A new study in mice might help to explain why it's so hard to drift off to dreamland[1] when you're engrossed in a page-turning book.


Researchers from the University of Texas Southwestern Medical Center found that mice that were kept awake by appealing to their curious natures had a harder time falling asleep than mice that were just gently kept awake -- even when both groups of mice were sleep-deprived.


"This study supports the idea that subjective sleepiness is influenced by the quality of experiences right before bedtime[2] . Are you reluctantly awake or excited to be awake?" study researcher Dr. Masashi Yanagisawa, a professor of molecular genetics and a Howard Hughes Medical Institute investigator at the university, said in a statement.


For the study, published in the journal Proceedings of the National Academy of Sciences[3] , researchers took mice that were virtually identical genetically and split them up into three groups. The first group of mice were allowed to sleep and be awake with no interruption by researchers. But the second and third groups of mice had sleep delayed by six hours.


Researchers kept the second group of mice awake by appealing to their sense of curiosity -- they changed their cages so that they would spend time exploring the new changes (which researchers likened to kids staying up late to play a brand-new video game). The third group, meanwhile, was kept awake just gently -- by tapping on the cage lightly when the mice looked like they were drifting off, for instance (similar to a parent who has to stay awake to wait for their child to come home from a late night outing).


They found that even though both the second and third groups of mice had delayed sleep and therefore the same kind of need for sleep, the ones that were gently kept awake drifted off to sleep faster than the mice that were kept awake because they wanted to explore.


Plus, researchers identified two new proteins that seemed to play a role in these sleep responses.



"Two of the great mysteries in neuroscience are 'Why do we sleep' and 'What is sleep's function?'" study researcher Dr. Robert Greene, a psychiatry professor at the university and a doctor at the Dallas VA Medical Center, said in a statement. "Separating sleep need from wakefulness and identifying two different proteins involved in these steps represents a fundamental advance."



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  • Lullabies


    Soothing music before bedtime can really do the trick. A 2005 study found that older people who listened to 45 minutes of soft tunes before hitting the hay reported a <a href="http://www.blackwellpublishing.com/nursing/news/news.asp?id=124" target="_hplink">35 percent improvement in their sleep problems</a>.

    But it doesn't have to be Brahms, if that's not your style. As long as the music was soft and slow -- around 60 to 80 beats per minute -- it can spur <a href="http://news.bbc.co.uk/2/hi/health/4228707.stm" target="_hplink">physical changes known to promote sleep</a>, like a slower heart rate and breathing, the BBC reported.

    "We know that when a person closes their eyes they induce a certain frequency of brain waves," says Decker. Slow music may have a similar effect, he surmises, leading to sleep onset.

    <em>Flickr photo by <a href="http://www.flickr.com/photos/llimaorosa/112246369/" target="_hplink">Llima</a></em>




  • Warm Milk


    It was once thought that a glass of warm milk at bedtime would help send you off to dreamland because of the tryptophan, <em>The New York Times</em> reported, but milk and other protein-rich foods actually <a href="http://www.nytimes.com/2007/09/04/health/04real.html" target="_hplink">block tryptophan's sleepiness-inducing effects</a>. However, there might still be a psychological benefit to that warm milk, the <em>Times</em> concluded, calling it "as soothing as a favorite old blanket."

    "There have been some studies showing that when infants receive warm milk before bed, they'll dream a little bit more," says Decker, but the results don't hold true in adults. "It may be one of those myths that because it happens in children, adults think it may be true for them, too," he explains. However, many adults are actually at least slightly lactose intolerant, he says, meaning a warm mlik at bedtime may just lead to discomfort.

    <em>Flickr photo by <a href="http://www.flickr.com/photos/julianrod/152930252/" target="_hplink">julianrod</a></em>




  • Counting Sheep


    If your goal is to bore yourself to sleep, you might try counting sheep, or counting backwards by multiples of three or any of a number of other counting-related mind-numbers. But a 2002 study found that <a href="http://www.ncbi.nlm.nih.gov/pubmed/11863237" target="_hplink">imagining a more relaxing scene might be more effective</a>.

    The study observed 41 people with insomnia over a number of nights and asked them to try a variety of different sleep-inducing techniques, like counting sheep.

    On the nights they were told to imagine relaxing scenes like a beach, a massage or a walk in the woods, <a href="http://www.mentalfloss.com/blogs/archives/53137" target="_hplink">they fell asleep an average of 20 minutes sooner</a> than on the nights they were told to count sheep or were given no instructions, Mental Floss reported.

    Decker agrees. "Counting sheep in and of itself may not help," but can act as a ritual that prepares us for sleep, making it not unlike meditation. Counting sheep -- or more relaxing guided imagery -- helps us "focus on something other than life's stressors," he says. "Thinking about a soothing environment may be more restful than the way you spent the last eight hours!"

    <em>Flickr photo by <a href="http://www.flickr.com/photos/narciss/3716241331/" target="_hplink">Kr. B.</a></em>




  • Breathing Exercises


    Focusing on the breath, whether it's as part of a pre-bed yoga sequence or just a tuned-in awareness, can also have meditation-like effects in preparing for bed, says Decker, like lowering the heart rate.

    <em>Flickr photo by <a href="http://www.flickr.com/photos/perfectoinsecto/2363255713/" target="_hplink">Perfecto Insecto</a></em>




  • Warm Bath


    Your body temp <a href="http://www.health.com/health/condition-article/0,,20189095,00.html" target="_hplink">dips about two hours before bedtime</a>, <em>Health </em>magazine reported, a natural change that "triggers our brain for sleep onset", says Decker. Soaking in a warm bath beforehand boosts your temperature temporarily, but results in a dramatic, rapid cooldown after you get out that relaxes you and eases you into sleep.

    It's not necessarily the bath that lulls you to sleep, it's that resulting cooling of your body temperature, Decker emphasizes. Research shows that people who take a warm bath before bed not only <a href="http://www.ncbi.nlm.nih.gov/pubmed/2578367" target="_hplink">fall asleep more quickly</a>, but also report better quality of sleep, he says.




  • Alcohol


    Many people swear by a drink to unwind at the end of the day, but alcohol before bed can actually <a href="http://www.huffingtonpost.com/2012/07/04/fourth-of-july-sleep_n_1644627.html#slide=1176662" target="_hplink">disrupt your sleep</a>. You'll be more likely to wake up more often in the early-morning hours, wake up and not be to fall back to sleep or have disturbing dreams. "As alcohol is metabolized by the liver, it has a disruptive effect," says Decker. It takes a few hours to metabolize, he says, so a drink with dinner shouldn't be a problem, but anything too close to bedtime can be counterproductive.

    <em>Flickr photo by <a href="http://www.flickr.com/photos/rob-qld/2889139445/" target="_hplink">Rob Qld</a></em>




  • Get Out Of Bed


    It sounds crazy -- how will you ever get to sleep if you're not even in bed?! -- but it works, says Decker.

    "When a person stays in bed and they can't sleep, the bedroom can induce a certain level of anxiety," he says. "We say after 15 or 20 minutes, get out of bed, sit in another part of the house until you feel a little groggy, then go back to sleep," he says. "Staying in bed can condition you to become anxious in bed."

    A small 2011 study published in the <em>Archives of Internal Medicine</em> found that among the <a href="http://healthland.time.com/2011/01/27/cant-sleep-it-may-help-to-get-out-of-bed/" target="_hplink">adults studied who reported trouble sleeping</a>, those who spent <a href="http://www.thirdage.com/news/insomnia-cant-sleep-get-out-bed_1-26-2011 " target="_hplink">less time in bed had better sleeping habits</a>.

    <em>Flickr photo by <a href="http://www.flickr.com/photos/perfectoinsecto/3948115802/" target="_hplink">Perfecto Insecto</a></em>




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