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Neuromuscular Junction Development In The Cutaneous Pectoris Muscle Of Rana Catesbeiana, Diana Linden, Susan Jerian, Michael Letinsky
Neuromuscular Junction Development In The Cutaneous Pectoris Muscle Of Rana Catesbeiana, Diana Linden, Susan Jerian, Michael Letinsky
Diana Linden
Synaptic specializations were studied in the developing cutaneous pectoris muscle of Rana catesbeiana tadpoles and froglets to correlate nerve terminal morphology (by light and electron microscopy), accumulation of acetylcholine receptors, and the ability of the muscle to contract following nerve stimulation. This correlated approach was used to determine the developmental timing and possible causal relationship of events in nerve and muscle maturation at the neuromuscular junction. Initially, the cutaneous pectoris nerve trunk was present in the undifferentiated presumptive cutaneous pectoris mesenchyme, prior to muscle maturation. At stage XII when the muscle was first able to contract weakly in response to …
Correlated Muscle And Nerve Development In The Bullfrog Cutaneous Pectoris, Diana Linden, Michael Letinsky
Correlated Muscle And Nerve Development In The Bullfrog Cutaneous Pectoris, Diana Linden, Michael Letinsky
Diana Linden
The development of the cutaneous pectoris muscle was studied and compared with the differentiation of its peripheral nerve in bullfrog (Rana catesbeiana) tadpoles and frogs by light and electron microscopic techniques. This muscle preparation was chosen for this study because it possesses a number of advantages for (and has become a model system for) the study of correlated nerve-muscle development. At the earliest stage examined (stage XI) the presumptive muscle did not contain any contractile or morphologically distinguishable myotubes, but was contacted by the well-defined cutaneous pectoris nerve trunk. Myotubes were present at stage XII, the same time that nerve-associated …
Rapid Decline In Acetylcholine Release And Content Of Rat Extensor Digitorum Longus Muscle After Denervation, Diana Linden, Michael Newton, Alan Grinnell, Donald Jenden
Rapid Decline In Acetylcholine Release And Content Of Rat Extensor Digitorum Longus Muscle After Denervation, Diana Linden, Michael Newton, Alan Grinnell, Donald Jenden
Diana Linden
The amount of acetylcholine (ACh) and choline (Ch) in normal and denervated rat extensor digitorum longus (EDL) muscles, as well as that released spontaneously from these muscles, was determined by an extremely sensitive gas chromatographicmass spectrometric assay method. We found decreases in ACh content and spontaneous, resting ACh release as early as 8 h after denervation. The ACh content decreased to a plateau of 30% of control by 11 h; ACh release attained a plateau of 50% of control several hours later. These results showed that in denervated EDL muscles ACh content and spontaneous release (measured biochemically) decreased before nerve-evoked …
Biosynthesis And Degradation Of Acetylcholine Receptors In Rat Skeletal Muscles. Effects Of Electrical Stimulation, Diana Linden, D.M. Fambrough
Biosynthesis And Degradation Of Acetylcholine Receptors In Rat Skeletal Muscles. Effects Of Electrical Stimulation, Diana Linden, D.M. Fambrough
Diana Linden
Synthesis and degradation of acetylcholine receptors in rat skeletal muscles were measured in organ culture. The rate of de novo biosynthesis and incorporation of acetylcholine receptors into extrajunctional membranes of denervated muscles was measured by determining the rate of appearance of [1] [2H, 13C, 15N]-acetylcholine receptors when muscles were cultured in medium containing [1] [2H, 13C, 15N]-amino acids. Denervated extensor digitorum longus and soleus muscles were found to synthesize new receptors for several days in organ culture at an average rate of 1.4%/h. The degradation rates for extrajunctional and junctional acetylcholine receptors were estimated by irreversibly labeling acétylcholine receptors on …