Mice: The Secret To Everlasting Youth

        Despite the benefits of living a long life, old age can herald increasing risk of a variety of terrible neurological diseases. Parkinson's and Alzheimer's disease happen as old brain cells deteriorate, leading to loss of memory, movement, and other functions. But it's possible that a cure might be found in the promising evidence of long-lived mouse cells.

A surprising experiment at the University of Pavia in Italy shows that mouse neurons will live twice as long as a mouse's regular lifespan when implanted into rat brains. Researchers transplanted neurons from mouse embryos into the brains of rat fetuses, tagging them with chemicals so that they would glow green under certain light. This helped them to distinguish the rat neurons from the mouse neurons, which, three years later, had developed into fully functional cells, though they were still smaller than rat neurons. These cells adapted to the rat brains without trouble. In a mouse's brain, these cells would only survive for 18 months before the mouse died. These cells, though, lived for the natural lifespan of the rat, which was about three years. In addition to adapting, they also showed the same signs of aging as the neighboring rat neurons. They'd essentially become rat neurons, instead of mouse neurons. 

"The findings suggest that long lives might not mean deteriorating brains. 'This could absolutely be true in other mammals — humans too,' says study author Lorenzo Magrassi, a neurosurgeon at the University of Pavia in Italy."

This study shows that neurons from different species can adapt perfectly if implanted into the brain, and that brain cells don't deteriorate due to age, but instead because of other factors. This is an important step in understanding diseases such as Alzheimer's. If we can determine what allows neurons to live so long, and what causes them to break down in ways that cause neurological diseases, steps can be taken towards preventing that breakdown. Cells in the body rely on many different systems to stay alive, but knowing what depends on what to live and function is the hard part. If it isn't the cell age that ruins neurons, it must be something else. Knowing that brain cells can adapt to new environments and function at the capacity of other species could mean that non-human neurons can be transplanted into humans in the future, to combat the effects of neurodegenerative diseases. One of the concepts brough up in the article is also the kdea that as our natural lifespan increases, so does the longevity of our cells. Brains don't run on a timer that spontaneously runs out, apparently, and they can work pretty well in other species. The cells themselves are pretty hardy, which just serves to raise more questions about the nature of diseases of the mind.

http://www.sciencenews.org/view/generic/id/348600/description/Mouse_brain_cells_live_long_and_prosper