BZ]Dendro dendritic and dendro somatic projections are common between spinal motoneurons. We attempted to clarify whether there are functional connections through these projections. Methods. Motoneurons were antidromically stimulated by the muscle nerve and recorded intracellularly to examine the direct interaction between them

after the related dorsal roots had been cut. Results. Excitatory connections

demonstrated by depolarizing potentials in response to muscle nerve stimulation

were found between motoneurons innervating the same muscle or synergistic muscles

but never between motoneurons innervating antagonistic muscles. These potentials were finely graded in response to a series of increasing stimuli and resistant to high frequency （50Hz） stimulation. Conclusions.These results indicate that excitatory connections

with certain specificity of spatial and temporal distribution

occur in the spinal motoneurons. It is also suggested that electrical coupling should be involved in these connections and this mechanism should improve the excitability of the motoneurons in the same column.