Turning Back the Brain Clock

“It is never too late to have a happy childhood” _TomRobbins

A team of UCSF scientists has turned back the clock of brain development for young mice by transplanting fetal mouse neurons into their brains.

...the researchers took a specific type of neuron from the brains of fetal mice and grafted them into mice that had either just been born or were approximately 10 days old. Known as inhibitory interneurons, these cells release a chemical signal that quiets neighboring cells, making it more difficult for them to fire. The transplanted neurons, labeled with a fluorescent marker, began migrating to their normal place in the brain and making connections with resident neurons.

The mice went through the typical critical period, at about 28 days of age. But the transplanted neurons seemed to induce a second critical period, which was timed to the age of the transplanted cells rather than the age of the animals. The later critical period occurred when the transplanted neurons were about 33 to 35 days old, the same age as resident inhibitory interneurons during the normal critical period. (The neurons arise in the brain before birth.)

Scientists aren't yet sure how the cells induce this second period of malleability. Stryker's team and others had previously shown that the cells' inhibitory signaling plays a key role--the critical period can be delayed or induced earlier by mimicking the inhibitory effects of the cells with drugs, such as valium. But in these previous experiments, it was not possible to induce a second critical period after the normal one. "Once you've had it, can never get another one, at least until these transplant experiments," says Stryker. "That shows there is something other than just the inhibitory [chemical] they release that must be involved in this process." Researchers plan to transplant different types of inhibitory neurons, in an attempt to find the specific cell type responsible.

"I would love to see if the same sort of transplant worked in older animals," says Jianhua Cang, neuroscientist at Northwestern University, in Chicago. "This work is a significant advance, but if one can do it in adult animals, it would be even more remarkable. And it opens the possibility of therapeutic potential." Cang was not involved in the current research, thought he has previously worked with the authors.

The findings could have wide-reaching implications for how we think about the nature of plasticity in the brain. Humans have a similar critical period, though in humans this phase is more extended than in mice. _TechnologyReview

Al Fin neuroscientists say that this research opens the door to the idea that even adult brains may be induced to undergo repeated "critical periods" for vision, math, music, language and foreign language, etc. It is not so much a question of "if" but of "when" the proper combination of precursor cells, growth factors, and other auxiliary factors can be devised and tested, to bring the exceptional brain plasticity of young animals to the adult human brain.

This is the type of foundational research that society's resources should be devoted toward, rather than the corrupt and wasteful scams of pseudo-science so favoured by the governments of Europe, Australia, the US, and the UK.