The effect of denervation on subsequent in vitro induction of myotonia

In order to study the influence of innervation on myotonia, an attempt was made to induce myotonia in previously denervated rat hemidiaphragm preparations in vitro with use of 2,4-dichlorophenoxy acetic acid (2,4-D) and low chloride solutions. Prior denervation prevented the onset of myotonia in both media except during the first 24 hours after nerve section. On the basis of already available data, we propose that the reduced potassium conductance accompanying denervation may be the main factor preventing induciton of myotonia in denervated muscle.