Differences among dystrophic, dwarf, and their crossbred mice in the time course of changes in extracellular muscle action potentials induced by 5-Hz stimulation.
With urethane anesthesia, extracellular action potentials were recorded in medial gastrocnemius muscles of dystrophic, dwarf, and their crossbred mice. When repetitive stimulation was delivered at 5 Hz for a relatively long period, characteristic features were revealed. (i) Dystrophic mice showed a slight decrease or even an increase in action potentials whereas in littermate normal mice the amplitudes were rapidly and notably reduced. (ii) In both dwarf and their littermate normal mice, a considerable reduction in amplitude was observed. Slightly more depression was produced than in nondystrophic mice of a comparable age. (iii) Crossbred mice were in two classes. A rapid and notable reduction in the amplitude of muscle action potentials was observed in one class, and slight changes in the potentials were produced in another class showing dystrophy-specific symptoms.
D000200:Action Potentials; D000818:Animals; D001947:Breeding / Q000379:methods; D004392:Dwarfism / Q000235:genetics / Q000503:physiopathology*; D004558:Electric Stimulation; D005110:Extracellular Space / Q000502:physiology; D051379:Mice / Q000235:genetics; D008817:Mice, Mutant Strains; D009132:Muscles / Q000503:physiopathology*; D009136:Muscular Dystrophies / Q000235:genetics / Q000503:physiopathology*; D013997:Time Factors