Scientists are debating whether the human brain can grow new cells past childhood. The developing brain gains billions of neurons during fetal development and in early childhood. However, recent research suggests that it may be possible for adults to form new neurons.
The process of creating new brain cells is called neurogenesis. In adult mice, researchers have found new neurons growing in the subventricular zone and hippocampus, areas linked to sense of smell and memory. Lifestyle factors such as exercise and a stimulating environment can promote neural growth in mice.
However, studying human adults is more complex due to methodological limitations. Unlike animals, humans cannot be injected with radioactive tracers to visualize new neurons. But researchers have used other methods, like radiocarbon dating, to identify newborn neurons in postmortem brain tissue from people aged 19-92.
Some studies have reported finding new neurons in the adult human hippocampus, but these results are not conclusive due to the complexity of the method. Despite this, more indirect markers of neurogenesis, such as specific proteins, have been found in adult brain tissue.
Not all researchers agree on the existence of human adult neurogenesis. Arturo Alvarez-Buylla believes that chemical markers may be misleading and carbon-14 dating is not a reliable method for confirming new neuron formation. However, others, like Kempermann, are convinced that people can grow new neurons well into adulthood.
The implications of this research are significant, as it could lead to new therapies for brain injuries and neurodegenerative disorders. Even if human adult neurogenesis is rare, the mechanisms used by animals to form new neurons may still be useful for human treatments.
Source: https://www.livescience.com/health/neuroscience/can-adults-grow-new-brain-cells