02-16-2014, 11:25 PM
A 55-yrs-old man sees a neurologist because of weakness in his legs that improves over the course of
the day or with exercise. Extracellular electrical recordings from a single skeletal muscle fiber reveal normal miniature end-plate potentials. Low-frequency electrical stimulation of the motor neuron, however, elicits an abnormally small depolarization of the muscle fibers. The amplitude of the depolarization is increased after exercise.The molecular mechanism underlying these symptoms is most similar to which of the following?
A) Acetylcholine
B) Botulinum toxin
C) Curare
D) Neostigmine
E) Tetrodotoxin
the day or with exercise. Extracellular electrical recordings from a single skeletal muscle fiber reveal normal miniature end-plate potentials. Low-frequency electrical stimulation of the motor neuron, however, elicits an abnormally small depolarization of the muscle fibers. The amplitude of the depolarization is increased after exercise.The molecular mechanism underlying these symptoms is most similar to which of the following?
A) Acetylcholine
B) Botulinum toxin
C) Curare
D) Neostigmine
E) Tetrodotoxin