Safety factor for neuromuscular transmission at type-identified diaphragm fibers.
The safety factor (SF) for neuromuscular transmission varies across limb muscles of different fiber-type composition. Using intracellular recordings in rat diaphragm fibers, we found that SF varies across muscle fiber types (even within a single muscle), being larger for type IIx or IIb fibers than for type I or IIa fibers. Fiber-type differences in activation history or mechanical load may contribute to differences in SF and are important determinants of neuromuscular plasticity.
Ermilov
Leonid G
LG
Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, 200 First Street SW, Joseph 4-184W, Rochester, Minnesota 55905, USA.
Mantilla
Carlos B
CB
Rowley
Katharine L
KL
Sieck
Gary C
GC
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D003964:Diaphragm / Q000294:innervation* / Q000502:physiology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D008297:Male; D009046:Motor Neurons / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D018763:Muscle Fatigue / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000502:physiology; D009469:Neuromuscular Junction / Q000502:physiology*; D010791:Phrenic Nerve / Q000502:physiology*; D017729:Presynaptic Terminals / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission / Q000502:physiology*