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The researchers tested mice brains for the secret behind brain cell death.  (Source: Recognizing Deven)

The researchers found an important culprit in the cause of brain cell death -- a tumor killing preventing enzyme surpress AKT (pictured here), a critical protein to cell survival.  (Source: The Institute of Cancer Research)
Nature's kill switch seems to activate for some brain cells but not others, according to researchers

Preventing and reversing memory loss is a key field of research in the area of prolonging human life spans.  While humans are living much longer than they once did, many suffer from debilitating conditions such as Alzheimer's disease, which limit their quality of life during their later years.

Scientists at the University of Florida may have gained a significant insight into understanding what causes some brain cells to die, triggering these diseases, while others cells remain alive.  The studies, performed on mice examined two neighboring regions in the hippocampus; an anatomical region shaped something like a curved kidney bean.  The region is thought to be central to the formation of memories, and is one of the first regions affected by brain blood flow problems or Alzheimer's.

What researchers discovered was that the higher susceptibility to cell death in part of the hippocampus versus the other region was due to the enzyme PHLPP, pronounced "flip", silences the transcription of a gene that produces a critical protein to cell survival, AKT.  AKT inhibits many causes of cell death.  The inactivation in essence, amounts to the cell flipping its own kill switch.

Thomas C. Foster, Ph.D., the Evelyn F. McKnight chair for research on aging and memory at UF describes, "The question is why does one set of brain cells live and another set die when they are only millimeters apart in the same small brain structure?  We looked at an important signaling pathway that tells cells to stay alive or die, and the enzymes that regulate that pathway. Implicated in all this is a new protein that before a couple of years ago no one actually knew much about."

The conclusions were drawn by first finding AKT levels to be a key chemical difference between the living and dying cells.  From there, the cause of the AKT shortage was traced to high levels of the enzyme PHLPP1, the mouse version of PHLPP, an enzyme found in other mammals.  Ironically, the recently discovered enzyme suppresses tumors in many cases.  The compound was discovered by Alexandra Newton, Ph.D., a professor of pharmacology at the University of California, San Diego.

Professor Newton comments on the new research, stating, "Basically, PHLPP is important in controlling whether cells survive and proliferate or die.  If you want cells to survive brain disease, diabetes or heart disease, you want active AKT signaling and therefore low PHLPP. But if you want to stop cells that have the 'go' signal, like cancer cells, PHLPP can function as a brake. In this case, it appears as if there is an area in the hippocampus that is easily stressed and might undergo ischemia easily, because PHLPP is not allowing the AKT survival mechanism to work."

According to Professor Foster, the breakthrough could lead to new drugs to combat memory loss and brain damage.  He states, "Possibly, we have found a target that could be manipulated with drugs so that these brain cells can be saved from threats.  If one area of the hippocampus has a deficiency in cell-survival signaling, it is possible to find a way to ramp up the AKT protein. The caveat is, there are studies that show over-activating AKT may not be good for memory — AKT may be naturally lower in this region for an important reason. But in times of intense damage, there may be a therapeutic window to upregulate AKT and get some benefit to health."

It is still unknown why some regions of the brain flip the switch to trigger cell death, while others, which appear equally vulnerable to tumor formation, do not.

The research is published online in the Nature publication Cell Death & Differentiation.  



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RE: Oh that's just perfect....
By JonnyDough on 12/12/2008 10:36:48 PM , Rating: 2
You hit the beer belly on the...uhh button? Brain cells are basically irreplaceable. The more you drink the dumber you get. Same goes with anything that starves your brain of oxygen or alters the chemical balance of your brain cells. Smoking pot to get high your whole life will ultimately leave you dumber than a box of rocks.


RE: Oh that's just perfect....
By myhipsi on 12/15/2008 12:53:59 PM , Rating: 2
quote:
Brain cells are basically irreplaceable. The more you drink the dumber you get.


I've known drinkers who are smart and I have known abstainers who are complete idiots. I don't think intelligence or "dumbness" can be explained in such simplistic terms. The brain will atrophy if not used, just like muscles will atrophy if not used. So technically not thinking is more damaging to the brain than drinking.

quote:
Same goes with anything that starves your brain of oxygen or alters the chemical balance of your brain cells.


Then I guess half of all the pharmaceutical drugs on the market make you dumb because they alter the chemical balance of your brain. Oh, and so does getting angry or sad or happy... you get my point. Just because a drug or chemical alters the brain in some way, doesn't mean it'll make you "dumb".

quote:
Smoking pot to get high your whole life will ultimately leave you dumber than a box of rocks.


Please explain to me how Tetrahydrocannabinol or any other chemical constituant in pot makes you "dumb". Do you know anything about the pharmacology of cannabis? I think not, as you wouldn't have made such an ignorant statement if you did.


By William Gaatjes on 12/15/2008 3:05:26 PM , Rating: 2
Although it primarily depends on the person(genetic code and lifestyle),it is known that with some people prolonged exposure can slow down the ability to learn, it limits the short term memory. With some other people , it makes them lazy, which in the end makes them not do anything : "The brain will atrophy if not used, just like muscles will atrophy if not used. So technically not thinking is more damaging to the brain than drinking."
With other people, it makes them more at ease and they learn faster. There has even been a study done a few years back that the THC chemical Tetrahydrocannabinol can be benificial because with some people it destroys there bad memories. In other words it helps you forget what you need to forget.

I am guessing here but sometimes it looks like that for every biological occuring chemical humans have some dna that is activated by it. I say humans but i must strongly point at the fact that this happens with every living animal. It seems that dna is possibly swapped and replaced all the time. Horizontal gene ransfers may be the reason and may be more occuring. Since horizontal gene transfers can cross species boundaries, something vertical gene transfers (aka using sex to create offspring) can not do.
Most of these changes are corrected by the cells dna repair mechanisms but some changes are permanent. Some of these changes are lethal to the cell, some changes do not bother it's function unless a specific chemical drops by...

To sum it up it is not that simple.


"If you mod me down, I will become more insightful than you can possibly imagine." -- Slashdot

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