Effects of impulse blockade on the contractile properties of rat skeletal muscle.

1. Pressure was used to produce a localized block of impulse conduction in motor nerve fibres supplying rat plantaris and soleus muscles. After 1 week of inactivity both muscles exhibited marked atrophy of type I and type II muscle fibres. 2. In treated plantaris and soleus muscles the specific tetanic tensions were reduced to approximately half those of untreated control muscles; the specific twitch tensions were unchanged. The fall in …