Observation of Velopharyngeal Closure Patterns following Isolated Stimulation of Levator Veli Palatini and Pharyngeal Constrictor Muscles

1996 ◽  
Vol 33 (4) ◽  
pp. 273-276 ◽  
Author(s):  
Mikihiko Kogo ◽  
Munehiro Hamaguchi ◽  
Tokuzo Matsuya
Keyword(s):  
Electrical Stimulation ◽  
Motor Nerve ◽  
Lateral Wall ◽  
Vertical Movement ◽  
Levator Veli Palatini ◽  
Velopharyngeal Closure ◽  
The Individual ◽  
Pharyngeal Constrictor Muscles ◽  
Peripheral Motor ◽  
Stimulation Of

This study, using mongrel dogs, showed the individual movements caused by the levator veli palatini muscle (LVP) and pharyngeal constrictor (PC) contraction, induced by electrical stimulation to each peripheral motor nerve. Each bilateral peripheral motor nerve of the LVP and PC muscles was isolated and stimulated electrically to induce the individual contraction of bilateral LVP and PC muscles. The movements were visualized by use of a fiberscope. Vertical movement of the middle soft palate was observed mainly at LVP contraction. Circular closure in the posterior region of the velopharynx was induced by contraction of the PC muscle. The posterior and lateral wall movements clearly occurred following PC contraction.

ATP concentrations and muscle tension increase linearly with muscle contraction

2003 ◽  
Vol 95 (2) ◽  
pp. 577-583 ◽  
Author(s):  
Jianhua Li ◽  
Nicholas C. King ◽  
Lawrence I. Sinoway
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscle Contraction ◽  
Motor Nerve ◽  
Muscle Tension ◽  
Nerve Fibers ◽  
Ventral Root ◽  
Ventral Roots ◽  
Root Stimulation ◽  
Stimulation Of

Previous studies have suggested that activation of ATP-sensitive P2X receptors in skeletal muscle play a role in mediating the exercise pressor reflex (Li J and Sinoway LI. Am J Physiol Heart Circ Physiol 283: H2636–H2643, 2002). To determine the role ATP plays in this reflex, it is necessary to examine whether muscle interstitial ATP (ATPi) concentrations rise with muscle contraction. Accordingly, in this study, muscle contraction was evoked by electrical stimulation of the L7 and S1 ventral roots of the spinal cord in 12 decerebrate cats. Muscle ATPi was collected from microdialysis probes inserted in the muscle. ATP concentrations were determined by the HPLC method. Electrical stimulation of the ventral roots at 3 and 5 Hz increased mean arterial pressure by 13 ± 2 and 16 ± 3 mmHg ( P < 0.05), respectively, and it increased ATP concentration in contracting muscle by 150% ( P < 0.05) and 200% ( P < 0.05), respectively. ATP measured in the opposite control limb did not rise with ventral root stimulation. Section of the L7 and S1 dorsal roots did not affect the ATPi seen with 5-Hz ventral root stimulation. Finally, ventral roots stimulation sufficient to drive motor nerve fibers did not increase ATP in previously paralyzed cats. Thus ATPi is not largely released from sympathetic or motor nerves and does not require an intact afferent reflex pathway. We conclude that ATPi is due to the release of ATP from contracting skeletal muscle cells.

scholarly journals Electrical stimulation of C2C12 myotubes induces contractions and represses thyroid-hormone-dependent transcription of the fast-type sarcoplasmic-reticulum Ca2+-ATPase gene

1997 ◽  
Vol 321 (3) ◽  
pp. 845-848 ◽  
Author(s):  
Marc H. M. THELEN ◽  
Warner S. SIMONIDES ◽  
Cornelis van HARDEVELD
Keyword(s):  
Electrical Stimulation ◽  
Thyroid Hormone ◽  
Sarcoplasmic Reticulum ◽  
Contractile Activity ◽  
Motor Nerve ◽  
C2c12 Myotubes ◽  
Transcriptional Level ◽  
Regulation Of Expression ◽  
Atpase Gene ◽  
Stimulation Of

Chronic low-frequency contraction of skeletal muscle, either induced by a slow motor nerve or through direct electrical stimulation, generally induces expression of proteins associated with the slow phenotype, while repressing the corresponding fast isoforms. Contractions thereby counteract the primarily transcriptional effect of thyroid hormone (T3), which results in the selective induction and stimulation of expression of fast isoforms. We studied the regulation of expression of the fast-type sarcoplasmic-reticulum Ca2+-ATPase (SERCA1), a characteristic component of the fast phenotype. Previous work suggested that reduction of SERCA1 expression by contractile activity might result from interference with the T3-dependent transcriptional stimulation of the SERCA1 gene. The present study was set up to test this unexpected mode of action of contractile activity. We show that electrical stimulation of C2C12 mouse myotubes, which results in synchronous contractions at the imposed frequency, reduces basal but virtually abolishes T3-dependent SERCA1 expression. T3-dependent expression of a reporter gene driven by the SERCA1 promoter was similarly affected by electrical stimulation. This is the first demonstration that the counteracting effects on muscle gene expression of electrically induced contractions and T3 may interact at the transcriptional level.

The co-ordination of the protective retraction of coral polyps

1957 ◽  
Vol 240 (675) ◽  
pp. 495-529 ◽  
Keyword(s):  
Electrical Stimulation ◽  
Electrical Stimulus ◽  
Simple Theory ◽  
Conducting System ◽  
Common Theme ◽  
Single Shock ◽  
Working Model ◽  
Successive Stimulus ◽  
The Individual ◽  
Stimulation Of

The responses to electrical stimulation of a number of alcyonarian, zoanthid and madreporarian corals are described. All groups studied except gorgonids show extensive coordination over the colony. In Sarcophyton (Alcyonacea) the response is typically local at first but eventually a wave of polyp retraction can be made to spread over the colony. The astraeid corals and the alcyonarian Tubipora have over the whole colony a through-conducting system which has refractory and neuromuscular properties similar to those found in the mesenteries of actinians. In the zoanthid Palythoa successive shocks produce excitation which spreads progressively farther across the colony at each shock for as many as fifty shocks at two-second intervals. The perforate corals , Acropora, Goniopora and Porites respond to a single shock by a co-ordinated retraction of many polyps. Except in Acropora , it is characteristic of the perforate corals studied that stimulation at one point never spreads over the whole colony no matter how many stimuli are applied. The responses of the individual polyps of many corals, including Fungia , are described, and in all there is a similarity to the column, disk and tentacle responses already known in actinians, e.g. Calliactis . The concept of interneural facilitation has been analyzed by use of a working model which shows that the simple theory is inadequate as an explanation of transmission between polyps of certain species because the predicted transmission distances are either too variable or too small compared with the actual distances observed at the first electrical stimulus of the animal. The properties of the co-ordinating systems between the polyps of the various groups of corals have been considered as variations on a common theme, conduction between units which form a network. The various stages from poor co-ordination, through progressive spread at each successive stimulus, to a through-conducting condition have been interpreted as a reflexion of increasing probability of transmission from one all-or-nothing unit of the pathway to the next unit in a population of a large number of units, only a proportion of which may be active at any one time. The units may be interpreted as neurones, as is probable in parts of a single polyp, or as small regions such as polyps within which there is normally through-conduction at the first stimulus.

scholarly journals Radiocalcium Release by Stimulated and Potassium-Treated Sartorius Muscles of the Frog

1960 ◽  
Vol 43 (3) ◽  
pp. 481-493 ◽  
Author(s):  
A. M. Shanes ◽  
C. P. Bianchi
Keyword(s):  
Electrical Stimulation ◽  
Time Course ◽  
Rana Pipiens ◽  
Calcium Release ◽  
Sartorius Muscle ◽  
Entry And Exit ◽  
Potassium Depolarization ◽  
Rate Of Escape ◽  
The Individual ◽  
Stimulation Of

Stimulation of frog (Rana pipiens) sartorius muscle accelerates release of Ca45, but only during the period of stimulation. No appreciable difference is obtained in the calcium released per impulse whether stimulation is at a rate of 20/sec. or 0.5/sec. However, prior stimulation may appreciably increase the loss per impulse. In unfatigued muscles, the minimum amount of calcium liberated during an isotonic twitch is estimated to be about that previously calculated to enter, viz. 0.2 µµmole/cm2. The time course of radiocalcium release during potassium depolarization depends on the nature of the contracture. When contracture is isometric, the rate of escape is doubled and declines only slowly; if isotonic, the rate is quadrupled but declines in a few minutes to a level maintained at about double that before potassium. The minimal calcium release during the first 10 minutes of potassium treatment is estimated to be about the same in both cases and about one-half to one-third the uptake. This, and especially the close equality of calcium entry and exit during electrical stimulation, are pointed out as not necessarily inconsistent with a transitory net entry of calcium, comparable to the influx, into restricted regions of the individual fibers.

Results of stimulation and destruction of the posterior hypothalamus in man

1970 ◽  
Vol 33 (6) ◽  
pp. 689-707 ◽  
Author(s):  
Keiji Sano ◽  
Yoshiaki Mayanagi ◽  
Hiroaki Sekino ◽  
Motohide Ogashiwa ◽  
Buichi Ishijima
Keyword(s):  
Electrical Stimulation ◽  
Third Ventricle ◽  
Violent Behavior ◽  
Lateral Wall ◽  
Posterior Hypothalamus ◽  
Content Type ◽  
Theta Waves ◽  
Fine Print ◽  
Stimulation Of

✓ Autonomic and somatomotor responses to electrical stimulation of the posterior hypothalamus are reported in 51 patients with pathologically aggressive behavior. The stimulated area causing rise in blood pressure, tachycardia, and maximal pupillary dilatation lies in the posteromedial hypothalamus, more than 1 mm and less than 5 mm lateral to the lateral wall of the third ventricle, occupying a triangle formed by the midpoint of the intercommissural line, the rostral end of the aqueduct, and the anterior border of the mammillary body. Electrical stimulation of this (ergotropic) triangle resulted in desynchronization of the electroencephalogram (EEG) with hippocampal theta waves, or diffuse irregular delta waves of high voltage. Cases with violent behavior showed higher plasma levels of non-esterified fatty acids (NEFA) in the fasting stage; these were markedly elevated by electrical stimulation of the ergotropic triangle. Points in the ergotropic triangle where signs of sympathetic discharge were most marked were electrocauterized bilaterally. This procedure produced marked calming effects (95% of the cases) during the follow-up period of more than 2 years. Postoperatively there was a tendency to a decrease in sympathicotonia or an increase in parasympathicotonia. The follow-up plasma level of NEFA was found to have decreased to approximately the normal value.

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