Eaters of unborn neurons
Immune brain cells eat up excess nerve stem cells
Kirill Stasevich, CompulentaThe function of microglial cells in the brain is well known:
it is a division of the immune system that destroys pathogens and diseased cells. But this is in the adult brain. Meanwhile, embryos also have microglial cells, and for a long time no one understood what they were doing there. They were often found next to stem cells that give rise to neurons, and microglia cells literally stuck in large numbers to stem cells.
As it turned out, microglia simply eats up excess stem cells, which can create a dangerous surplus of neurons in the brain.
Microglia cells in the mouse brain (photo mluon753).
Steven Noctor from the University of California, Davis (USA) and his colleagues labeled microglial cells and neural stem cells in the brain of a mouse embryo with different fluorescent dyes. Then they took tissue samples, placed it in an incubator and after a while watched what was happening. What happened was this: microglial cells approached a cluster of stem cells, isolated one among them and ate it. The whole process of attack and absorption took about two hours. The same result was also the case when a monkey embryo was used instead of a mouse embryo.
When researchers tried to affect the appetite of microglial cells, it immediately affected the total number of neurons: they became either more or less, depending on whether the activity of microglia was suppressed or stimulated. If microglia were removed from the developing brain at all, the formation of neurons became uncontrolled. And an excess of nerve cells, as you know, can have a very bad effect on the architecture of the brain, and it turns out that microglia monitors its proper brain development.
An excess of neurons is often noted in such neuropsychiatric diseases as autism and schizophrenia, and this may be due to the fact that during embryonic development, the service microglial cells for some reason did not do their job well.
The results of the study are published in the Journal of Neuroscience (Microglia Regulate the Number of Neural Precursor Cells in the Developing Cerebral Cortex).
Prepared based on the materials of ScienceNews: Immune cells chow down on living brain.
Portal "Eternal youth" http://vechnayamolodost.ru07.03.2013