title: Projections of the superior colliculus to the supraspinal nucleus and the cervical spinal cord gray of the cat.
abstract: Anterograde transport experiments reveal two novel findings regarding the distribution of descending tectofugal axons. First, such axons project to the supraspinal nucleus of the caudal medulla; this nucleus is known to project to the upper cervical spinal cord gray. Second, some tectospinal axons ramify within Rexed's lamina IX of the first 5 cervical spinal cord segments. This zone contains motoneurons which innervate neck musculature. Retrograde data reveal that tectospinal neurons occur in clusters within the intermediate and deep gray layers. A close relationship between the clusters of tectospinal neurons and a modular type of connectional organization of the intermediate and deep gray layers is suggested.
mesh_terms: D000818:Animals; D001370:Axonal Transport; D002415:Cats; D004525:Efferent Pathways / Q000502:physiology*; D006735:Horseradish Peroxidase; D008526:Medulla Oblongata / Q000502:physiology; D013116:Spinal Cord / Q000502:physiology*; D013477:Superior Colliculi / Q000033:anatomy & histology / Q000502:physiology*
chemical_list: D006735:Horseradish Peroxidase