title: [Sequential maturation of skeletal muscle groups during postnatal ontogenesis of rats].
abstract: Experiments were conducted on rats during the early postnatal period; a study was made of the membrane potential (MP) establishment of the fibers of the skeletal muscles of the neck, the anterior and the posterior limbs. At birth the most mature were the muscles of the neck, and the least -- the muscles of the posterior limb. Establishment of the stationary MP level in the muscles of the neck occurred during the first week after birth, in the muscles of the anterior limbs -- by the 10th-12th day, and of the posterior limbs -- by the 15th-20th day. The order of maturation of various groups of the skeletal muscles was associated with the peculiarities of the neuro-trophic influences at various age periods. Muscles of the neck were characterized at all the developmental stages by a rhythmic low-frequency electromyographic activity. In the muscles of the limbs the rhythmic electromyographic activity was transformed into the discharge high-frequency activity by the period of termination of increase of the MP of the muscles.
mesh_terms: D000818:Animals; D004576:Electromyography; D005552:Forelimb; D006614:Hindlimb; D008564:Membrane Potentials; D024510:Muscle Development; D009333:Neck; D051381:Rats
vernacular_title: O posledovatel'nosti sozrevaniia razlichnykh grupp skeletnykh myshts u krys v postnatal'nom ontogeneze