourself of this is a bad thing. I have started to feel better since getting a sleep apnea machine and I am sure I will feel even better once I get this extra weight off.