[Morpho-functional changes in the frog sartorius muscle fibers during the winter].

The electrical characteristics, sensitivity to acetylcholine, structure of nerve terminals and SDH activity were studied in the fibers of frog's m. sartorius in winter and summer. The resting MP of muscle fibers remains unchanged through the year but passive electrical characteristics of muscle electrogenic membrane were changed. Sensitivity to acetylcholine increased two-fold in winter. Silver method revealed some degenerative signs in the neuro-muscular junctions during winter.