The dorsal column fiber pathways are beginning to show gray mater regions forming nuclei that are the ascending sensory fiber targets. The descending tract and nuclei of the 5th nerve are the most transparent structures, laterally. Ventrally, the pyramids are crossing the midline to give rise to the lateral cortical spinal tract. The ventral horns are widely separated.

• The dorsal column fiber pathways are beginning to show gray mater regions forming nuclei that are the ascending sensory fiber targets. The descending tract and nuclei of the 5th nerve are the most transparent structures, laterally. Ventrally, the pyramids are crossing the midline to give rise to the lateral cortical spinal tract. The ventral horns are widely separated.