It is official: the hippocked neurons continue to train even in the adult brain

THE neurons in the hippocampusthe center of the memorylearning and regulation of emotional control in the brain, they continue to train even in adulthood. The discovery bears the signature of the group of Jonas Frisén, a professor of research on the stem cells of the Karolinska Institutet in Sweden: in 2013, the scientist had first shown the presence of new neurons in this structure of the human brain, and the new study confirmed and strengthens those first results. The research was published on Science.

For a long time it has been considered that we are born with a certain number of neurons and that these cells are only destined to die, gradually aged: it was thought, that is, that it was not possible for the brain to form new neurons after birth. Over time this dogma began to show the first cracks and started hypothesize that even in the adult brain occurred some production of new neuronsalthough the scope of the phenomenon was not clear.

In 2013, analyzing with a carbon-14 dating technique (similar to that used in archeology) the DNA of human brain tissue, Frisén showed that More than a third of the hippocampus neurons are regularly renewed during adult life. In the study, on the first signature of Kirsty L. Spalding, scientists used the residual radioactivity of the nuclear tests of the 50s and 60s to date human neurons, measuring the carbon-14 concentration in their DNA. And so they showed experimentally that in part, and throughout the course of life, those of the hippocampus were renewed.

However, no one had ever investigated the presence, in the hippocampus, of the cells preceding the new neurons, called neural progenitors. The new study not only shows that these cells exist in the hippocampus, but has “photographed” Several phases of neuronal developmentfrom progenitor cells to immature neurons, many of them in the division phase.

Scientists examined the post-moral brain fabric of individuals from 0 to 78 years kept in biobanche, structures that retain biological material. They used a method called Sequencing of the single nucleus (SNRNA-SEQ)which allows you to analyze genetic activity in the nucleus of a single cell, and a technique called flow cytometry to study the properties of specific groups of cells.

Thanks to these techniques and machine learning, they managed to identify the different phases of neuron development in the tissues analyzed, and to confirm that the newly trained neurons were in a specific area of the hippocampus, the giro.

For some time now it has been believed that the formation of new neurons in the tooth is important for the ability to associate different memories with each otherpartly compromised in the pathological forms of aging, such as Alzheimer’s disease.

THE Neurogenesis processes In the dented tour I am very variable between one individual and another. In some adult brain samples, scientists have found many progenitor cells of neurons, in others very few. «Our research could also have implications for the development of regenerative treatments That stimulate neurogenesis in neurodegenerative and psychiatric disorders »explains Frisén.