Activity-dependent modulation of developing neuromuscular synapses.
Spontaneous and impulse-evoked synaptic currents were observed immediately following nerve-muscle contact in Xenopus cell cultures. The functional significance of this early synaptic activity was examined. Stimulation of pre- and/or post-synaptic cells was found to exert immediate and persistent effects on the efficacy of synaptic transmission. Exogenous application of calcitonin gene-related peptide (CGRP) and neurotrophins, factors that may be coreleased with ACh in activity-dependent manner at the developing neuromuscular junctions, also modulate either the postsynaptic ACh response or presynaptic ACh release. These results underscore the plasticity of developing neuromuscular synapses and suggest a complex interplay between electrical activity and chemical factors during the formation and maturation of neuronal connections.
Department of Biological Sciences, Columbia University, New York, New York 10027.
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D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D002478:Cells, Cultured; D009414:Nerve Growth Factors / Q000502:physiology; D009469:Neuromuscular Junction / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology*; D013997:Time Factors
D009414:Nerve Growth Factors; D015740:Calcitonin Gene-Related Peptide; D000109:Acetylcholine