• The Korean Journal of Physiology
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• 제4권2호
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• pp.19-24
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• 1970

Since the discovery of the muscle spindle by Hassall (1831), an intensive studies of its anatomical and physiological characteristics had been undertaken. Recent morphological studies of Boyd (1962) demonstrated that the muscle spindles have two different intrafusal muscle fibers, nuclear bag and nuclear chain fiber, and these intrafusal fibers are under independent motor innervation by ${\gamma}_1$ and ${\gamma}_2$ motor neurone. Neurophysiological studies of Hunt and Kuffler (1951) showed regulatory effect of ${\gamma}$ motor neurone upon the excitability of the spindle afferents. Harvey and Mathews (1961) observed the dynamic and static characteristics of the two different spindle afferents, the primary and secondary ending. Furthermore, Mathews (1962) postulated the functional existance of two kind of ${\gamma}$ motor neurones, namely, the dynamic and static fusimotor fiber. Recent report of Kim and Partridge(1969) pointed out that the descending vestibular signals had increased the slope of the length-tension relationship in stretch reflex; Kim (1967) demonstrated that the descending vestibular impulses act upon the stretch reflex loop through the ${\gamma}$ motor pathway. These experimental evidences from the morphological and neurophysiological studies on the muscle spindles support the concept that the stretch reflex action of the skeletal muscle operates as a negative feedback control system. The author had discussed the way by which the f system participates in the control of stretch relfex feed back system. that was taken for a prototype of posture and movement.

• The Korean Journal of Physiology
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• 제7권1호
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• pp.49-51
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• 1973

Denuded nerve fibers containing the node of Ranvier were prepared from the nerve innervating the gastrocnemius muscle of the frog. The effects of temperature rise of the medium surrounding the naked nerve fibers were studied upon the muscle response. A rise in temperature of the order of $50^{\circ}{\sim}90^{\circ}C$ was proved ineffective in the production of contractions in the muscle. It is thus concluded that the widespread concept that heating is one of the nerve stimuli is inadequate, and that thermal pain is the indirect effect of thermal stimuli. The authors' standpoint about thermal stimulus is that thermal stimulus or heating is one thing, cooling is another.

• 대한본초학회지
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• 제23권2호
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• pp.159-168
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• 2008

Objectives : The present study has been undertaken to investigate the effects of Dipsaci Radix on Muscle Fiber Atrophy and MyoD Expression in Gastrocnemius of MCAO Rats Methods : In order to investigate effects of Dipsaci radix on the skeletal muscle atrophy following stroke, cerebral infarct was induced by the middle cerebral artery occlusion (MCAO) in the rats. Water extract of Dipsaci radix (184.4 mg/100 g) was treated for 4 weeks, once a day orally, after the MCAO. Effects were evaluated with muscle fiber type composition and cross-sectioned area of muscle fibers in gastrocnemius of the unaffected & affected hind limbs. And MyoD protein expression in gastrocnemius was demonstrated with immunohistochemistry and western blotting. Results : Obtained results were as follows; 1. Infarct volume was not attenuated by Dipsaci radix treatment in the MCAO rats. 2. At the affected-side hind limb of the MCAO rats, the increase of type-I fibers and the decrease of type-II fibers were induced by Dipsaci radix treatment. 3. At the affected-side hind limb of the MCAO rats, decreases of cross-sectioned areas of type-I and type-II fibers were attenuated by Dipsaci radix treatment. 4. At the affected-side hind limb of the MCAO rats, MyoD positive cells were increased by Dipsaci radix treatment. 5. At the affected-side hind limb of the MCAO rats, MyoD expressions were increased by Dipsaci radix treatment. Conclusions : These results suggest that Dipsaci radix has a protective effect against muscle atrophy, through the inhibition of the muscle cell apoptosis, following the central nervous system demage.

• 한국축산식품학회지
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• 제40권1호
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• pp.132-144
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• 2020

The aim of this study was to optimize staining procedures for muscle fiber typing efficiently and rapidly in bovine and porcine skeletal muscles, such as longissimus thoracis, psoas major, semimembranosus, and semitendinosus muscles. The commercially available monoclonal anti-myosin heavy chain (MHC) antibodies and fluorescent dye-conjugated secondary antibodies were applied to immunofluorescence histology. Two different procedures, such as cocktail and serial staining, were adopted to immunofluorescence analysis. In bovine muscles, three pure types (I, IIA, and IIX) and one hybrid type, IIA+IIX, were identified by the cocktail procedure with a combination of BA-F8, SC-71, BF-35, and 6H1 anti-MHC antibodies. Porcine muscle fibers were typed into four pure types (I, IIA, IIX, and IIB) and two hybrid types (IIA+IIX and IIX+IIB) by a serial procedure with a combination of BA-F8, SC-71, BF-35, and BF-F3. Unlike for bovine muscle, the cocktail procedure was not recommended in porcine muscle fiber typing because of the abnormal reactivity of SC-71 antibody under cocktail procedure. Within the four antibodies, combinations of two or more anti-MHC antibodies allowed us to distinguish pure fiber types or all fiber types including hybrid types. Application of other secondary antibodies conjugated with different fluorescent dyes allowed us to get improved image resolution that clearly distinguished hybrid fibers. Muscle fiber characteristics differed depending on species and muscle types.

• Archives of Reconstructive Microsurgery
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• 제6권1호
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• pp.29-38
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• 1997

A peripheral nerve when approximation of the ends imparts tension at the anastomosis and with a relatively long segment defect after excision of neuroma and neurofibroma cannnot be repaired by early primary suture. The one of the optimistic reconstruction method of severed peripheral nerves is to restore tension-free continuity at the repair site putting an autogenous nerve graft into the neural gap despite of ancipating motor or sensory deficit of the donor nerve area. To overcome the deficit of the autogenous nerve graft, several other conduits supplying a metabolically active environment which is able to support axon regeneration and progression, providing protection against scar invasion, and guiding the regrowing axons to the distal stump of the nerve have been studied. An author have used ipsilateral femoral vein, ipsilateral femoral vein filled with fresh thigh muscle, and autogenous sciatic nerve for the sciatic nerve defect of around 10 mm in length to observe the regeneration pattern in rat by light and electron microscopy. The results were as follows. 1. Light microscopically regeneration pattern of nerve fibers in the autogenous graft group was more abundant than vein graft and vein filled with muscle group. 2. On ultrastructural findings, the proxial end of the graft in various groups showed similar regenerating features of the axons, myelin sheaths, and Schwann cells. The fascicular arrangement of the myelinated and unmyelinated fibers was same regardless of the type of conduits. There were more or less increasing tendency in the number and the diameter of myelinated fibers correlated with the regeneration time. 3. In the middle of the graft, myelinated nerve fibers of vein filled with muscle group were more in number and myelin sheath was thinner than in the venous graft, but the number of regenerating axons in autogenous nerve graft was superior to that in both groups of the graft. The amount of collagen fibrils and amorphous materials in the endoneurial space was increased to elapsed time. 4. There was no difference in regenerating patterns of the nerve fibers of distal end of the graft. The size and shape of the myelinated nerve fbers were more different than that of proximal and middle portion of the graft. From the above results, the degree of myelination and regenerating activity in autogenous nerve is more effective and active in other types of the graft and there were no morphological differences in either ends of the graft regardless of regeneration time.

• Applied Microscopy
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• 제27권3호
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• pp.333-346
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• 1997

The ischemia and reperfusion injury of the skeletal muscles is caused by generation of reactive oxygen during ischemia and reperfusion. It is well known that over 4 hours of ischemia injures the skeletal muscles irreversibly. The author has demonstrated the effects of SOD (superoxide dismutase), DMTU (dimethyl thiourea) and ischemic preconditioning on ultrastructural changes of the muscle fibers in the rectus femoris muscles after 4 hours of ischemia and 1 day and 3 days of reperfusion. A total of 72 healthy Sprague-Dawley rats weighing from 200 gm to 250 gm were used as experimental animals. Under urethane(1.15 g/kg, IP, 2 times) anesthesia, lower abdominal incision was done and the left common iliac artery was occluded by using vascular clamp for 4 hours. The left rectus femoris muscles were obtained at 1 and 3 days after the removal of vascular clamp. The SOD (15,000 unit/kg) or DMTU (500 mg/kg) were administered intraperitoneally at 1 hour before induction of ischemia. The ischemic preconditioned group underwent three episodes of 5 minutes occlusion and 5 minutes reperfusion followed by 4 hours of ischemia and 1 day and 3 days of reperfusion. The specimens were sliced into $1mm^3$ and prepared by routine methods for electron microscopic observation. All specimens were stained with uranyl acetate and lead citrate and then observed with Hitachi-600 transmission electron microscope. The results were as follows: 1. SOD or DMTU alone did not affect the ultrastructure of muscle fibers in the rectus femoris muscles. The electron density of mitochondrial matrix was decreased by ischemic preconditioning. 2. Dilated cisternae of sarcoplasmic reticulum, triad, mitochondria and the loss of myofilament in the sarcomere were observed in the 4 hours ischemia and 1 day reperfused rectus femoris muscles. Markedly changed sarcoplasmic reticulum, triad, disordered or loss of myofilament, indistinct A-band and I-band, and irregular electron lucent M -line and Z-line are seen in the 4 hours ischemia and 3 days reperfused rectus femoris muscles. 3. SOD reduced the changes of organelles in the muscle fibers of the 4 hours ischemia and 1 day reperfused rectus femoris muscles of the rats, but SOD did not affect the changes of muscle fibers in the 4 hours ischemia and 3 days reperfused muscles. On the other hand, DMTU markedly attenuated considerably the ultrastructural change of the 4 hours ischemia and 1 day or 3 days reperfused rectus femoris muscles. 4. By the ischemic preconditioning, the change was attenuated remarkably in the 4 hours ischemia and 1 day reperfused rectus femoris muscles. As the ischemic reperfused changes of muscle fibers were regenerated or recovered by ischemic preconditioning, the ultrastructures of them were similar to those of normal control in the 4 hours ischemia and 3 days reperfused rectus formoris muscles. Consequently, it is suggested that DMTU is stronger inhibitor to ischemic reperfused change than SOD. The ischemia and reperfusion-induced muscular damage is remarkably inhibited by ischemic preconditioning.

• 대한전기학회논문지:전력기술부문A
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• 제48권11호
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• pp.1476-1478
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• 1999

A musculotendon model is proposed to predict muscle force during muscle fatigue due to the continuous functional electrical stimulation(FES). Muscle fatigue dynamics can be modeled as the electrical admittance of muscle fibers and included in activation dynamics based on the{{{{ { Ca}^{2+ } }}}} kinetics. The admittance depends on the fatigue variable that monotonically increase or decrease if electrical pulse exists or not, and on the stimulation parameters and the number of applied pulses. In the response of the change in activation the normalized Hill-type contraction dynamics connected with activation dynamics decline the muscle shortening velocity and thus its force under muscle fatigue. The computer simulation shows that the proposed model can express the muscle fatigue and its recovery without changing any stimulation parameters.

• 한국축산식품학회지
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• 제44권3호
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• pp.710-722
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• 2024

Extracellular matrix (ECM) proteins play a crucial role in culturing muscle stem cells (MuSCs). However, there is a lack of extensive research on how each of these proteins influences proliferation and differentiation of MuSCs from livestock animals. Therefore, we investigated the effects of various ECM coatings-collagen, fibronectin, gelatin, and laminin-on the proliferation, differentiation, and maturation of porcine MuSCs. Porcine MuSCs, isolated from 14-day-old Berkshire piglets, were cultured on ECM-coated plates, undergoing three days of proliferation followed by three days of differentiation. MuSCs on laminin showed higher proliferation rate than others (p<0.05). There was no significant difference in the mRNA expression levels of PAX7, MYF5, and MYOD among MuSCs on laminin, collagen, and fibronectin (p>0.05). During the differentiation period, MuSCs cultured on laminin exhibited a significantly higher differentiation rate, resulting in thicker myotubes compared to those on other ECMs (p<0.05). Also, MuSCs on laminin showed higher expression of mRNA related with maturated muscle fiber such as MYH1 and MYH4 corresponding to muscle fiber type IIx and muscle fiber type IIb, respectively, compared with MuSCs on other ECM coatings (p<0.05). In summary, our comparison of ECMs revealed that laminin significantly enhances MuSC proliferation and differentiation, outperforming other ECMs. Specifically, muscle fibers cultured on laminin exhibited a more mature phenotype. These findings underscore laminin's potential to advance in vitro muscle research and cultured meat production, highlighting its role in supporting rapid cell proliferation, higher differentiation rates, and the development of mature muscle fibers.

• Journal of Animal Science and Technology
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• 제54권3호
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• pp.175-183
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• 2012

The present study was conducted to investigate the relationships of muscle fiber characteristics to dietary energy density [3.0(Low-E) vs. 3.2 (Med-E) Mcal DE/kg)] and slaughter weight [SW; 110, 125, and 138 kg] in finishing pigs (gilt vs. barrow) using a $2{\times}3{\times}2$ factorial treatment design. Forty-one longissimus dorsi muscle (LM) samples were analyzed histochemically, with growth performance and physicochemical data for the 41 animals and their LM out of 192 animals and 72 LM used in a previous study retrospectively included. The ADG was less (P<0.01) in the Low-E than in the Med-E group (0.93 vs. 0.73 kg) whereas lightness ($L^*$) and redness ($a^*$) of LM were greater in the Low-E group SW did not influence these variables. The diameter and perimeter of the type I (slow-oxidative), type IIA (fast oxido-glycolytic) and type IIB (fast glycolytic) fibers increased with increasing SW whereas densities of the fibers decreased. However, the number and area percentages of the fiber types were not influenced by SW or dietary energy density. The percentage and per-$mm^2$ density of type IIB fibers were negatively correlated with SW (r = -0.33 and -0.57, with P<0.05 and <0.01, respectively), whereas type I fiber number percentage was positively correlated with SW (r = 0.31; P<0.05). Marbling score was negatively correlated (P<0.05) with type I (r = -0.36) and type IIB (r = -0.39) fiber densities. The $a^*$ was correlated (P<0.01) with both type I and type IIB fiber number percentages in the opposite way (r = 0.42 and -0.47, respectively). However, $L^*$ (lightness), drip loss and $pH_{24h}$ were not correlated with the fiber number percentage or density of any fiber type. Collectively, results indicate that muscle fibers grow by hypertrophy during the late finishing period, but that fiber characteristics other than the size are not significantly influenced by dietary energy density or SW.

• 대한정형도수물리치료학회지
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• 제12권1호
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• pp.57-67
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• 2006

Musculoskeletal neck dysfunction syndromes are common in outpatient musculoskeletal pain practice. The underlying musculoskeletal and neurologic causes of pain are variable. In the management of these patients, it is important to accurately identify and treat these pain generators to optimize patient outcome. It is the purpose of this review to discuss three main categories of functional anatomy, the role of superficial/deep muscular system and the scientific evidence for optimal physical therapy intervention for cervical dysfunction. Specifically there is evidence of lowered microcirculation in the upper trapezius muscle, morphological signs of disturbed mitochondrial function which appears to be limited to type I fibers and an increased cross-sectional area of type I muscle fibers despite a lower capillary to fiber area ratio. In acute neck pain syndrome, changes in muscle activity of painful muscles may result from segmental and supraspinal inhibitory effects. Muscle activation is closely related to the control of joint movements and postures and it is difficult to separate the influence of the two components. Both the altered muscle recruitment patterns and altered kinematics appear to be a poor adaptation for pain of the head - neck region, as they are likely to result in increased compressive loading in the cervical spine, affecting muscles, articular structures such as zygapophyseal joints, connective tissues and neural tissues which are all peripheral generators of referred pain. The rectus capitus posterior minor muscle shows that it is one of the most important muscles of the suboccipital region. In this article, i reviewed the anatomy, neurophysiology, function and dysfunction as well as the treatment of cervical dysfunction.