TY - JOUR
T1 - Effects of motor unit size on innervation patterns in neonatal mammals
AU - Bixby, John L.
AU - Maunsell, John H.R.
AU - Van Essen, David C.
N1 - Funding Information:
Abbreviations: EDL-extensor digitorum longus, HRP-horseradish peroxidase. ’ We thank Eric Frank and A. J. Hudspeth for helpful advice, and Elizabeth Hanson for typing the manuscript. This work was supported by National Institutes of Health grant BRSG RR07003. Dr. Bixby’s present address is Department of Biology, University of California, San Diego, La Jolla, CA 92093.
PY - 1980/12
Y1 - 1980/12
N2 - Different muscles in neonatal rabbits differ with respect to the extent of multiple innervation and the rate of synapse elimination. Counts were made of both α-motor neurons (using retrograde transport of horseradish peroxidase) and muscle fibers for each of three rabbit muscles, to see whether the differences between muscles in the degree of multiple innervation and/or the rate of synapse elimination were related to the motor neuron:muscle fiber ratio (the innervation ratio). The results suggest that individual motor neurons from muscles with a 10-fold range of muscle fiber number tend initially to establish a similar number of synapses, which results in different degrees of multiple innervation among muscles. The rate of synapse elimination in a muscle, however, does not appear to depend on the innervation ratio.
AB - Different muscles in neonatal rabbits differ with respect to the extent of multiple innervation and the rate of synapse elimination. Counts were made of both α-motor neurons (using retrograde transport of horseradish peroxidase) and muscle fibers for each of three rabbit muscles, to see whether the differences between muscles in the degree of multiple innervation and/or the rate of synapse elimination were related to the motor neuron:muscle fiber ratio (the innervation ratio). The results suggest that individual motor neurons from muscles with a 10-fold range of muscle fiber number tend initially to establish a similar number of synapses, which results in different degrees of multiple innervation among muscles. The rate of synapse elimination in a muscle, however, does not appear to depend on the innervation ratio.
UR - http://www.scopus.com/inward/record.url?scp=0019192839&partnerID=8YFLogxK
U2 - 10.1016/0014-4886(80)90178-8
DO - 10.1016/0014-4886(80)90178-8
M3 - Article
C2 - 6160045
AN - SCOPUS:0019192839
SN - 0014-4886
VL - 70
SP - 516
EP - 524
JO - Experimental Neurology
JF - Experimental Neurology
IS - 3
ER -