Essential
- Swedish scientists have identified the different stages of neuronal development, more precisely stem cells with immature neurons.
- The newly formed neurons are located in a specific zone of the hippocampus, called “Date gyrus.”
- “Some human adults had many neural progenitor cells, others very little.”
New neurons are also formed in the brain of adults. This was recently proven by scientists from Karolinska Institutet (Sweden). In a study published in the journal Sciencethey were interested in hippocampal neurogenesis in adults. As a reminder, the hippocampus is a region of the brain essential to learning and memory, and involved in the regulation of emotions. “The study of hippocampal neurogenesis in humans is complex. The difficulty in identifying progenitor cells calls into question the possibility and the methods of generation of new neurons.”
Brain: newly formed neurons are located in the toothed gyrus
As part of this work, the researchers combined several advanced methods to examine the brain tissue of people aged 0 to 78, from several international databases. The latter used a method called mononuclear RNA sequencing, which analyzes the activity of genes in individual cell nuclei, and flow cytometry to study cellular properties. Thanks to this approach, the authors have identified all the stages of development of neural progenitor cells from early childhood.
In order to locate these cells, they used two techniques to locate the different active genes in the tissues: the rnascope and the xenium. These methods have confirmed that newly formed neurons were located in a specific area of the hippocampus called “Date gyrus.” This area is important for memory training, learning and cognitive flexibility. These results show that offenseurs of adult neurons are similar to those of mice, pigs and monkeys, but that there are differences in active genes. “Important interindividual variations have also been observed: some human adults had many neural progenitor cells, others very little.”
Towards “regenerative treatments stimulating neurogenesis”?
“This brings us an important piece of the puzzle to understand the functioning of the human brain and its changes during life. Our research could also have implications for the development of regenerative treatments stimulating neurogenesis in neurodegenerative and psychiatric disorders”, concluded Jonas Frisé, who led the research.