Men have more synapses
Marina Astvatsaturyan, Echo of MoscowA thicker contact network of brain neurons implies a greater number of connections between nerve cells, synapses that serve to transmit a nerve impulse from one cell to another.
The difference between the sexes in the way of thinking has long been established by psychologists, but what the structural background of this phenomenon may be remains a mystery. A study conducted by Spanish neuroscientists and published in the September issue of Proceedings of the National Academy of Sciences (Proceedings of the National Academy of Sciences) of the USA also cannot give a complete answer to this question, but it is the first of its kind, detailed and presenting specific data.
To determine the difference in the numerical density of neurons, Javier DePhelipe's group from the Cajal Institute in Madrid studied brain tissue samples taken in the hippocampus area from 4 men and 4 women during surgery for epilepsy. The tissue was examined under an electron microscope. It turned out that with the same six-layer thickness of cortical tissue samples and the same number and density of nerve cells in them, the only difference between the sexes is the density of synapses, intercellular contacts. In men, their number on average per cubic millimeter of tissue is 33% more.
The tissue analyzed by Spanish scientists belongs to that part of the cerebral cortex (temporal neocortex), which is associated with speech, memory and perception of auditory information. The revealed sex differences in the density of contacts between nerve cells in this area, according to the researchers, may explain better spatial perception in men and faster speech in women. Although, according to the head of the Neuroscience Center at the University of California, Davis (Center for Neuroscience at the University of California, Davis) Edward Jones, referred to by the ScienceNews portal, "at present it is still very difficult to say exactly what these data mean." At the same time, the detail and thoroughness of the study, according to him, "inspire confidence in the results obtained." According to the expert, it is possible that the male brain is simply redundant.
The co-author of the work, Dr. DeFelipe, notes that only the first step has been taken, and it is focused only on one area of the brain. "Perhaps the female brain will detect a higher density of synapses in other areas," the Spanish neuroscientist conciliatingly adds.
Portal "Eternal youth" www.vechnayamolodost.ru13.10.2008