Localization of the Motoneurons Innervating the Hindlimb Muscles in the Spinal Cord of the Domestic Fowl

The origins of the motor nerve fibers supplying the individual hindlimb muscles were elucidated in the fowl by the retrograde degeneration method. Chromatolytic cells were seen in the ipsilateral lamina 9 of the lumbosacral enlargement. Motoneurons innervating the individual hindlimb muscles were localized in the characteristic position of lamina 9. Both hip and thigh muscles are supplied by motoneurons of almost all the columns in lumbar segments and by those of dorsolateral columns in sacral segments, while the shank and foot muscles are supplied by motoneurons of ventromedial columns in sacral segments. The origins of the dorsal cord of the lumbosacral plexus are situated laterally in the lamina 9 and those of the ventral cord are located medially in it.