Navigation Links
Chronic jet-lag conditions hasten death in aged mice

Researchers have found that aged mice undergoing weekly light-cycle shifts--similar to those that humans experience with jet lag or rotating shift work--experienced significantly higher death rates than did old mice kept on a normal daylight schedule over the same eight-week period. The findings may not come as a great surprise to exhausted globe-trotting business travelers, but the research nonetheless provides, in rather stark terms, new insight into how the disruption of circadian rhythms can impact well-being and physiology, and how those impacts might change with age. The mouse study is reported by a group led by Gene Block and Alec Davidson of the University of Virginia and appears in the November 7th issue of the journal Current Biology, published by Cell Press.

The researchers were led to examine a possible link between jet lag and mortality by something they had noticed in an earlier, unrelated study: A surprising fraction of old (but genetically altered) rats exposed to a six-hour advance in their light cycle died after the shift in schedule.

In the new work, the researchers examined the mortality link in earnest by looking at how young mice and old mice fared when subjected to two different types of light-cycle shifts. In one regimen, mice experienced a six-hour forward shift once a week, while in the other, mice experienced a six-hour backward shift. A "control" group of young and old mice did not experience any schedule shifts.

The researchers found that the young mice generally survived well under the various conditions. In contrast, the light-cycle shifts had a marked effect on the survivorship of the old mice. While 83% of old mice survived under the normal schedule, 68% survived under the backward-shift regimen and 47% survived under the forward-shift regimen.

Past work has also linked changes in light schedule with death in other animals and under different experimental circumstances, but the findings here indic ate that there may be a differential effect of mortality depending on the direction of the schedule shift--forward or backward. Schedule "advancers" did more poorly in the present experiment than did "delayers."

Notably, the researchers found that chronic stress--as measured by daily corticosterone levels--did not increase in the old mice experiencing the light-cycle shifts. The underlying cause of the increased mortality is not yet clear, but could involve sleep deprivation or immune-system disruption.

The body's physiological reaction to time change may be complex. Past research has indicated that circadian clocks govern physiological rhythms in a great variety of tissues in the body, and that different aspects of the physiological clock can adjust to schedule changes at different rates. The researchers speculate that the internal lack of synchrony among different physiological oscillations may have serious health consequences that are exacerbated in aged animals.
'"/>

Source:Cell Press


Related biology news :

1. FDA Clears the Way for Generic Versions of Transdermal Patches to Treat Chronic Pain
2. Chronic Sinus Infection Thought To Be Tissue Issue, Mayo Clinic Scientists Show Its Snot
3. FDA Approves New Treatment for Chronic Hepatitis B
4. Chronic pain up almost 40 percent among US workers in past decade
5. Chronic fatigue syndrome impairs a persons slow wave activity during sleep
6. Plant genes identified that can form basis for crops better adapted to environmental conditions
7. Life in deadly conditions
8. UF scientists test improved gene therapy method for hereditary heart conditions
9. Food-crop yields in future greenhouse-gas conditions lower than expected
10. How badger culling creates conditions for spread of bovine TB
11. Study challenges myth that sex late in pregnancy hastens birth

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:12/15/2016)... 15, 2016  There is much more to innovative ... the engine. Continental will demonstrate the intelligence of today,s ... . Through the combination of the keyless entry ... biometric elements, the international technology company is opening up ... authentication. "The integration of biometric elements brings ...
(Date:12/12/2016)... Dec. 12, 2016  Researchers at Trinity College, ... graphene by combining the material with Silly Putty. The ... pressure detector able to sense pulse, blood pressure, ... spider.  The research team,s findings ... read here:  http://science.sciencemag.org/content/354/6317/1257 ...
(Date:12/8/2016)... Calif. , Dec. 8, 2016  Singulex, Inc., ... Molecule Counting technology, entered into a license and supply ... serving science. The agreement provides Singulex access to Thermo ... Europe is used to diagnose systemic ... United States to aid in assessing the ...
Breaking Biology News(10 mins):
(Date:1/20/2017)... ... January 20, 2017 , ... The two newest companies ... options for patients. Vironika, a spin out from The Wistar Institute, and Sanguis, launched ... space at 3624 Market Street. , Vironika is developing a treatment for a ...
(Date:1/19/2017)... 2017 Research and Markets has announced the ... Cancer Type, Application - Global Opportunity Analysis and Industry Forecast, 2014-2022" ... ... market is projected to reach $15,737 million by 2022 from $6,521 ... 2022. Omic technologies segment accounted for more than ...
(Date:1/19/2017)... Basel, Switzerland (PRWEB) , ... ... ... leading provider of advanced software solutions for pharmaceutical research and development (R&D), ... project-based expertise in omic data analysis and interpretation for the rapidly evolving ...
(Date:1/19/2017)... ... 2017 , ... The American Medical Informatics Association (AMIA) today ... Policy. Specifically, the nation’s leading informatics experts, said data sharing plans should be ... recommended that NIH earmark funding for researchers to produce and execute data sharing ...
Breaking Biology Technology: