[Quantitative relationship between neurons of a different mediator nature in the motor nuclei of the cat spinal cord cervical thickening].

A histochemical analysis of the neuronal composition of the motor nuclei was performed on the cat cervical spinal cord. Motoneurons were distinguished by the location of AChE in the perinuclear space, on the membranes of the granular reticulum, on the axolemma, neurofilaments and neurotubuli, in the synaptosomes and the synaptic cleft; this evidences for the perinuclear synthesis of this enzyme and its transport within the axoplasm. Their amount reached 40-65% of the whole neuronal population. AChE identification together with autoradiographic tracing of glycine showed that large cholinergic motoneurons are accompanied by small glycine-accumulating neurons with short processes which form axo-somatic and axo-dendritic contacts with large neurons. The cholinergic motoneurons have polyreceptive properties, as can be concluded from the presence of AChE and glycine-containing terminals on their soma and processes, as well as some noradrenergic and serotoninergic and many unidentified terminals.