Dendro-dendritic connections between motoneurons in the rat spinal cord

The ultrastructural characteristics of identified dendrite bundles in the rat spinal cord were analyzed following retrograde tracing from the soleus muscles. Dendrite bundles are arranged in networks that an heavily interconnected by means of gap junctions. The bundles are formed by at least 10 crossing dendrites travelling in different focal planes. In between dendrites, elongated gap junctional complexes are frequently found. Dendrite lamellar bodies, recently described to occur in relation with gap junctions in the central nervous system were not observed in the present study. (C) 1998 Elsevier Science B.V.