A study in which the Higher Council for Scientific Research has participated (CSIC) has shown that a region of the human brain, known as dentate gyrus, produces new neurons until the ninth decade lifespan in people who do not suffer from any neurological disease; while this mechanism, called adult hippocampal neurogenesis, is damaged in patients with Alzheimer's disease.
\»Despite the occurrence of a slight reduction in the number of neurons generated during the aging, a large number of these neurons are still present in the dentate gyrus of individuals who do not suffer from any neurological disease at least until the age of 87," explains the study coordinator. María Llorens-Martín, researcher at the Severo Ochoa Center for Molecular Biology (a joint center of the CSIC and the Autonomous University of Madrid).
The results, which have been published in the journal \'Nature Medicine\', are transcendent because the birth of new neurons in it adult human brain has a great importance for modern medicine, since this special type of neurons generated in the hippocampus participate in the acquisition of new memories and in learning in mice.
Contradictory results
Recent results have reopened the debate in this field by not detecting the presence of these cells in the human brain. This work analyzes in depth the causes of the obtaining possible contradictory results found by different research groups.
The study also comparatively analyses the phippocampal neurogenesis process adult in a group of 13 healthy individuals and 45patients of the Alzheimer's diseaser. The authors have found that the number of new neurons decreases of drastic way in the early stages of the disease, and then gradually decrease as the condition progresses. Furthermore, these cells encounter problems at different stages of the neuronal maturation process.
As a consequence of this blockage, the number of neurons generated that finally reach full maturation is much lower in these patients. "These findings have a great importance in the study of the neurodegenerative diseases and specifically in the study of the Alzheimer's disease\», he adds.
In this sense, the early detection of a decrease In the generation of new neurons, this could be an early marker of the disease. Furthermore, he adds, "if it were possible to increase the birth and maturation of new neurons in a manner similar to that done in laboratory mice, new therapeutic possibilities could open up that could be useful in alleviating or slowing the progression of this disease."
This study is the result of a collaboration between researchers from the Autonomous University of Madrid, the CSIC (Spanish National Research Council), the Center for Biomedical Research in Neurodegenerative Diseases (Ciberned), the CIEN Foundation, and the European University of Madrid.
Research development
The study shows that the chemical treatments to those who need it submit the human brain tissue samples for your further study critically affect the detection the presence of immature neurons. The researchers demonstrated that, after subjecting samples obtained from the same subjects to different chemical treatments, very different cell numbers were observed.
Furthermore, when these treatments were more aggressive or prolonged in time, the signal emitted by the new neurons disappeared completely. "Our work identifies a combination of methods that allows visualize the birth of new neurons in the adult human dentate gyrus. This methodology has allowed us to gain, for the first time, unique insights into the maturation of newly generated neurons in this brain region," he notes.
Thus, he continues, "we have been able to study in depth the stages that the new neurons Before fully maturing, what proteins they synthesize, and how they change shape and position within the dentate gyrus. This maturation process shares several characteristics with those described in other mammalian species," adds Llorens-Martín.
Extracted article Source: Medical Writing