The process of biological aging or the state of an organism being biologically old.
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297 views
Are human bodies programmed to die?
Following from this question: What is the evolutionary advantage of death?:
Is there any evidence that human bodies have systemic self-destruction built into their developmental program? I'm not ...
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1answer
63 views
Exercise causes number of cell divisions to approach Hayflick limit faster? And hence shorten life expectancy?
A world class athlete spends a lot of time performing intense exercises. Correct me if I'm wrong, but I assume that these intense exercises causes significant damage to the athlete's cells, but with ...
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4answers
300 views
Why is the Hydra Biologically Immortal?
I have heard that the Hydra organism is biologically immortal (later I found that there are more immortal organisms). Now I know that its immortality is related to its telomerase. The thing is that we ...
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78 views
How are new people created from the DNA of an aged person. i.e. Why are we young?
The question "why do we age" has been asked numerous times. But why are we young? The cells of the adult human being are an age (time>0), but how can old cells create new cells that are younger than ...
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1answer
395 views
Is there an advantage to linear chromosomes?
The DNA copying enzymes have a hard time working to the end of a chromosome. For circular chromosomes this is not a problem, since there is not a sharp 'end'. However, for a linear chromosome, without ...
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1answer
2k views
Do crocodiles age?
I was watching a talk by Michio Kaku (sp?) and he mentioned that crocodiles (or possibly alligators, I forget offhand) don't actually age-- they can die, but they essentially go through no aging ...
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54 views
Papers linking telomeres and aging [closed]
I'm currently writing a piece of work about telomeres and aging, and wondered if you could share some good papers you've either read or know of.
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31 views
Is there any kind of immortality in plants?
I asked a question about immortality of hydra and leaned good things about senescence. Now I like to know about immortality signs in plants. If there is some kind of immortality in plants its process ...
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33 views
Difference In Telomeres Between A Thale Cress Plant And A Methuselah Tree
From what I have read and understood telomeres cap off how many times a cell can divide before it can no longer divide and that is what causes aging.
A thale cress plant apparently has a life cycle ...
4
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1answer
69 views
Is cell senescence in culture comparable to that in vivo?
A cell is 'senescent' when is has permanently left the cell-cycle. This can be caused by stresses, or by reaching the 'Hayflick limit' (the cell has reached its replicative lifespan, as defined by its ...
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2answers
125 views
Does the speed of electrical impulses through neurones decrease with age?
From what I read on the NatGeo app, it stated that the speed of the electrical impulses that are sent by a neurone will be approximately 332 kilometers per hour.
Will the speed of this electrical ...
4
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1answer
108 views
What evolutionary pressures pushed Galápagos tortoises to mature so slowly and live so long?
I read that they take up to 40 years (in the wild) to reach the age of reproduction and are thought to live over 100 years, with one in captivity reaching over 170 years.
Can someone explain in ...
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1answer
799 views
How does the NAD+/NADH ratio affect lifespan in vertebrates?
Here's the proximate physical implication of the ratio (from the Wikipedia article on NADH).
The balance between the oxidized and reduced forms of nicotinamide
adenine dinucleotide is called the ...
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3answers
110 views
What reasons allow for women to outlive men?
It is a well-known fact that women tend to outlive men.
I often hear people unscientifically stating that men generally generally die younger because of the higher stress encountered in their work ...
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1answer
52 views
Why would we overexpress Sir2 by overexpressing its hypomorph (dSir2-EP2300) in C. elegans?
Can't we just overexpress regular Sir2 in the paper? Rather than overexpress a reduced-function gene?
The paper is Burnett C, Valentini S, Cabreiro F, Goss M, Somogyvári M, Piper MD, Hoddinott M, ...
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1answer
50 views
Age-associated neurodegenerative diseases
Age-associated neurodegenerative diseases encompass Alzheimer's Disease and Parkinson's Disease. What other neurodegenerative diseases could be described as age-associated? Multiple Sclerosis? Brain ...
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1answer
43 views
During human ageing, which immune cell sub-types are most affected?
It is now well established that human ageing is accompanied by an increase in systemic, low-grade (chronic) inflammation, sometimes termed inflammaging (Franceschi, 2007). This is in part due to more ...
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5answers
440 views
Why do we age? or Do we have a theory of senescence?
There seem to be a number of ideas about why we age. Hypotheses include the gradual accumulation of cell metabolic products affecting organism function and the reduction of telomere length during cell ...
8
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1answer
180 views
Why does hair turn grey or white, and why does it happen later for some?
The question is pretty simple: what is happening molecularly when hair turns grey or white? I would imagine that it is due to the lack of a particular compound. I'm also interested in why some ...
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3answers
169 views
Does current evidence support the use of resveratrol as an anti-ageing drug?
A while back there was a lot of noise about resveratrol, a naturally occurring phenol which was touted as a potential anti-aging drug due to its role in regulating the SIRT 1 gene. A number of studies ...
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3answers
100 views
Free Radicals for aging
From my understanding free radicals play a slight role in ageing.
In what ways are they so damaging, and can a restricted diet reduce production of free radicals?
3
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1answer
123 views
Could inhibition of progerin formation slow the rate at which a body ages?
According to wikipedia, progerin is activated in senescent cells. The protein itself is known to be the cause of a rare affliction 'progeria' - a disease marked by accelerated aging of the body. This ...
11
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1answer
127 views
Have any mutations or genetic loci been associated with exceptional longevity in humans?
Individuals that avoid age-related diseases into later life are known as 'exceptional survivors', and have increased longevity compared to their 'controls' (those that were born at a similar time, yet ...
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1answer
80 views
In what ways, if any, does administration of rapamycin *not* mimic calorie restriction?
Numerous sources like this say that rapamycin increases lifespan. And mTOR antagonism appears to be a large part of this (mTOR antagonism also appears to be a large part of calorie restriction's ...
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1answer
64 views
If inhibiting S6 kinase decreases protein translation, then could inhibiting S6 kinase could possibly slow down long-term potentiation in neurons?
From http://en.wikipedia.org/wiki/P70S6_kinase...
Phosphorylation of S6 induces protein synthesis at the ribosome.
P70S6 kinase is in a signaling pathway that includes mTOR (the
mammalian ...
5
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1answer
126 views
Why isn't the p16-INK4a gene involved in apoptosis expressed in heart or liver tissues?
New York Times article explains how killing p16-INK4a positive senescent cells can help keep the surrounding cells vigorous.
So here's my question: why is p16-INK4a expressed in most cells other than ...
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1answer
103 views
What are the effects of combining rapamycin with dietary restriction?
Are the effects additive or subadditive? In many ways, rapamycin acts like a CR mimetic, but even CR can only go so far.
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0answers
30 views
RHEB senses amino acids in order to recruit mTOR. Do we know if RHEB is more sensitive to some amino acids (like methionine) than other amino acids?
See http://www.ncbi.nlm.nih.gov/pubmed/21157483 for the full paper describing the process of how RHEB recruits mTOR.
We also discussed this in Matt Kaeberlein's class yesterday and I posed this ...
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1answer
183 views
Why are beta-galactosidase proteins overexpressed in senescent cells?
Wikipedia explains that it's a hypothetical hydrolase enzyme that catalyzes the hydrolysis of β-galactosides into monosaccharides only in senescent cells.
I'm just wondering - what causes it to be ...
4
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1answer
280 views
How do caspase proteins kill a cell?
Wikipedia just says...
The active effector caspases then proteolytically degrade a host of
intracellular proteins to carry out the cell death program.
Okay, but what parts of the cell do they ...
5
votes
1answer
125 views
Does AMP/ATP ratio affect lifespan in vertebrates?
The reference below says that a higher AMP/ATP ratio is associated with lower lifespan in C. elegans.
Is this finding also generalizable to vertebrates as well?
Reference:
Apfeld, J., O’Connor, ...
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1answer
207 views
Why does regular exercise increase brain volume?
It has been shown in several studies that regular aerobic exercise increases brain volume in aging humans. The changes were observed in hippocampus and were correlated with dramatic reduction of ...
