According to an article I read through the Fox News web site, researchers have reported success in growing brain cells. That's right, brain cells. The cells in are called astrocytes and can play an important role in diseases like dementia and others effecting the central nervous system (astrocytes are found in the brain and spinal cord).
Naturally I'm sharing this for what it could mean to writers of science fiction. Technology to regrow brain cells could eventually lead to curing many brain-related illnesses, correcting brain damage suffered from accidents...
On another note, this article shows how quickly things we see as possible only in science fiction can quickly make the sci-fi technology obsolete. Fans of Star Trek: The Original Series will no doubt remember the episode "Spock's Brain" where Spock's brain is stolen and used to run an underground complex. McCoy, with the help of an alien teaching device eventually puts Spock's brain back. But with this technology, perhaps it would be possible in 200-300 years to regrow the brain. Perhaps they could just download the consciousness.
Another Star Trek reference is the Next Generation episode when Worf's spine is broken and an experimental treatment is used to regrow his spine. In about 300 years, that could be more common than shown.
Okay, Worf and Spock aren't human, but that's not relevant. In both shows, it was indicated that the situation would have been as dire for humans (or worse). Who knows. By the time those dates really come around, such repairs could be as routine as an appendectomy is now.