I never was one to fret about my sleep debt, but I’ve always suspected there’s a sort of downward spiral I which bad sleep leads to worse sleep. Now I read,
“Humans and animals that have chronic sleep deprivation might reach a point at which the very ability to catch up on lost sleep is damaged, says Fred Turek, a sleep researcher at Northwestern University.”
Kathleen Fackelmann, “Study: Sleep deficit may be impossible to make up,” USA Today, Nov. 27, 2007
“Repeated sleep restriction in rats leads to homeostatic and allostatic responses during recovery sleep,” Youngsoo Kim, Aaron D. Laposky, Bernard M. Bergmann, and Fred Turek http://www.pnas.org/cgi/reprint/0610351104v1
As someone who always has trouble getting REM sleep—I can sleep for 2-3-4 hours and that’s it—I read with dismay that four days’ exposure to REM sleep deprivation suppressed cell proliferation (neurogenesis) in the hippocampus, an area of the brain associated with memory formation, by 63 percent. So that’s where my memory went!
McGinty, lead researcher on the study, says, “Several studies have shown that sleep contributes to brain plasticity in general, and to adult neurogenesis, in particular …Neurogenesis is a concrete example of brain plasticity, suppression of adult neurogenesis is thought to be important in pathologies such as depression…. This study showed that REM sleep has a critical role in facilitating brain plasticity… In other recent work, we have shown that sleep fragmentation can also suppress adult neurogenesis.”
“Four days of REM sleep deprivation affects forebrain, long-term memory in rats,” Science Daily, Feb. 6, 2008. Read more…
The study: “Rapid eye movement sleep deprivation contributes to reduction of neurogenesis in the hippocampal dentate gyrus of the adult rat,” Ruben Guzman-Marin, Natalia Suntsova, Tariq Bashir, Robert Nienhuis, Ronald Szymusia, Dennis McGinty, Sleep, February 1, 2008, 167-75
And this might explain why we’re on the verge of tears or tantrum, on sleep starved days:
“Lack of sleep sends emotions off the deep end,” Sharon Jayson, USA Today, Oct. 22, 2007
Matthew Walker, head of U.C. Berkeley’s Sleep and Neuroimaging Laboratory and senior author of the study, had subjects stay up for 35 hours. He then showed them disturbing photographs, of mutilated bodies, children with tumors, a shark attack, etc, monitoring their responses with brain scans, using Magnetic Resource Imaging (fMRI). “The emotional centers of the brain were over 60 percent more reactive under conditions of sleep deprivation than in subjects who had obtained a normal night of sleep,” Walker reported. The amygdala, “the region of the brain that alerts the body to protect itself in times of danger, goes into overdrive on no sleep…[which] shuts down the prefontal cortex, which commands logical reasoning, and thus prevents the release of chemicals needed to calm down the fight-or-flight reflex,” explains Yasmin Anwar, “Sleep loss linked to psychiatric disorders,” UC Berkeley Press Release, Oct 22, 2007.
“The emotional centers of the brain were over 60 percent more reactive under conditions of sleep deprivation than in subjects who had obtained a normal night of sleep.” “It’s almost as though, without sleep, the brain had reverted back to more primitive patterns of activity, in that it was unable to put emotional experiences into context and produce controlled, appropriate responses,” said Matthew Walker. “Neural link between sleep loss and psychiatric disorders,” TS-Si Medicine, Oct. 25, 2007.
“We’ve been struggling with the battle between the chicken and egg question. Is it the psychiatric condition that’s causing the sleep impairment, or is it the sleep impairment that’s causing the psychiatric condition?” says Walker; “This is the first set of experiments that demonstrate that even healthy people’s brains mimic certain pathological psychiatric patterns when deprived of sleep….Now we’re closer to being able to look into whether the person has a psychiatric disease or a sleep disorder.”
Rose Hoban, “Sleep deprivation plays with our emotions,” NewsVOA.com, Nov. 2, 2007,
“Can a Lack of Sleep Cause Psychiatric Disorders?”
Study shows that sleep deprivation leads to a rewiring of the brain’s emotional circuitry
Nikhil Swaminathan, Scientific American, Oct. 23, 2007. Read more…
The study: “The human emotional brain without sleep—a prefrontal amygdala disconnect,” Current Biology, 2007, 17, 20, R877-8.
TS-Si – Reader Comments
Ms. Greene, who commented earlier, is the author of a major new book. A generalized citation is included below. Insomniac. Gayle Greene. …
And another thing:
“In one of the largest epidemiologic studies of insomnia among adolescents ever conducted in the United States, this study allows for an estimation of the impact of chronic insomnia on future functioning of adolescents. Youths with insomnia, particularly chronic insomnia, are at greater risk of future somatic and especially psychological problems, the study found.”
Read more: Chronic Insomnia Can Predict Future Functioning Of Adolescents, Feb. 4, 2008
The study: “Persistence and chance in symptoms of insomnia among adolescents,” Robert Roberts, Catherine Roberts, Sleep, Feb. 1, 2008, 177-84