Human brains continue to make new cells up to age 79 and possibly beyond, according to a new study published Thursday.
Scientists from Columbia University’s department of psychiatry studied the frozen brains of 28 deceased people and found that even the oldest brain, aged 79, had evidence of new brain cells in the form of immature neurons, the Los Angeles Times reported.
Unlike mice and nonhuman primates, in which neurogenesis has been shown to decrease with age, the hippocampus of the human brains studied showed that neural progenitor cells and immature neurons were present in similar numbers regardless of age.
There were some differences in the older brains, however, including fewer new blood vessels and less of a protein that helps new neurons make connections. These findings could account for the memory loss and emotional resiliency problems that some people experience as they age, the LA Times reported.
The findings contradicted a study published only one month earlier that did not find evidence of new brain cells after adolescence, but Columbia study author Dr. Maura Boldrini said the previous study used brains that were not as well-preserved and had smaller samples of the brain rather than the entire hippocampus, the LA Times reported.
“In science, the absence of evidence is not evidence of absence,” Boldrini said, the LA Times reported. “If you can’t find something it doesn’t mean that it is not there 100 percent.”
The author of the previous study, Dr. Mercedes Paredes, was not convinced by Boldrini’s findings, however.
“For now, we do not think this new study challenges what we have concluded from our own recently published observations,” she said, The Guardian reported, stating that the cells the new study identified as new neurons may not have been neurons at all.