Cortical projections to brain stem and spinal cord in the goat by way of the pyramidal tract and the bundle of Bagley

Abstract

In this paper the cortical fibers in the brain stem of the goat are studied. The preparations were stained according to the method of Nauta‐Gygax. It was proved that the fibers descend both through the pyramidal tract and Bagley's corticotegmental tract. The latter terminates in the ipsilateral trigmidal spinal tract nucleus and the lateral part of the reticular formation of the medulla, but pyramidal fibers do not terminate in the first nucleus. At the transition of the medulla and the cord three pyramidal tracts, all consisting of both direct and crossed cortical fibers enter the cord, whereas in all probability the fibers of Bagley's tract do not reach the cord. A ventral intercommissural tract carries the majority of the fibers, it reaches the seventh cervical segment. A small lateral tract in the lateral funiculus and a dorsal in the dorsal funiculus reach the third and the second cervical segments. The site of origin of Bagley's tract appeared to be identical to that of the medullary pyramid.