Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fat Sand Rats Are SAD Like Us

09.11.2010
TAU shines a light on a mood disorder

Saying goodbye to summer can be difficult for everybody. In some people the onset of winter triggers Seasonal Affective Disorder, or SAD, a mood disorder in which sufferers experience symptoms of depression. Happily, a special kind of gerbil exhibits remarkably similar reactions to SAD treatments as humans, opening a promising new channel for study and treatment of the common complaint.

With her work on the Israeli desert inhabitant gerbil called the Fat Sand Rat (Psammomys obesus), Prof. Noga Kronfeld-Schor of Tel Aviv University's Department of Zoology and her fellow researcher, Prof. Haim Einat of the University of Minnesota, have found new hope for the study of these and similar disorders. Her results, recently published in the International Journal of Neuropsychopharmacology, indicate that her new test subjects are more suitable model animal for the study of SAD than the rats and mice used previously.

Until now, Prof. Kronfeld-Schor explains, most research on the mechanisms of affective disorders was carried out on mice and rats. But this has been problematic in applying the research results to humans — mice are nocturnal, while humans are diurnal. Clearly, when we conduct research of disorders like SAD which affect our circadian system, she says, our model animals should be diurnal as well.

Different as night and day

Most laboratory mice don't produce melatonin, a natural hormone produced by humans and other mammals during the night. Moreover, as nocturnal animals, mice and rats become more active at night, when melatonin levels are high, while humans are active during the day, when melatonin levels are now. For most biomedical research, Prof. Kronfeld-Schor explains, mice are excellent model subjects. But for affective disorders, which rely heavily on the human circadian system, she hypothesized that a diurnal mammal would provide a superior animal model.

To test this theory, Prof. Kronfeld-Schor and her fellow researcher put two groups of Fat Sand Rats through several experiments. First, to test the effect of the length of light exposure on the rats' emotional state, one group was exposed to long hours of light similar to that of the summer season, and the other to shorter hours of the winter length daylight. In several tests, the sand rats of the second group behaved in ways similar to depressed humans, exhibiting despair, reduced social interactions and increased anxiety.

Once the researchers established that Fat Sand Rats and humans had a similar reaction to light, the team explored whether common medications or other SAD therapies would be as effective in their rat population. These studies included a variety of medications commonly used to treat the disorder in humans, as well as a program of exposing the depressed sand rats to brighter light for one hour every morning or evening.

More than a placebo

According to Prof. Kronfeld-Schor, the results were surprising. The medications were effective in treating the sand rats' depression, but even more effective was the daily exposure to bright light in the mornings, a common treatment for human SAD. "Humans have been using this treatment for a long time," she explains, "but many of us thought that a large part of its success was based on the placebo effect. For the first time, we've found it to be effective in animals as well, which weakens the possibility of the placebo effect."

The breakthrough, says Prof. Kronfeld-Schor, is the discovery of a superior and viable animal model for studying affective disorders. Though several biological mechanisms for SAD have been proposed, they have not been scientifically proven. A good animal model to study the mechanisms of SAD will advance understanding of the disorder, help screen for effective treatments and allow for the development of new therapies.

George Hunka | EurekAlert!
Further information:
http://www.aftau.org
http://www.aftau.org/site/News2?page=NewsArticle&id=13257

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>