[Structural organization of the synaptic connections of developing neurons in the anterior horns of the spinal cord in early human fetuses].

Synaptogenesis in the presumptive anterior horns of the spinal cord in early human fetuses (weeks 11 -- 12 of intrauterine development) was studied by electron microscopy. In this period of human nervous system development, various stages of the synaptic contact forming process were elucidated in the region under study: from the growth cone attachment to the neuroblastic surfaces up to mature synapses. The appearance of the first synaptic complexes provides evidence of the presence of the high-functional specialization of the synaptic apparatus in the course of differentiation of motoneurons of the spinal cord in the early stages of human antenatal ontogenesis.