説明
The Many Ways to Grow New Brain Cells and Stimulate Neurogenesis.
Conventional wisdom has long suggested that we cannot grow new brain cells; that we are born with all of the brain cells we will ever have and that once those gray cells expire, they're gone for good.
This belief was fueled, in part, by the fact that certain motor (movement) and cognitive (thought) functions tend to decline the older we get. But should this suggest that it's all downhill once we approach a certain age and that we have no choice but to wait for the inevitable decline?
Brain Cells and the Hippocampus
While the vast majority of our brain's cells are formed while we are in the womb, there are certain parts of the brain that continue to create new neural cells during infancy. Until recent decades, however, the brain’s limited capacity to regenerate triggered the belief that neurogenesis—the birth of new brain cells—ceased soon after this stage.
Recent research has shown otherwise and suggests, in fact, that at least one part of the brain continues to create new cells throughout a person's lifespan.
During the late 1990s, researchers at Rockefellers University in New York City conducted studies in which marmoset monkeys were injected with a tracer chemical that could differentiate between slow-dividing mature brain cells and fast-dividing new ones. What they found was that the hippocampus (a region of the brain associated with memories, learning, and emotions) continued to create new cells without the constraint of age or time.
Later studies using carbon-14 dating (which evaluate the age and process of cellular development) confirmed that cells in the hippocampus, while continually dying, were quickly replaced by new ones. It is only by the formation of these cells that the hippocampus is able to maintain its central functions.
What it also showed us is that the number of new cells, and the frequency by which they are created, begin to decline with age. With that being said, the rate of decline wasn't seen to be consistent and could vary significantly from subject to subject.
The research is considered important as is suggests that there are factors that can stimulate and inhibit the process of adult neurogenesis. It even hints at possible models for treating degenerative diseases, such as Alzheimer's and Parkinson's diseases, and even reversing damage caused by traumatic brain injury.