Cognitive decline in old age is linked to decreasing production of new neurons. Scientists from the German Cancer Research Center have discovered in mice that significantly more neurons are generated in the brains of older animals if a signaling molecule called Dickkopf-1 is turned off. In tests for spatial orientation and memory, mice in advanced adult age whose Dickkopf gene had been silenced reached an equal mental performance as young animals.
This is a surprising result (at least for me). The ability to make new neurons does not make the rest of the neurons in the brain any younger. So I expected less total restoration from the ability to make new neurons.
The hippocampus – a structure of the brain whose shape resembles that of a seahorse – is also called the "gateway" to memory. This is where information is stored and retrieved. Its performance relies on new neurons being continually formed in the hippocampus over the entire lifetime. "However, in old age, production of new neurons dramatically decreases. This is considered to be among the causes of declining memory and learning ability", Prof. Dr. Ana Martin-Villalba, a neuroscientist, explains.
The big risk if this same change could be done in humans: brain cancer. Old neural stem cells are at greater risk of turning into cancer if they replicate. What we need: youthful neural stem cells delivered (how?) into the various places in the brain where aged neural stem cells no longer divide fast enough. The youthful cells would first need to be selected for high genetic quality with no dangerous mutations of the sort that contribute to cancer.
The ability to inject youthful safe neural stem cells into our brains would boost the mental performance of the middle aged and elderly. Productivity would rise as brains with lots of accumulated experience would also have the mental agility of youth. The incidence of brain diseases (e.g. Parkinson's, dementia, Alzheimer's) would plummet.
The report, posted online on Sunday by the journal Nature Neuroscience, suggests that structural brain changes occurring naturally over time interfere with sleep quality, which in turn blunts the ability to store memories for the long term.
I'm for brain rejuvenation. When I get it done I also want to opt for some genetic engineering to the neural stem cells that will cause a slow gradual rise in my intelligence as higher performing neurons become a larger fraction of the neurons in my brain.
|Share |||Randall Parker, 2013 February 10 08:03 PM|