4.7 Ageing brains: hope for the future
Due to the enormous progress in the field of molecular and cell biology, new avenues in brain research have opened up. In the past few years, investigators have shown that the ageing brain has several natural mechanisms for promoting recovery. If these mechanisms can be understood, it may be possible to draw upon them in order to preserve brain functioning at ‘higher’ levels during ageing. Among the most promising studies in humans are those that have shown that physical and mental activity can influence brain chemistry and may aid in the maintenance of brain function with ageing. Another exciting advance in the study of the nerve cells that make up the brain is the discovery that new neurons can be produced in adulthood, from a pool of unspecialised cells called neural stem cells – a process known as neurogenesis. The degree to which neuronal replacement can occur, and the extent, locations and triggers for neurogenesis are not yet known, but are being intensively studied. While it remains the case that the brain as a whole has limited powers of repair, the potential use of stem cells offers new hope for future therapy for degenerative brain diseases.