Study Finds Neurogenesis Linked to Better Cognitive Function
A new study has revealed that adults who can still produce neurons actively tend to have better memory and cognitive abilities compared to those whose neuron production declines. This research, published in Nature, scrutinized brain samples from deceased individuals, including both younger adults and ‘super agers’—those over 80 with remarkable memory.
The researchers observed that both young and older adults with sound cognitive health generated neurons, a process known as neurogenesis, at relatively high levels for their respective ages. Interestingly, they found that new neurons constituted a mere 0.01% of the total in the hippocampus, an area crucial for memory. In contrast, individuals facing cognitive decline, like those with Alzheimer’s, showed reduced neurogenesis; fewer immature neurons were present in their samples.
What’s quite intriguing is that the ‘super agers’ exhibited a higher quantity of immature neurons than other groups and significantly more than those affected by Alzheimer’s. However, because the sample sizes were small, not all the results reached statistical significance.
Maura Boldrini Dupont, a neuroscientist and psychiatrist at Columbia University, pointed out that the limited number of participants—each group had ten or fewer individuals—should lead us to interpret these findings cautiously.
Co-author Orly Lazarov, a neuroscientist from the University of Illinois Chicago, mentioned that understanding how the brain generates neurons and maintains cognitive health in older age could pave the way for new drugs aimed at promoting neurogenesis in those experiencing cognitive decline.
Debate Surrounding Neurogenesis
This research provides support for the idea that brains continue to produce neurons even during adulthood. However, that notion has faced skepticism historically.
In the early 20th century, neuroscientist Santiago Ramón y Cajal proposed that humans could not generate new neurons after birth. While it was later established that neurogenesis occurs in childhood, it was generally accepted that this was where it ended.
“That was the prevailing view when I was in medical school,” Dupont recalls.
In recent decades, this longstanding belief has been challenged by new evidence supporting neurogenesis within the adult hippocampus, stirring an ongoing debate in the field of neurobiology.
