[Ultrastructural characteristics of the dendrites of spinal neurons].

Some kinds of dendritic protrusions were found in the different parts of the spinal cord grey matter connected with the long descending fibre systems. The small simple dendritic protrusions were localized in the medial part of the ventral horn. As a rule they were invaginated in the axon terminal which made the simultaneous synaptic contacts with them and with the basic trunk of dendrite. In the lateral parts of the V-VII laminae of the grey matter the dendritic branches were getting longer and more complex, the breaking forms and "crest" synapses appeared. There were some inclusions in the matrix which were probably the precursor of the spine apparatus and were called spine-like protrusions. Statistically authentic difference was determined between the size of the dendritic protrusions in the medial and lateral parts of the ventral horn grey matter.