New findings could help pave the way for therapies to treat depression, Alzheimer’s, and age-related cognitive decline.
Even after death, the brain of a 78-year-old held a surprise—researchers found clusters of immature brain cells, suggesting the human brain may keep making new neurons long after childhood.
The discovery, made by researchers at Sweden’s Karolinska Institutet, provides the clearest proof yet that our brains don’t stop growing by adulthood, but continue to make new brain cells throughout life.
Scientists found rare neural progenitor cells in the hippocampus of adult human brains. The hippocampus, a seahorse-shaped structure located deep in the brain, is the brain’s memory center, responsible for storing and forming memories.
“We have now been able to identify these cells of origin, which confirms that there is an ongoing formation of neurons in the hippocampus of the adult brain,” Jonas Frisén, lead researcher and professor of stem cell research at the Karolinska Institutet, said in a statement.
“Adult neurogenesis offers a glimmer of hope for brain repair,” co-researcher Marta Paterlini told The Epoch Times in an email, and could help pave the way for therapies to treat depression, Alzheimer’s, and age-related cognitive decline.
Inside the Brain’s Hidden Workshop
The team analyzed post-mortem brain tissue from 36 donors ranging in age from infancy to 78 years. They identified three key types of neural progenitor cells by analyzing their gene activity. These cells had genes active in cell division and early-stage neuron development—hallmarks of neurogenesis.
According to Paterlini, the cells showed gene activity associated with cell division and early-stage neuron development—hallmarks of neurogenesis—and were found clustered near mature neurons in the dentate gyrus, together providing strong evidence that new brain cells continue to form in adulthood.
The researchers focused on the dentate gyrus within the hippocampus, as it has long been suspected to support neurogenesis in animals. Often described as the brain’s “memory gate,” the dentate gyrus helps us distinguish between similar experiences and form distinct memories.
Previous studies had identified immature neurons in adults, but it was unclear whether those cells were newly formed or simply remained immature because they took too long to mature.
While progenitor cells were most abundant in children, they remained detectable in adult brains, though more sparsely.
However, the study also revealed significant individual variation. Some donors had many new cells, others had few or none. The researchers noted this variation could be influenced by factors such as genetics, stress, mental health, or lifestyle.
