The leaching of electrolytes in normal and denervated chick gastrocnemius muscle has been studied by recording electroconductivity changes in donor-solvent (muscle-water) system at 11 intervals leading to a total immersion of 5 hr 15 min, at days 1,5,10,21 and 28, post-hatching. The results show age related changes in the permeability properties of normal muscle membrane system. The loss of neural control induces a blocking of electrolytes 10 days post-denervation. The possible nature of blocking mechanism has been related to the non-availability of neuro-trophic factors in the tissue.