Deep Sleep Plays Role In Visual Learning

A relationship has been observed between deep sleep and the ability of the brain to learn specific tasks. Researchers at Brigham and Women’s Hospital (BWH) have now shown that the processes that regulate deep sleep may affect visual learning.
“These findings show that deep sleep is important for visual learning and possibly the ability of the brain to learn new tasks,” said Daniel Aeschbach, researcher in the Division of Sleep Medicine at BWH and lead author of the study.
Deep sleep, also called slow wave sleep, is a period of non-rapid-eye-movement sleep when very large brain waves, called slow waves, can be observed in the EEG, which is a recording of the brain waves. Slow waves are thought to reflect the need for sleep, but their exact function is unknown. Researchers sought to determine the function of these waves in visual learning.
Aeschbach and colleagues trained healthy subjects on a visual learning task in which they were required to determine on a computer screen the orientation of a few dashes that were embedded in a field of horizontal dashes. Subjects were tested on their accuracy of performing this task before and after they had slept for a period of four hours. One group of subjects slept normally, with no interruptions, and their visual skill in performing the task improved after sleep. In another group, researchers suppressed the occurrence of slow waves by playing targeted acoustic tones while subjects were asleep. The tones did not wake the subjects, but prevented them from slipping into deep sleep as monitored on the EEG. This group was also tested in the visual task after sleep and their skill did not improve.
Researchers suggest that these findings could have clinical implications for conditions like depression and insomnia, as well as aging, which are associated with learning deficits and also a reduction of deep sleep.
This research was funded by awards from the National Alliance for Research on Schizophrenia and Depression, the Milton Fund of Harvard University, and the National Institutes of Health.

Insomnia Drug Tasimelteon Resets Sleep, Helps Jet Lag

Results of phase II and III trials of an insomnia drug pill from Vanda Pharmaceuticals suggest that the melatonin analogue tasimelteon could be a therapeutic approach to manage transient insomnia caused by jet lag and shift work.
The way tasimelteon works is that this sleeping pill helps the body produce more of the sleep hormone melatonin may improve sleep for jet-lagged travelers and shift workers. It resets the body's natural sleep rhythm and could be in the market available for sleepless consumers within three years.
Vanda Pharmaceuticals report is published in The Lancet. The publication is entitled "Melatonin agonist tasimelteon (VEC-162) for transient insomnia after sleep-time shift: two randomised controlled multicentre trials."
In the phase II study, tasimelteon reduced sleep latency and increased sleep efficiency compared with placebo. The shift in plasma melatonin rhythm to an earlier hour was dose dependent. In the phase III study, tasimelteon improved sleep latency, sleep efficiency, and wake after sleep onset (ie, sleep maintenance). The frequency of adverse events was similar between tasimelteon and placebo.
After an abrupt advance in sleep time, tasimelteon improved sleep initiation and maintenance concurrently with a shift in endogenous circadian rhythms. Tasimelteon may have therapeutic potential for transient insomnia in circadian rhythm sleep disorders. Read: Insomnia Treatment Shows Positive Results >>
Circadian rhythm sleep disorders are common causes of insomnia for millions of individuals. We did a phase II study to establish efficacy and physiological mechanism, and a phase III study to confirm efficacy of the melatonin agonist tasimelteon (VEC-162) for treatment of transient insomnia associated with shifted sleep and wake time.
The body's circadian clock plays significant roles in regulating sleep, mood as well as cardiovascular and metabolic processes. Circadian rhythm sleep disorders include insomnia associated with shift work (overnight, rotating and early riser), travel across time zones, delayed sleep phase syndrome, advanced phase syndrome and the non-24-hour sleep-wake syndrome in the blind. These disorders represent a large public health problem and, as presented in the 2006 Institute of Medicine (IOM) report on sleep disorders, the annual economic impact of sleep problems due to night shift work alone is estimated to exceed $65 billion.
The novel circadian regulator tasimelteon holds promise for the treatment of patients with misalignments of the body clock. The work presented in The Lancet examines the potential application in sleep disorders. Additional clinical trials will have to be conducted to examine the role of circadian regulators in the treatment of other disorders such as depression, nondipper hypertension, and others.
Elizabeth Klerman, an associate professor at Harvard Medical School in Boston, in a telephone interview today told Bloomberg that "Sleeping pills take care of one of the symptoms, the difficulty you have in falling asleep. This takes care of the underlying effect by shifting your body to the right time zone."
We just returned from a trip to Europe and suffered jet lag as a result of our ten-hour Trans-Atlantic flight. I thought we could overcome it fairly soon, in a 3-4 day period, however, it took me and my family at least 7 days to fully recover from jet lag and insomnia. About 30 million Americans, the two-third of those who traveled internationally in 2007 and 20 million shift workers that work between 2AM and 7AM can benefit from Vanda's tasimelteon by helping jet lag and insomnia.
Read more about Sleep Disorders.
The article in the Lancet presents results from two clinical studies with more than 400 volunteers, who were asked to initiate sleep five hours before their usual bedtimes. Tasimelteon was shown to reset the molecular machinery of the circadian clock and restore the sleep-wake cycle by improving both the ability to initiate and to maintain sleep as compared to placebo-treated patients.
Tasimelteon works by mimicking the effects of sleep hormone Melatonin in the body. Melatonin releases a natural hormone in the brain, which plays a key role in regulating sleep. "The scientists believe that as well as offering a potential cure for jet lag and other sleep problems the drug, made by Vanda Pharmaceuticals, could also help to explain how melatonin regulates sleep patterns, " comments the Telegraph.