A clonal cell line derived from a mouse neoplasm is described which shares many properties with smooth muscle. The cells have electrically excitable membranes capable of generating overshooting action potentials, and they contract both spontaneously electrical stimulation. They respond to the iontophoretic application acetylcholine depolarizing response, norepinephrine hyperpolarizing response. Electron microscopy reveals that morphology similar in many, but not all, respects muscle vivo....

1. Botulinum toxin type D blocks neuromuscular transmission in frogs. Motor nerve impulses continue to invade the terminals but cease evoke phasic release of transmitter normally associated with them.2. Sensory receptors muscle generate even after 4 days continuous exposure botulinum toxin.3. Contrary expectations, spontaneous miniature end-plate potentials did not disappear completely intoxication; they still occurred, although reduced frequency, most end-plates. These had a skew amplitude...

Synaptic transmission has been analysed in parasympathetic nerve cells that lie the transparent interatrial septum of heart frog. Using Nomarski interference optics, one can see much cellular detail, including synaptic boutons living preparations. 1. On each ganglion cell, 10 to 20 are usually derived from a single vagal fibre. These fibres branch extensively innervate number septal cells. 2. The chemical transmitter, acetylcholine (ACh), liberated by presynaptic impulse survives for up 40...

ABSTRACT The expression of myosin isoforms was studied during development calf muscles in foetal and neonatal rats, using monoclonal antibodies against slow, embryonic heavy chain (MHC). Primary myotubes had appeared all prospective rat by day 16 (E16). On both E16 E17, primary with the exception soleus stained for MHC isoforms; did not express MHC. In earlier stages muscle formation staining isoform absent or faint. Secondary were present E18, these MHCs, but slow. mixed muscles, destined...

Action potentials resulted from iontophoretic application of acetylcholine to cloned mouse neuroblastoma cells maintained in culture. Cell bodies were sensitive acetylcholine, but half the insensitive along one their processes, suggesting an analogy with normal axons and dendrites. Some electrically coupled via no chemically mediated synaptic transmission was seen.

Individual rat embryos were chronically paralysed during development in utero by insertion of small slow-release capsules containing tetrodotoxin (TTX). In others, motoneurons destroyed individual injections P-bungarotoxin (P-BTX). These compared with normal controls so that the effects innervation and use on embryonic skeletal muscles could be defined. The Sirius Red to stain muscle basal lamina made it possible count units (one or more myotubes contained within a single sheath) light...

This paper describes a procedure for identifying mass and stiffness imperfections present in microring gyroscope. In general will be as result of fabrication variances contribute to mistuning the Both are treated perturbations ideal isotropic stiffness. The combined form structural imperfection, which is shown determinable from Nyquist plots frequency response functions. An analysis electrostatic "tuning" presented demonstrates that nonlinear negative spring component produced particular...

MyoD belongs to a family of helix-loop-helix proteins that control myogenic differentiation. Transfection various non-myogenic cell lines with transforms them into cells. In normal embryonic development is upregulated at the time when hypaxial musculature begins form, but its role in function adult muscle remains be elucidated. this study we examined cellular locations protein and abnormal muscles see whether presence correlated particular behaviour assess usefulness as marker for satellite...

ABSTRACT Numbers of myoblasts, primary myotubes and secondary in developing rat embryo hindlimb IVth lumbrical muscles were counted at daily intervals up until the time birth, using electron mi-croscopy. Motoneurone death spinal cord level supplying lumbricals was assessed by counting axons 4th lumbar ventral root. Death motoneurones that supply intrinsic hindfoot monitored comparing timecourse development total muscle choline acetyltransferase activity control embryos with where motoneurone...

Chronic paralysis of rat embryos during the last 4 to 6 prenatal days causes a diminution in skeletal muscle fiber numbers but inhibits motoneuron death. Consequently, as paralyzed muscles develop, an increased number motoneurons attempts form synapses at reduced synaptic sites. Paralyzed fibers receive their single endplate, control muscles, these endplates are hyperinnervated, with about twice normal inputs. Counts axons, inputs, and units showed that normally contact maximum shortly...

Myotubes were isolated from enzymically disaggregated embryonic muscles and examined with light microscopy. Primary myotubes seen as classic chains of central nuclei within a tube myofilaments, whereas secondary had smaller diameter more widely spaced nuclei. could also be distinguished by their specific reaction two monoclonal antibodies (MAbs) against adult slow myosin heavy chain (MHC). Myonuclei birth dated [3H]thymidine autoradiography or 2-bromo-5'-deoxyuridine (BrdU) detected...

ABSTRACT The distribution of secondary myotubes and undifferentiated mononucleated cells (presumed to be myoblasts) within foetal IVth lumbrical muscles the rat was analyzed with serial section electron microscopy. In all myotube clusters for which innervation zone located, every overlapped endplate region primary myotube. No were ever demonstrated occur at a distance from zone. This indicates that new begin form only in muscle. Some young made direct contact nerve terminal, but we cannot...

The generation and development of muscle cells in the IVth hindlimb lumbrical rat was studied following total or partial denervation. Denervation carried out by injection beta-bungarotoxin (beta-BTX), a neurotoxin which binds to destroys peripheral nerves. Primary myotubes were generated denervated muscles reached their normal stable number on embryonic day 17 (E17). This not maintained examined E19 E21 contained many degenerating primary myotubes. Embryos injected with (beta-BTX) E12 E13...

1. The vagosympathetic trunks innervating the heart of frog were cut on both sides. Two to 28 days following this denervation chemosensitivity surface denervated neurons was explored with iontophoretic microapplication ACh restricted areas. 2. While in normally innervated synaptic areas alone are highly chemosensitive, after whole cell becomes sensitive ACh. Synaptic transmission fails second day (30 40 h) (in frogs kept at 22 24 °C) and same time new chemoreceptive start appear. After 4 8...

1. The chemosensitivity of the surface parasympathetic neurons in interatrial septum heart frog has been explored by focal iontophoretic application acetylcholine (ACh). 2. There is a specific highly chemosensitive area on cell near synaptic boutons. ACh released close to visually identified boutons produced depolarizing responses which arise more rapidly and are larger than evoked at randomly chosen spots neuronal surface. 3. Individual synapses, or small numbers them, can be desensitized...

The eupolypods II ferns represent a classic case of evolutionary radiation and, simultaneously, exhibit high substitution rate heterogeneity. These factors have been proposed to contribute the contentious resolutions among clades within this fern group in multilocus phylogenetic studies. We investigated deep relationships eupolypod by sampling all major families and using 40 plastid genomes, or plastomes, which 33 were newly sequenced with next-generation sequencing technology. performed...