Adult Brain Continues Neurogenesis in the Hippocampus: New Research Findings

Recent research published in the journal Science provides compelling evidence that the human hippocampus, a critical brain region involved in learning, memory, and emotion regulation, continues to generate new neurons well into adulthood. The study, conducted by scientists at Karolinska Institutet in Sweden, addresses a long-standing debate about the brain's ability to produce neurons after development.

The hippocampus has been known for its role in cognitive processes, and previous studies have suggested that neurogenesis—the formation of new neurons—might occur in this area. Back in 2013, Frisén's research group published findings indicating that new neurons could form in the adult human hippocampus by analyzing carbon-14 levels in brain tissue DNA, which helped estimate the age of cells. However, questions remained about the presence and significance of neural progenitor cells—the precursor cells responsible for generating new neurons—in adult humans.

In the latest study, researchers confirmed the existence of these progenitor cells, demonstrating ongoing neurogenesis across a broad age range from infancy to 78 years old. Using advanced techniques such as single-nucleus RNA sequencing, flow cytometry, RNAscope, and Xenium, the team identified stages of neuronal development—from stem cells to immature neurons—many of which were actively dividing. The newly formed cells were localized specifically in the dentate gyrus of the hippocampus, a region vital for memory formation and cognitive flexibility.

The findings reveal that neural progenitor cells in adult humans behave similarly to those in other animals like mice, pigs, and monkeys, although there are notable differences in gene activity and individual variation. While some adults show abundant neural progenitors, others have very few, highlighting variability in neurogenic potential.

This groundbreaking research opens new avenues for understanding brain plasticity and has significant implications for developing regenerative treatments for neurodegenerative and psychiatric disorders. The team emphasizes that their findings bring us closer to potentially stimulating neurogenesis therapeutically, which could lead to innovative approaches for healing brain injuries and combating cognitive decline.

Source: Medical Xpress