CHRNA4 and Paralysis: The effects of levamisole on motility are time- and concentration-dependent and characterized by the initial spastic paralysis phase (< 20 min) due to the opening of nAChR channels on body muscle; this is followed by a phase of flaccid paralysis as the body muscles relax (from the end of spastic paralysis to < 4 h), despite elevated cytosolic calcium levels, and AChR channel desensitization.