Less Flexible Adult Brains, a Cause
Interesting longer-term possibilities arise from a knowledge of why adult brains cease to rewire themselves. From the Times Online: researchers "have identified a protein [PirB] that stops new neural connections forming in adult brains. ... brains of adult mice that lacked PirB retained the same rewiring ability of much younger brains. Without PirB to hold them back, the old mice were, in effect, able to learn new tricks. ... connections in the brain that form and rewire during childhood become more fixed later in life. This is why human beings are so versatile and receptive to learning earlier in life and become less flexible with age. Keeping connections fixed in the same place is normally an advantage, but after brain injury it would be helpful to have more flexibility. Being able to form new pathways might also allow adults to learn a new language, for example, with the facility of a child. ... By inhibiting the proteins that stop new connections growing, it may be possible for stroke victims to recover those missing links."
Link: http://www.timesonline.co.uk/printFriendly/0,,1-3-2319339-3,00.html