Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chronic jet-lag conditions hasten death in aged mice

07.11.2006
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 indicate 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.

Heidi Hardman | EurekAlert!
Further information:
http://www.current-biology.com

Further reports about: Researchers light-cycle mortality physiological survived

More articles from Life Sciences:

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>