[Development of synaptic contacts in the human brain during the early stages of embryogenesis].

The author studied the ultrastructure of forming synaptical contacts in the human brain at the early stages of development (7--8 and 9--11 week embryos). It was established that during the 7--8th week of the embryo ontogenesis the brain has already contacts of the puncta adhaerentia type and structures which by several signs can referred to transitory stages in the formation of synapses. During this period of development contacts between the axons of neuroblasts were encountered more frequently that those between the axons and bodies of nervous cells. During the 9--11th weeks of embryogenesis the human brain acquires more contacts between both the axons and the neuroblasts. At this stage there is a first appearance of synaptical structures, similar to functionally and morphologically mature synapses.