Integration in descending motor pathways controlling the forelimb in the cat

摘要

Short cervical propriospinal neurones projecting to cat forelimb segments were identified and compared in their longitudinal segmental location and transverse distribution with a propriospinal relay recently described in C3–C4 with electrophysiological methods (Illert et al., 1977, 1978). Localized horseradish peroxidase injections into the C6–C7 forelimb motornuclei demonstrated propriospinal cells in rostral cervical segments. The multiple injection technique in combination with control experiments seemed to allow delimitation of the uptake region in the ventral horn responsible for the retrograde cell labelling. Injections laterally in the ventral horn labelled propriospinal neurones ipsilaterally in C3–C5, mainly in the lateral parts of laminae VI and VII. More medially located injections labelled cells with a similar distribution ipsilaterally, but contralateral cells were found in addition. They were located in laminae VII and VIII of the C2–C5 segments, mainly m