Navigation Links
Fat sand rats are SAD like us
Date:11/8/2010

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.


'/>"/>

Contact: George Hunka
ghunka@aftau.org
212-742-9070
American Friends of Tel Aviv University
Source:Eurekalert  

Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Fat sand rats are SAD like us
(Date:4/26/2016)... and LONDON , April ... part of EdgeVerve Systems, a product subsidiary of ... today announced a partnership to integrate the Onegini ...      (Logo: http://photos.prnewswire.com/prnh/20151104/283829LOGO ) ... their customers enhanced security to access and transact ...
(Date:4/15/2016)... 2016 Research and Markets has ... Market 2016-2020,"  report to their offering.  , ... ,The global gait biometrics market is expected to ... period 2016-2020. Gait analysis generates multiple ... used to compute factors that are not or ...
(Date:3/31/2016)... -- Genomics firm Nabsys has completed a financial  restructuring under ... M.D., who returned to the company in October 2015. ... including Chief Technology Officer, John Oliver , Ph.D., ... Vice President of Software and Informatics, Michael Kaiser ... Bready served as CEO of Nabsys from 2005-2014 and ...
Breaking Biology News(10 mins):
(Date:5/25/2016)... (PRWEB) , ... May 25, 2016 , ... ... Michael Fitzmaurice recently became double board-certified in surgery and surgery of the hand ... Dr. Fitzmaurice is no stranger to going above and beyond in his pursuit ...
(Date:5/25/2016)... (PRWEB) , ... May 25, 2016 , ... Scientists at ... line options being tried for mesothelioma may be hampering the research that could lead ... research. Click here to read it now. , The team evaluated 98 ...
(Date:5/25/2016)... ... 25, 2016 , ... Lady had been battling arthritis since the age of ... left knee. Lady’s owner Hannah sought the help of Dr Jeff Christiansen of ... her cruciate ligament and help with the pain of Lady’s arthritis. Dr Christiansen suggested ...
(Date:5/24/2016)... ... May 24, 2016 , ... Cell therapies for a range ... by research at Worcester Polytechnic Institute (WPI) that yielded a newly patented method ... , The novel method, developed by WPI faculty members Raymond Page, PhD, professor ...
Breaking Biology Technology: