at the neuromuscular junction, an electrical signal from the motor neuron is translated to a chemical signal and then back to an electrical signal in the muscle cell. what proteins interact with the released chemical to cause the electrical signal in the muscle cell?

The rate that would change would be the  searching efficiency/attack rate. there are only two other rates in this model: the  growth rate of prey, and the  predator or consumer mortality rate.the  searching efficiency/attack rate is what indicates how effectively can a predator capture its prey whether in the searching process or actual capturing/attacking process. 

Cell wall permeability changes and sodium rushes into the cell.