Written by Annie Duong
Is it possible for us to generate new brain cells in late adulthood? A recent research study from Columbia University, led by Dr. Maura Boldrini, provides evidence that neurogenesis, the creation of new brain cells, can persist in the human hippocampus, which is responsible for the formation and retention of new memories during the later stages of life . Dr. Boldrini’s study challenges past research studies that suggest that the human neuron development drops sharply after infancy and any continued neurogenesis is highly rare past adulthood .
Dr. Boldrini carried out her research study by examining certain sections of the brain and comparing those sections to brains of differing ages. The dentate gyrus, also known as episodic memories, is important for the formation of memories of autobiographical events and was examined in the study. Autopsies were done on healthy individuals ages 14 to 79 who did not have neurodegenerative diseases. The samples taken were frozen immediately after the individual’s time of death to eliminate any confounding variables . One important kind of cell important for the creation of new brain cells are called progenitor cells. Boldrini and her lab discovered that one type of neural progenitor cells declined in quantity while several other types remained stable during aging in the anterior, mid, and posterior dentate gyrus of individuals of both sexes .
Even though we might be able to generate new cells in our brains, why does our cognitive function decline? Boldrini also discovered that there was decreased angiogenesis— the production of new blood cells. There was also a smaller total capillary surface area, which are tiny blood vessels that have numerous branches throughout the body, These results correlate with the brains reduced ability to form new connections with other cells in the brain despite the volume of neural cells remaining stable over late adulthood . This could explain why, despite the formation of neural cells during old age, the connections made between them are not strengthened, which leads to declining cognitive abilities.
These findings are extremely relevant in today’s aging world. The changes in angiogenesis is linked to Alzheimer's disease. Despite this, a healthy lifestyle, meaningful social interaction, and continued exercise, neural cells can be kept functioning. Hopefully, in the future, new treatments can be developed to combat neurodegenerative diseases.
 Boldrini, M., Fulmore, C.A., Dwork A.J., Hen R., Mann, J.J. 2018. Human Hippocampal Neurogenesis Persists throughout Aging. Cell Stem Cell. 22:589-599.
 Sorrels, S.F., Paredes, M.F., Cebrian-Silla, A., Sandoval, K., Qi, D., Kelly, K.W., James, D., Mayer, S., Chang, J., Auguste, K.I., Chang, E.F., Gutierrez, A.J., Kriegstein, A.R., Mathern, G.W., Oldham M.C., Huang, E.J., Garcia-Verdugo, J.M., Yang, Z., and Alvarez-Buylla, A. 2018. Human hippocampal neurogenesis drops sharply in children to undetectable levels in adults. Nature. 555: 377-399.
Netburn, Deborah. “Surprise! Scientists Find Signs of New Brain Cells in Adults as Old as 79.” Los Angeles Times, Los Angeles Times, 5 Apr. 2018