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:4/15/2016)... 2016  A new partnership announced today will ... decisions in a fraction of the time it ... high-value life insurance policies to consumers without requiring ... Force Diagnostics, rapid testing (A1C, Cotinine and HIV) ... pressure, weight, pulse, BMI, and activity data) available ...
(Date:3/31/2016)...   LegacyXChange, Inc. ... LegacyXChange is excited to release its first ... be launched online site for trading 100% guaranteed authentic ... also provide potential shareholders a sense of the value ... industry that is notorious for fraud. The video is ...
(Date:3/22/2016)... March 22, 2016 ... Sensors Market for Consumer Industry by Type (Image, ... Application (Communication & IT, Entertainment, Home Appliances, ... Forecast to 2022", published by MarketsandMarkets, the ... to reach USD 26.76 Billion by 2022, ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... WI (PRWEB) , ... June 23, 2016 , ... ... supplements, is pleased to announce the launch of their brand, UP4™ Probiotics, into ... for over 35 years, is proud to add Target to its list of ...
(Date:6/23/2016)... -- Houston Methodist Willowbrook Hospital has signed a ... serve as their official health care provider. As ... provide sponsorship support, athletic training services, and most ... athletes and families. "We are excited ... to bring Houston Methodist quality services and programs ...
(Date:6/23/2016)... SAN FRANCISCO , June 23, 2016   ... it has secured $1 million in debt financing from ... to ramp up automation and to advance its drug ... for its new facility. "SVB has been ... goes beyond the services a traditional bank would provide," ...
(Date:6/23/2016)... June 23, 2016 Apellis Pharmaceuticals, Inc. ... clinical trials of its complement C3 inhibitor, APL-2. ... multiple ascending dose studies designed to assess the ... subcutaneous injection in healthy adult volunteers. ... as a single dose (ranging from 45 to ...
Breaking Biology Technology: