Advertisement
Sino Biological
Sino Biological

Circadian Signs of Aging

The neural nexus of the circadian clock shows signs of functional decline as mice age, providing clues as to why sleep patterns tend to change as people grow older.

By | July 13, 2011

FLICKR, DEBS

In the first in vivo study of its kind, researchers show that the pattern of neural activity in the brain's circadian hub—the suprachiasmatic nucleus (SCN)—begins to decay as mice hit middle age, though the expression of a clockwork gene in the SCN remains unaffected. The findings, published today (July 12) in The Journal of Neuroscience, provide a sketch of the possible sequence of events that contribute to sleep troubles of the elderly.

“Surprisingly to us, at least to the point that we looked, we did not see any major deficits in gene expression. So the molecular clockwork is working fine, but the neural activity is running down,” said Christopher Colwell, a professor in UCLA's School of Medicine and one of the authors of the study.

“Even though the gene expression is normal, that doesn't mean the clock isn't aging,” added Fred Turek, the director of the Center for Sleep and Circadian Biology at Northwestern University, who was not involved in the research.

The aging of the circadian clock is thought to underlie the common sleep maladies older people experience, Colwell said. “More or less, one of the things we can count on [as we age] is going to bed earlier, waking up earlier, waking up during the night, and having difficulty staying awake during the day.”

Mice too experience circadian disturbances as they age. Colwell's group observed that young mice (aged 2-4 months) consistently ran on the wheel during dark periods, while middle-aged mice (12 months old) had more fragmented spurts of running, and they ran less vigorously.

Those activity patterns, the researchers learned, reflect changes in the neural firing patterns of the SCN, a brain region long touted as the master regulator of circadian rhythms. For more than a month, Colwell and his colleagues recorded activity from neurons in the SCN while the mice behaved normally. In young mice, the neural firing followed a clear pattern of high during light periods and low during dark periods, when the mice are most active. In middle-aged mice, the circadian pattern was a lot less consistent, with the SCN showing a broader range of activity levels during dark and light cycles. On average, the ratio of neural activity between light and dark cycles in young mice was double that of middle-aged mice, confirming in vivo what others have found in a dish.

“I think that's the most important part of the paper, showing that the amplitude of the clock itself is reduced,” said Turek. “This could be an underlying cause in a number of age-related changes in [circadian] rhythm.”

In contrast to previous studies, however, which reported age-related disruptions in the rhythmic expression of the clockwork protein PER2, the researchers found no differences in PER2 expression in the SCN between young and middle-aged mice. Consistent PER2 expression in the face of changing SCN  activity illustrates that “we don't know the full relationship between the firing activity and the molecular clockwork,” Stephany Biello, a University of Glasgow professor who did not participate in the research, told The Scientist.

With gene expression ruled out, it remains unclear what molecular mechanisms contribute to the changes in the SCN in older mice—a question Colwell and his colleagues plan to investigate. “We don't know the answer, but we're very interested in following up [on] that,” Colwell said.

T.J. Nakamura, et al., “Age-related decline in circadian output,” The Journal of Neuroscience, 31(28):10201–5, 2011.

Advertisement

Add a Comment

Avatar of: You

You

Processing...
Processing...

Sign In with your LabX Media Group Passport to leave a comment

Not a member? Register Now!

LabX Media Group Passport Logo

Comments

Avatar of: morekare

morekare

Posts: 1

July 13, 2011

Not only older people have these sleep patterns but some normal young people also have the same sleep patterns.  Circadian patterns are "individual" and cannot be blamed on aging, although perhaps as one ages, there is a likelihood that one's lifestyle, in general, changes allowing one to sleep erratically.

Avatar of: Eugeniy Ivanov

Eugeniy Ivanov

Posts: 1457

July 13, 2011

My parents are old and for me it's obvious that aged people having tendency to nap during daytime and having trouble sleeping at night. My dad has a "dry mouth" feeling or high blood pressure or just simply can't sleep - which could be change of circadian clock amplitude change. Sleeping is very important, during sleeping body actively regulates
itself. There is a lethal gene disease that disables the sleeping. Actually I'm sure that aging is a part of a human ontogeny that slowly but surely uninstalls (kills) the whole organism, so the specie would be better ready to evolve when the environment niche change, what they do more successfully when they procreate and die continuously (even the yeast ages). As I don't care about the species a tiny bit, but do care very much about my mom and dad, and myself, and all the people that suffer from aging, I want do hack aging somehow, stop aging, which is ImmInst advocates too. Perhaps it is possible to find and disrupt aging signals at the blood-stream, because it's known, that aged mouse ages the young mouse, when they pared together and share the same blood-stream.

Avatar of: Anumakonda Jagadeesh

Anonymous

July 13, 2011

Excellent research on sleep patterns that tend to change as people grow older.

It is a common experience in older people but  this research gives scientific explanation.

Dr.A.Jagadeesh  Nellore(AP),India
E-mail: anumakonda.jagadeesh@gmail.com

Avatar of: emyrtlemartin

emyrtlemartin

Posts: 5

July 13, 2011

Don"t the rodents in the photo look like rats instead of mice?

Avatar of: Drvinodnikhra

Anonymous

July 13, 2011

It is useful to note that the researchers did not find any major deficits in gene expression and they concluded that the molecular clockwork was
working fine, but the neural activity is running down.  To me it seems that it was more a physiological change, and thus the circadian signs of aging will depend on so many factors some of which can be modified.

Avatar of: jerry d

jerry d

Posts: 1457

July 13, 2011

I question the use of lab mice in any experiment utilizing running, as these mice haven't had to do any serious running in many generations.  Also they need more extensive study of both younger and older mice across the age spectrum to formulate this type of conclusion.  Too preliminary to predict this conclusion.

Avatar of:

Posts: 0

July 13, 2011

Not only older people have these sleep patterns but some normal young people also have the same sleep patterns.  Circadian patterns are "individual" and cannot be blamed on aging, although perhaps as one ages, there is a likelihood that one's lifestyle, in general, changes allowing one to sleep erratically.

Avatar of:

Posts: 0

July 13, 2011

My parents are old and for me it's obvious that aged people having tendency to nap during daytime and having trouble sleeping at night. My dad has a "dry mouth" feeling or high blood pressure or just simply can't sleep - which could be change of circadian clock amplitude change. Sleeping is very important, during sleeping body actively regulates
itself. There is a lethal gene disease that disables the sleeping. Actually I'm sure that aging is a part of a human ontogeny that slowly but surely uninstalls (kills) the whole organism, so the specie would be better ready to evolve when the environment niche change, what they do more successfully when they procreate and die continuously (even the yeast ages). As I don't care about the species a tiny bit, but do care very much about my mom and dad, and myself, and all the people that suffer from aging, I want do hack aging somehow, stop aging, which is ImmInst advocates too. Perhaps it is possible to find and disrupt aging signals at the blood-stream, because it's known, that aged mouse ages the young mouse, when they pared together and share the same blood-stream.

Avatar of:

Posts: 0

July 13, 2011

Excellent research on sleep patterns that tend to change as people grow older.

It is a common experience in older people but  this research gives scientific explanation.

Dr.A.Jagadeesh  Nellore(AP),India
E-mail: anumakonda.jagadeesh@gmail.com

Avatar of:

Posts: 0

July 13, 2011

Don"t the rodents in the photo look like rats instead of mice?

Avatar of:

Posts: 0

July 13, 2011

It is useful to note that the researchers did not find any major deficits in gene expression and they concluded that the molecular clockwork was
working fine, but the neural activity is running down.  To me it seems that it was more a physiological change, and thus the circadian signs of aging will depend on so many factors some of which can be modified.

Avatar of:

Posts: 0

July 13, 2011

I question the use of lab mice in any experiment utilizing running, as these mice haven't had to do any serious running in many generations.  Also they need more extensive study of both younger and older mice across the age spectrum to formulate this type of conclusion.  Too preliminary to predict this conclusion.

Avatar of:

Posts: 0

July 13, 2011

Not only older people have these sleep patterns but some normal young people also have the same sleep patterns.  Circadian patterns are "individual" and cannot be blamed on aging, although perhaps as one ages, there is a likelihood that one's lifestyle, in general, changes allowing one to sleep erratically.

Avatar of:

Posts: 0

July 13, 2011

My parents are old and for me it's obvious that aged people having tendency to nap during daytime and having trouble sleeping at night. My dad has a "dry mouth" feeling or high blood pressure or just simply can't sleep - which could be change of circadian clock amplitude change. Sleeping is very important, during sleeping body actively regulates
itself. There is a lethal gene disease that disables the sleeping. Actually I'm sure that aging is a part of a human ontogeny that slowly but surely uninstalls (kills) the whole organism, so the specie would be better ready to evolve when the environment niche change, what they do more successfully when they procreate and die continuously (even the yeast ages). As I don't care about the species a tiny bit, but do care very much about my mom and dad, and myself, and all the people that suffer from aging, I want do hack aging somehow, stop aging, which is ImmInst advocates too. Perhaps it is possible to find and disrupt aging signals at the blood-stream, because it's known, that aged mouse ages the young mouse, when they pared together and share the same blood-stream.

Avatar of:

Posts: 0

July 13, 2011

Excellent research on sleep patterns that tend to change as people grow older.

It is a common experience in older people but  this research gives scientific explanation.

Dr.A.Jagadeesh  Nellore(AP),India
E-mail: anumakonda.jagadeesh@gmail.com

Avatar of:

Posts: 0

July 13, 2011

Don"t the rodents in the photo look like rats instead of mice?

Avatar of:

Posts: 0

July 13, 2011

It is useful to note that the researchers did not find any major deficits in gene expression and they concluded that the molecular clockwork was
working fine, but the neural activity is running down.  To me it seems that it was more a physiological change, and thus the circadian signs of aging will depend on so many factors some of which can be modified.

Avatar of:

Posts: 0

July 13, 2011

I question the use of lab mice in any experiment utilizing running, as these mice haven't had to do any serious running in many generations.  Also they need more extensive study of both younger and older mice across the age spectrum to formulate this type of conclusion.  Too preliminary to predict this conclusion.

Avatar of:

Posts: 0

July 14, 2011

Lipofuscin begins to build-up in our cells within a month or so of birth, and is well revcognized as a marker of aging level.   It is the agent responsible for the "liver spots" that develop in the skin of the elderly, and more significantly is also responsible for a portion of the mental decline experienced by many elderly people.  In addition, lipofuscin has also been implicated in the development of the adult macular degeneration which is largely a problem of the elderly.  There is experimental evidence that chronic administration of curcumin is effective in significantly reducing the lipofuscin level in the brain as well as also increasing the levels of natural antioxidants in the brain. Other research has shown that curucumin also removes the amyloid plaque characteristically present  in the brains of those with Alzheimer;s.

Unfortunately, humans are not able to absorb curcumin sufficiently well (my own very rough estimate is about a fiftieth as well as rodents) to enable them to get much in the way of lipofuscin reduction benefit from taking curcumin. There is, as it turns out, a way around this limitation. However, research in increasing curcumin bioavailabbility is underway, and improved versions of curcumin are begining to appear on the market. 

Avatar of:

Posts: 0

July 14, 2011

Lipofuscin begins to build-up in our cells within a month or so of birth, and is well revcognized as a marker of aging level.   It is the agent responsible for the "liver spots" that develop in the skin of the elderly, and more significantly is also responsible for a portion of the mental decline experienced by many elderly people.  In addition, lipofuscin has also been implicated in the development of the adult macular degeneration which is largely a problem of the elderly.  There is experimental evidence that chronic administration of curcumin is effective in significantly reducing the lipofuscin level in the brain as well as also increasing the levels of natural antioxidants in the brain. Other research has shown that curucumin also removes the amyloid plaque characteristically present  in the brains of those with Alzheimer;s.

Unfortunately, humans are not able to absorb curcumin sufficiently well (my own very rough estimate is about a fiftieth as well as rodents) to enable them to get much in the way of lipofuscin reduction benefit from taking curcumin. There is, as it turns out, a way around this limitation. However, research in increasing curcumin bioavailabbility is underway, and improved versions of curcumin are begining to appear on the market. 

Avatar of: Charles Colenaty

Anonymous

July 14, 2011

Lipofuscin begins to build-up in our cells within a month or so of birth, and is well revcognized as a marker of aging level.   It is the agent responsible for the "liver spots" that develop in the skin of the elderly, and more significantly is also responsible for a portion of the mental decline experienced by many elderly people.  In addition, lipofuscin has also been implicated in the development of the adult macular degeneration which is largely a problem of the elderly.  There is experimental evidence that chronic administration of curcumin is effective in significantly reducing the lipofuscin level in the brain as well as also increasing the levels of natural antioxidants in the brain. Other research has shown that curucumin also removes the amyloid plaque characteristically present  in the brains of those with Alzheimer;s.

Unfortunately, humans are not able to absorb curcumin sufficiently well (my own very rough estimate is about a fiftieth as well as rodents) to enable them to get much in the way of lipofuscin reduction benefit from taking curcumin. There is, as it turns out, a way around this limitation. However, research in increasing curcumin bioavailabbility is underway, and improved versions of curcumin are begining to appear on the market. 

Avatar of: Keith Loritz

Anonymous

July 19, 2011

Black pepper helps with absorption.

Avatar of: Keith Loritz

Anonymous

July 19, 2011

The older population is responsible for the health and safety of the younger population. If that means staying awake longer and waking easier then nature found a way to make sure that this happens. Propagation of the species!

Avatar of:

Posts: 0

July 19, 2011

Black pepper helps with absorption.

Avatar of:

Posts: 0

July 19, 2011

The older population is responsible for the health and safety of the younger population. If that means staying awake longer and waking easier then nature found a way to make sure that this happens. Propagation of the species!

Avatar of:

Posts: 0

July 19, 2011

Black pepper helps with absorption.

Avatar of:

Posts: 0

July 19, 2011

The older population is responsible for the health and safety of the younger population. If that means staying awake longer and waking easier then nature found a way to make sure that this happens. Propagation of the species!

Follow The Scientist

icon-facebook icon-linkedin icon-twitter icon-vimeo icon-youtube
Advertisement

Stay Connected with The Scientist

  • icon-facebook The Scientist Magazine
  • icon-facebook The Scientist Careers
  • icon-facebook Neuroscience Research Techniques
  • icon-facebook Genetic Research Techniques
  • icon-facebook Cell Culture Techniques
  • icon-facebook Microbiology and Immunology
  • icon-facebook Cancer Research and Technology
  • icon-facebook Stem Cell and Regenerative Science
Advertisement
Teknova
Teknova
Advertisement
PITTCON
PITTCON
Life Technologies