Sometimes this statement becomes the main argument when we are trying to convince another person to worry less about problems and troubles. And before he really had a scientific basis. But now there are new data, says neuropsychologist Margarita Alfimova, which refute the usual ideas.
“The centers of the adult brain are something established, complete and unchanging. Everything can die, nothing can be restored,” wrote the histologist Ramón y Cajal, who studied brain cells, in 1913.
“This idea has become one of the main dogmas of neuroscience,” says neuropsychologist, leading researcher at the Mental Health Research Center Margarita Alfimova. – It seemed logical, because in the brain there are established circuits of neurons, and the formation of new cells could destabilize this system.
Many people believed in the immutability of brain cells so much that they ignored the discovery in 1965 by Joseph Altman and Gopal D. Das – neurogenesis, that is, the process of formation of new neurons, in the hippocampus of rats. It was not until 1998 that Peter Erickson convincingly proved the existence of neurogenesis in the human brain.”
What do we know today? The birth of new neurons in the human brain occurs throughout life, slowing down slightly after the age of 40. Moreover, neurons are not born in the entire brain, but only in two areas – in the dentate gyrus of the hippocampus and in the olfactory system.
“The hippocampus is of particular interest to scientists, since this area of the brain is associated with memory, with emotions,” says Margarita Alfimova. – It is believed that about 700 neurons of the dentate gyrus are updated every day. Some of the old ones are dying off, and the new ones are being built into established networks.”
What benefits can be derived from these processes?
“First of all,” explains Margarita Alfimova, “biologists are exploring the possibility of transplanting new neurons into damaged areas of the brain, which may be relevant for the treatment of Alzheimer’s disease and other diseases associated with degeneration and brain injury. The fact that nerve tissue after transplantation takes root and stimulates brain regeneration, for example, after strokes, has already been proven in animals.”
In addition, the influence of neurogenesis on memory and cognitive processes, on pattern recognition, on the ability to navigate in space and act in context are being actively studied.
Studies show that moderate exercise enhances neurogenesis and improves cognitive function. The same effect has an increase in the intervals between meals. But depression, alcoholism and severe stress slow down the formation of new neurons.
So the meaning that we put in the call to maintain composure – “Calm down, nerve cells are not recovering” – remains the same. But, based on modern scientific data, it would be correct to put it differently: “Calm down, you slow down neurogenesis.”
About expert
Margarita Alfimova – Doctor of Psychology, Leading Researcher, Laboratory of Clinical Genetics, Mental Health Research Center.