Featured Research

from universities, journals, and other organizations

New Research Explores 'Early Bird' And 'Night Owl' Sleep Patterns

Date:
April 21, 2004
Source:
American Physiological Society
Summary:
Linking our genetic make-up and sleep related disorders require data that compare genetic differences that might explain the basis of sleep disorders.

Washington, DC -- Are you annoyed by cheerful "morning people?" Do you ever wonder how "night owls" can keep going? Most of us ask these questions because we are in between these two extremes, and take a while to get going early in the morning and tire long before midnight. This entire spectrum reflects the broad, normal variation in sleep patterns in humans that is rooted in the very genetic foundations of how our body works. Because these variations occur within our population and differ with age, the presumption exists that the differences in sleep patterns are controlled by complex mechanisms with contributions from multiple genes and influenced by environmental factors.

Related Articles


Linking our genetic make-up and sleep related disorders require data that compare genetic differences that might explain the basis of sleep disorders. Knowing what causes these disorders is important -- getting a good night sleep is now a challenge for some 50 to 70 millions American of all ages. A 2002 National Sleep Foundation annual survey reported that nearly 40 percent of adults 30 to 64 years old, and 44 percent of those age 18 to 29, reported that daytime sleepiness is so severe that it interferes with work and social functioning at least a few days each month. Excessive daytime sleepiness has been blamed on interference in cognitive functioning, motor vehicle crashes (especially at night), poor job performance and reduced productivity. While researchers have learned much about the basic mechanism underlying the control of sleep and its importance on our daily function and health, they have only just begun to examine the complex genetic and environmental interactions that shape sleep and health.

A New Study

An important step in this research is a new study that involved three different strains of inbred laboratory rats and measurements of their movement and continuous sleep in controlled environmental chambers for three days and nights. The study examined 24-hour variations in the animals' slow wave sleep, activity and changes from rest to activity. The comparisons between the three strains have led the researchers to conclude that there were significant variations in these measures, strongly suggesting that the findings were due to genetic differences.

The authors of "Circadian Slow Wave Sleep and Movement Behavior are under Genetic Control in Inbred Strains of Rat," are Thom R. Feroah, Todd Sleeper, Dan Brozoski, Joan Forder, Tom B. Rice, and Hubert V. Forster from the Medical College of Wisconsin, Milwaukee, WI. Dr. Feroah will present his team's findings at the American Physiological Society's (APS) (www.the-aps.org) annual scientific conference, Experimental Biology 2004, being held April 17-21, 2004, at the Washington, D.C. Convention Center.

Methodology

Research in inbred strains of mice has previously shown distinct variations in the pattern of slow wave sleep between some strains. This study investigated differences in circadian slow wave sleep and activity patterns in three inbred strains of rats previously used in sequencing the rat genome. If a difference in the pattern of slow wave sleep and activity was found, then a dissection of the multigenic basis of the neurophysiological mechanisms involved in the control of slow wave sleep and behavior could then be explored using consomic (chromosomal substitution) rat panels.

In Brown Norway (BN/mcw), Dahl Salt Sensitive (SS), and Fawn Hooded (FH) inbred rats, movement and slow wave sleep were measured continuously for three days in an environmental controlled chambers in which temperature and humidity were held within a limited operating range. Slow wave sleep was determined from electroencephalograph electrodes attached to the skull and electromyograph electrodes in the neck muscles of the rat. The percent of slow wave sleep (percent of SWS; SWS bout length relative to rest time interval), percent of rest (total rest time relative to interval time) and fragmentation of rest (Frag; calculated as the number of transitions (per hour) from a minimum six second rest period to a minimum four second period of activity) was obtained from a computerized open-field activity monitoring system that was integrated with the sleep system.

Results

Unique and significant differences were found within and between strains over the study period. The researchers found that the percentage of slow wave sleep, rest and transitions between rest and activity varied uniquely between strains. This suggests that these findings are due to genetic differences. Furthermore, the inverse relationship between the percentages of slow wave sleep and rest within strains supports the homeostatic control theory of slow wave sleep, which is to restore glycogen during non-REM sleep.

Conclusions

The next step in this research is to examine the consomic rat panels cross of FH and BN that could aid in locating the chromosome region(s) that are at the very basis of the relationship between the slow wave sleep and activity. Similarly, examining the consomic rat panel cross between the SS and FH inbred strains for the chromosomal region(s) that influence the phase shift in the circadian pattern of slow wave sleep and activity could also help understand the complex basis of the early bird and night owl pattern of sleep that is observed in our society.

This research would be important in establishing the genomic basis of normal and abnormal variation in sleep patterns. Further research into the genetic basis of these differences may very well help dissect the multigenic and physiologic mechanistic pathways involved in circadian sleep and behavior in rats that would be homologous to those in humans.

###

The American Physiological Society (APS) was founded in 1887 to foster basic and applied science, much of it relating to human health. The Bethesda, MD-based Society has more than 11,000 members and publishes 3,800 articles in its 14 peer-reviewed journals every year.


Story Source:

The above story is based on materials provided by American Physiological Society. Note: Materials may be edited for content and length.


Cite This Page:

American Physiological Society. "New Research Explores 'Early Bird' And 'Night Owl' Sleep Patterns." ScienceDaily. ScienceDaily, 21 April 2004. <www.sciencedaily.com/releases/2004/04/040420012234.htm>.
American Physiological Society. (2004, April 21). New Research Explores 'Early Bird' And 'Night Owl' Sleep Patterns. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2004/04/040420012234.htm
American Physiological Society. "New Research Explores 'Early Bird' And 'Night Owl' Sleep Patterns." ScienceDaily. www.sciencedaily.com/releases/2004/04/040420012234.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Rural India's Low-Cost Sanitary Pad Revolution

Rural India's Low-Cost Sanitary Pad Revolution

AFP (Nov. 28, 2014) — One man hopes his invention -– a machine that produces cheap sanitary pads –- will help empower Indian women. Duration: 01:51 Video provided by AFP
Powered by NewsLook.com
Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) — In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins