Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Alcohol ’binges’ in rats during early brain development cause circadian rhythm problems

04.04.2005


In a study believed to have implications for children and adults suffering from Fetal Alcohol Syndrome, rat pups given alcohol during a period of rapid brain development demonstrated significant changes in circadian or 24-hour rhythms as adults. The alcohol dosage was the equivalent of several nights of binge drinking on the part of a pregnant woman, and it was given at a time during rat brain development (shortly after birth) equivalent to the third trimester of human fetal development.



Dr. David J. Earnest, Texas A&M University Health Sciences Center, presented the findings Sunday, April 3, at an American Association of Anatomists’ session on dissecting the biological clock during Experimental Biology 2005 in San Diego.

Dr. Earnest says the findings are significant for three reasons:

  • First, they demonstrate for the first time that the damaging effects of alcohol exposure during brain development impinge on the part of the brain responsible for circadian rhythmicity, the body’s night/day clock and the mechanism through which it regulates various physiological processes throughout the body and types of behaviors.
  • Second, the findings may help shed new light on why many children and adults with Fetal Alcohol Syndrome (FAS) have altered sleep wake cycles, attention deficit and hyperactivity disorders, and display other disruptions in behavior.
  • And third, the changes in circadian rhythms caused by developmental alcohol exposure may affect chronotherapeutic treatment of diseases because the efficacy and side effects of many drugs are known to depend on the time of administration in relation to normal body rhythmicity.

Fetal Alcohol syndrome (FAS) can occur in the offspring of mothers who abuse alcohol during pregnancy. Some of the deleterious effects of maternal alcohol use on the developing fetus include craniofacial alterations (e.g. a thin upper lip and a small nose) and defects in brain development. Animal studies examining the spectrum of alcohol-induced brain injuries have revealed that affected offspring are most vulnerable to the damaging effects of alcohol during the brain growth spurt period, which is the human equivalent of the third trimester and that these defects in brain development often persist into adulthood.


Unlike the craniofacial differences sometimes seen in FAS children (which may lessen into adolescence and adulthood), the impact of alcohol on brain function as the child grows is less measurable and knowledge of the timing and amount of alcohol consumed during pregnancy is based only on the account of the mother. Dr. Earnest says animal studies using a rat model provide a way to obtain clearer information as well as focus on potential disturbances in a specific brain function - circadian rhythms - that has not been studied in relationship to FAS but which has implications for FAS and, indeed, for all of us.

During this period equivalent to the third trimester in humans, rat pups were given either formula or mixture formula containing alcohol that raised the pups’ blood alcohol levels equivalent to what human fetuses experience during binge drinking episodes on the part of their mother.

As adults, the rats that had been exposed to alcohol during brain development showed similar activity levels as rats of the same age that had not experienced alcohol. But the rats exposed to alcohol showed a number of remarkable changes in the circadian rhythm of activity that put them on a different schedule and pattern than other rats.

Rats are nocturnal animals and normally begin their activity slightly after darkness sets in. The rats that had been exposed to alcohol began activities slightly before darkness set in.

When normal rats - or for that matter, humans and other animals - are in situations without environmental cues about day and night, the body’s circadian clock generally drives behaviors on a cycle slightly greater than 24 hours. Untreated animals woke up approximately 20 minutes later each day in the absence of a light-dark cycle. The rats that had been exposed to alcohol consistently became active 30 minutes earlier every day.

In situations when the light-dark cycle was shifted six hours earlier, the "jet lag" equivalent for humans having to shift their body clocks when traveling across different time zones, the rats exposed to alcohol in infancy shifted much more quickly, as they did to 15-minute light pulses. While this may sound good to most traveling humans, it reflects permanent changes that have ramifications on how systems in the body function in relation to each other, says Dr. Earnest.

The researchers also were able to measure changes in the expression of genes related to the clock timing these cycles in the brain and in peripheral tissues, such as the liver, that need to coordinate their own physiological activities with the core clock in the brain.

Sarah Goodwin | EurekAlert!
Further information:
http://www.faseb.org

More articles from Studies and Analyses:

nachricht Do microplastics harbour additional risks by colonization with harmful bacteria?
05.04.2018 | Leibniz-Institut für Ostseeforschung Warnemünde

nachricht Rutgers-led innovation could spur faster, cheaper, nano-based manufacturing
14.02.2018 | Rutgers University

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

Im Focus: The Future of Ultrafast Solid-State Physics

In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.

Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Diamond-like carbon is formed differently to what was believed -- machine learning enables development of new model

19.04.2018 | Materials Sciences

Electromagnetic wizardry: Wireless power transfer enhanced by backward signal

19.04.2018 | Physics and Astronomy

Ultrafast electron oscillation and dephasing monitored by attosecond light source

19.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>