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.
ASJC Scopus subject areas
- Developmental Neuroscience