[The ultrastructural characteristics of the sensorimotor synapses in the amphibian spinal cord].

The present electron microscopic study aims to analyse sensomotor synapses ultrastructural peculiarities in part deafferentation and neuroplasmic transport to horse-radish peroxidase through the sectioned dorsal radix. Three zones of primary afferent fibres endings, including motor nuclear zone were found in the amphibian spinal cord. The data obtained demonstrated the probability of both chemical and combined (electrochemical, mostly of axodendritic type) origin of synapses, formed by primary afferent fibres on motor neurons somato-dendritic membrane. Complex synapses are likely to acquire peculiar importance in deafferentation. These data correlate with microphysiological research on amphibians sensomotor synaptic contacts.