Competition between motor nerves in the establishment of neuromuscular junctions in striated muscles of Xenopus laevis.
After sectioning one of the two nerves of the pauci-innervated pectoralis muscle of Xenopus laevis, a sprouting of the intact nerve is observed in the denervated zone. On subsequent reinnvervation by the original nerve, dually innervated end-plates are found in which the quantal content of the responses to foreign nerve stimulation does not change significantly while that from the original nerve increases during the course of reinnervation. On the other hand, functional innervation from both the original and foreign nerves may persist in the same muscle fibre at separated end-plates. It is concluded that original axons depress foreign synapses by a local action.
Haimann
C
C
Unité de Physiologie Neuromusculaire, Laboratoire de Neurobiologie Cellulaire, CNRS, F-91190 Gif-sur-Yuette France.
Mallart
A
A
Zilber-Gachelin
N F
NF