XML Feed for RxPG News   Add RxPG News Headlines to My Yahoo!   Javascript Syndication for RxPG News

Research Health World General
 
  Home
 
 Latest Research
 Cancer
 Psychiatry
  Depression
  Neuropsychiatry
  Personality Disorders
  Bulimia
  Anxiety
  Substance Abuse
  Suicide
  CFS
  Psychoses
  Child Psychiatry
  Learning-Disabilities
  Psychology
  Forensic Psychiatry
  Mood Disorders
  Sleep Disorders
   Circardian Rhythm
  Peri-Natal Psychiatry
  Psychotherapy
  Anorexia Nervosa
 Genetics
 Surgery
 Aging
 Ophthalmology
 Gynaecology
 Neurosciences
 Pharmacology
 Cardiology
 Obstetrics
 Infectious Diseases
 Respiratory Medicine
 Pathology
 Endocrinology
 Immunology
 Nephrology
 Gastroenterology
 Biotechnology
 Radiology
 Dermatology
 Microbiology
 Haematology
 Dental
 ENT
 Environment
 Embryology
 Orthopedics
 Metabolism
 Anaethesia
 Paediatrics
 Public Health
 Urology
 Musculoskeletal
 Clinical Trials
 Physiology
 Biochemistry
 Cytology
 Traumatology
 Rheumatology
 
 Medical News
 Health
 Opinion
 Healthcare
 Professionals
 Launch
 Awards & Prizes
 
 Careers
 Medical
 Nursing
 Dental
 
 Special Topics
 Euthanasia
 Ethics
 Evolution
 Odd Medical News
 Feature
 
 World News
 Tsunami
 Epidemics
 Climate
 Business
 
 India
Search

Last Updated: Nov 18, 2006 - 12:32:53 PM

Sleep Disorders Channel
subscribe to Sleep Disorders newsletter

Latest Research : Psychiatry : Sleep Disorders

   DISCUSS   |   EMAIL   |   PRINT
Mushroom bodies regulate sleep like a snooze button
Jun 8, 2006 - 5:37:00 AM, Reviewed by: Dr. Priya Saxena

Sleep, in fact, is such a mystery that scientists are not even sure why animals require it. No purpose or underlying mechanism for the phenomenon has ever been proven.

 
With help from some drowsy fruit flies, a team of researchers from the Howard Hughes Medical Institute (HHMI) at the University of Pennsylvania School of Medicine has identified a region of the fruit fly's brain that is crucial to controlling sleep.

The finding, reported in the June 8, 2006, issue of the journal Nature, is important because it identifies a new role for brain structures, called mushroom bodies, which have now been shown to control fruit fly slumber. Mushroom bodies were known to be involved in processing sensory information and memory. Thus, the new studies lend support to the idea that sleep helps the brain consolidate learning and memory.

�We spend one-third of our lives sleeping, but we know very little about sleep and how it is regulated,� explained Amita Sehgal, the senior author of the new Nature paper and an HHMI investigator at the University of Pennsylvania School of Medicine. �The research actually doesn't tell us much directly about the purpose of sleep,� said Sehgal. �But one of the things suggested (from past research) is that sleep helps consolidate memory.�

Consequently, the finding by Sehgal and her colleagues showing that sleep and memory share a common locus in the brain may begin to substantiate why our brains must routinely descend into the idling metabolic and electrical state that defines sleep.

Sehgal's group conducted a series of experiments with sleeping flies that fingered mushroom bodies as at least one of the brain's primary snooze buttons.

�Mushroom bodies are an anatomical structure in the fly brain, mostly associated with learning and memory,� said Sehgal, who conducted the research at Penn's Center for Sleep and Respiratory Neurobiology. �They also process olfactory cues and locomotor activity.�

It is possible, Sehgal and her colleagues speculate, that the mushroom bodies constitute a gate to fly dreamland: sleep occurs when the stream of sensory information processed by the structure � an elaborate net of neural cells � is inhibited.

In humans and other higher animals, sleep has been associated with several different structures in the brain, mostly by looking at brain waves, the patterns of electrical signals generated during sleep or wakefulness. There are no structures analogous to mushroom bodies in vertebrates, but the hippocampus and/or thalamus may harbor a similar control center for human sleep, Sehgal noted.

�In the fly, the mushroom bodies are probably not the only thing associated with sleep.�

�Once you have (linked sleep to an anatomical structure), you can figure out changes taking place at the molecular level in that region of the brain,� Sehgal explained. �It allows us to shift our efforts to see what happens during sleep and what happens when we're awake that leads to sleep.�

The HHMI team was able to home in on mushroom bodies' role in regulating sleep in flies by using the drug RU-486 in their studies. �RU-486 is a steroid that acts on steroid-regulated promoters,� she explained. �We used RU-484-responsive sequences to control our gene of interest and once we had done that in the fly, we could feed the fly RU-486 to turn that gene on.�

Sehgal and her team were then able to induce large changes in sleep by using RU-486 to manipulate a critical gene known as protein kinase (PKA), which makes a protein that, in the brain, activates other proteins and switches other genes on or off.

In flies, the duration of sleep is inversely related to PKA activity. By expressing the gene in different regions of the brain, including mushroom bodies, it was possible to assess the roles of those structures in the phenomenon of sleep.

Sehgal said that a fly is sleeping if it remains motionless for extended periods. �At the moment, our definition of fly sleep is five minutes of immobility,� she explained. In addition to identifying the structure that governs sleep in invertebrates, the new HHMI work promises to help researchers zero in on the anatomical structures in the brains of higher animals, including humans, which govern sleep.
 

- June 8, 2006, issue of the journal Nature
 

Howard Hughes Medical Institute

 
Subscribe to Sleep Disorders Newsletter
E-mail Address:

 

Co-authors of the new Nature study include William J. Joiner and Amanda Crocker of the University of Pennsylvania's Center for Sleep and Respiratory Neurobiology, and Benjamin H. White of the National Institute of Mental Health in Bethesda, Md.


Related Sleep Disorders News

Risk Factors For Developing Complications From Sleep Apnea Surgery
Studying sleep deprivation's effect on decisions
New sleep gene discovery wakes up scientists
Diphenhydramine Does Not Improve Infant Sleep
People sleep even less than they think
Computer models may reveal what makes human body clock tick
New fruit fly protein JET illuminates circadian response to light
CBT More Effective Than Zopiclone in Insomnia
Severe hot flashes associated with chronic insomnia
Acting out vivid dreams may forewarn of more serious illness


For any corrections of factual information, to contact the editors or to send any medical news or health news press releases, use feedback form

Top of Page

 

© Copyright 2004 onwards by RxPG Medical Solutions Private Limited
Contact Us