[Synaptogenesis in the anterior horns of the spinal cord of human embryos].

Synaptogenesis in the anterior horns of the brachial spinal cord in 6-week-old human embryos (CR : 13) was studied by electron microscopy. Asymmetrical and symmetrical contacts on the soma of differentiating neurons and on the leading processes were found in the ventrolateral area of the anterior horns of the test embryos. A hypothesis is suggested about the role of these early synapses in neuronal differentiation in the embryonal nervous system.