In an experiment, a frog neuromuscular preparation had been processed with a curare-like substance, which led to the disappearance of muscle contractions in response to electrical stimulation. What function of the muscle cell membrane is disrupted by curare-like substance?

Answer options

1. Change in permeability for different substances
2. Creation of the electric potentials on the both sides of the membrane.
3. Maintenance of the internal cell structure, its cytoskeleton
4. Reception of the mediators in the neuromuscular synapse
5. Creation of a barrier between the intracellular environment and surrounding intercellular fluid