Rostrocaudal distribution of motoneurones and variation in ventral horn area within a segment of the feline thoracic spinal cord.
Retrograde transport of horseradish peroxidase, applied to cut peripheral nerves, was used to determine the rostrocaudal distribution of motoneurones supplying different branches of the ventral ramus for a single mid- or caudal thoracic segment in the cat. The motoneurones occupied a length of spinal cord equal to the segmental length but displaced rostrally from the segment as defined by the dorsal roots, with the number of motoneurones per unit length of cord higher in the rostral part of a segment (close to the entry of the most rostral dorsal root) than in the caudal part. The cross-sectional area of the ventral horn showed a rostrocaudal variation that closely paralleled the motoneurone distribution. The ratio between the number of motoneurones per unit length in the caudal and rostral regions of a segment (0.70) was similar to the ratio previously reported for the strength of functional projections of expiratory bulbospinal neurones (0.63). This is consistent with the motoneurones being the main targets of the bulbospinal neurones.
Meehan
Claire F
CF
Sobell Department for Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London WC1N 3BG, United Kingdom.
Ford
Tim W
TW
Road
Jeremy D
JD
Donga
Revers
R
Saywell
Shane A
SA
Anissimova
Natalia P
NP
Kirkwood
Peter A
PA
D000344:Afferent Pathways / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D000870:Anterior Horn Cells / Q000166:cytology* / Q000378:metabolism; D002415:Cats; D005260:Female; D006652:Histological Techniques / Q000379:methods; D006735:Horseradish Peroxidase / Q000378:metabolism; D007796:Laminectomy / Q000379:methods; D008297:Male; D009046:Motor Neurons / Q000166:cytology* / Q000378:metabolism; D013116:Spinal Cord / Q000166:cytology* / Q000378:metabolism; D013900:Thoracic Nerves / Q000502:physiology
D006735:Horseradish Peroxidase