For decades, scientists debated whether adult human brains can generate new neurons, a process known as neurogenesis. While neurogenesis had been documented in animals, evidence in humans was inconsistent—until now. A July 2025 study (Dumitru et al., 2025) offers compelling proof that new neurons are produced in the adult human brain, with clear identification of the neural precursor cells responsible for this process.
Researchers at the Karolinska Institute examined postmortem brain tissue from individuals aged 13 to 78. Using advanced RNA sequencing techniques, they identified molecular markers of immature neurons and precursor cells in most brains. These findings confirm that neurogenesis occurs throughout life, particularly in the hippocampus, a brain structure central to memory and learning—and a key site of neurotransmission.
This discovery is relevant to the study of neurotransmission because new neurons contribute to brain plasticity, synaptic communication, and potentially the regulation of neurotransmitters. The hippocampus, rich in glutamate, GABA, and dopamine receptors, may rely on newly generated neurons for encoding new memories and emotional regulation.
Interestingly, two adult brains showed unusually high levels of neurogenesis; one belonged to a person with epilepsy, raising questions about how increased or disrupted neurogenesis might affect brain activity. In animal studies, altered neurogenesis has been linked to depression and Alzheimer’s disease, suggesting a role for new neurons in mental health and neurological disorders.
This study closes a major gap in our understanding of brain development and opens new avenues for researching how neurotransmission is influenced by ongoing neuron formation. It also raises key questions for psychology: How might neurogenesis affect behaviour? And can this process be enhanced to support mental health?
Reference:
Dumitru, I., Paterlini, M., Zamboni, M., Ziegenhain, C., Giatrellis, S., Saghaleyni, R., … Frisén, J. (2025, July 3). Identification of proliferating neural progenitors in the adult human hippocampus. Science, 389(6755), 58–63. https://doi.org/10.1126/science.adu9575
Tom Coster - Psychology 