Until recently, it was believed that adult brains could not produce new neurons. We were all presumed to be doomed by age to an inevitable, precipitous slide into mental degeneration. But the discovery of a new form of neuroplasticity, known as “adult neurogenesis”, has shown that this is not the case. In some brain regions, it turns out, neurons generate throughout life. One of these is the hippocampus, part of the brain’s memory formation management system. And more areas of neurogenesis are being uncovered with encouraging regularity.
Neuroplasticity can also occur in response to brain injury, such as strokes. Within hours of the traumatic event, substantial rewiring occurs, sometimes allowing recovery of function, especially if the injured person is encouraged to begin rehabilitation as soon as possible.
Given this incredible power for the brain to reorganize and repair itself, one might wonder why our brains fail to overcome diseases such as Alzheimer’s, Huntington’s, Parkinson’s and dementia. The thinking is that both genetic and environmental factors, may overcome the brain’s capacity for self-repair and functional compensation. But stay tuned – research in neuroscience is constantly uncovering information that may help us delay or avoid these diseases.
For example, research is clear that increased levels of cognitive stimulation and physical activity can delay disease onset and slow progression even in a genetic model of the fatal inherited disorder, Huntington’s disease. Prior to this work, Huntington’s had been considered the “epitome of genetic determinism”. But this discovery suggests there’s no such thing as a purely genetic brain disorder and that “exercising the brain” can influence or even delay the progress of a disease.
Given the current pace of hopeful new discoveries and treatments, neuroscience will likely be back with more good news, soon!
And remember, whether we’re in possession of a healthy or functionally compromised brain, we’re always participating in the wiring of our brains – either accidentally or intentionally. Merely by being aware and intentional about our thoughts and actions, we can influence the performance and very structures of our brains.
D.C. McGuire, and Devon McNaughton