Brain repair

The adult human central nervous system lacks the ability to spontaneously repair itself after injury or disease, unlike peripheral nerves. Research into development and cell lineages is uncovering the reasons behind this and exploring methods to improve repair. At the same time, understanding neurodegenerative processes is leading to treatments to reduce neuronal and glial damage. Cell implantation has shown some promise in restoring normal cell arrangements in the central nervous system. A comprehensive strategy is emerging to both limit damage and repair the brain. The clinical translation of these findings is eagerly anticipated. An essential aspect of brain repair is understanding the rules of development in the nervous system. The mature CNS may have the potential for axonal recovery, but is actively inhibited. Structural and functional repair may require cell replacement.

• 1
  Growth factors can protect neurons and glia from injury, promoting survival and potentially restoring normal cellular arrangements. Specifically, BDNF protects dopaminergic neurons, and bFGF protects hippocampal neurons from excitotoxic injury.
• 2
  Axon regeneration depends on the ability of nerve cells to extend new growth cones and a permissive environment. The inhibitory effects of glia, particularly astrocytes and oligodendrocytes, on neuronal regeneration have been identified.
• 3
  Cell implantation, particularly of dopaminergic neurons in Parkinson's disease, has shown promise in improving motor function and graft survival. Furthermore, remyelination can be achieved by transplanting oligodendrocyte precursors.