Gap junctions between lateral spinal motoneurons in the rat.

Ultrastructural examination reveals gap junctional plaques between motoneurons in the dorsolateral nucleus (DLN), an androgen-sensitive motor nucleus in the lumbar spinal cord of rats. This nucleus contains motoneurons innervating the ischiocavernosus muscle and urethral sphincter. Gap junctional plaques were found along the somatic and proximal dendritic membranes of DLN motoneurons, and between membranes of bundled dendrites in the neuropil of this nucleus. Castration and androgen treatment had no significant effect on the size or frequency of gap junctions.