Everything Old is New Again

Old brains can start acting like young brains again, thanks to University of British Columbia researchers:

The research reveals that the loss of plasticity is due to the protein calpain actively blocking the protein cortactin, which is responsible for the sprouting of new connections. The researchers reduced calpain activity in animal models to unlock the sprouting potential of neurons and found that when calpain activity is reduced neural plasticity is enhanced.

“The maintenance of neuronal connections is an active process that requires constant repression of the formation of nerve sprouts by the protein calpain to avoid uncontrolled growth,” says Mingorance-Le Meur, who is also a member of the Brain Research Centre at UBC and VCH Research Institute. “But a consequence of this role is that calpain limits neural plasticity and the brain’s ability to repair itself. The next step is to find a way to enhance neural plasticity without interfering with the good connections that are already in place. The next step is to find a way to enhance neural plasticity without interfering with the good connections that are already in place.” _PO

Younger brains capable of learning rapidly could change a lot of things in the developed world, where populations are aging. Between 1% and 2% of populations in the developed world may be walking around with Alzheimer's, and the proportion will only grow unless we learn how to stop the inexorable senescence.

What about the rest of the body? How do we regenerate aging livers, kidneys, hearts, lungs, pancreases, lymphatics and blood vessels? We would probably start with stem cells. But we want our own stem cells -- stem cells that are compatible with our immune systems. Fortunately, science is unraveling the tangled knot of inducing pluripotent stem cells from adult cells:

A team led by Scripps Research Institute scientists has for the first time developed a technique for generating novel types of....human stem cells with characteristics similar to mouse embryonic stem cells, currently the predominant type of stem cells used for creating animal models of human diseases in research. The technique potentially provides scientists with new sources of stem cells to develop drugs and treatments for human diseases.

The study, which appears in the December 18 online version of Cell Stem Cell and the January 2009 print edition of the journal, provides proof of principle that alternative sources of stem cells can be created. _SD

The new technique apparently creates human induced pluripotent stem cells (hiPSCs) that are very close to hESCs in behaviour. This research suggests that before long, all of us will be able to bank our own hiPSCs as a type of "old age insurance" against the loss of function of virtually any tissue type.

The ability to grow entire new organs from hiPSCs has not been demonstrated, but it is only a matter of time and engineering. If hiPSCs behave like hESCs, all of the cell types to make any tissue or organ are there, potentially.

A lot more work is necessary before we can expect routine rejuvenation procedures from these breakthroughs. A lot of other breakthroughs will be necessary before the entire repertoire of rejuvenation techniques are available to significantly prolong the period of fulfilled and productive human lifespan.

Good news? Yes, but superficial good news. Underneath it all, humans are still generally stupid, unwise, ignorant, bigoted, easily led, fanatically violent creatures. The path to the next level does not involve superimposing all of the marvelous high tech accomplishments of western science and engineering onto the masses of humans. The transplant simply will not take, despite the best wishes of Kurzweil and friends.

More later.