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Sample records for striated shieldbug graphosoma

  1. Striated morphology during electrodeposition

    SciTech Connect

    Jorne, J.; Lee, M.G.

    1996-03-01

    Comparative study of striated morphologies obtained during the electrodeposition of various metals is performed using rotating electrodes. The formation of striation during electrodeposition of zinc, copper, and silver follows the streamlines of the fluid, and is observed to be accompanied by small or negative polarization resistance. The spacings between striae depends strongly on the applied current density. The spacing decreases with current density in the case of zinc and silver, however, a reverse trend is observed in the case of copper. Linear stability analysis shows that spatial multiplicity occurs when ({partial_derivative}i/{partial_derivative}C){sub {eta}} < 0. The experimentally observed spacings between striae (0.1 {approximately} 1 mm) are in agreement with the wavelength obtained from the linear stability analysis. The analysis of polarization and striation data shows fairly good qualitative agreement with respect to the effects of current density, diffusion layer thickness, and electrolyte concentration on striation.

  2. Gammaproteobacteria as essential primary symbionts in the striped shield bug, Graphosoma Lineatum (Hemiptera: Pentatomidae).

    PubMed

    Karamipour, Naeime; Mehrabadi, Mohammad; Fathipour, Yaghoub

    2016-01-01

    Many members of suborder Heteroptra harbor heritable symbiotic bacteria. Here we characterize the gut symbiotic bacterium in Graphosoma lineatum (Hemiptera: Pentatomidae) by using molecular phylogeny, real-time PCR analysis as well as light and electron microscopy observations. The microscopy observations revealed the presence of a large number of rod-shaped bacterial cells in the crypts. A very high prevalence (98 to 100%) of the symbiont infection was found in the insect populations that strongly supports an intimate association between these two organisms. Real-time PCR analysis also showed that the Gammaproteobacteria dominated the crypts. The sequences of 16sr RNA and groEL genes of symbiont showed high levels of similarity (93 to 95%) to Pantoea agglomeranse and Erwinia herbicola Gammaproteobacteria. Phylogenetic analyses placed G. lineatum symbiont in a well-defined branch, divergent from other stink bug bacterial symbionts. Co-evolutionary analysis showed lack of host-symbiont phylogenetic congruence. Surface sterilization of eggs resulted in increased pre-adult stage in the offspring (aposymbionts) in comparison to the normal. Also, fecundity, longevity, and adult stage were significantly decreased in the aposymbionts. Therefore, it seems that the symbiont might play a vital function in the host biology, in which host optimal development depends on the symbiont. PMID:27609055

  3. Gammaproteobacteria as essential primary symbionts in the striped shield bug, Graphosoma Lineatum (Hemiptera: Pentatomidae)

    PubMed Central

    Karamipour, Naeime; Mehrabadi, Mohammad; Fathipour, Yaghoub

    2016-01-01

    Many members of suborder Heteroptra harbor heritable symbiotic bacteria. Here we characterize the gut symbiotic bacterium in Graphosoma lineatum (Hemiptera: Pentatomidae) by using molecular phylogeny, real-time PCR analysis as well as light and electron microscopy observations. The microscopy observations revealed the presence of a large number of rod-shaped bacterial cells in the crypts. A very high prevalence (98 to 100%) of the symbiont infection was found in the insect populations that strongly supports an intimate association between these two organisms. Real-time PCR analysis also showed that the Gammaproteobacteria dominated the crypts. The sequences of 16sr RNA and groEL genes of symbiont showed high levels of similarity (93 to 95%) to Pantoea agglomeranse and Erwinia herbicola Gammaproteobacteria. Phylogenetic analyses placed G. lineatum symbiont in a well-defined branch, divergent from other stink bug bacterial symbionts. Co-evolutionary analysis showed lack of host-symbiont phylogenetic congruence. Surface sterilization of eggs resulted in increased pre-adult stage in the offspring (aposymbionts) in comparison to the normal. Also, fecundity, longevity, and adult stage were significantly decreased in the aposymbionts. Therefore, it seems that the symbiont might play a vital function in the host biology, in which host optimal development depends on the symbiont. PMID:27609055

  4. First record of Graphosoma inexpectatum (Hemiptera, Pentatomidae, Podopinae) from Turkey with description of the female

    PubMed Central

    Fent, Meral; Dursun, Ahmet; Tezcan, Serdar

    2013-01-01

    Abstract Graphosoma inexpectatum Carapezza & Jindra, 2008 is described from Syria, the southern neighbor of Turkey, and is known only from the type locality. The first observation of the species in Turkey dates back to 1995 with two females obtained from the provinces of Gaziantep (Şehitkamil–Aktoprak) and Adana (Pozantı–Bürücek Plateau). These two localities are situated inside the part of the Mediterranean region along the Syrian border. Females of the species, whose original description was based on males, are described here for the first time. A map showing the collecting localities and photographs of the female specimens are given. PMID:24039511

  5. Fine structure and chemical analysis of the metathoracic scent gland secretion in Graphosoma lineatum (Linnaeus, 1758) (Heteroptera, Pentatomidae).

    PubMed

    Durak, Dilek; Kalender, Yusuf

    2009-01-01

    Morphology and ultrastructure of metathoracic scent glands (MTGs) of Graphosoma lineatum (Heteroptera, Pentatomidae) were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Extracts of the volatile fraction of the MTG secretion from males and females were subjected to initial analysis. One pair of the MTG is composed of a reservoir and a pair of lateral glands connected to the reservoir with a duct. MTGs are open in between the meso- and metacoxae, on evaporation areas with a mushroom-like structure. Reservoir walls embody two types of cells, type I and type II, respectively. Cells of type I have numerous organelles, while type II cells have only been found in a certain area of the reservoir wall. They have large secretory ducts lined by a cuticular intima layer. The lateral glands connected to reservoir have two further types of cells. Lateral glands are lined by type A secretory cells and secretory duct is found in their cytoplasm. Type B cells are poor in organelles and are smaller than type A cells. Coupled gas chromatography-mass spectrometry examinations revealed that both in males and females of G. lineatum MTGs 14 chemical compounds occur, among which only 10 are common. These secretions indicate information such as defensive and pheromonal activities, other functions could be attributed to the secretion of the MTG of G. lineatum by comparison with other closely related bug species. In the analyses of MTGs of females of G. lineatum, n-octadecanoic acid was observed at the most and n-undecane was determined at lowest level, while males of G. lineatum n-tridecane was determined at the highest level; and (E)-2-hexenyl acetate has been observed at the lowest. PMID:19200924

  6. Objective forensic analysis of striated, quasi-striated and impressed toolmarks

    NASA Astrophysics Data System (ADS)

    Spotts, Ryan E.

    Following the 1993 Daubert v. Merrell Dow Pharmaceuticals, Inc. court case and continuing to the 2010 National Academy of Sciences report, comparative forensic toolmark examination has received many challenges to its admissibility in court cases and its scientific foundations. Many of these challenges deal with the subjective nature in determining whether toolmarks are identifiable. This questioning of current identification methods has created a demand for objective methods of identification - "objective" implying known error rates and statistically reliability. The demand for objective methods has resulted in research that created a statistical algorithm capable of comparing toolmarks to determine their statistical similarity, and thus the ability to separate matching and nonmatching toolmarks. This was expanded to the creation of virtual toolmarking (characterization of a tool to predict the toolmark it will create). The statistical algorithm, originally designed for two-dimensional striated toolmarks, had been successfully applied to striated screwdriver and quasi-striated plier toolmarks. Following this success, a blind study was conducted to validate the virtual toolmarking capability using striated screwdriver marks created at various angles of incidence. Work was also performed to optimize the statistical algorithm by implementing means to ensure the algorithm operations were constrained to logical comparison regions (e.g. the opposite ends of two toolmarks do not need to be compared because they do not coincide with each other). This work was performed on quasi-striated shear cut marks made with pliers - a previously tested, more difficult application of the statistical algorithm that could demonstrate the difference in results due to optimization. The final research conducted was performed with pseudostriated impression toolmarks made with chisels. Impression marks, which are more complex than striated marks, were analyzed using the algorithm to separate

  7. Cone inputs to murine striate cortex

    PubMed Central

    Ekesten, Björn; Gouras, Peter

    2008-01-01

    Background We have recorded responses from single neurons in murine visual cortex to determine the effectiveness of the input from the two murine cone photoreceptor mechanisms and whether there is any unique selectivity for cone inputs at this higher region of the visual system that would support the possibility of colour vision in mice. Each eye was stimulated by diffuse light, either 370 (strong stimulus for the ultra-violet (UV) cone opsin) or 505 nm (exclusively stimulating the middle wavelength sensitive (M) cone opsin), obtained from light emitting diodes (LEDs) in the presence of a strong adapting light that suppressed the responses of rods. Results Single cells responded to these diffuse stimuli in all areas of striate cortex. Two types of responsive cells were encountered. One type (135/323 – 42%) had little to no spontaneous activity and responded at either the on and/or the off phase of the light stimulus with a few impulses often of relatively large amplitude. A second type (166/323 – 51%) had spontaneous activity and responded tonically to light stimuli with impulses often of small amplitude. Most of the cells responded similarly to both spectral stimuli. A few (18/323 – 6%) responded strongly or exclusively to one or the other spectral stimulus and rarely in a spectrally opponent manner. Conclusion Most cells in murine striate cortex receive excitatory inputs from both UV- and M-cones. A small fraction shows either strong selectivity for one or the other cone mechanism and occasionally cone opponent responses. Cells that could underlie chromatic contrast detection are present but extremely rare in murine striate cortex. PMID:19014590

  8. Collisionless Plasma Shocks in Striated Electron Temperatures

    SciTech Connect

    Guio, P.; Pecseli, H. L.

    2010-02-26

    The existence of low frequency waveguide modes of ion acoustic waves is demonstrated in magnetized plasmas for electron temperatures striated along the magnetic field lines. At higher frequencies, in a band between the ion cyclotron and the ion plasma frequency, radiative modes develop and propagate obliquely to the field away from the striation. Arguments for the subsequent formation and propagation of electrostatic shock are presented and demonstrated numerically. For such plasma conditions, the dissipation mechanism is the 'leakage' of the harmonics generated by the wave steepening.

  9. Independent evolution of striated muscles in cnidarians and bilaterians

    PubMed Central

    Steinmetz, Patrick R.H.; Kraus, Johanna E.M.; Larroux, Claire; U. Hammel, Jörg; Amon-Hassenzahl, Annette; Houliston, Evelyn; Wörheide, Gert; Nickel, Michael; Degnan, Bernard M.; Technau, Ulrich

    2012-01-01

    Striated muscles are present in bilaterian animals (e.g. vertebrates, insects, annelids) and some non-bilaterian eumetazoans (i.e. cnidarians and ctenophores). The striking ultrastructural similarity of striated muscles between these animal groups is thought to reflect a common evolutionary origin1, 2. Here we show that a muscle protein core set, including a Myosin type II Heavy Chain motor protein characteristic of striated muscles in vertebrates (MyHC-st), was already present in unicellular organisms before the origin of multicellular animals. Furthermore, myhc-st and myhc-non-muscle (myhc-nm) orthologues are expressed differentially in two sponges, compatible with the functional diversification of myhc paralogues before the origin of true muscles and the subsequent deployment of MyHC-st in fast-contracting smooth and striated muscle. Cnidarians and ctenophores possess myhc-st orthologues but lack crucial components of bilaterian striated muscles, such as troponin complex and titin genes, suggesting the convergent evolution of striated muscles. Consistently, jellyfish orthologues of a shared set of bilaterian z-disc proteins are not associated with striated muscles, but are instead expressed elsewhere or ubiquitously. The independent evolution of eumetazoan striated muscles through the addition of novel proteins to a pre-existing, ancestral contractile apparatus may serve as a paradigm for the evolution of complex animal cell types. PMID:22763458

  10. Interrelated striated elements in vestibular hair cells of the rat

    NASA Technical Reports Server (NTRS)

    Ross, M. D.; Bourne, C.

    1983-01-01

    A series of interrelated striated organelles in types I and II vestibular hair cells of the rat which appear to be less developed in cochlear hair cells have been revealed by unusual fixation procedures, suggesting that contractile elements may play a role in sensory transduction in the inner ear, especially in the vestibular system. Included in the series of interrelated striated elements are the cuticular plate and its basal attachments to the hair cell margins, the connections of the strut array of the kinociliary basal body to the cuticular plate, and striated organelles associated with the plasma membrane and extending below the apical junctional complexes.

  11. Representation of the visual field in the occipital striate cortex.

    PubMed Central

    McFadzean, R; Brosnahan, D; Hadley, D; Mutlukan, E

    1994-01-01

    The representation of the field of vision in the human striate cortex is based on the Holmes map in which about 25% of the surface area of the striate cortex is allocated to the central 15 degrees of vision. Following the introduction of computed tomography of the brain, the accuracy of the Holmes map was apparently confirmed by clinical/radiological correlation, but a revision has been proposed by Horton and Hoyt based on a magnetic resonance imaging study of three patients with visual field defects due to striate lesions. They propose that the central cortical representation of vision occupies a much larger area. This study reviews the perimetric and imaging findings in a larger series of patients with striate cortical disease and provides support for the revised representation. The clinical phenomenon of macular sparing and its relation to representation of the macula at the occipital pole is also discussed. Images PMID:8148333

  12. [Electron microscopic study of striate keratosis palmoplantaris (Wachters type)].

    PubMed

    Küchmeister, B; Mahrle, G

    1985-06-15

    We report on a patient suffering from striate palmoplantar keratoderma (Wachters' type). Ultrastructural findings are presented for the first time. There was orthohyperkeratosus without alterations indicating a specific disturbance of keratinisation. PMID:2411057

  13. An invertebrate smooth muscle with striated muscle myosin filaments

    PubMed Central

    Sulbarán, Guidenn; Alamo, Lorenzo; Pinto, Antonio; Márquez, Gustavo; Méndez, Franklin; Padrón, Raúl; Craig, Roger

    2015-01-01

    Muscle tissues are classically divided into two major types, depending on the presence or absence of striations. In striated muscles, the actin filaments are anchored at Z-lines and the myosin and actin filaments are in register, whereas in smooth muscles, the actin filaments are attached to dense bodies and the myosin and actin filaments are out of register. The structure of the filaments in smooth muscles is also different from that in striated muscles. Here we have studied the structure of myosin filaments from the smooth muscles of the human parasite Schistosoma mansoni. We find, surprisingly, that they are indistinguishable from those in an arthropod striated muscle. This structural similarity is supported by sequence comparison between the schistosome myosin II heavy chain and known striated muscle myosins. In contrast, the actin filaments of schistosomes are similar to those of smooth muscles, lacking troponin-dependent regulation. We conclude that schistosome muscles are hybrids, containing striated muscle-like myosin filaments and smooth muscle-like actin filaments in a smooth muscle architecture. This surprising finding has broad significance for understanding how muscles are built and how they evolved, and challenges the paradigm that smooth and striated muscles always have distinctly different components. PMID:26443857

  14. Poorly Understood Aspects of Striated Muscle Contraction

    PubMed Central

    Månsson, Alf

    2015-01-01

    Muscle contraction results from cyclic interactions between the contractile proteins myosin and actin, driven by the turnover of adenosine triphosphate (ATP). Despite intense studies, several molecular events in the contraction process are poorly understood, including the relationship between force-generation and phosphate-release in the ATP-turnover. Different aspects of the force-generating transition are reflected in the changes in tension development by muscle cells, myofibrils and single molecules upon changes in temperature, altered phosphate concentration, or length perturbations. It has been notoriously difficult to explain all these events within a given theoretical framework and to unequivocally correlate observed events with the atomic structures of the myosin motor. Other incompletely understood issues include the role of the two heads of myosin II and structural changes in the actin filaments as well as the importance of the three-dimensional order. We here review these issues in relation to controversies regarding basic physiological properties of striated muscle. We also briefly consider actomyosin mutation effects in cardiac and skeletal muscle function and the possibility to treat these defects by drugs. PMID:25961006

  15. Subcellular distribution of potassium in striated muscles

    SciTech Connect

    Edelmann, L.

    1984-01-01

    Microanalytical experiments have been performed to answer the question whether the main cellular cation, K+, follows the water distribution in the striated muscle cell or whether K+ follows the distribution of negative fixed charges (beta- and gamma-carboxyl groups of aspartic and glutamic acid residues). Subcellular localization of K and/or of the K surrogates Rb, Cs, and Tl has been investigated by the following methods: Chemical precipitation of K with tetraphenylborate. Autoradiography of alkali-metals and Tl in air-dried and frozen-hydrated preparations. TEM visualization of electron dense Cs and Tl in sections of freeze-dried and plastic embedded muscle. X-ray microanalysis of air-dried myofibrils and muscle cryosections. The experiments consistently show that K, Rb, Cs, and Tl do not follow the water distribution but are mainly accumulated in the A band, especially in the marginal regions, and at Z lines. The same sites preferentially accumulate Cs or uranyl cations when sections of freeze-dried, embedded muscle are exposed to these electron microscopic stains. It is concluded that the detected uneven distribution of K, Rb, Cs, and Tl in muscle is neither a freeze-drying artifact nor an embedding artifact and may result from a weak ion binding to the beta- and gamma-carboxyl groups of cellular proteins.

  16. Neurohypophyseal Hormones: Novel Actors of Striated Muscle Development and Homeostasis

    PubMed Central

    Costa, Alessandra; Rossi, Eleonora; Scicchitano, Bianca Maria; Coletti, Dario; Moresi, Viviana

    2014-01-01

    Since the 1980’s, novel functional roles of the neurohypophyseal hormones vasopressin and oxytocin have emerged. Several studies have investigated the effects of these two neurohormones on striated muscle tissues, both in vitro and in vivo. The effects of vasopressin on skeletal myogenic cells, developing muscle and muscle homeostasis have been documented. Oxytocin appears to have a greater influence on cardiomyocite differentiation and heart homeostasis. This review summarizes the studies on these novel roles of the two neurohypophyseal hormones, and open the possibility of new therapeutic approaches for diseases affecting striated muscle. PMID:26913138

  17. Extensive and intensive factors determining the performance of striated muscle.

    PubMed

    Josephson, R K

    1975-10-01

    Striated muscle is obviously a versatile tissue, one which has been malleable to selective pressure and has become modified for many specific tasks. The variations which adapt striated muscle to particular functions involve both changes in its structural organization and changes in the chemical nature of its components. Although a number of factors have been identified which contribute to the diversity of muscle performance, it is not yet possible to account adequately for the wide range in muscle performance throughout the animal kingdom. While not a new direction in comparative physiology, developing quantitative explanations for the diversity of muscle performance is still an obvious, remaining task. PMID:1104752

  18. Electromyography of the perineal striated muscles during cystometry.

    PubMed

    Vereecken, R L; Derluyn, J; Verduyn, H

    1975-01-01

    The electromyographic patterns of the external urethral sphincter, the anal sphincter, and the levator ani during cystometries have been analyzed. Synchronized activity changes occur during abdominal straining. Muscle fatigue is very pronounced. Activity may be less synchronized during bladder filling and micturition, even in normal cystometries. In neurogenic diseases, true dyssynergia between the striated muscles may be observed. PMID:1118953

  19. Voltage-dependent sodium channels in an invertebrate striated muscle.

    PubMed

    Schwartz, L M; Stühmer, W

    1984-08-01

    Striated skeletal muscles from the planktonic arrowworm Sagitta elegans (phylum Chaetognatha) were voltage-clamped. The muscles displayed classical voltage-dependent sodium channels that (i) showed peak transient currents when the membrane was depolarized 90 millivolts from rest, (ii) opened rapidly with peak currents flowing within 0.4 milliseconds at 4 degrees C, (iii) showed voltage-dependent inactivation with 50 percent inactivation at +25 millivolts from rest, and (iv) were blocked by 500 nanomolar tetrodotoxin. PMID:6330898

  20. Psychophysics of electrical stimulation of striate cortex in macaques.

    PubMed

    Bartlett, John R; DeYoe, Edgar A; Doty, Robert W; Lee, Barry B; Lewine, Jeffrey D; Negrão, Nubio; Overman, William H

    2005-11-01

    Macaques indicated their detection of onset or alteration of 0.2-ms pulses applied in various configurations through electrodes implanted in striate cortex. When microelectrodes were introduced and left in place, the threshold for detection of 100-Hz pulses nearly doubled within 24 h. However, for chronically implanted platinum-alloy macroelectrodes detection thresholds usually remained stable for many months, independently of location within striate cortex or its immediately subjacent white matter. Thresholds were unaffected by the visual conditions, such as light versus darkness, or movement of the eyes; but in one animal blind after acute glaucoma thresholds for loci in striate cortex were permanently decreased by about 50%. Learning to respond to electrical stimulation of the optic tract produced no tendency to respond to such stimulation of striate cortex. Onset of stimulation at a given locus could be detected even in the face of continuous supraliminal stimulation at four surrounding loci on a 3-mm radius. The surround stimulation did alter the threshold of the central locus, but such stimuli could not summate if they were subliminal by some 10%. Cessation of stimulation that had been continuing for 1 min to 1 h could be detected if it were being applied at a level 20-75% above that needed for detection of stimulus onset. Continuous stimulation had a pronounced "priming" effect, in that modulation of frequency or intensity of such stimulation by as little as 5% could be detected (e.g., 20 microA in a background of 500 microA, or <2-ms interpulse interval with pulses at 50 Hz). Using pulses inserted in various phase relations to ongoing pulses at 2-5 Hz, it could be determined that stimulus pulses were surrounded by a strong facilitatory period for about 30 ms, which was then replaced by refractoriness. Given the congruence of macaque and human visual anatomy and psychophysics, these results further encourage efforts to develop a cortical prosthesis for the

  1. Clinical and Experimental Pancreatic Islet Transplantation to Striated Muscle

    PubMed Central

    Christoffersson, Gustaf; Henriksnäs, Johanna; Johansson, Lars; Rolny, Charlotte; Ahlström, Håkan; Caballero-Corbalan, José; Segersvärd, Ralf; Permert, Johan; Korsgren, Olle; Carlsson, Per-Ola; Phillipson, Mia

    2010-01-01

    OBJECTIVE Curing type 1 diabetes by transplanting pancreatic islets into the liver is associated with poor long-term outcome and graft failure at least partly due to inadequate graft revascularization. The aim of the current study was to evaluate striated muscle as a potential angiogenic site for islet transplantation. RESEARCH DESIGN AND METHODS The current study presents a new experimental model that is found to be applicable to clinical islet transplantation. Islets were implanted into striated muscle and intraislet vascular density and blood flow were visualized with intravital and confocal microscopy in mice and by magnetic resonance imaging in three autotransplanted pancreatectomized patients. Mice were rendered neutropenic by repeated injections of Gr-1 antibody, and diabetes was induced by alloxan treatment. RESULTS Contrary to liver-engrafted islets, islets transplanted to mouse muscle were revascularized with vessel densities and blood flow entirely comparable with those of islets within intact pancreas. Initiation of islet revascularization at the muscular site was dependent on neutrophils, and the function of islets transplanted to muscle was proven by curing diabetic mice. The experimental data were confirmed in autotransplanted patients where higher plasma volumes were measured in islets engrafted in forearm muscle compared with adjacent muscle tissue through high-resolution magnetic resonance imaging. CONCLUSIONS This study presents a novel paradigm in islet transplantation whereby recruited neutrophils are crucial for the functionally restored intraislet blood perfusion following transplantation to striated muscle under experimental and clinical situations. PMID:20651296

  2. Deoxyglucose Analysis of Retinotopic Organization in Primate Striate Cortex

    NASA Astrophysics Data System (ADS)

    Tootell, Roger B. H.; Silverman, Martin S.; Switkes, Eugene; de Valois, Russell L.

    1982-11-01

    We have anatomically analyzed retinotopic organization using the 14C-labeled 2-deoxy-D-glucose method. The method has several advantages over conventional electrophysiological mapping techniques. In the striate cortex, the anatomical substrate for retinotopic organization is suprisingly well ordered, and there seems to be a systematic relationship between ocular dominance strips and cortical magnification. The 2-deoxyglucose maps in this area appear to be largely uninfluenced by known differences in long-term metabolic activity. This method should prove useful in analyzing retinotopic organization in various visual areas of the brain and in different species.

  3. Enrichment and terminal differentiation of striated muscle progenitors in vitro

    SciTech Connect

    Becher, Ulrich M.; Breitbach, Martin; Sasse, Philipp; Garbe, Stephan; Ven, Peter F.M. van der; Fuerst, Dieter O.; Fleischmann, Bernd K.

    2009-10-01

    Enrichment and terminal differentiation of mammalian striated muscle cells is severely hampered by fibroblast overgrowth, de-differentiation and/or lack of functional differentiation. Herein we report a new, reproducible and simple method to enrich and terminally differentiate muscle stem cells and progenitors from mice and humans. We show that a single gamma irradiation of muscle cells induces their massive differentiation into structurally and functionally intact myotubes and cardiomyocytes and that these cells can be kept in culture for many weeks. Similar results are also obtained when treating skeletal muscle-derived stem cells and progenitors with Mitomycin C.

  4. Virtual and simulated striated toolmarks for forensic applications.

    PubMed

    Baiker, Martin; Petraco, Nicholas D K; Gambino, Carol; Pieterman, René; Shenkin, Peter; Zoon, Peter

    2016-04-01

    Large numbers of experimental toolmarks of screwdrivers are often required in casework of toolmark examiners and in research environments alike, to be able to recover the angle of attack of a crime scene mark and to determine statistically meaningful properties of toolmarks respectively. However, in practice the number of marks is limited by the time needed to create them. In this article, we present an approach to predict how a striated mark of a particular tool would look like, using 3D surface datasets of screwdrivers. We compare these virtual toolmarks qualitatively and quantitatively with real experimental marks in wax and show that they are very similar. In addition we study toolmark similarity, dependent on the angle of attack, with a very high angular resolution of 1°. The results show that for the tested type of screwdriver, our toolmark comparison framework yields known match similarity scores that are above the mean known non-match similarity scores, even for known match differences in angle of attack of up to 40°. In addition we demonstrate an approach to automatically recover the angle of attack of an experimental toolmark and experiments yield high accuracy and precision of 0.618 ± 4.179°. Furthermore, we present a strategy to study the structural elements of striated toolmarks using wavelet analysis, and show how to use the results to simulate realistic toolmarks. PMID:26874738

  5. Allergic Interstitial Nephritis Manifesting as a Striated Nephrogram

    PubMed Central

    Moinuddin, Irfan; Bracamonte, Erika; Thajudeen, Bijin; Sussman, Amy; Madhrira, Machaiah; Costello, James

    2015-01-01

    Allergic interstitial nephritis (AIN) is an underdiagnosed cause of acute kidney injury (AKI). Guidelines suggest that AIN should be suspected in a patient who presents with an elevated serum creatinine and a urinalysis that shows white cells, white cell casts, or eosinophiluria. Drug-induced AIN is suspected if AKI is temporally related to the initiation of a new drug. However, patients with bland sediment and normal urinalysis can also have AIN. Currently, a definitive diagnosis of AIN is made by renal biopsy which is invasive and fraught with risks such as bleeding, infection, and hematoma. Additionally, it is frequently unclear when a kidney biopsy should be undertaken. We describe a biopsy proven case of allergic interstitial nephritis which manifested on contrast enhanced Magnetic Resonance Imaging (MRI) as a striated nephrogram. Newer and more stable macrocyclic gadolinium contrast agents have a well-demonstrated safety profile. Additionally, in the presentation of AKI, gadolinium contrast agents are safe to administer in patients who demonstrate good urine output and a downtrending creatinine. We propose that the differential for a striated nephrogram may include AIN. In cases in which the suspicion for AIN is high, this diagnostic consideration may be further characterized by contrast enhanced MRI. PMID:26664405

  6. Weakly nonlinear ion waves in striated electron temperatures

    NASA Astrophysics Data System (ADS)

    Guio, P.; Pécseli, H. L.

    2016-04-01

    The existence of low-frequency waveguide modes of electrostatic ion acoustic waves is demonstrated in magnetized plasmas for cases where the electron temperature is striated along magnetic field lines. For low frequencies, the temperature striation acts as waveguide that supports a trapped mode. For conditions where the ion cyclotron frequency is below the ion plasma frequency we find a dispersion relation having also a radiative frequency band, where waves can escape from the striation. Arguments for the formation and propagation of an equivalent of electrostatic shocks are presented and demonstrated numerically for these conditions. The shock represents here a balance between an external energy input maintained by ion injection and a dissipation mechanism in the form of energy leakage of the harmonics generated by nonlinear wave steepening. This is a reversible form for energy loss that can replace the time-irreversible losses in a standard Burgers equation.

  7. Degree of polarization of light diffracted from resting striated muscle.

    PubMed

    Leung, A F

    1987-04-01

    A laser light diffractometer has been developed to measure directly the total degree of polarization of (alpha t) of light diffracted and randomly scattered from striated muscle fibers. From alpha t the degree of polarization (alpha d) of light diffracted from the periodically arranged contractile filaments is determined. Measurements on single muscle fibers and small fiber bundles indicate that both alpha t and alpha d of the first-order diffraction decrease monotonically with sarcomere length. For the second-order diffraction, alpha t and alpha d exhibit a peak at sarcomere length of about 3.0 micron. A proposed theory based on the anisotropic light scattering efficiencies of the thick and thin filaments can account for the measurements. The comparison between the theory and measurements indicates that the A-band, as well as the I-band, are optically anisotropic. PMID:2443248

  8. The Chromatin Remodeling Complex Chd4/NuRD Controls Striated Muscle Identity and Metabolic Homeostasis.

    PubMed

    Gómez-Del Arco, Pablo; Perdiguero, Eusebio; Yunes-Leites, Paula Sofia; Acín-Pérez, Rebeca; Zeini, Miriam; Garcia-Gomez, Antonio; Sreenivasan, Krishnamoorthy; Jiménez-Alcázar, Miguel; Segalés, Jessica; López-Maderuelo, Dolores; Ornés, Beatriz; Jiménez-Borreguero, Luis Jesús; D'Amato, Gaetano; Enshell-Seijffers, David; Morgan, Bruce; Georgopoulos, Katia; Islam, Abul B M M K; Braun, Thomas; de la Pompa, José Luis; Kim, Johnny; Enriquez, José A; Ballestar, Esteban; Muñoz-Cánoves, Pura; Redondo, Juan Miguel

    2016-05-10

    Heart muscle maintains blood circulation, while skeletal muscle powers skeletal movement. Despite having similar myofibrilar sarcomeric structures, these striated muscles differentially express specific sarcomere components to meet their distinct contractile requirements. The mechanism responsible is still unclear. We show here that preservation of the identity of the two striated muscle types depends on epigenetic repression of the alternate lineage gene program by the chromatin remodeling complex Chd4/NuRD. Loss of Chd4 in the heart triggers aberrant expression of the skeletal muscle program, causing severe cardiomyopathy and sudden death. Conversely, genetic depletion of Chd4 in skeletal muscle causes inappropriate expression of cardiac genes and myopathy. In both striated tissues, mitochondrial function was also dependent on the Chd4/NuRD complex. We conclude that an epigenetic mechanism controls cardiac and skeletal muscle structural and metabolic identities and that loss of this regulation leads to hybrid striated muscle tissues incompatible with life. PMID:27166947

  9. X-ray Diffraction Studies of Striated Muscles

    SciTech Connect

    Squire, J.M.; Knupp, C.; Roessle, M.; Al-Khayat, H.A.; Irving, T.C.; Eakins, F.; Mok, N.-S.; Harford, J.J.; Reedy, M.K.

    2006-04-24

    In this short review a number of recent X-ray diffraction results on the highly ordered striated muscles in insects and in bony fish have been briefly described. What is clear is that this technique applied to muscles which are amenable to rigorous analysis, taken together with related data from other sources (e.g. protein crystallography, biochemistry, mechanics, computer modelling) can provide not only the best descriptions yet available on the myosin head organisations on different myosin filaments in the relaxed state, but can also show the sequence of molecular events that occurs in the contractile cycle, and may also help to explain such phenomena as stretch-activation. X-ray diffraction is clearly an enormously powerful tool in studies of muscle. It has already provided a wealth of detail on muscle ultrastructure; it is providing ever more fascinating insights into molecular events in the 50-year old sliding filament mechanism, and there remains a great deal more potential that is as yet untapped.

  10. Neuronal basis of perceptual learning in striate cortex

    PubMed Central

    Ren, Zhen; Zhou, Jiawei; Yao, Zhimo; Wang, Zhengchun; Yuan, Nini; Xu, Guangwei; Wang, Xuan; Zhang, Bing; Hess, Robert F.; Zhou, Yifeng

    2016-01-01

    It is well known that, in humans, contrast sensitivity training at high spatial frequency (SF) not only leads to contrast sensitivity improvement, but also results in an improvement in visual acuity as assessed with gratings (direct effect) or letters (transfer effect). However, the underlying neural mechanisms of this high spatial frequency training improvement remain to be elucidated. In the present study, we examined four properties of neurons in primary visual cortex (area 17) of adult cats that exhibited significantly improved acuity after contrast sensitivity training with a high spatial frequency grating and those of untrained control cats. We found no difference in neuronal contrast sensitivity or tuning width (Width) between the trained and untrained cats. However, the trained cats showed a displacement of the cells’ optimal spatial frequency (OSF) to higher spatial frequencies as well as a larger neuronal signal-to-noise ratio (SNR). Furthermore, both the neuronal differences in OSF and SNR were significantly correlated with the improvement of acuity measured behaviorally. These results suggest that striate neurons might mediate the perceptual learning-induced improvement for high spatial frequency stimuli by an alteration in their spatial frequency representation and by an increased SNR. PMID:27094565

  11. Spatially congruent model for the striate visual cortex

    NASA Astrophysics Data System (ADS)

    da Fontoura Costa, Luciano

    1994-05-01

    A spatially congruent new model for the striate visual cortex (SVC) is proposed which accounts for some of the known functional and organizational properties of the superior mammalian SVC. Even though there is a broad consensus that the topographical representation of the visual field is one of the principal structuring principles underlying the SVC organization, the orientation maps in the SVC have often been described as non-topographical maps. In the present model, the adopted foot-of-normal representation of straight lines has allowed full congruency between the visual field topographic map and the orientation maps in the SVC. The proposed computational model includes three neural layers and assumes that the ocular dominance columns are already established at birth; three possibilities of neural mechanisms leading to orientation encoding are outlined and discussed. The model provides reasonable explanation to some of the most intriguing recently verified properties of the SVC such as the increased neural activity at the cytochrome oxidase blobs, the reduced orientation selectivity at these same places, and the pinwheel-like organization of the orientation selectivity in the SVC.

  12. Receptive fields of simple cells in the cat striate cortex

    PubMed Central

    Bishop, P. O.; Coombs, J. S.; Henry, G. H.

    1973-01-01

    1. The excitatory and inhibitory components in the receptive fields of unimodal simple cells in the striate cortex of the cat anaesthetized with nitrous oxide have been described using slits of light and single light-dark edges as stimuli. 2. There is a small excitatory region (excitatory complex) centrally located in the receptive field that is made up of various combinations and spatial arrangements of subliminal excitatory and discharge subregions or centres. 3. The subliminal excitatory centres were revealed by a binocular facilitation technique. The excitability of the cell was raised by repeated stimulation via one eye while the neurone was tested with single edges via the other eye. 4. The subliminal excitatory and discharge centres are each specifically activated by only one type of edge, light-dark or dark-light, and then only in one direction of motion. All the subregions in the excitatory complex have the same optimal stimulus orientation. 5. Inhibitory components in the receptive field were identified by stimulating the cell with bars of light and single edges against an artificial background discharge produced by repeated stimulation separately applied either to the same eye (monocular conditioning) or to the other eye (binocular conditioning). There are powerful inhibitory sidebands to either side of the excitatory complex and these inhibitory regions merge to include the excitatory complex when stimulus orientation is angled away from the optimal. 6. Excitation is highly stimulus specific whereas inhibition is non-specific. 7. The organization of the two receptive fields of a binocularly discharged cell can be closely similar. 8. The attempt is made to translate the concept of subliminal excitatory and discharge centres into specific neural mechanisms involving both the geniculo-cortical input and various intracortical circuits. 9. These new developments call for only minor modifications to the model we have proposed for the organization of the

  13. Orientation selectivity, preference, and continuity in monkey striate cortex.

    PubMed

    Blasdel, G G

    1992-08-01

    Maps of orientation preference and selectivity, inferred from differential images of orientation (Blasdel, 1992), reveal linear organizations in patches, 0.5-1.0 mm across, where orientation selectivities are high, and where preferred orientations rotate linearly along one axis while remaining constant along the other. Most of these linear zones lie between the centers of adjacent ocular dominance columns, with their short iso-orientation slabs oriented perpendicular, in regions enjoying the greatest binocular overlap. These two-dimensional linear zones are segregated by one- and zero-dimensional discontinuities that are particularly abundant in the centers of ocular dominance columns, and that are also correlated with cytochrome oxidase-rich zones within them. Discontinuities smaller than 90 degrees extend in one dimension, as fractures, while discontinuities greater than 90 degrees are confined to points, in the form of singularities, that are generated when orientation preferences rotate continuously through +/- 180 degrees along circular paths. The continuous rotations through 180 degrees imply that direction preferences are not organized laterally in striate cortex. And they also ensure that preferences for all orientations converge at each singularity, with perpendicular orientations represented uniquely close together on opposite sides. The periodic interspersing of linear zones and singularities suggests that orientation preferences are organized by at least two competing schemes. They are optimized for linearity, along with selectivity and binocularity, in the linear zones, and they are optimized for density near singularities. Since upper-layer neurons are likely to have similarly sized dendritic fields in all regions (Lund and Yoshioka, 1991), those in the linear zones should receive precise information about narrowly constrained orientations, while those near singularities should receive coarse information about all orientations--very different inputs

  14. The striated muscles in pulmonary arterial hypertension: adaptations beyond the right ventricle.

    PubMed

    Manders, Emmy; Rain, Silvia; Bogaard, Harm-Jan; Handoko, M Louis; Stienen, Ger J M; Vonk-Noordegraaf, Anton; Ottenheijm, Coen A C; de Man, Frances S

    2015-09-01

    Pulmonary arterial hypertension (PAH) is a fatal lung disease characterised by progressive remodelling of the small pulmonary vessels. The daily-life activities of patients with PAH are severely limited by exertional fatigue and dyspnoea. Typically, these symptoms have been explained by right heart failure. However, an increasing number of studies reveal that the impact of the PAH reaches further than the pulmonary circulation. Striated muscles other than the right ventricle are affected in PAH, such as the left ventricle, the diaphragm and peripheral skeletal muscles. Alterations in these striated muscles are associated with exercise intolerance and reduced quality of life. In this Back to Basics article on striated muscle function in PAH, we provide insight into the pathophysiological mechanisms causing muscle dysfunction in PAH and discuss potential new therapeutic strategies to restore muscle dysfunction. PMID:26113677

  15. Use of flow, electrical, and mechanical stimulation to promote engineering of striated muscles

    PubMed Central

    Rangarajan, Swathi; Madden, Lauran; Bursac, Nenad

    2014-01-01

    The field of tissue engineering involves design of high-fidelity tissue substitutes for predictive experimental assays in vitro and cell-based regenerative therapies in vivo. Design of striated muscle tissues, such as cardiac and skeletal muscle, has been particularly challenging due to a high metabolic demand and complex cellular organization and electromechanical function of the native tissues. Successful engineering of highly functional striated muscles may thus require creation of biomimetic culture conditions involving medium perfusion, electrical and mechanical stimulation. When optimized, these external cues are expected to synergistically and dynamically activate important intracellular signaling pathways leading to accelerated muscle growth and development. This review will discuss the use of different types of tissue culture bioreactors aimed at providing conditions for enhanced structural and functional maturation of engineered striated muscles. PMID:24366526

  16. Two rules for callosal connectivity in striate cortex of the rat.

    PubMed

    Lewis, J W; Olavarria, J F

    1995-10-01

    In the rat, callosal cells occupy lateral as well as medial portions of striate cortex. In the region of the border between areas 17 and 18, which contains a representation of the vertical meridian of the visual field, cells projecting through the corpus callosum are concentrated throughout the depth of the cortex. In contrast, in medial portion of striate cortex, where peripheral portions of the visual field are represented, callosal cells are preferentially found in infragranular layers. These differences in topography and laminar distribution suggest that these callosal regions, referred to as medial and lateral callosal regions in the present study, subserve different functions. We explored this possibility by analyzing the patterns of callosal linkages in these two callosal regions. We charted the location of retrogradely labeled cells within striate cortex of one hemisphere after placing restricted injections of one or more fluorescent tracers into selected sites in the contralateral striate cortex. We found the medial and lateral callosal regions have distinctly different topographic organizations. Injections into medial striate cortex of one hemisphere produced labeled cells predominantly in mirror-symmetric loci in medial portions of contralateral striate cortex. The arrangement of these connections suggests that they mediate direct interactions between cortical regions representing visual fields located symmetrically on opposite sides of the vertical meridian of the visual field. In contrast, the mapping in the lateral callosal region is reversed: injections into the 17/18a border produced labeled fields located medial to the contralateral 17/18a border, while injections slightly medial to the 17/18a border produced labeled fields located at the contralateral 17/18a border.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8550874

  17. Ultrastructure of geniculocortical synaptic connections in the tree shrew striate cortex.

    PubMed

    Familtsev, Dmitry; Quiggins, Ranida; Masterson, Sean P; Dang, Wenhao; Slusarczyk, Arkadiusz S; Petry, Heywood M; Bickford, Martha E

    2016-04-15

    To determine whether thalamocortical synaptic circuits differ across cortical areas, we examined the ultrastructure of geniculocortical terminals in the tree shrew striate cortex to compare directly the characteristics of these terminals with those of pulvinocortical terminals (examined previously in the temporal cortex of the same species; Chomsung et al. [] Cereb Cortex 20:997-1011). Tree shrews are considered to represent a prototype of early prosimian primates but are unique in that sublaminae of striate cortex layer IV respond preferentially to light onset (IVa) or offset (IVb). We examined geniculocortical inputs to these two sublayers labeled by tracer or virus injections or an antibody against the type 2 vesicular glutamate antibody (vGLUT2). We found that layer IV geniculocortical terminals, as well as their postsynaptic targets, were significantly larger than pulvinocortical terminals and their postsynaptic targets. In addition, we found that 9-10% of geniculocortical terminals in each sublamina contacted GABAergic interneurons, whereas pulvinocortical terminals were not found to contact any interneurons. Moreover, we found that the majority of geniculocortical terminals in both IVa and IVb contained dendritic protrusions, whereas pulvinocortical terminals do not contain these structures. Finally, we found that synaptopodin, a protein uniquely associated with the spine apparatus, and telencephalin (TLCN, or intercellular adhesion molecule type 5), a protein associated with maturation of dendritic spines, are largely excluded from geniculocortical recipient layers of the striate cortex. Together our results suggest major differences in the synaptic organization of thalamocortical pathways in striate and extrastriate areas. PMID:26399201

  18. Striated boulder pavements within glaciomarine diamicts of the Yakataga Formation, Middleton Island, Alaska

    SciTech Connect

    Eyles, C.H.

    1985-01-01

    The presence of striated boulder pavements in glacial sequences is often cited as evidence of transport and deposition by grounded glacier ice. However, recent reports show that striated pavements also form in non-glacial environments by the abrasion of boulder lag surfaces by floating glacier and seasonal ice. Several striated boulder pavements are identified within Early Pleistocene upper Yakataga Formation sediments exposed on Middleton Island close to the southern edge of the Gulf of Alaska continental shelf. The sequence is dominated by thick stratiform units of massive and stratified diamict formed by the settling of fine-grained sands and muds from suspension together with ice-rafted debris. Boulder pavements outcrop as extensive planar horizons within the diamicts, can be traced for several kilometers along strike and consist of single lines of clasts with faceted upper surfaces showing consistently oriented striation directions. Clasts are not preferentially aligned, however, and do not have the characteristic bullet shape of boulders transported at a glacier base and deposited by lodgement processes. Striated boulder pavements on Middleton Island appear to have formed as boulder lag surfaces generated by wave and tidal current reworking of diamict on relatively shallow banks. Lags were then overridden and abraded by a grounding ice shelf. The glacially-abraded boulder pavements on Middleton Island record the repeated expansion of a continuous ice shelf to the edge of the Gulf of Alaska continental shelf during the Early Pleistocene.

  19. Embracing change: striated-for-smooth muscle replacement in esophagus development.

    PubMed

    Krauss, Robert S; Chihara, Daisuke; Romer, Anthony I

    2016-01-01

    The esophagus functions to transport food from the oropharyngeal region to the stomach via waves of peristalsis and transient relaxation of the lower esophageal sphincter. The gastrointestinal tract, including the esophagus, is ensheathed by the muscularis externa (ME). However, while the ME of the gastrointestinal tract distal to the esophagus is exclusively smooth muscle, the esophageal ME of many vertebrate species comprises a variable amount of striated muscle. The esophageal ME is initially composed only of smooth muscle, but its developmental maturation involves proximal-to-distal replacement of smooth muscle with striated muscle. This fascinating phenomenon raises two important questions: what is the developmental origin of the striated muscle precursor cells, and what are the cellular and morphogenetic mechanisms underlying the process? Studies addressing these questions have provided controversial answers. In this review, we discuss the development of ideas in this area and recent work that has shed light on these issues. A working model has emerged that should permit deeper understanding of the role of ME development and maturation in esophageal disorders and in the functional and evolutionary underpinnings of the variable degree of esophageal striated myogenesis in vertebrate species. PMID:27504178

  20. Non-conscious recognition of affect in the absence of striate cortex.

    PubMed

    de Gelder, B; Vroomen, J; Pourtois, G; Weiskrantz, L

    1999-12-16

    Functional neuroimaging experiments have shown that recognition of emotional expressions does not depend on awareness of visual stimuli and that unseen fear stimuli can activate the amygdala via a colliculopulvinar pathway. Perception of emotional expressions in the absence of awareness in normal subjects has some similarities with the unconscious recognition of visual stimuli which is well documented in patients with striate cortex lesions (blindsight). Presumably in these patients residual vision engages alternative extra-striate routes such as the superior colliculus and pulvinar. Against this background, we conjectured that a blindsight subject (GY) might recognize facial expressions presented in his blind field. The present study now provides direct evidence for this claim. PMID:10716205

  1. Z-line formins promote contractile lattice growth and maintenance in striated muscles of C. elegans

    PubMed Central

    Mi-Mi, Lei; Votra, SarahBeth; Kemphues, Kenneth; Bretscher, Anthony

    2012-01-01

    Muscle contraction depends on interactions between actin and myosin filaments organized into sarcomeres, but the mechanism by which actin filaments incorporate into sarcomeres remains unclear. We have found that, during larval development in Caenorhabditis elegans, two members of the actin-assembling formin family, CYK-1 and FHOD-1, are present in striated body wall muscles near or on sarcomere Z lines, where barbed ends of actin filaments are anchored. Depletion of either formin during this period stunted growth of the striated contractile lattice, whereas their simultaneous reduction profoundly diminished lattice size and number of striations per muscle cell. CYK-1 persisted at Z lines in adulthood, and its near complete depletion from adults triggered phenotypes ranging from partial loss of Z line–associated filamentous actin to collapse of the contractile lattice. These results are, to our knowledge, the first genetic evidence implicating sarcomere-associated formins in the in vivo organization of the muscle cytoskeleton. PMID:22753896

  2. Role of retinal input on the development of striate-extrastriate patterns of connections in the rat.

    PubMed

    Laing, R J; Bock, A S; Lasiene, J; Olavarria, J F

    2012-10-01

    Previous studies have shown that retinal input plays an important role in the development of interhemispheric callosal connections, but little is known about the role retinal input plays on the development of ipsilateral striate-extrastriate connections and the interplay that might exist between developing ipsilateral and callosal pathways. We analyzed the effects of bilateral enucleation performed at different ages on both the distribution of extrastriate projections originating from restricted loci in medial, acallosal striate cortex, and the overall pattern of callosal connections revealed following multiple tracer injections. As in normal rats, striate-extrastriate projections in rats enucleated at birth consisted of multiple, well-defined fields that were largely confined to acallosal regions throughout extrastriate cortex. However, these projections were highly irregular and variable, and they tended to occupy correspondingly anomalous and variable acallosal regions. Moreover, area 17, but not area 18a, was smaller in enucleates compared to controls, resulting in an increase in the divergence of striate projections. Anomalies in patterns of striate-extrastriate projections were not observed in rats enucleated at postnatal day (P)6, although the size of area 17 was still reduced in these rats. These results indicate that the critical period during which the eyes influence the development of striate-extrastriate, but not the size of striate cortex, ends by P6. Finally, enucleation did not change the time course and definition of the initial invasion of axons into gray matter, suggesting that highly variable striate projections patterns do not result from anomalous pruning of exuberant distributions of 17-18a fibers in gray matter. PMID:22430936

  3. Segregation of striated and smooth muscle lineages by a Notch-dependent regulatory network

    PubMed Central

    2014-01-01

    Background Lineage segregation from multipotent epithelia is a central theme in development and in adult stem cell plasticity. Previously, we demonstrated that striated and smooth muscle cells share a common progenitor within their epithelium of origin, the lateral domain of the somite-derived dermomyotome. However, what controls the segregation of these muscle subtypes remains unknown. We use this in vivo bifurcation of fates as an experimental model to uncover the underlying mechanisms of lineage diversification from bipotent progenitors. Results Using the strength of spatio-temporally controlled gene missexpression in avian embryos, we report that Notch harbors distinct pro-smooth muscle activities depending on the duration of the signal; short periods prevent striated muscle development and extended periods, through Snail1, promote cell emigration from the dermomyotome towards a smooth muscle fate. Furthermore, we define a Muscle Regulatory Network, consisting of Id2, Id3, FoxC2 and Snail1, which acts in concert to promote smooth muscle by antagonizing the pro-myogenic activities of Myf5 and Pax7, which induce striated muscle fate. Notch and BMP closely regulate the network and reciprocally reinforce each other’s signal. In turn, components of the network strengthen Notch signaling, while Pax7 silences this signaling. These feedbacks augment the robustness and flexibility of the network regulating muscle subtype segregation. Conclusions Our results demarcate the details of the Muscle Regulatory Network, underlying the segregation of muscle sublineages from the lateral dermomyotome, and exhibit how factors within the network promote the smooth muscle at the expense of the striated muscle fate. This network acts as an exemplar demonstrating how lineage segregation occurs within epithelial primordia by integrating inputs from competing factors. PMID:25015411

  4. The significance of striated muscle in the mammary glands of marsupials.

    PubMed Central

    Griffiths, M; Slater, E

    1988-01-01

    The distribution and amounts of striated muscle within the mammary glands of pouched and pouchless marsupials from Australia and South America are described. Invasions into the mammary secretory parenchyma in pouchless marsupials by swathes of striated muscle from the ilio-marsupialis muscle are massive, in some instances concentrated into discrete muscles, which are inserted on to the bases of the teats; the name retractor mammae is proposed for these muscles. In pouched marsupials striated muscle penetrates the parenchyma, but the distribution is diffuse and the muscle strands are not inserted on to teats except in the instance of the glands of the honey possum Tarsipes rostratus. The young of anaesthetised pouchless marsupials hang down from the teats; as anaesthesia wears off they are hauled up tightly into the mammary area. It is concluded that this is a result of contraction of the retractor mammae muscles and that it is a means of protecting the naked young from injury by rough terrain. The mammary gland musculature in pouched marsupials is considered to be vestigial, but its contraction may have the function of initiating a 'tap-response' contraction of myoepithelium acting synergistically with the 'let-down' hormone mesotocin. Mechanisms of imbibition of milk by marsupial neonates, based on observations that they can suck fluid from non-distortable tubes, are discussed. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 PMID:3417541

  5. DisAp-dependent striated fiber elongation is required to organize ciliary arrays

    PubMed Central

    Galati, Domenico F.; Bonney, Stephanie; Kronenberg, Zev; Clarissa, Christina; Yandell, Mark; Elde, Nels C.; Jerka-Dziadosz, Maria; Giddings, Thomas H.; Frankel, Joseph

    2014-01-01

    Cilia-organizing basal bodies (BBs) are microtubule scaffolds that are visibly asymmetrical because they have attached auxiliary structures, such as striated fibers. In multiciliated cells, BB orientation aligns to ensure coherent ciliary beating, but the mechanisms that maintain BB orientation are unclear. For the first time in Tetrahymena thermophila, we use comparative whole-genome sequencing to identify the mutation in the BB disorientation mutant disA-1. disA-1 abolishes the localization of the novel protein DisAp to T. thermophila striated fibers (kinetodesmal fibers; KFs), which is consistent with DisAp’s similarity to the striated fiber protein SF-assemblin. We demonstrate that DisAp is required for KFs to elongate and to resist BB disorientation in response to ciliary forces. Newly formed BBs move along KFs as they approach their cortical attachment sites. However, because they contain short KFs that are rotated, BBs in disA-1 cells display aberrant spacing and disorientation. Therefore, DisAp is a novel KF component that is essential for force-dependent KF elongation and BB orientation in multiciliary arrays. PMID:25533842

  6. Striated muscle involvement in experimental oral infection by herpes simplex virus type 1.

    PubMed

    Gonzalez, María Inés; Sanjuan, Norberto A

    2013-07-01

    Herpes simplex virus type 1 is one of the most frequent causes of oral infection in humans, especially during early childhood. Several experimental models have been developed to study the pathogenesis of this virus but all of them employed adult animals. In this work, we developed an experimental model that uses mice younger than 4 days old, to more closely resemble human infection. Mice were infected subcutaneously with the prototype strain McIntyre of Herpes simplex-1, and the progression of infection was studied by immunoperoxidase. All animals died within 24-72 h post-infection, while viral antigens were found in the oral epithelium, nerves and brain. The most striking result was the finding of viral antigens in the nucleus and cytoplasm of cells belonging to striated muscles. Organotypic cultures of striated muscles were performed, and viral replication was observed in them by immunocytochemistry, electron microscopy and viral isolation. We conclude that the infection of striated muscles is present from the onset of oral infection and, eventually, could explain some clinical observations in humans. PMID:23445118

  7. Molecular organization in striated domains induced by transmembrane alpha-helical peptides in dipalmitoyl phosphatidylcholine bilayers.

    PubMed

    Sparr, Emma; Ganchev, Dragomir N; Snel, Margot M E; Ridder, Anja N J A; Kroon-Batenburg, Loes M J; Chupin, Vladimir; Rijkers, Dirk T S; Killian, J Antoinette; de Kruijff, Ben

    2005-01-11

    Transmembrane (TM) alpha-helical peptides with neutral flanking residues such as tryptophan form highly ordered striated domains when incorporated in gel-state 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayers and inspected by atomic force microscopy (AFM) (1). In this study, we analyze the molecular organization of these striated domains using AFM, photo-cross-linking, fluorescence spectroscopy, nuclear magnetic resonance (NMR), and X-ray diffraction techniques on different functionalized TM peptides. The results demonstrate that the striated domains consist of linear arrays of single TM peptides with a dominantly antiparallel organization in which the peptides interact with each other and with lipids. The peptide arrays are regularly spaced by +/-8.5 nm and are separated by somewhat perturbed gel-state lipids with hexagonally organized acyl chains, which have lost their tilt. This system provides an example of how domains of peptides and lipids can be formed in membranes as a result of a combination of specific peptide-peptide and peptide-lipid interactions. PMID:15628840

  8. Myocardium and striated muscle damage caused by licit or illicit drugs.

    PubMed

    Tóth, Anita Réka; Varga, Tibor

    2009-04-01

    Illicit and central nervous system active licit drug consumption related deaths are mainly the consequences of either unintentional or intentional overdose. According to the data in the relevant literature occurrences of different organ damages are also observable and this can play a role in death, as well. Organ damages may appear simultaneously with overdosing or can be extended in time, which may lead to proving the cause of death and establishing the relationships with previous medication difficult. The most frequent damage observed is rhabdomyolysis syndrome, which has been mainly described after cocaine or opium consumption. Authors present four cases from the autopsy documentation of the period between 2003 and 2008 at the Institute of Forensic Medicine, University of Szeged, Hungary in which illicit drug consumption or neuroleptic licit drug medication resulted in development of myocardium and striated muscle damage. The dominant clinical symptoms were hyperthermia, renal and circulatory failure. The laboratory tests showed renal and liver insufficiency; in addition the CK and CK-MB level increase suggested damage in striated muscles. The focal myocardium and striated muscle damage could be assessed as the cause of death in one case, but microscopic investigation proved the presence of damage in each. PMID:19342269

  9. Ultrastructural studies of the mitochondriae in the striated muscles of birds with regard to experimental hypokinesis

    NASA Technical Reports Server (NTRS)

    Belak, M.; Kocisova, J.; Boda, K.

    1980-01-01

    Electron microscopic studies were carried out on the mitochrondria of the transversely striated muscles with regard to experimental hypokinesia. As compared to the central group the mitochondria of m. pectoralis thoracicus and the m. iliotibialis posterior in hypokinetic birds reveal marked changes. In filamentous and ovoid mitochondria, vacuoles can be observed which in some cases produced larger light formations with following disappearance of the cristae and destruction of mitochondria. Fat particles located at the poles of the altered mitochondria, sporadically occurring also laterally, presented another finding. The Z-lines of the sarcomere did not form a continuous line, but were somewhat shifted.

  10. Form, function and intracortical projections of spiny neurones in the striate visual cortex of the cat.

    PubMed Central

    Martin, K A; Whitteridge, D

    1984-01-01

    We have studied the neuronal circuitry and structure-function relationships of single neurones in the striate visual cortex of the cat using a combination of electrophysiological and anatomical techniques. Glass micropipettes filled with horseradish peroxidase were used to record extracellularly from single neurones. After studying the receptive field properties, the afferent inputs of the neurones were studied by determining their latency of response to electrical stimulation at different positions along the optic pathway. Some cells were thus classified as receiving a mono- or polysynaptic input from afferents of the lateral geniculate nucleus (l.g.n.), via X- or Y-like retinal ganglion cells. Two striking correlations were found between dendritic morphology and receptive field type. All spiny stellate cells, and all star pyramidal cells in layer 4A, had receptive fields with spatially separate on and off subfields (S-type receptive fields). All the identified afferent input to these, the major cell types in layer 4, was monosynaptic from X- or Y-like afferents. Neurones receiving monosynaptic X- or Y-like input were not strictly segregated in layer 4 and the lower portion of layer 3. Nevertheless the X- and Y-like l.g.n. fibres did not converge on any of the single neurones so far studied. Monosynaptic input from the l.g.n. afferents was not restricted to cells lying within layers 4 and 6, the main termination zones of the l.g.n. afferents, but was also received by cells lying in layers 3 and 5. The projection pattern of cells receiving monosynaptic input differed widely, depending on the laminar location of the cell soma. This suggests the presence of a number of divergent paths within the striate cortex. Cells receiving indirect input from the l.g.n. afferents were located mainly within layers 2, 3 and 5. Most pyramidal cells in layer 3 had axons projecting out of the striate cortex, while many axons of the layer 5 pyramids did not. The layer 5 cells showed

  11. Perineal striated muscles: Anatomy, spinal motoneurons, and participation on copulatory behavior in male rabbits (Oryctolagus cuniculus).

    PubMed

    Zempoalteca, R; Lucio, R A; Eguibar, J R

    2008-09-01

    Despite the importance of rabbits in reproductive studies, little information is available on the anatomy and participation of the striated-perineal muscles in male copulatory behavior. In our study, we describe the gross anatomy of two striated-perineal muscles: the ischiocavernosus (ICm) and the bulbospongiosus (BSm). Both muscles have their origin at the ischiadic arc, but the ICm is inserted into the penile crura and the BSm onto the ligamentum suspensorium of the penis. The motoneurons of both muscles were identified using retrograde labeling with horseradish peroxidase coupled to wheat-germ agglutinin. Motoneurons were dispersed in the lower-lumbar and upper-sacral spinal-cord segments, instead of being aggregated in the neuronal nucleus as in other species: the rat, mouse, gerbil, cat, and man. Bilateral dennervation of the ICm or BSm or both in sexually experienced male rabbits did not affect copulatory variables measured at 10, 20, and 30 days after surgery. However, muscular dennervation produced extravaginal ejaculations in 42% of copulatory tests and no ejaculation in 7% of tests, although male pelvic thrusting occurred. These results suggest the participation of the ICm and BSm perineal muscles in penile orientation during copulation but not in seminal emission as described in other mammalian species. PMID:18563835

  12. Systemic delivery of genes to striated muscles using adeno-associated viral vectors.

    PubMed

    Gregorevic, Paul; Blankinship, Michael J; Allen, James M; Crawford, Robert W; Meuse, Leonard; Miller, Daniel G; Russell, David W; Chamberlain, Jeffrey S

    2004-08-01

    A major obstacle limiting gene therapy for diseases of the heart and skeletal muscles is an inability to deliver genes systemically to muscles of an adult organism. Systemic gene transfer to striated muscles is hampered by the vascular endothelium, which represents a barrier to distribution of vectors via the circulation. Here we show the first evidence of widespread transduction of both cardiac and skeletal muscles in an adult mammal, after a single intravenous administration of recombinant adeno-associated virus pseudotype 6 vectors. The inclusion of vascular endothelium growth factor/vascular permeability factor, to achieve acute permeabilization of the peripheral microvasculature, enhanced tissue transduction at lower vector doses. This technique enabled widespread muscle-specific expression of a functional micro-dystrophin in the skeletal muscles of dystrophin-deficient mdx mice, which model Duchenne muscular dystrophy. We propose that these methods may be applicable for systemic delivery of a wide variety of genes to the striated muscles of adult mammals. PMID:15273747

  13. The Popeye Domain Containing Genes and their Function in Striated Muscle

    PubMed Central

    Schindler, Roland FR; Scotton, Chiara; French, Vanessa; Ferlini, Alessandra; Brand, Thomas

    2016-01-01

    The Popeye domain containing (POPDC) genes encode a novel class of cAMP effector proteins, which are abundantly expressed in heart and skeletal muscle. Here we will review their role in striated muscle as deduced from work in cell and animal models and the recent analysis of patients carrying a missense mutation in POPDC1. Evidence suggests that POPDC proteins control membrane trafficking of interacting proteins. Furthermore, we will discuss the current catalogue of established protein-protein interactions. In recent years, the number of POPDC-interacting proteins is rising and currently includes ion channels (TREK-1), sarcolemma-associated proteins serving functions in mechanical stability (Dystrophin), compartmentalization (Caveolin 3), scaffolding (ZO-1), trafficking (NDRG4, VAMP2/3) and repair (Dysferlin), or acting as a guanine nucleotide exchange factor for Rho-family GTPases (GEFT). Recent evidence suggests that POPDC proteins might also control the cellular level of the nuclear proto-oncoprotein c-Myc. These data suggests that this family of cAMP-binding proteins probably serves multiple roles in striated muscle. PMID:27347491

  14. Single-unit and 2-deoxyglucose studies of side inhibition in macaque striate cortex.

    PubMed Central

    Born, R T; Tootell, R B

    1991-01-01

    In the course of studies to map spatial frequency tuning of neurons in layers 2 and 3 of macaque striate cortex, we found that a high proportion (70%) of cells in the interblob regions responded poorly to full-field gratings, compared with responses to single bars, edges, or delimited gratings. This was most often due to side inhibition, in which increasing the number of cycles of a grating placed within the cell's receptive field causes progressive inhibition of response. Quantitative receptive-field mappings showed, however, that the inhibition can occur within the region activated by a bar, as well as beyond it. The inhibition appears to be orientation-selective, in that a surround grating was more effective at inhibiting the response to a center grating patch if it was of similar orientation. 2-Deoxyglucose experiments confirmed that side inhibition is very widespread in the interblobs of layers 2 and 3 and suggested that it is reduced or lacking in layers 4A through 6. Since layers 2 and 3 of striate cortex are the major source of cortical projections to area V2 and beyond, the prevalence of side stopping in these laminae has implications for theories of cortical visual function. Side-stopped interblob cells may be acting as "contour-pass filters" that filter out redundant information in textured or noisy surfaces, focusing subsequent form processing on contrasts corresponding to object boundaries. Images PMID:1871122

  15. 'Striated Delta' Clouds As Tracers Of Inertia-Gravity Wave Emission From Upper Jets And Extratropical Cyclones

    NASA Astrophysics Data System (ADS)

    Morgan, A. L.; Reeder, M. J.

    2012-12-01

    'Striated Delta' cloud formations are frequently tracers of upper-tropospheric inertia-gravity wave disturbances near the jet stream, coincident with rapid extratropical cyclogenesis (Feren, 1995). The investigation of source mechanisms in this context is important for better understanding of how and where large-amplitude inertia-gravity waves are generated, which propagate energy throughout the atmosphere and transfer it to the mean flow through breaking or attenuation processes. A seasonal study of twenty-eight Striated Delta events in the Australia/New Zealand region during May to September 2009 is analysed in the high-resolution ECMWF YOTC dataset. Mean composite analyses show that Striated Deltas occur in an upper-tropospheric environment of strong horizontal divergence, strong parcel accelerations, strong vertical motion and geostrophic imbalance. Synoptically, the Striated Delta cases occur in the poleward jet exit region near the axis of inflexion between an upstream upper trough and a downstream upper ridge. This is consistent with findings of previous studies regarding the synoptic environment characteristic of gravity wave generation. A Q-vector partitioning analysis suggests that flow curvature and advection of shear are the two greatest components to synoptic scale vertical motion forcing. The Q-Vector analysis also explains the characteristic triangular shape of the Striated Delta cloud formation. It is hypothesised that strong parcel accelerations due to curvature of the flow, as well as air parcel deceleration in the jet streak exit region, are responsible for the generation of inertia-gravity waves evident in the banding of Striated Delta clouds. Furthermore, deep convection is favoured in the poleward jet exit region by the ageostrophic circulation and is also thought to play a role in the generation of waves and the modulation of wavelengths. A distinct and interesting Striated Delta and extratropical cyclogenesis event from September 2009 is

  16. Reappraisal of intergender differences in the urethral striated sphincter explains why a completely circular arrangement is difficult in females: a histological study using human fetuses

    PubMed Central

    Takenaka, Atsushi; Rodríguez-Vázquez, Jose Francisco; Murakami, Gen; Matsubara, Akio

    2012-01-01

    To investigate why the development of a completely circular striated sphincter is so rare, we examined histological sections of 11 female and 11 male mid-term human fetuses. In male fetuses, the striated muscle initially extended in the frontal, rather than in the horizontal plane. However, a knee-like portion was absent in the female fetal urethra because, on the inferior side of the vaginal end, a wide groove for the future vestibule opened inferiorly. Accordingly, it was difficult for the developing striated muscle to surround the groove, even though there was not a great difference in width or thickness between the female vestibule and the male urethra. The development of a completely circular striated sphincter seems to be impossible in females because of interruption of the frontal plane by the groove-like vestibule. However, we cannot rule out the possibility that before descent of the vagina, the urethral striated muscle extends posteriorly. PMID:22822461

  17. Modulation of the cytosolic androgen receptor in striated muscle by sex steroids

    NASA Technical Reports Server (NTRS)

    Rance, N. E.; Max, S. E.

    1982-01-01

    The influence of orchiectomy (GDX) and steroid administration on the level of the cytosolic androgen receptor in the rat levator ani muscle and in rat skeletal muscles (tibialis anterior and extensor digitorum longus) was studied. Androgen receptor binding to muscle cytosol was measured using H-3 methyltrienolone (R1881) as ligand, 100 fold molar excess unlabeled R1881 to assess nonspecific binding, and 500 fold molar excess of triamcinolone acetonide to prevent binding to glucocorticoid and progestin receptors. Results demonstrate that modification of the levels of sex steroids can alter the content of androgen receptors of rat striated muscle. Data suggest that: (1) cytosolic androgen receptor levels increase after orchiectomy in both levator ani muscle and skeletal muscle; (2) the acute increase in receptor levels is blocked by an inhibitor of protein synthesis; and (3) administration of estradiol-17 beta to castrated animals increases receptor binding in levator ani muscle but not in skeletal muscle.

  18. Analytical study of striated nozzle flow with small radius of curvature ratio throats

    NASA Technical Reports Server (NTRS)

    Norton, D. J.; White, R. E.

    1972-01-01

    An analytical method was developed which is capable of estimating the chamber and throat conditions in a nozzle with a low radius of curvature throat. The method was programmed using standard FORTRAN 4 language and includes chemical equilibrium calculation subprograms (modified NASA Lewis program CEC71) as an integral part. The method determines detailed and gross rocket characteristics in the presence of striated flows and gives detailed results for the motor chamber and throat plane with as many as 20 discrete zones. The method employs a simultaneous solution of the mass, momentum, and energy equations and allows propellant types, 0/F ratios, propellant distribution, nozzle geometry, and injection schemes to be varied so to predict spatial velocity, density, pressure, and other thermodynamic variable distributions in the chamber as well as the throat. Results for small radius of curvature have shown good comparison to experimental results. Both gaseous and liquid injection may be considered with frozen or equilibrium flow calculations.

  19. Local and global principles of striate cortical organization: an advanced model.

    PubMed

    Bauer, R; Dow, B M

    1991-01-01

    A model of the functional architecture in monkey striate cortex is proposed, based on recent data, in which the global structure is a result of the local structure. The local structure itself is organized around the cytochrome oxidase blobs. It is characterized by different anisotropic distributions of preferred orientations in upper and lower layers. In particular, the upper layers show a bias for "radial" orientations and the lower layers show a bias for "concentric" orientations (Bauer and Dow 1989). This organization may derive from the symmetry of the visual field and visual system which tends to be radial or concentric rather than cartesian. Functionally, the increased sensitivities of the different radial and concentric maps of orientation and movement detectors seem to be an adaptive fit to optic flow fields on the retina during complex movements of the subject in its environment. PMID:1650592

  20. The regulation and function of the striated muscle activator of rho signaling (STARS) protein

    PubMed Central

    Wallace, Marita A.; Lamon, Séverine; Russell, Aaron P.

    2012-01-01

    Healthy living throughout the lifespan requires continual growth and repair of cardiac, smooth, and skeletal muscle. To effectively maintain these processes muscle cells detect extracellular stress signals and efficiently transmit them to activate appropriate intracellular transcriptional programs. The striated muscle activator of Rho signaling (STARS) protein, also known as Myocyte Stress-1 (MS1) protein and Actin-binding Rho-activating protein (ABRA) is highly enriched in cardiac, skeletal, and smooth muscle. STARS binds actin, co-localizes to the sarcomere and is able to stabilize the actin cytoskeleton. By regulating actin polymerization, STARS also controls an intracellular signaling cascade that stimulates the serum response factor (SRF) transcriptional pathway; a pathway controlling genes involved in muscle cell proliferation, differentiation, and growth. Understanding the activation, transcriptional control and biological roles of STARS in cardiac, smooth, and skeletal muscle, will improve our understanding of physiological and pathophysiological muscle development and function. PMID:23248604

  1. Isoform composition, gene expression and sarcomeric protein phosphorylation in striated muscle of mice after space flight

    NASA Astrophysics Data System (ADS)

    Vikhlyantsev, Ivan; Ulanova, Anna; Salmov, Nikolay; Gritsyna, Yulia; Bobylev, Alexandr; Rogachevsky, Vadim; Shenkman, Boris; Podlubnaya, Zoya

    Using RT-PCR and SDS-PAGE, changes in isoform composition, gene expression, titin and nebulin phosphorylation, as well as changes in isoform composition of myosin heavy chains in striated muscles of mice were studied after 30-day-long space flight onboard the Russian spacecraft “BION-M” No. 1. The muscle fibre-type shift from slow-to-fast was observed in m. gastrocnemius and m. tibialis anterior of animals from “Flight” group. A decrease in the content of the NT and N2A titin isoforms and nebulin in the skeletal muscles of animals from “Flight” group was found. Meanwhile, significant differences in gene expression of these proteins in skeletal muscles of mice from “Flight” and “Control” groups were not observed. Using Pro-Q Diamond stain, an increase in titin phosphorylation in m. gastrocnemius of mice from “Flight” group was detected. The content of the NT, N2BA and N2B titin isoforms in cardiac muscle of mice from “Flight” and “Control” groups did not differ, nevertheless an increase in titin gene expression in the myocardium of the “Flight” group animals was found. The observed changes will be discussed in the context of theirs role in contractile activity of striated muscles of mice in conditions of weightlessness. This work was supported by the Russian Foundation for Basic Research (grants No. 14-04-32240, 14-04-00112). Acknowledgement. We express our gratitude to the teams of Institute of Biomedical Problems RAS and “PROGRESS” Corporation involved in the preparation of the “BION-M” mission.

  2. Neurons in Striate Cortex Signal Disparity in Half-Matched Random-Dot Stereograms

    PubMed Central

    Read, Jenny C. A.; Cumming, Bruce G.

    2016-01-01

    Human stereopsis can operate in dense “cyclopean” images containing no monocular objects. This is believed to depend on the computation of binocular correlation by neurons in primary visual cortex (V1). The observation that humans perceive depth in half-matched random-dot stereograms, although these stimuli have no net correlation, has led to the proposition that human depth perception in these stimuli depends on a distinct “matching” computation possibly performed in extrastriate cortex. However, recording from disparity-selective neurons in V1 of fixating monkeys, we found that they are in fact able to signal disparity in half-matched stimuli. We present a simple model that explains these results. This reinstates the view that disparity-selective neurons in V1 provide the initial substrate for perception in dense cyclopean stimuli, and strongly suggests that separate correlation and matching computations are not necessary to explain existing data on mixed correlation stereograms. SIGNIFICANCE STATEMENT The initial step in stereoscopic 3D vision is generally thought to be a correlation-based computation that takes place in striate cortex. Recent research has argued that there must be an additional matching computation involved in extracting stereoscopic depth in random-dot stereograms. This is based on the observation that humans can perceive depth in stimuli with a mean binocular correlation of zero (where a correlation-based mechanism should not signal depth). We show that correlation-based cells in striate cortex do in fact signal depth here because they convert fluctuations in the correlation level into a mean change in the firing rate. Our results reinstate the view that these cells provide a sufficient substrate for the perception of stereoscopic depth. PMID:27559177

  3. Mechanical Stretch-Induced Activation of ROS/RNS Signaling in Striated Muscle

    PubMed Central

    Ward, Christopher W.; Prosser, Benjamin L.

    2014-01-01

    Significance: Mechanical activation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) occurs in striated muscle and affects Ca2+ signaling and contractile function. ROS/RNS signaling is tightly controlled, spatially compartmentalized, and source specific. Recent Advances: Here, we review the evidence that within the contracting myocyte, the trans-membrane protein NADPH oxidase 2 (Nox2) is the primary source of ROS generated during contraction. We also review a newly characterized signaling cascade in cardiac and skeletal muscle in which the microtubule network acts as a mechanotransduction element that activates Nox2-dependent ROS generation during mechanical stretch, a pathway termed X-ROS signaling. Critical Issues: In the heart, X-ROS acts locally and affects the sarcoplasmic reticulum (SR) Ca2+ release channels (ryanodine receptors) and tunes Ca2+ signaling during physiological behavior, but excessive X-ROS can promote Ca2+-dependent arrhythmias in pathology. In skeletal muscle, X-ROS sensitizes Ca2+-permeable sarcolemmal “transient receptor potential” channels, a pathway that is critical for sustaining SR load during repetitive contractions, but when in excess, it is maladaptive in diseases such as Duchenne Musclar dystrophy. Future Directions: New advances in ROS/RNS detection as well as molecular manipulation of signaling pathways will provide critical new mechanistic insights into the details of X-ROS signaling. These efforts will undoubtedly reveal new avenues for therapeutic intervention in the numerous diseases of striated muscle in which altered mechanoactivation of ROS/RNS production has been identified. Antioxid. Redox Signal. 20, 929–936. PMID:23971496

  4. Involvement of catecholaminergic neurons in motor innervation of striated muscle in the mouse esophagus.

    PubMed

    van der Keylen, Piet; Garreis, Fabian; Steigleder, Ruth; Sommer, Daniel; Neuhuber, Winfried L; Wörl, Jürgen

    2016-05-01

    Enteric co-innervation is a peculiar innervation pattern of striated esophageal musculature. Both anatomical and functional data on enteric co-innervation related to various transmitters have been collected in different species, although its function remains enigmatic. However, it is unclear whether catecholaminergic components are involved in such a co-innervation. Thus, we examined to identify catecholaminergic neuronal elements and clarify their relationship to other innervation components in the esophagus, using immunohistochemistry with antibodies against tyrosine hydroxylase (TH), vesicular acetylcholine transporter (VAChT), choline acetyltransferase (ChAT) and protein gene product 9.5 (PGP 9.5), α-bungarotoxin (α-BT) and PCR with primers for amplification of cDNA encoding TH and dopamine-β-hydroxylase (DBH). TH-positive nerve fibers were abundant throughout the myenteric plexus and localized on about 14% of α-BT-labelled motor endplates differing from VAChT-positive vagal nerve terminals. TH-positive perikarya represented a subpopulation of only about 2.8% of all PGP 9.5-positive myenteric neurons. Analysis of mRNA showed both TH and DBH transcripts in the mouse esophagus. As ChAT-positive neurons in the compact formation of the nucleus ambiguus were negative for TH, the TH-positive nerve varicosities on motor endplates are presumably of enteric origin, although a sympathetic origin cannot be excluded. In the medulla oblongata, the cholinergic ambiguus neurons were densely supplied with TH-positive varicosities. Thus, catecholamines may modulate vagal motor innervation of esophageal-striated muscles not only at the peripheral level via enteric co-innervation but also at the central level via projections to the nucleus ambiguus. As Parkinson's disease, with a loss of central dopaminergic neurons, also affects the enteric nervous system and dysphagia is prevalent in patients with this disease, investigation of intrinsic catecholamines in the esophagus may

  5. A striated pattern of wear in ultrahigh-molecular-weight polyethylene components of Miller-Galante total knee arthroplasty.

    PubMed

    Wimmer, M A; Andriacchi, T P; Natarajan, R N; Loos, J; Karlhuber, M; Petermann, J; Schneider, E; Rosenberg, A G

    1998-01-01

    Wear of the polyethylene tibial components is a potential cause of failure in total knee arthroplasty. In addition to pitting, burnishing, and scratching, subtle striations on the bearing portion of the tibial surface have been observed in components retrieved relatively early after implantation. The striated pattern most typically occurred in areas centrally located within the articulating surface. The striations were anteroposterior directed and were identified as local cold flow at the surface. There was a strong correlation between the medial and lateral striated areas, suggesting that these patterns are related to cyclic rolling of the knee. The general characteristics and alignment of the striations could be attributed to the compressive and tractive forces occurring during femoral rollback. For the clinician, these results suggest that kinematics, as well as contact stress, should be considered when evaluating wear of polyethylene components. PMID:9493532

  6. Striated domains: self-organizing ordered assemblies of transmembrane alpha-helical peptides and lipids in bilayers.

    PubMed

    de Kruijff, Ben; Killian, J Antoinette; Ganchev, Dragomir N; Rinia, Hilde A; Sparr, Emma

    2006-03-01

    This review summarizes the knowledge on striated domains, which are ordered assemblies of transmembrane peptides and lipids under gel-state conditions. The structure, mechanism of function and utility of this system as a model for domain formation is described, resulting in a molecular description of the domains and a discussion on the relevance of these insights for the function/formation and structure of similar domains in biological membranes. PMID:16542143

  7. Evaluation of Vascular Delivery Methodologies to Enhance rAAV6-mediated Gene Transfer to Canine Striated Musculature

    PubMed Central

    Gregorevic, Paul; Schultz, Brian R; Allen, James M; Halldorson, Jeffrey B; Blankinship, Michael J; Meznarich, Norman A; Kuhr, Christian S; Doremus, Caitlin; Finn, Eric; Liggitt, Denny; Chamberlain, Jeffrey S

    2009-01-01

    A growing body of research supports the development of recombinant adeno-associated viral (rAAV) vectors for delivery of gene expression cassettes to striated musculature as a method of treating severe neuromuscular conditions. However, it is unclear whether delivery protocols that achieve extensive gene transfer in mice can be adapted to produce similarly extensive gene transfer in larger mammals and ultimately patients. Consequently, we sought to investigate methodological modifications that would facilitate rAAV-mediated gene transfer to the striated musculature of canines. A simple procedure incorporating acute (i) occlusion of limb blood flow, (ii) exsanguination via compression bandage, and (iii) vector “dwell” time of <20 minutes, markedly enhanced the transduction of limb muscles, compared with a simple bolus limb infusion of vector. A complementary method whereby vector was infused into the jugular vein led to efficient transduction of cardiomyocytes and to a lesser degree the diaphragm. Together these methods can be used to achieve transgene expression in heart, diaphragm, and limb muscles of juvenile dogs using rAAV6 vectors. These results establish that rAAV-mediated gene delivery is a viable approach to achieving systemic transduction of striated musculature in mammals approaching the dimensions of newborn humans. PMID:19471246

  8. Regulation of structure and function of sarcomeric actin filaments in striated muscle of the nematode Caenorhabditis elegans

    PubMed Central

    Ono, Shoichiro

    2014-01-01

    The nematode Caenorhabditis elegans has been used as a valuable system to study structure and function of striated muscle. The body wall muscle of C. elegans is obliquely striated muscle with highly organized sarcomeric assembly of actin, myosin, and other accessary proteins. Genetic and molecular biological studies in C. elegans have identified a number of genes encoding structural and regulatory components for the muscle contractile apparatuses, and many of them have counterparts in mammalian cardiac and skeletal muscles or striated muscles in other invertebrates. Applicability of genetics, cell biology, and biochemistry has made C. elegans an excellent system to study mechanisms of muscle contractility and assembly and maintenance of myofibrils. This review focuses on the regulatory mechanisms of structure and function of actin filaments in the C. elegans body wall muscle. Sarcomeric actin filaments in C. elegans muscle are associated with the troponin-tropomyosin system that regulates the actin-myosin interaction. Proteins that bind to the side and ends of actin filaments support ordered assembly of thin filaments. Furthermore, regulators of actin dynamics play important roles in initial assembly, growth, and maintenance of sarcomeres. The knowledge acquired in C. elegans can serve as bases to understand the basic mechanisms of muscle structure and function. PMID:25125169

  9. Dietary Fish Oil Blocks the Microcirculatory Manifestations of Ischemia- Reperfusion Injury in Striated Muscle in Hamsters

    NASA Astrophysics Data System (ADS)

    Lehr, Hans-Anton; Hubner, Christoph; Nolte, Dirk; Kohlschutter, Alfried; Messmer, Konrad

    1991-08-01

    Epidemiologic observations and experimental studies have demonstrated a protective effect of dietary fish oil on the clinical manifestations of ischemia-reperfusion injury. To investigate the underlying mechanisms, we used the dorsal skinfold chamber model for intravital fluorescence microscopy of the microcirculation in striated muscle of awake hamsters. In control hamsters (n = 7), reperfusion after a 4-hr pressure-induced ischemia to the muscle tissue elicited the adhesion of fluorescently stained leukocytes to the endothelium of postcapillary venules, capillary obstruction, and the breakdown of endothelial integrity. These microvascular manifestations of ischemia-reperfusion injury were significantly attenuated in animals (n = 7) when fed with a fish oil-enriched diet for 4 weeks prior to the experiments. In leukocyte total lipids, the fish oil diet resulted in a substantial displacement of arachidonic acid, the precursor of the potent adhesionpromoting leukotriene (LT) B_4, by fish oil-derived eicosapentaenoic acid, the precursor of biologically less potent LTB_5, emphasizing the mediator role of LTB_4 in ischemia-reperfusion injury. These results suggest that the preservation of microvascular perfusion by dietary fish oil contributes to its protective effects on the clinical manifestations of ischemia-reperfusion injury.

  10. Pulsed nuclear magnetic resonance study of 39K in frog striated muscle.

    PubMed Central

    Civan, M M; McDonald, G G; Pring, M; Shporer, M

    1976-01-01

    Samples of 1 M KCl solution and 10 samples of intact frog striated muscle were studied at 4-7 degrees C and/or at 21-22 degrees C. Field inhomogeneity was minimized by using small sample volumes and by using a superconducting magnet designed specifically to provide highly homogeneous fields. In the present experiments, magnetic field inhomogeneity was measured to contribute less than 15% to the free induction decay observed for intracellular 39K. The signal-to-noise ratio of the measurements was enhanced by means of extensive time-averaging. The rates of nuclear relaxation for 39K in aqueous solution were 22 +/- 3 (mean +/- 95% confidence limits) s-1 at 4-7 degrees C and 15 +/- 2 s-1 at 21-22 degrees C. For intracellular 39K, (1/T2) was measured to be 327 +/- 22 s-1 and 229 +/- 10 s-1 at the lower and higher temperatures, respectively. The corresponding values for (1/T1) in the same muscle samples were 198 +/- 31 s-1 and 79 +/- 15 s-1 at 4-7 degrees C and at 21-22 degrees C, respectively. These results for 39K are similar to those previously obtained for intracellular 23Na. Since less than 1% of the intracellular 23Na has been estimated to be immobilized, fractional immobilization of intracellular 39K is also likely to be insubstantial. PMID:1086686

  11. Background luminance affects the detection of microampere currents delivered to macaque striate cortex.

    PubMed

    Tehovnik, Edward J; Slocum, Warren M

    2009-07-01

    Monkeys detect electrical microstimulation delivered to the striate cortex (area V1). We examined whether the ability of monkeys to detect such stimulation is affected by background luminance. While remaining fixated on a spot of light centered on a monitor, a monkey was required to detect a 100 ms train of electrical stimulation delivered to a site within area V1 situated from 1 to 1.5 mm below the cortical surface. A monkey signaled the delivery of stimulation by depressing a lever after which it was rewarded with a drop of apple juice. Control trials were interleaved during which time no stimulation was delivered and the monkey was rewarded for not depressing the lever. Biphasic pulses were delivered at 200 Hz and the current ranged from 2 to 30 microA using 0.2 ms anode-first biphasic pulses. The background luminance level of the monitor could be varied from 0.005 to 148 cd/m(2). It was found that, for monitor luminance levels below 10 cd/m(2), the current threshold to evoke a detection response increased. We discuss the significance of this result with regard to phosphenes elicited from human V1 and in relation to visual perception. PMID:19558620

  12. Increased cytosolic androgen receptor binding in rat striated muscle following denervation and disuse

    NASA Technical Reports Server (NTRS)

    Bernard, P. A.; Fishman, P. S.; Max, S. R.; Rance, N. E.

    1984-01-01

    The effects of denervation and disuse on cytosolic androgen receptor binding by rat striated muscle are investigated. Denervation of the extensor digitorum longus and tibialis anterior muscles caused by a 40-50-percent increase in cytosolic androgen receptor concentration with no change in apparent binding affinity. This effect was evident at 6 h postdenervation, maximal at 24 h, and declined to 120 percent of the control level 72 h after denervation. A 40-percent increase in cytosolic androgen receptor concentration was also noted 24 hr after denervation of the hormone-sensitive levator ani muscle. The effect of denervation on androgen receptors was blocked by in vivo injection of cycloheximide; therefore, de novo receptor synthesis probably is not involved in the observed increase. Disuse, produced by subperineurial injection of tetrodotoxin into the tibial and common peroneal branches of the sciatic nerve, mimicked the effect of denervation on androgen receptor binding, suggesting that neuromuscular activity is important in regulation of receptor concentration. Possible mechanisms subserving this effect are discussed.

  13. Revealing T-Tubules in Striated Muscle with New Optical Super-Resolution Microscopy Techniquess.

    PubMed

    Jayasinghe, Isuru D; Clowsley, Alexander H; Munro, Michelle; Hou, Yufeng; Crossman, David J; Soeller, Christian

    2015-01-01

    The t-tubular system plays a central role in the synchronisation of calcium signalling and excitation-contraction coupling in most striated muscle cells. Light microscopy has been used for imaging t-tubules for well over 100 years and together with electron microscopy (EM), has revealed the three-dimensional complexities of the t-system topology within cardiomyocytes and skeletal muscle fibres from a range of species. The emerging super-resolution single molecule localisation microscopy (SMLM) techniques are offering a near 10-fold improvement over the resolution of conventional fluorescence light microscopy methods, with the ability to spectrally resolve nanometre scale distributions of multiple molecular targets. In conjunction with the next generation of electron microscopy, SMLM has allowed the visualisation and quantification of intricate t-tubule morphologies within large areas of muscle cells at an unprecedented level of detail. In this paper, we review recent advancements in the t-tubule structural biology with the utility of various microscopy techniques. We outline the technical considerations in adapting SMLM to study t-tubules and its potential to further our understanding of the molecular processes that underlie the sub-micron scale structural alterations observed in a range of muscle pathologies. PMID:26913143

  14. Characterization of beta-connectin (titin 2) from striated muscle by dynamic light scattering.

    PubMed Central

    Higuchi, H; Nakauchi, Y; Maruyama, K; Fujime, S

    1993-01-01

    Connectin (titin) is a large filamentous protein (single peptide) with a molecular mass of approximately 3 MDa, contour length approximately 900 nm, and diameter approximately 4 nm, and resides in striated muscle. Connectin links the thick filaments to the Z-lines in a sarcomere and produces a passive elastic force when muscle fiber is stretched. The aim of this study is to elucidate some aspects of physical properties of isolated beta-connectin (titin 2), a proteolytic fragment of connectin, by means of dynamic light-scattering (DLS) spectroscopy. The analysis of DLS spectra for beta-connectin gave the translational diffusion coefficient of 3.60 x 10(-8) cm2/s at 10 degrees C (or the hydrodynamic radius of 44.1 nm), molecular mass little smaller than 3.0 MDa (for a literature value of sedimentation coefficient), the root-mean-square end-to-end distance of 163 nm (or the radius of gyration of 66.6 nm), and the Kuhn segment number of 30 and segment length of 30 nm (or the persistence length of 15 nm). These results permitted to estimate the flexural rigidity of 6.0 x 10(-20) dyn x cm2 for filament bending, and the elastic constant of 7 dyn/cm for extension of one persistence length. Based on a simple model, implications of the present results in muscle physiology are discussed. Images FIGURE 1 PMID:8298020

  15. Large-scale Models Reveal the Two-component Mechanics of Striated Muscle

    PubMed Central

    Jarosch, Robert

    2008-01-01

    This paper provides a comprehensive explanation of striated muscle mechanics and contraction on the basis of filament rotations. Helical proteins, particularly the coiled-coils of tropomyosin, myosin and α-actinin, shorten their H-bonds cooperatively and produce torque and filament rotations when the Coulombic net-charge repulsion of their highly charged side-chains is diminished by interaction with ions. The classical “two-component model” of active muscle differentiated a “contractile component” which stretches the “series elastic component” during force production. The contractile components are the helically shaped thin filaments of muscle that shorten the sarcomeres by clockwise drilling into the myosin cross-bridges with torque decrease (= force-deficit). Muscle stretch means drawing out the thin filament helices off the cross-bridges under passive counterclockwise rotation with torque increase (= stretch activation). Since each thin filament is anchored by four elastic α-actinin Z-filaments (provided with force-regulating sites for Ca2+ binding), the thin filament rotations change the torsional twist of the four Z-filaments as the “series elastic components”. Large scale models simulate the changes of structure and force in the Z-band by the different Z-filament twisting stages A, B, C, D, E, F and G. Stage D corresponds to the isometric state. The basic phenomena of muscle physiology, i. e. latency relaxation, Fenn-effect, the force-velocity relation, the length-tension relation, unexplained energy, shortening heat, the Huxley-Simmons phases, etc. are explained and interpreted with the help of the model experiments. PMID:19330099

  16. Evidence for multiple extra-striate mechanisms behind perception of visual motion gradients.

    PubMed

    Meso, Andrew Isaac; Hess, Robert F

    2012-07-01

    Perceiving motion patterns in visual scenes in which speed or motion direction varies over space while average luminance remains constant presents a processing task that requires at least two separate stages of neural spatio-temporal filtering. We have previously probed the transfer of information between these stages of filtering identifying a largely scale invariant process in which narrowband initial motion sensitive filters are coupled with a broad range of spatial frequencies of secondary filters, with an optimal coupling - in terms of optimal observer visual sensitivity - at a frequency ratio of around twelve. In the current work, we used the same stimulus to investigate the possible presence of multiple secondary filtering mechanisms and their associated bandwidths. Using a forced choice psychophysical task with both a detection and an identification component, we presented experimental blocks containing stimuli with one of two different modulator frequencies in each trial to measure the frequency difference at which the detection performance matched the identification of the frequency. We found that at a frequency differences of about 2.2 octaves, performance of both tasks was similar, and the processing could therefore be inferred to occur in independent frequency channels. The same observation was confirmed for stimuli presented at a longer viewing distance. We conclude that for the motion gradient stimuli, there are secondary filtering mechanisms with a moderately broad bandwidth of over 2 octaves that underlie our sensitivity for detecting motion gradients of different modulation frequency. These are likely to be implemented at least in part within the dorsal stream of extra-striate cortex. PMID:22659589

  17. Lessons from mammalian hibernators: molecular insights into striated muscle plasticity and remodeling.

    PubMed

    Tessier, Shannon N; Storey, Kenneth B

    2016-05-01

    Striated muscle shows an amazing ability to adapt its structural apparatus based on contractile activity, loading conditions, fuel supply, or environmental factors. Studies with mammalian hibernators have identified a variety of molecular pathways which are strategically regulated and allow animals to endure multiple stresses associated with the hibernating season. Of particular interest is the observation that hibernators show little skeletal muscle atrophy despite the profound metabolic rate depression and mechanical unloading that they experience during long weeks of torpor. Additionally, the cardiac muscle of hibernators must adjust to low temperature and reduced perfusion, while the strength of contraction increases in order to pump cold, viscous blood. Consequently, hibernators hold a wealth of knowledge as it pertains to understanding the natural capacity of myocytes to alter structural, contractile and metabolic properties in response to environmental stimuli. The present review outlines the molecular and biochemical mechanisms which play a role in muscular atrophy, hypertrophy, and remodeling. In this capacity, four main networks are highlighted: (1) antioxidant defenses, (2) the regulation of structural, contractile and metabolic proteins, (3) ubiquitin proteosomal machinery, and (4) macroautophagy pathways. Subsequently, we discuss the role of transcription factors nuclear factor (erythroid-derived 2)-like 2 (Nrf2), Myocyte enhancer factor 2 (MEF2), and Forkhead box (FOXO) and their associated posttranslational modifications as it pertains to regulating each of these networks. Finally, we propose that comparing and contrasting these concepts to data collected from model organisms able to withstand dramatic changes in muscular function without injury will allow researchers to delineate physiological versus pathological responses. PMID:26982616

  18. The Intriguing Dual Lattices of the Myosin Filaments in Vertebrate Striated Muscles: Evolution and Advantage

    PubMed Central

    Luther, Pradeep K.; Squire, John M.

    2014-01-01

    Myosin filaments in vertebrate striated muscle have a long roughly cylindrical backbone with cross-bridge projections on the surfaces of both halves except for a short central bare zone. In the middle of this central region the filaments are cross-linked by the M-band which holds them in a well-defined hexagonal lattice in the muscle A-band. During muscular contraction the M-band-defined rotation of the myosin filaments around their long axes influences the interactions that the cross-bridges can make with the neighbouring actin filaments. We can visualise this filament rotation by electron microscopy of thin cross-sections in the bare-region immediately adjacent to the M-band where the filament profiles are distinctly triangular. In the muscles of teleost fishes, the thick filament triangular profiles have a single orientation giving what we call the simple lattice. In other vertebrates, for example all the tetrapods, the thick filaments have one of two orientations where the triangles point in opposite directions (they are rotated by 60° or 180°) according to set rules. Such a distribution cannot be developed in an ordered fashion across a large 2D lattice, but there are small domains of superlattice such that the next-nearest neighbouring thick filaments often have the same orientation. We believe that this difference in the lattice forms can lead to different contractile behaviours. Here we provide a historical review, and when appropriate cite recent work related to the emergence of the simple and superlattice forms by examining the muscles of several species ranging back to primitive vertebrates and we discuss the functional differences that the two lattice forms may have. PMID:25478994

  19. Effects of 6-hydroxydopamine on visual deprivation in the kitten striate cortex.

    PubMed

    Daw, N W; Rader, R K; Robertson, T W; Ariel, M

    1983-05-01

    We tested the effects of 6-hydroxydopamine (6-OHDA) on two forms of visual deprivation--monocular and directional deprivation. In normal kittens monocular deprivation leads to a change in the ocular dominance histogram recorded from the visual cortex, and directional deprivation leads to a change in the percentage of directionally sensitive cells responding to the appropriate direction of movement. 6-OHDA was infused into the occipital cortex prior to the peak of the critical period for the effects of visual deprivation. In agreement with the results of Kasamatsu et al. (Kasamatsu, T., and J. D. Pettigrew (1979) J. Comp. Neurol. 185: 139-162; Kasamatsu, T., J. D. Pettigrew, and M. Ary (1979) J. Comp. Neurol. 185: 163-182), suture of one eye (monocular deprivation) after the 6-OHDA treatment did not lead to a shift in ocular dominance in the area of striate cortex infused. Moreover, rearing kittens in an environment continually moving past them in one direction (directional deprivation) did not lead to a change in the percentage of cells preferring movement in that direction. In both rearing procedures the 6-OHDA did not make the cells in the cortex nonspecific, compared to cells recorded from the cortex of animals reared similarly but without infusion of 6-OHDA. Monocular and directional deprivation are forms of visual deprivation with different critical periods, probably involving different synapses. Therefore, the effect of 6-OHDA on visual deprivation is a general one, involving more than one kind of visual deprivation. In both cases 6-OHDA abolishes the plasticity of the visual cortex. PMID:6405018

  20. Binocular interaction fields of single units in the cat striate cortex

    PubMed Central

    Bishop, P. O.; Henry, G. H.; Smith, C. J.

    1971-01-01

    1. Based on average response histograms to an optimal stimulus, binocular interaction field plots were obtained from twenty-five simple neurones in the striate cortex of the cat. Each binocularly activated cell has two interaction fields, one for each eye. The binocular interaction field for one eye plots the changes in the amplitude of the response from the other eye as the two receptive fields of the binocularly activated cell are moved across one another, first into and then out of alignment in the plane of the optimal stimulus (tangent screen). 2. The binocular interaction field provides an important clue to the nature of the spatial organization of the excitatory and inhibitory regions of the monocular receptive field. The commonest type of receptive field organization has regions of inhibition (inhibitory side bands) to either side of the discharge centre in the direction at right angles to the optimal stimulus orientation. As well as inhibition, there are subliminal excitatory effects. 3. Binocular interaction fields differ with the various cell types, i.e. cells that are discharged only from the one eye, cells binocularly discharged with very weak or absent monocular responses and cells showing binocularly opposite direction selectivity. 4. Marked facilitation to an optimal stimulus occurs when the two receptive fields of a binocularly activated neurone are in accurate alignment. Facilitation switches to depression for very small degrees of receptive field misalignment in a direction at right angles to the optimal stimulus orientation. These observations are of importance in relation to mechanisms for binocular single vision and depth discrimination. PMID:4934209

  1. Digital image analysis of striated skeletal muscle tissue injury during reperfusion after induced ischemia

    NASA Astrophysics Data System (ADS)

    Rosero Salazar, Doris Haydee; Salazar Monsalve, Liliana

    2015-01-01

    Conditions such as surgical procedures or vascular diseases produce arterial ischemia and reperfusion injuries, which generate changes in peripheral tissues and organs, for instance, in striated skeletal muscle. To determine such changes, we conducted an experimental method in which 42 male Wistar rat were selected, to be undergone to tourniquet application on the right forelimb and left hind limb, to induce ischemia during one and three hours, followed by reperfusion periods starting at one hour and it was prolonged up to 32 days. Extensor carpi radialis longus and soleus respectively, were obtained to be processed for histochemical and morphometric analysis. By means of image processing and detection of regions of interest, variations of areas occupied by muscle fibers and intramuscular extracellular matrix (IM-ECM) throughout reperfusion were observed. In extensor carpi radialis longus, results shown reduction in the area occupied by muscle fibers; this change is significant between one hour and three hours ischemia followed by 16 hours, 48 hours and 32 days reperfusión (p˂0.005). To compare only periods of reperfusión that continued to three hours ischemia, were found significant differences, as well. For area occupied by IM-ECM, were identified increments in extensor carpi radialis longus by three hours ischemia and eight to 16 days reperfusion; in soleus, was observed difference by one hour ischemia with 42 hours reperfusion, and three hours ischemia followed by four days reperfusion (p˂0.005). Skeletal muscle develops adaptive changes in longer reperfusion, to deal with induced injury. Descriptions beyond 32 days reperfusion, can determine recovering normal pattern.

  2. Contrasting effects of strabismic amblyopia on metabolic activity in superficial and deep layers of striate cortex.

    PubMed

    Adams, Daniel L; Economides, John R; Horton, Jonathan C

    2015-05-01

    To probe the mechanism of visual suppression, we have raised macaques with strabismus by disinserting the medial rectus muscle in each eye at 1 mo of age. Typically, this operation produces a comitant, alternating exotropia with normal acuity in each eye. Here we describe an unusual occurrence: the development of severe amblyopia in one eye of a monkey after induction of exotropia. Shortly after surgery, the animal demonstrated a strong fixation preference for the left eye, with apparent suppression of the right eye. Later, behavioral testing showed inability to track or to saccade to targets with the right eye. With the left eye occluded, the animal demonstrated no visually guided behavior. Optokinetic nystagmus was absent in the right eye. Metabolic activity in striate cortex was assessed by processing the tissue for cytochrome oxidase (CO). Amblyopia caused loss of CO in one eye's rows of patches, presumably those serving the blind eye. Layers 4A and 4B showed columns of reduced CO, in register with pale rows of patches in layer 2/3. Layers 4C, 5, and 6 also showed columns of CO activity, but remarkably, comparison with more superficial layers showed a reversal in contrast. In other words, pale CO staining in layers 2/3, 4A, and 4B was aligned with dark CO staining in layers 4C, 5, and 6. No experimental intervention or deprivation paradigm has been reported previously to produce opposite effects on metabolic activity in layers 2/3, 4A, and 4B vs. layers 4C, 5, and 6 within a given eye's columns. PMID:25810480

  3. Effect of temporal predictability on exogenous attentional modulation of feedforward processing in the striate cortex.

    PubMed

    Dassanayake, Tharaka L; Michie, Patricia T; Fulham, Ross

    2016-07-01

    Non-informative peripheral visual cues facilitate extrastriate processing of targets [as indexed by enhanced amplitude of contralateral P1 event-related potential (ERP) component] presented at the cued location as opposed to those presented at uncued locations, at short cue-target stimulus onset asynchrony (SOA). Recently, two lines of research are emerging to suggest that the locus of attentional modulation is flexible and depends on 1) perceptual load and 2) temporal predictability of visual stimuli. We aimed to examine the effect of temporal predictability on attentional modulation of feed-forward activation of the striate cortex (as indexed by the C1 ERP component) by high-perceptual-load (HPL) stimuli. We conducted two ERP experiments where exogenously-cued HPL targets were presented under two temporal predictability conditions. In Experiment 1 [high-temporal-predictability (HTP) condition], 17 healthy subjects (age 18-26years) performed a line-orientation discrimination task on HPL targets presented in the periphery of the left upper or diagonally opposite right lower visual field, validly or invalidly cued by peripheral cues. SOA was fixed at 160ms. In Experiment 2 [low-temporal-predictability (LTP) condition], (n=10, age 19-36years) we retained HPL stimuli but randomly intermixed short-SOA trials with long-SOA (1000ms) trials in the task-blocks. In Experiment 1 and the short-SOA condition of the Experiment 2, validly-cued targets elicited significantly faster reaction times and larger contralateral P1, consistent with previous literature. A significant attentional enhancement of C1 amplitude was also observed in the HTP, but not LTP condition. The findings suggest that exogenous visual attention can facilitate the earliest stage of cortical processing under HTP conditions. PMID:27114044

  4. Contrasting effects of strabismic amblyopia on metabolic activity in superficial and deep layers of striate cortex

    PubMed Central

    Adams, Daniel L.; Economides, John R.

    2015-01-01

    To probe the mechanism of visual suppression, we have raised macaques with strabismus by disinserting the medial rectus muscle in each eye at 1 mo of age. Typically, this operation produces a comitant, alternating exotropia with normal acuity in each eye. Here we describe an unusual occurrence: the development of severe amblyopia in one eye of a monkey after induction of exotropia. Shortly after surgery, the animal demonstrated a strong fixation preference for the left eye, with apparent suppression of the right eye. Later, behavioral testing showed inability to track or to saccade to targets with the right eye. With the left eye occluded, the animal demonstrated no visually guided behavior. Optokinetic nystagmus was absent in the right eye. Metabolic activity in striate cortex was assessed by processing the tissue for cytochrome oxidase (CO). Amblyopia caused loss of CO in one eye's rows of patches, presumably those serving the blind eye. Layers 4A and 4B showed columns of reduced CO, in register with pale rows of patches in layer 2/3. Layers 4C, 5, and 6 also showed columns of CO activity, but remarkably, comparison with more superficial layers showed a reversal in contrast. In other words, pale CO staining in layers 2/3, 4A, and 4B was aligned with dark CO staining in layers 4C, 5, and 6. No experimental intervention or deprivation paradigm has been reported previously to produce opposite effects on metabolic activity in layers 2/3, 4A, and 4B vs. layers 4C, 5, and 6 within a given eye's columns. PMID:25810480

  5. Mitochondrial DNA structure and expression in specialized subtypes of mammalian striated muscle.

    PubMed Central

    Annex, B H; Williams, R S

    1990-01-01

    Mitochondrial DNA (mt DNA) in cells of vertebrate organisms can assume an unusual triplex DNA structure known as the displacement loop (D loop). This triplex DNA structure forms when a partially replicated heavy strand of mtDNA (7S mtDNA) remains annealed to the light strand, displacing the native heavy strand in this region. The D-loop region contains the promoters for both heavy- and light-strand transcription as well as the origin of heavy-strand replication. However, the distribution of triplex and duplex forms of mtDNA in relation to respiratory activity of mammalian tissues has not been systematically characterized, and the functional significance of the D-loop structure is unknown. In comparisons of specialized muscle subtypes within the same species and of the same muscle subtype in different species, the relative proportion of D-loop versus duplex forms of mtDNA in striated muscle tissues of several mammalian species demonstrated marked variation, ranging from 1% in glycolytic fast skeletal fibers of the rabbit to 65% in the mouse heart. There was a consistent and direct correlation between the ratio of triplex to duplex forms of mtDNA and the capacity of these tissues for oxidative metabolism. The proportion of D-loop forms likewise correlated directly with mtDNA copy number, mtRNA abundance, and the specific activity of the mtDNA (gamma) polymerase. The D-loop form of mtDNA does not appear to be transcribed at greater efficiency than the duplex form, since the ratio of mtDNA copy number to mtRNA was unrelated to the proportion of triplex mtDNA genomes. However, tissues with a preponderance of D-loop forms tended to express greater levels of cytochrome b mRNA relative to mitochondrial rRNA transcripts, suggesting that the triplex structure may be associated with variations in partial versus full-length transcription of the heavy strand. Images PMID:1700273

  6. Position-specific adaptation in complex cell receptive fields of the cat striate cortex.

    PubMed

    Marlin, S; Douglas, R; Cynader, M

    1993-06-01

    1. Responses of complex cells in cat striate cortex were studied with flashed light slit stimuli. The responses to slits flashed in different positions in the receptive field were assessed quantitatively before and after periods of prolonged stimulation of one small region of the receptive field. This type of prolonged stimulation resulted in reduced responsivity over a limited zone within the complex cell receptive field. 2. The adaptation-induced responsivity decrement was generally observed in both the ON and OFF response profiles but could also be restricted to one or the other. In general, the magnitude of the response decrements was greatest in the ON response profiles. The adaptation-induced response decrement did not necessarily spread throughout the receptive field but was restricted to a small region surrounding the adapted receptive field position (RFP). Adaptation spread equally widely across the ON and OFF response profiles despite the smaller adaptation effects in the OFF profile. 3. The adaptation effects from repeated stimulation at a single RFP did not spread symmetrically across the receptive field, and a given cell's preferred direction of motion indicated the direction of the asymmetric spread of the adaptation. RFPs that would be stimulated by a light slit originating at the point of adaptation and moving in the preferred direction (preferred side) showed greater adaptation-induced response decrements than did RFPs that would be stimulated by a light slit moving in the opposite direction from the point of adaptation (nonpreferred side). There was significant enhancement of responses at some RFPs on the non-preferred side of the point of adaptation. This asymmetric spread of adaptation could be caused by adaptation of inhibitory connections that contribute to complex cell direction selectivity. 4. The asymmetry of adaptation was significantly different for the ON and OFF response profiles. The asymmetric spread of adaptation for the ON response

  7. Receptive field organization of complex cells in the cat's striate cortex.

    PubMed Central

    Movshon, J A; Thompson, I D; Tolhurst, D J

    1978-01-01

    1. All complex cells in the cat's striate cortex exhibit gross non-linearities of spatial summation when tested with sinusoidal grating stimuli. Their responses to moving gratings of all but the lowest spatial frequencies are usually dominated by a component that is not modulated by the passage of the bars of the grating across the receptive field. They give responses to temporally modulated stationary gratings that consist mostly of even harmonics of the stimulus frequency and that vary little in amplitude or wave form as the spatial phase of the grating is varied. 2. We compared complex cells' receptive fields with their sensitivity to sinusoidal gratings of different spatial frequencies. Qualitatively, the receptive fields are usually two to five times wider than the bars of the gratings that stimulate them most effectively. Quantitatively, the receptive field profiles of complex cells are invariably broader than those predicted by Fourier synthesis of their spatial frequency tuning curves, and in particular lack predicted spatially antagonistic regions. 3. We further examined the receptive field organization of these cells, using pairs of stationary lines flashed synchronously on their receptive fields. If both lines are of the same polarity (bright or dark), complex cells respond to the paired stimulus much less well than they do to either of its component bars, unless the bars are separated by less than about one quarter of the width of the receptive field. If the lines are of opposite polarity, one bright and one dark, the opposite situation obtains: closely spaced bars elicit small responses, while paired bars of larger separation are much more effective. In either case, the results are independent in general character of the absolute positions of the stimuli within the receptive field; rather, they depend in a manner characteristic of each cell on the relative positions of the two bars. 4. The two-line interaction profile that plots the change in a complex

  8. Effect of halothane on isometric twitch and tetanus response and the associated heat production in striated muscle of frogs.

    PubMed

    Price, K A; Matsumoto, Y; Frederickson, E L

    1975-01-01

    The purpose of these investigations was to determine the effect of halothane on isometric contraction of striated muscle and to measure the associated heat production. This basic information is necessary before studies more directly relating to malignant hyperthermia are undertaken. Sartorius muscles were isolate from Rana pipiens during winter and summer months. It appears from these experiments that there is a prolongation of the relaxation phase of the twitch and tetanus responses with low concentrations of halothane, with a more diffuse effect on the contractile process evident at higher administered concentrations. The results of heat measurements, using a sensitive thermopile-galvanometer system, are compatible with the hypotheses that this effect on relaxation could result from either an interference with calcium reuptake by the sarcoplasmic reticulum or an increased affinity of the troponintropomyosin complex for available calcium. PMID:1080024

  9. Potential dynamics of the human striate cortex cerebrum realistic neural network under the influence of an external signal

    NASA Astrophysics Data System (ADS)

    Melnikov, Leonid A.; Novosselova, Anna V.; Blinova, Nadejda V.; Vinitsky, Sergey I.; Serov, Vladislav V.; Bakutkin, Valery V.; Camenskich, T. G.; Guileva, E. V.

    2000-03-01

    In this work the numerical investigations of a potential dynamics of a neural network as the non-linear system and dynamics of the visual nerve which connect the eye retina receptors with the striate cortex cerebrum as the answer to the through-skin excitement of the eye retina by the electrical signal were realized. The visual evoked potential is the answer and characterizes the human brain state over the structures retina state and the conduction of the visual nerve fibers. The results of these investigations were presented. Specific features of the neural network, such as the excitation and depression, we took into account too. The discussion about the model parameters, used at the time of the numerical investigation, was made. The comparative analysis of the retina potential data and the data of the external signal filing by the brain hemicerebrum visual centers was made too.

  10. Decelerating burst and complex repetitive discharges in the striated muscle of the urethral sphincter, associated with urinary retention in women.

    PubMed Central

    Fowler, C J; Kirby, R S; Harrison, M J

    1985-01-01

    A type of electromyographic activity, formerly referred to as "pseudomyotonia", can be recorded from the striated muscle of the urethral sphincter using a concentric needle electrode. There are two components to this activity, complex repetitive discharges and decelerating bursts. The latter usually dominate recordings and sound very like myotonic discharges. Analysis of these discharges indicates that they are a form of "bizarre repetitive discharge", and as such, result from ephaptic spread of excitation between muscle fibres rather than from excitation arising in the terminal branches of the motor axon. Profuse activity of this type has been found in 15 women with symptoms of urethral dysfunction, including 11 with urinary retention. It is suggested that this activity is associated with a failure of urethral sphincter relaxation. Images PMID:4056803

  11. ZASP Interacts with the Mechanosensing Protein Ankrd2 and p53 in the Signalling Network of Striated Muscle

    PubMed Central

    Martinelli, Valentina C.; Kyle, W. Buck; Kojic, Snezana; Vitulo, Nicola; Li, Zhaohui; Belgrano, Anna; Maiuri, Paolo; Banks, Lawrence; Vatta, Matteo; Valle, Giorgio; Faulkner, Georgine

    2014-01-01

    ZASP is a cytoskeletal PDZ-LIM protein predominantly expressed in striated muscle. It forms multiprotein complexes and plays a pivotal role in the structural integrity of sarcomeres. Mutations in the ZASP protein are associated with myofibrillar myopathy, left ventricular non-compaction and dilated cardiomyopathy. The ablation of its murine homologue Cypher results in neonatal lethality. ZASP has several alternatively spliced isoforms, in this paper we clarify the nomenclature of its human isoforms as well as their dynamics and expression pattern in striated muscle. Interaction is demonstrated between ZASP and two new binding partners both of which have roles in signalling, regulation of gene expression and muscle differentiation; the mechanosensing protein Ankrd2 and the tumour suppressor protein p53. These proteins and ZASP form a triple complex that appears to facilitate poly-SUMOylation of p53. We also show the importance of two of its functional domains, the ZM-motif and the PDZ domain. The PDZ domain can bind directly to both Ankrd2 and p53 indicating that there is no competition between it and p53 for the same binding site on Ankrd2. However there is competition for this binding site between p53 and a region of the ZASP protein lacking the PDZ domain, but containing the ZM-motif. ZASP is negative regulator of p53 in transactivation experiments with the p53-responsive promoters, MDM2 and BAX. Mutations in the ZASP ZM-motif induce modification in protein turnover. In fact, two mutants, A165V and A171T, were not able to bind Ankrd2 and bound only poorly to alpha-actinin2. This is important since the A165V mutation is responsible for zaspopathy, a well characterized autosomal dominant distal myopathy. Although the mechanism by which this mutant causes disease is still unknown, this is the first indication of how a ZASP disease associated mutant protein differs from that of the wild type ZASP protein. PMID:24647531

  12. The myosin interacting-heads motif is present in the relaxed thick filament of the striated muscle of scorpion.

    PubMed

    Pinto, Antonio; Sánchez, Fredi; Alamo, Lorenzo; Padrón, Raúl

    2012-12-01

    Electron microscopy (EM) studies of 2D crystals of smooth muscle myosin molecules have shown that in the inactive state the two heads of a myosin molecule interact asymmetrically forming a myosin interacting-heads motif. This suggested that inactivation of the two heads occurs by blocking of the actin-binding site of one (free head) and the ATP hydrolysis site of the other (blocked head). This motif has been found by EM of isolated negatively stained myosin molecules of unregulated (vertebrate skeletal and cardiac muscle) and regulated (invertebrate striated and vertebrate smooth muscle) myosins, and nonmuscle myosin. The same motif has also been found in 3D-reconstructions of frozen-hydrated (tarantula, Limulus, scallop) and negatively stained (scallop, vertebrate cardiac) isolated thick filaments. We are carrying out studies of isolated thick filaments from other species to assess how general this myosin interacting-heads motif is. Here, using EM, we have visualized isolated, negatively stained thick filaments from scorpion striated muscle. We modified the iterative helical real space reconstruction (IHRSR) method to include filament tilt, and band-pass filtered the aligned segments before averaging, achieving a 3.3 nm resolution 3D-reconstruction. This reconstruction revealed the presence of the myosin interacting-heads motif (adding to evidence that is widely spread), together with 12 subfilaments in the filament backbone. This demonstrates that conventional negative staining and imaging can be used to detect the presence of the myosin interacting-heads motif in helically ordered thick filaments from different species and muscle types, thus avoiding the use of less accessible cryo-EM and low electron-dose procedures. PMID:22982253

  13. Complementary global maps for orientation coding in upper and lower layers of the monkey's foveal striate cortex.

    PubMed

    Bauer, R; Dow, B M

    1989-01-01

    A population of 269 cells recorded from the foveal representation of striate cortex in 2 rhesus macaque monkeys was examined for orientation preference as a function of receptive field position relative to the center of gaze. Cells recorded in supragranular and infragranular layers were segregated and compared. Within the foveolar region (0.0-0.5 degrees) supragranular cells showed a vertical bias which was not evident in the infragranular layers. At larger eccentricities (0.5-2.5 degrees) supragranular cells showed a radial bias (preferred orientation points toward the center of gaze), whereas infragranular cells showed a concentric bias (preferred orientation is tangent to a circle around the center of gaze). These results are consistent with our earlier report of an orientation shift between the supragranular and infragranular layers (Bauer et al. 1980, 1983; Dow and Bauer 1984). The diagonal orientation bias which we noted earlier (Bauer et al. 1980; Dow and Bauer 1984) in supragranular cells at eccentricities between 0.5 and 2.5 degrees can be explained by the radial bias, combined with a tendency for recording sites to favor receptive field locations closer to the diagonal meridia than to either the horizontal or vertical meridia. Given other evidence that upper layer cells in macaque striate cortex tend to show either orientation or color selectivity, while lower layer cells tend to show movement sensitivity (Dow 1974; Livingstone and Hubel 1984), the present data suggest a functional dichotomy between a supragranular system involved in fixational eye movements and pattern vision and an infragranular system activated primarily by optical flow fields during ambulation. PMID:2792244

  14. Correction of multiple striated muscles in murine Pompe disease through adeno-associated virus-mediated gene therapy.

    PubMed

    Sun, Baodong; Young, Sarah P; Li, Ping; Di, Chunhui; Brown, Talmage; Salva, Maja Z; Li, Songtao; Bird, Andrew; Yan, Zhen; Auten, Richard; Hauschka, Stephen D; Koeberl, Dwight D

    2008-08-01

    Glycogen storage disease type II (Pompe disease; MIM 232300) stems from the deficiency of acid alpha-glucosidase (GAA; acid maltase; EC 3.2.1.20), which primarily involves cardiac and skeletal muscles. An adeno-associated virus 2/8 (AAV2/8) vector containing the muscle creatine kinase (MCK) (CK1) reduced glycogen content by approximately 50% in the heart and quadriceps in GAA-knockout (GAA-KO) mice; furthermore, an AAV2/8 vector containing the hybrid alpha-myosin heavy chain enhancer-/MCK enhancer-promoter (MHCK7) cassette reduced glycogen content by >95% in heart and >75% in the diaphragm and quadriceps. Transduction with an AAV2/8 vector was higher in the quadriceps than in the gastrocnemius. An AAV2/9 vector containing the MHCK7 cassette corrected GAA deficiency in the distal hindlimb, and glycogen accumulations were substantially cleared by human GAA (hGAA) expression therein; however, the analogous AAV2/7 vector achieved much lower efficacy. Administration of the MHCK7-containing vectors significantly increased striated muscle function as assessed by increased Rotarod times at 18 weeks after injection, whereas the CK1-containing vector did not increase Rotarod performance. Importantly, type IIb myofibers in the extensor digitalis longus (EDL) were transduced, thereby correcting a myofiber type that is unresponsive to enzyme replacement therapy. In summary, AAV8 and AAV9-pseudotyped vectors containing the MHCK7 regulatory cassette achieved enhanced efficacy in Pompe disease mice. PMID:18560415

  15. Geologic continuous casting below continental and deep-sea detachment faults and at the striated extrusion of Sacsayhuaman, Peru

    USGS Publications Warehouse

    Spencer, J.E.

    1999-01-01

    In the common type of industrial continuous casting, partially molten metal is extruded from a vessel through a shaped orifice called a mold in which the metal assumes the cross-sectional form of the mold as it cools and solidifies. Continuous casting can be sustained as long as molten metal is supplied and thermal conditions are maintained. I propose that a similar process produced parallel sets of grooves in three geologic settings, as follows: (1) corrugated metamorphic core complexes where mylonized mid-crustal rocks were exhumed by movement along low-angle normal faults known as detachment faults; (2) corrugated submarine surfaces where ultramafic and mafic rocks were exhumed by normal faulting within oceanic spreading centers; and (3) striated magma extrusions exemplified by the famous grooved outcrops at the Inca fortress of Sacsayhuaman in Peru. In each case, rocks inferred to have overlain the corrugated surface during corrugation genesis molded and shaped a plastic to partially molten rock mass as it was extruded from a moderate- to high-temperature reservoir.

  16. Dietary fish oil blocks the microcirculatory manifestations of ischemia-reperfusion injury in striated muscle in hamsters.

    PubMed Central

    Lehr, H A; Hübner, C; Nolte, D; Kohlschütter, A; Messmer, K

    1991-01-01

    Epidemiologic observations and experimental studies have demonstrated a protective effect of dietary fish oil on the clinical manifestations of ischemia-reperfusion injury. To investigate the underlying mechanisms, we used the dorsal skinfold chamber model for intravital fluorescence microscopy of the microcirculation in striated muscle of awake hamsters. In control hamsters (n = 7), reperfusion after a 4-hr pressure-induced ischemia to the muscle tissue elicited the adhesion of fluorescently stained leukocytes to the endothelium of postcapillary venules, capillary obstruction, and the break-down of endothelial integrity. These microvascular manifestations of ischemia-reperfusion injury were significantly attenuated in animals (n = 7) when fed with a fish oil-enriched diet for 4 weeks prior to the experiments. In leukocyte total lipids, the fish oil diet resulted in a substantial displacement of arachidonic acid, the precursor of the potent adhesion-promoting leukotriene (LT) B4, by fish oil-derived eicosapentaenoic acid, the precursor of biologically less potent LTB5, emphasizing the mediator role of LTB4 in ischemia-reperfusion injury. These results suggest that the preservation of microvascular perfusion by dietary fish oil contributes to its protective effects on the clinical manifestations of ischemia-reperfusion injury. PMID:1650479

  17. Overexpression of Striated Muscle Activator of Rho Signaling (STARS) Increases C2C12 Skeletal Muscle Cell Differentiation

    PubMed Central

    Wallace, Marita A.; Della Gatta, Paul A.; Ahmad Mir, Bilal; Kowalski, Greg M.; Kloehn, Joachim; McConville, Malcom J.; Russell, Aaron P.; Lamon, Séverine

    2016-01-01

    Background: Skeletal muscle growth and regeneration depend on the activation of satellite cells, which leads to myocyte proliferation, differentiation and fusion with existing muscle fibers. Skeletal muscle cell proliferation and differentiation are tightly coordinated by a continuum of molecular signaling pathways. The striated muscle activator of Rho signaling (STARS) is an actin binding protein that regulates the transcription of genes involved in muscle cell growth, structure and function via the stimulation of actin polymerization and activation of serum-response factor (SRF) signaling. STARS mediates cell proliferation in smooth and cardiac muscle models; however, whether STARS overexpression enhances cell proliferation and differentiation has not been investigated in skeletal muscle cells. Results: We demonstrate for the first time that STARS overexpression enhances differentiation but not proliferation in C2C12 mouse skeletal muscle cells. Increased differentiation was associated with an increase in the gene levels of the myogenic differentiation markers Ckm, Ckmt2 and Myh4, the differentiation factor Igf2 and the myogenic regulatory factors (MRFs) Myf5 and Myf6. Exposing C2C12 cells to CCG-1423, a pharmacological inhibitor of SRF preventing the nuclear translocation of its co-factor MRTF-A, had no effect on myotube differentiation rate, suggesting that STARS regulates differentiation via a MRTF-A independent mechanism. Conclusion: These findings position STARS as an important regulator of skeletal muscle growth and regeneration. PMID:26903873

  18. (-)-Epicatechin improves mitochondrial-related protein levels and ameliorates oxidative stress in dystrophic δ-sarcoglycan null mouse striated muscle.

    PubMed

    Ramirez-Sanchez, Israel; De los Santos, Sergio; Gonzalez-Basurto, Silvia; Canto, Patricia; Mendoza-Lorenzo, Patricia; Palma-Flores, Carlos; Ceballos-Reyes, Guillermo; Villarreal, Francisco; Zentella-Dehesa, Alejandro; Coral-Vazquez, Ramon

    2014-12-01

    Muscular dystrophies (MDs) are a group of heterogeneous genetic disorders characterized by progressive striated muscle wasting and degeneration. Although the genetic basis for many of these disorders has been identified, the exact mechanism of disease pathogenesis remains unclear. The presence of oxidative stress (OS) is known to contribute to the pathophysiology and severity of the MD. Mitochondrial dysfunction is observed in MD, and probably represents an important determinant of increased OS. Experimental antioxidant therapies have been implemented with the aim of protecting against disease progression, but results from clinical trials have been disappointing. In this study, we explored the capacity of the cacao flavonoid (-)-epicatechin (Epi) to mitigate OS by acting as a positive regulator of mitochondrial structure/function endpoints and redox balance control systems in skeletal and cardiac muscles of dystrophic, δ-sarcoglycan (δ-SG) null mice. Wild-type or δ-SG null 2.5-month-old male mice were treated via oral gavage with either water (controls) or Epi (1 mg·kg(-1) , twice daily) for 2 weeks. The results showed significant normalization of total protein carbonylation, recovery of the glutathione/oxidized glutathione ratio and enhanced superoxide dismutase 2, catalase and citrate synthase activities with Epi treatment. These effects were accompanied by increases in the protein levels of thioredoxin, glutathione peroxidase, superoxide dismutase 2, catalase, and mitochondrial endpoints. Furthermore, we found decreases in heart and skeletal muscle fibrosis, accompanied by an improvement in skeletal muscle function, with treatment. These results warrant further investigation of Epi as a potential therapeutic agent to mitigate MD-associated muscle degeneration. PMID:25284161

  19. Structure and interactions of the carboxyl terminus of striated muscle alpha-tropomyosin: it is important to be flexible.

    PubMed Central

    Greenfield, Norma J; Palm, Thomas; Hitchcock-DeGregori, Sarah E

    2002-01-01

    Tropomyosin (TM) binds to and regulates the actin filament. We used circular dichroism and heteronuclear NMR to investigate the secondary structure and interactions of the C terminus of striated muscle alpha-TM, a major functional determinant, using a model peptide, TM9a(251-284). The (1)H(alpha) and (13)C(alpha) chemical shift displacements show that residues 252 to 277 are alpha-helical but residues 278 to 284 are nonhelical and mobile. The (1)H(N) and (13)C' displacements suggest that residues 257 to 269 form a coiled coil. Formation of an "overlap" binary complex with a 33-residue N-terminal chimeric peptide containing residues 1 to 14 of alpha-TM perturbs the (1)H(N) and (15)N resonances of residues 274 to 284. Addition of a fragment of troponin T, TnT(70-170), to the binary complex perturbs most of the (1)H(N)-(15)N cross-peaks. In addition, there are many new cross-peaks, showing that the binding is asymmetric. Q263, in a proposed troponin T binding site, shows two sets of side-chain (15)N-(1)H cross-peaks, indicating conformational flexibility. The conformational equilibrium of the side chain changes upon formation of the binary and ternary complexes. Replacing Q263 with leucine greatly increases the stability of TM9a(251-284) and reduces its ability to form the binary and ternary complexes, showing that conformational flexibility is crucial for the binding functions of the C terminus. PMID:12414708

  20. Correction of Multiple Striated Muscles in Murine Pompe Disease Through Adeno-associated Virus-Mediated Gene Therapy

    PubMed Central

    Sun, Baodong; Young, Sarah P.; Li, Ping; Di, Chunhui; Brown, Talmage; Salva, Maia Z.; Li, Songtao; Bird, Andrew; Yan, Zhen; Auten, Richard; Hauschka, Stephen D.; Koeberl, Dwight D.

    2009-01-01

    Glycogen storage disease type II (GSD-II; Pompe disease; MIM 232300) stems from the deficiency of acid-α-glucosidase (GAA; acid maltase; EC 3.2.1.20), which primarily involves cardiac and skeletal muscles. We hypothesized that systemic administration of an adeno-associated virus (AAV) vector containing a muscle specific regulatory cassette could drive efficacious transgene expression in GAA-knockout (GAA-KO) mice. AAV2/8 vectors containing the muscle creatine kinase (CK1) or hybrid α-myosin heavy chain enhancer-/muscle creatine kinase enhancer-promoter (MHCK7) cassettes were compared. The CK1 reduced glycogen content by approximately 50% in the heart and quadriceps, in comparison to untreated GAA-KO mice, whereas the MHCK7 containing vector reduced glycogen content even further: >95% in heart and >75% in the diaphragm and quadriceps. Administration of the MHCK7-containing vector significantly increased striated muscle function as assessed by increased Rotarod times at 18 weeks post-injection, whereas the CK1-containing vector did not increase Rotarod performance. Transduction efficiency was evaluated with an AAV2/8 vector in which MHCK7 drives alkaline-phosphatase, revealing that many more myofibers were transduced in the quadriceps than in the gastrocnemius. An AAV2/9 vector containing the MHCK7 cassette corrected GAA deficiency in the skeletal muscles of the distal limb, including the gastrocnemius, extensor digitalis longus, and soleus; furthermore, glycogen accumulations were substantially cleared by hGAA expression therein. Importantly, type IIb myofibers in the extensor digitalis longus were transduced, thereby correcting a myofiber type that is unresponsive to enzyme replacement therapy. In summary, AAV8 and AAV9-pseudotyped vectors containing the MHCK7 regulatory cassette achieved enhanced efficacy in Pompe disease mice. PMID:18560415

  1. (−)-EPICATECHIN IMPROVES MITOCHONDRIAL RELATED PROTEIN LEVELS AND AMELIORATES OXIDATIVE STRESS IN DYSTROPHIC DELTA SARCOGLYCAN NULL MOUSE STRIATED MUSCLE

    PubMed Central

    Ramirez-Sanchez, Israel; De los Santos, Sergio; Gonzalez-Basurto, Silvia; Canto, Patricia; Mendoza-Lorenzo, Patricia; Palma-Flores, Carlos; Ceballos-Reyes, Guillermo; Villarreal, Francisco; Zentella-Dehesa, Alejandro; Coral-Vazquez, Ramon

    2014-01-01

    Muscular dystrophies (MD) are a group of heterogeneous genetic disorders characterized by progressive striated muscle wasting and degeneration. Although the genetic basis for many of these disorders has been identified, the exact mechanism for disease pathogenesis remains unclear. The presence of oxidative stress (OS) is known to contribute to the pathophysiology and severity of the MD. Mitochondrial dysfunction is observed in MD and likely represents an important determinant of increased OS. Experimental antioxidant therapies have been implemented with the aim of protecting against disease progression, but results from clinical trials have been disappointing. In this study, we explored the capacity of the cacao flavonoid (−)-epicatechin (Epi) to mitigate OS by acting as a positive regulator of mitochondrial structure/function endpoints and redox balance control systems in skeletal and cardiac muscles of dystrophic, δ-sarcoglycan (δ-SG) null mice. Wild type or δ-SG null 2.5 month old male mice were treated via oral gavage with either water (control animals) or Epi (1 mg/kg, twice/day) for 2 weeks. Results evidence a significant normalization of total protein carbonylation, recovery of reduced/oxidized glutathione (GSH/GSSG ratio) and enhanced superoxide dismutase 2, catalase and citrate synthase activities with Epi treatment. These effects were accompanied by increases in protein levels for thiolredoxin, glutathione peroxidase, superoxide dismutase 2, catalase and mitochondrial endpoints. Furthermore, we evidence decreases in heart and skeletal muscle fibrosis, accompanied with an improvement in skeletal muscle function with treatment. These results warrant the further investigation of Epi as a potential therapeutic agent to mitigate MD associated muscle degeneration. PMID:25284161

  2. The “Goldilocks Zone” from a redox perspective—Adaptive vs. deleterious responses to oxidative stress in striated muscle

    PubMed Central

    Alleman, Rick J.; Katunga, Lalage A.; Nelson, Margaret A. M.; Brown, David A.; Anderson, Ethan J.

    2014-01-01

    Consequences of oxidative stress may be beneficial or detrimental in physiological systems. An organ system's position on the “hormetic curve” is governed by the source and temporality of reactive oxygen species (ROS) production, proximity of ROS to moieties most susceptible to damage, and the capacity of the endogenous cellular ROS scavenging mechanisms. Most importantly, the resilience of the tissue (the capacity to recover from damage) is a decisive factor, and this is reflected in the disparate response to ROS in cardiac and skeletal muscle. In myocytes, a high oxidative capacity invariably results in a significant ROS burden which in homeostasis, is rapidly neutralized by the robust antioxidant network. The up-regulation of key pathways in the antioxidant network is a central component of the hormetic response to ROS. Despite such adaptations, persistent oxidative stress over an extended time-frame (e.g., months to years) inevitably leads to cumulative damages, maladaptation and ultimately the pathogenesis of chronic diseases. Indeed, persistent oxidative stress in heart and skeletal muscle has been repeatedly demonstrated to have causal roles in the etiology of heart disease and insulin resistance, respectively. Deciphering the mechanisms that underlie the divergence between adaptive and maladaptive responses to oxidative stress remains an active area of research for basic scientists and clinicians alike, as this would undoubtedly lead to novel therapeutic approaches. Here, we provide an overview of major types of ROS in striated muscle and the divergent adaptations that occur in response to them. Emphasis is placed on highlighting newly uncovered areas of research on this topic, with particular focus on the mitochondria, and the diverging roles that ROS play in muscle health (e.g., exercise or preconditioning) and disease (e.g., cardiomyopathy, ischemia, metabolic syndrome). PMID:25278906

  3. Development of Trichosomoides nasalis (Nematoda: Trichinelloidea) in the murid host: evidence for larval growth in striated muscle fibres

    PubMed Central

    Fall, E.H.; Diagne, M.; Junker, K.; Duplantier, J.M.; Ba, K.; Vallée, I.; Bain, O.

    2012-01-01

    Trichosomoides nasalis (Trichinelloidea) is a parasite of Arvicanthis niloticus (Muridae) in Senegal. Female worms that harbour dwarf males in their uteri, occur in the epithelium of the nasal mucosa. Young laboratory-bred A. niloticus were either fed females containing larvated eggs or intraperitoneally injected with motile first-stage larvae recovered from female uteri. Both resulted in successful infection. Organs examined during rodent necropsy were blood and lymphatic circulatory systems (heart, large vessels, lymphnodes), lungs, liver, kidneys, thoracic and abdominal cavities, thoracic and abdominal muscular walls, diaphragm, tongue, and nasal mucosa. Development to adult nasal stages took three weeks. Recovery of newly hatched larvae from the peritoneal fluid at four-eight hours after oral infection suggests a direct passage from the stomach or intestinal wall to the musculature. However, dissemination through the blood, as observed with Trichinella spiralis, cannot be excluded even though newly hatched larvae of T. nasalis are twice as thick (15 μm). Developing larvae were found in histological sections of the striated muscle of the abdominal and thoracic walls, and larvae in fourth moult were dissected from these sites. Adult females were found in the deep nasal mucosa where mating occurred prior to worms settling in the nasal epithelium. The present study shows a remarkable similarity between T. nasalis and Trichinella species regarding muscle tropism, but the development of T. nasalis is not arrested at the late first-larval stage and does not induce transformation of infected fibres into nurse cells. T. nasalis seems a potential model to study molecular relations between trichinelloid larvae and infected muscle fibres. PMID:22314237

  4. Sensory and autonomic neurons project both to the smooth retractor penis and to the striated bulbospongiosus muscles. Neurochemical features of the sympathetic subset.

    PubMed

    Botti, Maddalena; Gazza, Ferdinando; Ragionieri, Luisa; Minelli, Luisa Bo; Panu, Rino

    2012-08-01

    Aim of the present study was to verify, by means of double retrograde neuronal tracers technique, the hypothesis that a subpopulation of sensory and autonomic neurons send collateral axons to both smooth and striated genital muscles. We also wanted to define the neurochemical content of the eventually retrogradelly double labeled (RDL) neurons in the sympathetic trunk ganglia (STG). We used six intact pigs and we injected the tracer Diamidino Yellow (DY) in the smooth left retractor penis muscle (RPM) and the tracer Fast Blue (FB) in the striated left bulbospongiosus muscle (BSM). Rare (2 ± 0.6) RDL neurons were found in the ipsilateral S2 spinal ganglion (SG), 220 ± 42 in the ipsilateral STGs, from L3 to S3, 19 ± 15 in the contralateral S1-S2 ones and 22 ± 5 in the bilateral caudal mesenteric ganglia (CMG). The RDL neurons of the STG were IR for TH (85 ± 13%), DβH (69 ± 17%), NPY (69 ± 23%), nNOS (60 ± 11%), LENK (54 ± 19%), VIP (53±26%), SOM (40 ± 8%), CGRP (34 ± 12%), SP (31 ± 16%), and VAChT (28 ± 3%). Our research highlights the presence of sensory and sympathetic neurons with qualitatively different neurochemical content sending axons both to the smooth RPM and to the striated BSM of the pig. These RDL neurons are likely to project to the smooth vasal musculature to create the ideal physiological conditions in which these muscles can optimize the erectile function. PMID:22707224

  5. Computer analysis between nucleotide and amino acid sequences of bean golden mosaic virus and those of maize streak, wheat dwarf, chloris striate mosaic, and beet curly top viruses.

    PubMed

    Ikegami, M

    1989-01-01

    Bean golden mosaic virus (BGMV) DNA 1 and 2 have little sequence homology with maize streak virus (MSV), wheat dwarf virus (WDV), and chloris striate mosaic virus (CSMV) DNAs. BGMV DNA 1 and beet curly top virus (BCTV) DNA are closely related, whereas BGMV DNA 2 and BCTV DNA are not related. Direct amino acid homologies of predicted proteins between BGMV ORFs and MSV ORFs, WDV ORFs or CSMV ORFs were 40-50%. BGMV 1L1 and BCTV L1, and BGMV IL3 and BCTV L4 were highly conserved. The sequence TAATATTAC was detected in the loops of hairpin structures of 5 gemini-viruses. PMID:2615677

  6. Chronic recordings from single sites of kitten striate cortex during experience-dependent modifications of receptive-field properties.

    PubMed

    Mioche, L; Singer, W

    1989-07-01

    1. With the use of chronically implanted floating microelectrodes, we obtained simultaneous single-unit recordings from multiple sites in the kitten striate cortex and followed experience-dependent modifications of receptive-field properties. For induction of experimental modifications, we used the paradigm of monocular deprivation and reverse occlusion. Kittens were implanted when 4-5 wk old. During the following 2 days, receptive-field properties of the recorded units were determined once under light ketamine anesthesia and repeatedly while the kittens were awake and only lightly restrained. Subsequently, one eye was patched, and the resulting changes in neuronal eye preference were followed by repeated measurements of response properties. For investigation of the effects of reverse occlusion, the deprived eye was opened and the previously open eye closed when the neurons had become unresponsive to the initially deprived eye. Alternatively, kittens were monocularly deprived for 1 wk by lid suture before implantation. The closed eye was then opened, the other eye patched, and the effects of reverse occlusion were studied for up to 1 wk by repeated measurements of receptive-field properties. 2. The earliest effect of monocular deprivation was the disappearance of binocular summation, i.e., binocular responses ceased to be superior over monocular responses. Overt changes of ocular dominance were observed as early as 6 h after the beginning of monocular deprivation. These consisted of a gradual decrease of the excitatory response to deprived eye stimulation and, on occasions, of an additional moderate increase of responses to the normal eye. A complete loss of excitatory responses to deprived-eye stimulation was seen as early as 12 h after occlusion. In numerous cells, however, stimulation of the deprived eye continued to evoke inhibitory responses even after excitatory responses had vanished completely. During this shift in ocularity, neurons preserved their

  7. Changes in Late Cretaceous-Quaternary Caribbean plate motion directions inferred from paleostress measurements from striated fault planes

    NASA Astrophysics Data System (ADS)

    Batbayar, K.; Mann, P.; Hippolyte, J.

    2013-12-01

    We compiled paleostress analyses from previous research works collected at 591 localities of striated fault planes in rocks ranging in age from Late Cretaceous to Quaternary in the circum-Caribbean and Mexico. The purpose of the study is to quantify a progressive clockwise rotation of the Caribbean plate during its Late Cretaceous to recent subduction of the Proto-Caribbean seaway. Paleostress analysis is based on the assumption that slickenside lineations indicate both the direction and sense of maximum resolved shear stress on that fault plane. We have plotted directions of maximum horizontal stress onto plate tectonic reconstructions of the circum-Caribbean plate boundaries and infer that these directions are proxies for paleo-plate motion directions of the Caribbean plate. Plotting these stress directions onto reconstructions provided a better visualization of the relation of stress directions to blocks at their time of Late Cretaceous to recent deformation. Older, more deformed rocks of Late Cretaceous to Eocene ages yield a greater scatter in derived paleostress directions as these rocks have steeper dips, more pervasive faulting, and were likely affected by large rotations as known from previous paleomagnetic studies of Caribbean plate margins. Despite more scatter in measurements from older rock units, four major events that affected the Caribbean plate and the Great Arc of the Caribbean (GAC) are recognizable from changing orientations of stress directions: 1) Late Cretaceous collision of the GAC with southern Mexico and Colombia is consistent with NE directions of maximum compression in rocks of this age range in southern Mexico and EW directions in Colombia as the GAC approached the Proto-Caribbean seaway; 2) Paleocene-Eocene collision of the GAC with the Bahamas platform in Cuba and Hispaniola and with the South American plate in Venezuela is consistent with CW rotations of stress directions in rocks of these ages in the northern Caribbean and CCW

  8. Reticulated, Hyperchromic Rash in a Striated Pattern Mimicking Atopic Dermatitis and Fungal Infection in a 2-Month-Old Female: A Case of Incontinentia Pigmenti

    PubMed Central

    Poliak, Nina; Le, Alexandre; Rainey, Anthony

    2016-01-01

    We present a 12-month-old Hispanic female with a reticulated, hyperchromic rash in a striated pattern appearing on upper and lower extremities and trunk and back since the age of 6 weeks. Over the next 10 months, the rash persisted. The rash did not respond to treatment with antifungals and steroids. During her 6-month wellness visit, the patient was diagnosed with incontinentia pigmenti (IP), a rare X-linked dominant disorder, fatal to male fetuses in utero. IP can lead to serious neurological and ophthalmologic consequences. Early diagnosis by primary care physicians and parental education about the condition are essential for prevention of retinal detachment, developmental delay, and dental abnormalities. PMID:27195166

  9. Three-dimensional structure of the M-region (bare zone) of vertebrate striated muscle myosin filaments by single-particle analysis.

    PubMed

    Al-Khayat, Hind A; Kensler, Robert W; Morris, Edward P; Squire, John M

    2010-11-12

    The rods of anti-parallel myosin molecules overlap at the centre of bipolar myosin filaments to produce an M-region (bare zone) that is free of myosin heads. Beyond the M-region edges, myosin molecules aggregate in a parallel fashion to yield the bridge regions of the myosin filaments. Adjacent myosin filaments in striated muscle A-bands are cross-linked by the M-band. Vertebrate striated muscle myosin filaments have a 3-fold rotational symmetry around their long axes. In addition, at the centre of the M-region, there are three 2-fold axes perpendicular to the filament long axis, giving the whole filament dihedral 32-point group symmetry. Here we describe the three-dimensional structure obtained by a single-particle analysis of the M-region of myosin filaments from goldfish skeletal muscle under relaxing conditions and as viewed in negative stain. This is the first single-particle reconstruction of isolated M-regions. The resulting three-dimensional reconstruction reveals details to about 55 Å resolution of the density distribution in the five main nonmyosin densities in the M-band (M6', M4', M1, M4 and M6) and in the myosin head crowns (P1, P2 and P3) at the M-region edges. The outermost crowns in the reconstruction were identified specifically by their close similarity to the corresponding crown levels in our previously published bridge region reconstructions. The packing of myosin molecules into the M-region structure is discussed, and some unidentified densities are highlighted. PMID:20851129

  10. Effects of the phlebotropic drug Daflon 500 mg on postischemic reperfusion injury in striated skin muscle: a histomorphologic study in the hamster.

    PubMed

    Pickelmann, S; Nolte, D; Leiderer, R; Möllmann, M; Schütze, E; Messmer, K

    1999-11-01

    The objective of this study was to investigate the effects of the purified, micronized, flavonoid fraction Daflon 500 mg (S 5682, 90% diosmin and 10% hesperidin) on tissue damage and leukocyte emigration in striated skin muscle after ischemia-reperfusion, as assessed by histomorphometric analysis. The experimental model used was the transparent dorsal skin fold chamber in the awake Syrian golden hamster. Sixty-four animals were randomly allotted to two treatment groups and time points of investigation. Animals were fed with 30 mg kg(-1) body weight Daflon 500 mg (n = 32) or its vehicle, 5% Arabic gum solution (n = 32), as control 8 hours before ischemia. Before induction of a tourniquet ischemia of 4 hours' duration and at 0.5, 2, and 24 hours of reperfusion, tissue sections were preserved for light and electron microscopic analysis (n = seven or eight animals per time point). The number of intravascular and extravascular leukocytes was determined by light microscopic analysis of esterase-positive leukocytes. For quantitative analysis of ischemia-induced endothelial cell damage, the endothelial thickness of capillaries was calculated by a computer-assisted imaging system, whereas the ischemic tissue damage was assessed by means of a score system (grade 0-3) by an independent investigator. The number of emigrated leukocytes was significantly reduced in Daflon 500 mg-treated animals compared with numbers found in control animals. The histomorphologic muscle fiber damage increased after reperfusion in both groups but was significantly reduced in the Daflon 500 mg-treated animals 2 and 24 hours after reperfusion. These results suggest that the emigration of leukocytes plays an important role in the development of postischemic reperfusion injury of striated skin muscle. PMID:10560948

  11. Behaviour of the urethral striated sphincter and of the bladder in the chronic spinal cat. Implications at the Central Nervous System Level.

    PubMed

    Rampal, G; Mignard, P

    1975-01-01

    Nine cats were spinalized at the thoraco-lumbar junction (T12-L7) and the subsequent behaviour of the bladder and urethral striated sphincter was observed during periods of up to 27 days after spinalization by means of bladder manometry and of urethral electromyography. On the day following operation, the urethral sphincter responds to stimulation of its intact motor nerve, the pudic nerve by reflex (R) and direct (M) responses analogous to those of the intact animal anaesthetized with chloralose. The ratio R/M lies between 1 and 0.6 in the chronic spinal cat whereas it is generally less than 0.5 in the intact chloralose-anaesthetized cat. The tonic activity of the sphincter is weak or not present. The continence, however, is well maintained. The bladder activity appears only 4 to 8 days after spinalization. The bladder can thus void urine during brief contractions. These micturitions are always incomplete. The urethral reflex activity, either spontaneous or triggered by stimulation of the pudic nerve, may be inhibited, i: to a moderate degree by passive bladder distension; ii: almost completely by activation of vesicomotor neurones which provoke the bladder contraction. The first inhibition is seen the day after spinalization and is probably a protective reflex against vesical hypertension. The second inhibition develops progressively and in parallel to the functional recovery of vesical preganglionic neurones. It takes place on a background of antagnostic equilibrium of bladder and of urethral sphincter activities during micturition. PMID:1168331

  12. Identification of striated muscle activator of Rho signaling (STARS) as a novel calmodulin target by a newly developed genome-wide screen.

    PubMed

    Furuya, Yusui; Denda, Miwako; Sakane, Kyohei; Ogusu, Tomoko; Takahashi, Sumio; Magari, Masaki; Kanayama, Naoki; Morishita, Ryo; Tokumitsu, Hiroshi

    2016-07-01

    To search for novel target(s) of the Ca(2+)-signaling transducer, calmodulin (CaM), we performed a newly developed genome-wide CaM interaction screening of 19,676 GST-fused proteins expressed in human. We identified striated muscle activator of Rho signaling (STARS) as a novel CaM target and characterized its CaM binding ability and found that the Ca(2+)/CaM complex interacted stoichiometrically with the N-terminal region (Ala13-Gln35) of STARS in vitro as well as in living cells. Mutagenesis studies identified Ile20 and Trp33 as the essential hydrophobic residues in CaM anchoring. Furthermore, the CaM binding deficient mutant (Ile20Ala, Trp33Ala) of STARS further enhanced its stimulatory effect on SRF-dependent transcriptional activation. These results suggest a connection between Ca(2+)-signaling via excitation-contraction coupling and the regulation of STARS-mediated gene expression in muscles. PMID:27132186

  13. Isoform composition and gene expression of thick and thin filament proteins in striated muscles of mice after 30-day space flight.

    PubMed

    Ulanova, Anna; Gritsyna, Yulia; Vikhlyantsev, Ivan; Salmov, Nikolay; Bobylev, Alexander; Abdusalamova, Zarema; Rogachevsky, Vadim; Shenkman, Boris; Podlubnaya, Zoya

    2015-01-01

    Changes in isoform composition, gene expression of titin and nebulin, and isoform composition of myosin heavy chains as well as changes in titin phosphorylation level in skeletal (m. gastrocnemius, m. tibialis anterior, and m. psoas) and cardiac muscles of mice were studied after a 30-day-long space flight onboard the Russian spacecraft "BION-M" number 1. A muscle fibre-type shift from slow-to-fast and a decrease in the content of titin and nebulin in the skeletal muscles of animals from "Flight" group was found. Using Pro-Q Diamond staining, an ~3-fold increase in the phosphorylation level of titin in m. gastrocnemius of mice from the "Flight" group was detected. The content of titin and its phosphorylation level in the cardiac muscle of mice from "Flight" and "Control" groups did not differ; nevertheless an increase (2.2 times) in titin gene expression in the myocardium of flight animals was found. The observed changes are discussed in the context of their role in the contractile activity of striated muscles of mice under conditions of weightlessness. PMID:25664316

  14. Isoform Composition and Gene Expression of Thick and Thin Filament Proteins in Striated Muscles of Mice after 30-Day Space Flight

    PubMed Central

    Ulanova, Anna; Gritsyna, Yulia; Vikhlyantsev, Ivan; Salmov, Nikolay; Bobylev, Alexander; Abdusalamova, Zarema; Rogachevsky, Vadim; Shenkman, Boris; Podlubnaya, Zoya

    2015-01-01

    Changes in isoform composition, gene expression of titin and nebulin, and isoform composition of myosin heavy chains as well as changes in titin phosphorylation level in skeletal (m. gastrocnemius, m. tibialis anterior, and m. psoas) and cardiac muscles of mice were studied after a 30-day-long space flight onboard the Russian spacecraft “BION-M” number 1. A muscle fibre-type shift from slow-to-fast and a decrease in the content of titin and nebulin in the skeletal muscles of animals from “Flight” group was found. Using Pro-Q Diamond staining, an ~3-fold increase in the phosphorylation level of titin in m. gastrocnemius of mice from the “Flight” group was detected. The content of titin and its phosphorylation level in the cardiac muscle of mice from “Flight” and “Control” groups did not differ; nevertheless an increase (2.2 times) in titin gene expression in the myocardium of flight animals was found. The observed changes are discussed in the context of their role in the contractile activity of striated muscles of mice under conditions of weightlessness. PMID:25664316

  15. Geologic continuous casting below continental and deep-sea detachment faults and at the striated extrusion of Sacsayhuamán, Peru

    NASA Astrophysics Data System (ADS)

    Spencer, Jon E.

    1999-04-01

    In one common type of industrial continuous casting, partially molten metal is extruded from a vessel through a shaped orifice called a mold in which the metal assumes the cross-sectional form of the mold as it cools and solidifies. Continuous casting can be sustained as long as molten metal is supplied and thermal conditions are maintained. I propose that a similar process produced parallel sets of grooves in three geologic settings, as follows: (1) corrugated metamorphic core complexes where mylonitized mid-crustal rocks were exhumed by movement along low-angle normal faults known as detachment faults; (2) corrugated submarine surfaces where ultramafic and mafic rocks were exhumed by normal faulting within oceanic spreading centers; and (3) striated magma extrusions exemplified by the famous grooved outcrops at the Inca fortress of Sacsayhuamán in Peru. In each case, rocks inferred to have overlain the corrugated surface during corrugation genesis molded and shaped a plastic to partially molten rock mass as it was extruded from a moderate- to high-temperature reservoir.

  16. A Novel Conserved Isoform of the Ubiquitin Ligase UFD2a/UBE4B Is Expressed Exclusively in Mature Striated Muscle Cells

    PubMed Central

    Mammen, Andrew L.; Mahoney, James A.; St. Germain, Amanda; Badders, Nisha; Taylor, J. Paul; Rosen, Antony; Spinette, Sarah

    2011-01-01

    Yeast Ufd2p was the first identified E4 multiubiquitin chain assembly factor. Its vertebrate homologues later referred to as UFD2a, UBE4B or E4B were also shown to have E3 ubiquitin ligase activity. UFD2a function in the brain has been well established in vivo, and in vitro studies have shown that its activity is essential for proper condensation and segregation of chromosomes during mitosis. Here we show that 2 alternative splice forms of UFD2a, UFD2a-7 and -7/7a, are expressed sequentially during myoblast differentiation of C2C12 cell cultures and during cardiotoxin-induced regeneration of skeletal muscle in mice. UFD2a-7 contains an alternate exon 7, and UFD2a-7/7a, the larger of the 2 isoforms, contains an additional novel exon 7a. Analysis of protein or mRNA expression in mice and zebrafish revealed that a similar pattern of isoform switching occurs during developmental myogenesis of cardiac and skeletal muscle. In vertebrates (humans, rodents, zebrafish), UFD2a-7/7a is expressed only in mature striated muscle. This unique tissue specificity is further validated by the conserved presence of 2 muscle-specific splicing regulatory motifs located in the 3′ introns of exons 7 and 7a. UFD2a interacts with VCP/p97, an AAA-type ATPase implicated in processes whose functions appear to be regulated, in part, through their interaction with one or more of 15 previously identified cofactors. UFD2a-7/7a did not interact with VCP/p97 in yeast 2-hybrid experiments, which may allow the ATPase to bind cofactors that facilitate its muscle-specific functions. We conclude that the regulated expression of these UFD2a isoforms most likely imparts divergent functions that are important for myogenisis. PMID:22174917

  17. Spectral sideband produced by a hemispherical concave multilayer on the African shield-bug Calidea panaethiopica (Scutelleridae)

    NASA Astrophysics Data System (ADS)

    Vigneron, Jean Pol; Ouedraogo, Moussa; Colomer, Jean-François; Rassart, Marie

    2009-02-01

    The African shield-backed bug Calidea panaethiopica is a very colorful insect which produces a range of iridescent yellow, green, and blue reflections. The cuticle of the dorsal side of the insect, on the shield, the prothorax and part of the head, is pricked of uniformly distributed hemispherical hollow cavities a few tens micrometers deep. Under normal illumination and viewing the insect’s muffin-tin shaped surface gives rise to two distinct colors: a yellow spot arising from the bottom of the well and a blue annular cloud that appears to float around the yellow spot. This effect is explained by multiple reflections on a hemispherical Bragg mirror with a mesoscopic curvature. A multiscale computing methodology was found to be needed to evaluate the reflection spectrum for such a curved multilayer. This multiscale approach is very general and should be useful for dealing with visual effects in many natural and artificial systems.

  18. Spectroscopic and ITC study of the conformational change upon Ca{sup 2+}-binding in TnC C-lobe and TnI peptide complex from Akazara scallop striated muscle

    SciTech Connect

    Yumoto, Fumiaki; Tanaka, Hiroyuki; Nagata, Koji; Miyauchi, Yumiko; Miyakawa, Takuya; Ojima, Takao; Tanokura, Masaru

    2008-04-25

    Akazara scallop (Chlamys nipponensis akazara) troponin C (TnC) of striated adductor muscle binds only one Ca{sup 2+} ion at the C-terminal EF-hand motif (Site IV), but it works as the Ca{sup 2+}-dependent regulator in adductor muscle contraction. In addition, the scallop troponin (Tn) has been thought to regulate muscle contraction via activating mechanisms that involve the region spanning from the TnC C-lobe (C-lobe) binding site to the inhibitory region of the TnI, and no alternative binding of the TnI C-terminal region to TnC because of no similarity between second TnC-binding regions of vertebrate and the scallop TnIs. To clarify the Ca{sup 2+}-regulatory mechanism of muscle contraction by scallop Tn, we have analyzed the Ca{sup 2+}-binding properties of the complex of TnC C-lobe and TnI peptide, and their interaction using isothermal titration microcalorimetry, nuclear magnetic resonance, circular dichroism, and gel filtration chromatography. The results showed that single Ca{sup 2+}-binding to the Site IV leads to a structural transition not only in Site IV but also Site III through the structural network in the C-lobe of scallop TnC. We therefore assumed that the effect of Ca{sup 2+}-binding must lead to a change in the interaction mode between the C-lobe of TnC and the TnI peptide. The change should be the first event of the transmission of Ca{sup 2+} signal to TnI in Tn ternary complex.

  19. Hyperactivation of L-type voltage-gated Ca2+ channels in Caenorhabditis elegans striated muscle can result from point mutations in the IS6 or the IIIS4 segment of the α1 subunit.

    PubMed

    Lainé, Viviane; Ségor, Jean Rony; Zhan, Hong; Bessereau, Jean-Louis; Jospin, Maelle

    2014-11-01

    Several human diseases, including hypokalemic periodic paralysis and Timothy syndrome, are caused by mutations in voltage-gated calcium channels. The effects of these mutations are not always well understood, partially because of difficulties in expressing these channels in heterologous systems. The use of Caenorhabditis elegans could be an alternative approach to determine the effects of mutations on voltage-gated calcium channel function because all the main types of voltage-gated calcium channels are found in C. elegans, a large panel of mutations already exists and efficient genetic tools are available to engineer customized mutations in any gene. In this study, we characterize the effects of two gain-of-function mutations in egl-19, which encodes the L-type calcium channel α1 subunit. One of these mutations, ad695, leads to the replacement of a hydrophobic residue in the IIIS4 segment. The other mutation, n2368, changes a conserved glycine of IS6 segment; this mutation has been identified in patients with Timothy syndrome. We show that both egl-19 (gain-of-function) mutants have defects in locomotion and morphology that are linked to higher muscle tone. Using in situ electrophysiological approaches in striated muscle cells, we provide evidence that this high muscle tone is due to a shift of the voltage dependency towards negative potentials, associated with a decrease of the inactivation rate of the L-type Ca(2+) current. Moreover, we show that the maximal conductance of the Ca(2+) current is decreased in the strongest mutant egl-19(n2368), and that this decrease is correlated with a mislocalization of the channel. PMID:25214488

  20. Ontogenesis of receptive fields in the rabbit striate cortex

    NASA Technical Reports Server (NTRS)

    Mathers, L. H.; Chow, K. L.; Spear, P. D.; Grobstein, P.

    1974-01-01

    The development of receptive fields in rabbit pups was investigated by measuring their responses to various light stimuli and to electric shock delivered to the optic nerve head. The pups ranged in age from three to twenty-five days, allowing correlation of findings with maturation. The data, classified according to relation with symmetric or asymmetric field types, strongly suggest that retina maturation is the key factor in the rate of development in central visual pathways, and that central synaptic connections are made before the onset of retinal activity.

  1. Statistical methods for the forensic analysis of striated tool marks

    SciTech Connect

    Hoeksema, Amy Beth

    2013-01-01

    In forensics, fingerprints can be used to uniquely identify suspects in a crime. Similarly, a tool mark left at a crime scene can be used to identify the tool that was used. However, the current practice of identifying matching tool marks involves visual inspection of marks by forensic experts which can be a very subjective process. As a result, declared matches are often successfully challenged in court, so law enforcement agencies are particularly interested in encouraging research in more objective approaches. Our analysis is based on comparisons of profilometry data, essentially depth contours of a tool mark surface taken along a linear path. In current practice, for stronger support of a match or non-match, multiple marks are made in the lab under the same conditions by the suspect tool. We propose the use of a likelihood ratio test to analyze the difference between a sample of comparisons of lab tool marks to a field tool mark, against a sample of comparisons of two lab tool marks. Chumbley et al. (2010) point out that the angle of incidence between the tool and the marked surface can have a substantial impact on the tool mark and on the effectiveness of both manual and algorithmic matching procedures. To better address this problem, we describe how the analysis can be enhanced to model the effect of tool angle and allow for angle estimation for a tool mark left at a crime scene. With sufficient development, such methods may lead to more defensible forensic analyses.

  2. Charge movement in the membrane of striated muscle.

    PubMed Central

    Adrian, R H; Almers, W

    1976-01-01

    1. Non-linear polarization currents apparently due to permanent dipoles or mobile charges in the membrane can be measured by appropriate comparison of the transient currents required to produce small and large steps of membrane potential. Integration of these transient polarization currents estimates the charge transfer associated with the movement of membrane dipoles or charges. 2. Depolarization from -100 to 0 mV requires a charge transfer of 35 nC/muF in addition to the charge transfer predicted by linear extrapolation of the charge required for a small depolarization from -100 mV. Depolarizations of varying size give a charge-voltage relation which is sigmoid saturating beyond o mV and with a midpoint at about -50 mV. The ratnged depolarization reduces or removes charge movement detected by comparing currents for small and large voltage steps from -100 mV (Charge 1). However in depolarized fibres comparison of currents from a small potential step at +40 mV and a large hyperpolarizing potential step from -20 mV reveals large movements of a second charge (Charge 2). Movement of Charge 2 is less steeply dependent on voltage than movement of Charge 2 both in magnitude and in rate. 4. In size and voltage dependence these two kinds of charge movement correspond to measured voltage dependence of capacity in normally polarized and depolarized fibres (Adrian & Almers, 1976). PMID:1082509

  3. Striated Muscle as Implantation Site for Transplanted Pancreatic Islets

    PubMed Central

    Espes, Daniel; Eriksson, Olof; Lau, Joey; Carlsson, Per-Ola

    2011-01-01

    Islet transplantation is an attractive treatment for selected patients with brittle type 1 diabetes. In the clinical setting, intraportal transplantation predominates. However, due to extensive early islet cell death, the quantity of islets needed to restore glucose homeostasis requires in general a minimum of two donors. Moreover, the deterioration of islet function over time results in few insulin-independent patients after five-year followup. Specific obstacles to the success of islet transplantation include site-specific concerns for the liver such as the instant blood mediated inflammatory reaction, islet lipotoxicity, low oxygen tension, and poor revascularization, impediments that have led to the developing interest for alternative implantation sites over recent years. Within preclinical settings, several alternative sites have now been investigated and proven favorable in various aspects. Muscle is considered a very promising site and has physiologically properties and technical advantages that could make it optimal for islet transplantation. PMID:22174984

  4. Mapping striate and extrastriate visual areas in human cerebral cortex.

    PubMed Central

    DeYoe, E A; Carman, G J; Bandettini, P; Glickman, S; Wieser, J; Cox, R; Miller, D; Neitz, J

    1996-01-01

    Functional magnetic resonance imaging (fMRI) was used to identify and map the representation of the visual field in seven areas of human cerebral cortex and to identify at least two additional visually responsive regions. The cortical locations of neurons responding to stimulation along the vertical or horizontal visual field meridia were charted on three-dimensional models of the cortex and on unfolded maps of the cortical surface. These maps were used to identify the borders among areas that would be topographically homologous to areas V1, V2, V3, VP, and parts of V3A and V4 of the macaque monkey. Visually responsive areas homologous to the middle temporal/medial superior temporal area complex and unidentified parietal visual areas were also observed. The topography of the visual areas identified thus far is consistent with the organization in macaque monkeys. However, these and other findings suggest that human and simian cortical organization may begin to differ in extrastriate cortex at, or beyond, V3A and V4. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8637882

  5. Frog striated muscle is permeable to hydroxide and buffer anions.

    PubMed

    Venosa, R A; Kotsias, B A; Horowicz, P

    1994-04-01

    Hydroxide, bicarbonate and buffer anion permeabilities in semitendinosus muscle fibers of Rana pipiens were measured. In all experiments, the fibers were initially equilibrated in isotonic, high K2SO4 solutions at pHo = 7.2 buffered with phosphate. Two different methods were used to estimate permeabilities: (i) membrane potential changes were recorded in response to changes in external ion concentrations, and (ii) intracellular pH changes were recorded in response to changes in external concentrations of ions that alter intracellular pH. Constant field equations were used to calculate relative or absolute permeabilities. In the first method, to increase the size of the membrane potential change produced by a sudden change in anion entry, external K+ was replaced by Cs+ prior to changes of the anion under study. At constant external Cs+ activity, a hyperpolarization results from increasing external pH from 7.2 to 10.0 or higher, using either CAPS (3-[cyclohexylamino]-1-propanesulfonic acid) or CHES (2-[N-cyclohexylamino]-ethanesulfonic acid) as buffer. For each buffer, the protonated form is a zwitterion of zero net charge and the nonprotonated form is an anion. Using reported values of H+ permeability, calculations show that the reduction in [H+]o cannot account for the hyperpolarizations produced by alkaline solutions. Membrane hyperpolarization increases with increasing total external buffer concentration at constant external pH, and with increasing external pH at constant external buffer anion concentration. Taken together, these observations indicate that both OH- and buffer anions permeate the surface membrane. The following relative permeabilities were obtained at pHo = 10.0 +/- 0.3: (POH/PK) = 890 +/- 150, (PCAPS/PK) = 12 +/- 2, (PCHES/PK) = 5.3 +/- 0.9, and (PNO3/PK) = 4.7 +/- 0.5. PNO3/PK was independent of pHo up to 10.75. At pHo = 9.6, (PHCO3/PK) = 0.49 +/- 0.03; at pHo = 8.9, (PCl/PK) = 18 +/- 2 and at pHo = 7.1, (PHEPES/PK) = 20 +/- 2. In the second method, on increasing external pH from 7.2 to 10.0, using 2.5 mM CAPS (total buffer concentration), the internal pH increases linearly with time over the next 10 min. This alkalinization is due to the entry of OH- and the absorption of internal H+ by entering CAPS- anion. The rate of CAPS- entry was determined in experiments in which the external CAPS concentration was increased at constant external pH. Such increases invariably produced an increase in the rate of internal alkalinization, which was reversed when the CAPS concentration was reduced to its initial value.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8071988

  6. Holonomy, quantum mechanics and the signal-tuned Gabor approach to the striate cortex

    NASA Astrophysics Data System (ADS)

    Torreão, José R. A.

    2016-02-01

    It has been suggested that an appeal to holographic and quantum properties will be ultimately required for the understanding of higher brain functions. On the other hand, successful quantum-like approaches to cognitive and behavioral processes bear witness to the usefulness of quantum prescriptions as applied to the analysis of complex non-quantum systems. Here, we show that the signal-tuned Gabor approach for modeling cortical neurons, although not based on quantum assumptions, also admits a quantum-like interpretation. Recently, the equation of motion for the signal-tuned complex cell response has been derived and proven equivalent to the Schrödinger equation for a dissipative quantum system whose solutions come under two guises: as plane-wave and Airy-packet responses. By interpreting the squared magnitude of the plane-wave solution as a probability density, in accordance with the quantum mechanics prescription, we arrive at a Poisson spiking probability — a common model of neuronal response — while spike propagation can be described by the Airy-packet solution. The signal-tuned approach is also proven consistent with holonomic brain theories, as it is based on Gabor functions which provide a holographic representation of the cell’s input, in the sense that any restricted subset of these functions still allows stimulus reconstruction.

  7. Fluid model of a single striated filament in an RF plasma jet at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Sigeneger, F.; Loffhagen, D.

    2016-06-01

    The filaments occurring in an RF argon atmospheric-pressure plasma jet are investigated by means of numerical modelling. The special setup of the jet leads to the establishment of filaments in very regular modes under certain conditions. Such a single filament generated in the active volume between the powered and grounded electrode is described by a time-dependent, spatially two-dimensional fluid model. This self-consistent model includes those mechanisms which can lead to constriction and stratification such as the heat balance equation and the dependence of electron collision rate coefficients on the ionization degree. A curved filament with a contracted radial profile of particle densities and very pronounced striations along its trace has been obtained by the model calculation for a typical discharge parameter condition of the plasma jet. The resulting calculated electron density and mean energy in the filament as well as the period length of the striations agree qualitatively with recent experimental observations. The analysis of the ionization budget makes clear that the constriction and stratification is mainly caused by the different nonlinear dependences of ionization and recombination rates on the electron density.

  8. Neural Representations of Natural and Scrambled Movies Progressively Change from Rat Striate to Temporal Cortex.

    PubMed

    Vinken, Kasper; Van den Bergh, Gert; Vermaercke, Ben; Op de Beeck, Hans P

    2016-07-01

    In recent years, the rodent has come forward as a candidate model for investigating higher level visual abilities such as object vision. This view has been backed up substantially by evidence from behavioral studies that show rats can be trained to express visual object recognition and categorization capabilities. However, almost no studies have investigated the functional properties of rodent extrastriate visual cortex using stimuli that target object vision, leaving a gap compared with the primate literature. Therefore, we recorded single-neuron responses along a proposed ventral pathway in rat visual cortex to investigate hallmarks of primate neural object representations such as preference for intact versus scrambled stimuli and category-selectivity. We presented natural movies containing a rat or no rat as well as their phase-scrambled versions. Population analyses showed increased dissociation in representations of natural versus scrambled stimuli along the targeted stream, but without a clear preference for natural stimuli. Along the measured cortical hierarchy the neural response seemed to be driven increasingly by features that are not V1-like and destroyed by phase-scrambling. However, there was no evidence for category selectivity for the rat versus nonrat distinction. Together, these findings provide insights about differences and commonalities between rodent and primate visual cortex. PMID:27146315

  9. Visual field defects after missile injuries to the geniculo-striate pathway in man.

    NASA Technical Reports Server (NTRS)

    Koerner, F.; Teuber, H.-L.

    1973-01-01

    The main objective of the survey reported was a quantitative comparison of different visual functions at identical retinal points of individual patients. The possibility to develop objective forms of visual-field testing was also explored, taking into account reports by Frydrychowicz and Harms (1940) and Harms (1951). These investigators had insisted that pupillary responses to light are depressed in areas of homonymous scotomata. The shapes of homonymous visual field defects are discussed together with questions regarding the association and dissociation of symptoms.

  10. The toxic effect of R350P mutant desmin in striated muscle of man and mouse.

    PubMed

    Clemen, Christoph S; Stöckigt, Florian; Strucksberg, Karl-Heinz; Chevessier, Frederic; Winter, Lilli; Schütz, Johanna; Bauer, Ralf; Thorweihe, José-Manuel; Wenzel, Daniela; Schlötzer-Schrehardt, Ursula; Rasche, Volker; Krsmanovic, Pavle; Katus, Hugo A; Rottbauer, Wolfgang; Just, Steffen; Müller, Oliver J; Friedrich, Oliver; Meyer, Rainer; Herrmann, Harald; Schrickel, Jan Wilko; Schröder, Rolf

    2015-02-01

    Mutations of the human desmin gene on chromosome 2q35 cause autosomal dominant, autosomal recessive and sporadic forms of protein aggregation myopathies and cardiomyopathies. We generated R349P desmin knock-in mice, which harbor the ortholog of the most frequently occurring human desmin missense mutation R350P. These mice develop age-dependent desmin-positive protein aggregation pathology, skeletal muscle weakness, dilated cardiomyopathy, as well as cardiac arrhythmias and conduction defects. For the first time, we report the expression level and subcellular distribution of mutant versus wild-type desmin in our mouse model as well as in skeletal muscle specimens derived from human R350P desminopathies. Furthermore, we demonstrate that the missense-mutant desmin inflicts changes of the subcellular localization and turnover of desmin itself and of direct desmin-binding partners. Our findings unveil a novel principle of pathogenesis, in which not the presence of protein aggregates, but disruption of the extrasarcomeric intermediate filament network leads to increased mechanical vulnerability of muscle fibers. These structural defects elicited at the myofiber level finally impact the entire organ and subsequently cause myopathy and cardiomyopathy. PMID:25394388

  11. In vitro and in vivo single myosin step-sizes in striated muscle.

    PubMed

    Burghardt, Thomas P; Sun, Xiaojing; Wang, Yihua; Ajtai, Katalin

    2015-12-01

    Myosin in muscle transduces ATP free energy into the mechanical work of moving actin. It has a motor domain transducer containing ATP and actin binding sites, and, mechanical elements coupling motor impulse to the myosin filament backbone providing transduction/mechanical-coupling. The mechanical coupler is a lever-arm stabilized by bound essential and regulatory light chains. The lever-arm rotates cyclically to impel bound filamentous actin. Linear actin displacement due to lever-arm rotation is the myosin step-size. A high-throughput quantum dot labeled actin in vitro motility assay (Qdot assay) measures motor step-size in the context of an ensemble of actomyosin interactions. The ensemble context imposes a constant velocity constraint for myosins interacting with one actin filament. In a cardiac myosin producing multiple step-sizes, a "second characterization" is step-frequency that adjusts longer step-size to lower frequency maintaining a linear actin velocity identical to that from a shorter step-size and higher frequency actomyosin cycle. The step-frequency characteristic involves and integrates myosin enzyme kinetics, mechanical strain, and other ensemble affected characteristics. The high-throughput Qdot assay suits a new paradigm calling for wide surveillance of the vast number of disease or aging relevant myosin isoforms that contrasts with the alternative model calling for exhaustive research on a tiny subset myosin forms. The zebrafish embryo assay (Z assay) performs single myosin step-size and step-frequency assaying in vivo combining single myosin mechanical and whole muscle physiological characterizations in one model organism. The Qdot and Z assays cover "bottom-up" and "top-down" assaying of myosin characteristics. PMID:26728749

  12. The morphology and cell culture of the striated musculature of the rat azygos vein.

    PubMed

    Cullinan, V; Campbell, J H; Mosse, P R; Campbell, G R

    1986-01-01

    The azygos vein of the rat can be divided into three regions: The proximal cardiac region, where the wall is composed of two and sometimes three layers of cardiac muscle and a thin discontinuous layer of smooth muscle cells. Vascular casts of this region demonstrate layers of capillaries closely following the orientation of the cardiac fibres. A transitional zone, where both cardiac and smooth muscle cells interdigitate. In this zone, close associations between smooth muscle and cardiac muscle cells can be observed, however, gap junctions do not appear to be present. Beyond this transitional zone the vessel resembles a typical thin-walled vein. The cells of the media of the entire length of azygous vein have been isolated and grown in culture and two separate viable populations identified corresponding to smooth and cardiac muscle. PMID:3510740

  13. Androgens enhance in vivo 2-deoxyglucose uptake by rat striated muscle

    NASA Technical Reports Server (NTRS)

    Max, S. R.; Toop, J.

    1983-01-01

    It is shown that testosterone propionate (TP) causes a striking increase in the in vivo uptake of 2-deoxyglucose (2-DG) by the levator ani muscle of immature male rats, which was found to be uniformly distributed over the entire muscle. After a single subcutaneous injection of TP, no enhancement of 2-DG was observed before 3.5 hr, at which time uptake was increased 2-fold; maximum enhancement (4-fold) was attained at 12 hr. At 72 hr, 2-DG uptake remained elevated at twice the control value. It was determined that the effect of TP probably is mediated by specific androgen receptors. In addition, it was found that the effect of TP was blocked by the simultaneous administration of an androgen antagonist, cyproterone acetate. TP also was found to enhance the uptake of 2-DG in the bulbocavernosus (253 percent over control) and extensor digitorum longus muscles (150 percent over control), but not in the biceps brachii or soleus. It is suggested that the increased uptake of glucose may be an important early step in the anabolic response of muscle to androgens.

  14. Topographic reorganization in the striate cortex of the adult cat and monkey is cortically mediated.

    PubMed

    Darian-Smith, C; Gilbert, C D

    1995-03-01

    In primary sensory and motor cortex of adult animals, alteration of input from the periphery leads to changes in cortical topography. These changes can be attributed to processes that are intrinsic to the cortex, or can be inherited from alterations occurring at stages of sensory processing that are antecedent to the primary sensory cortical areas. In the visual system, focal binocular retinal lesions initially silence an area of cortex that represents the region of retina destroyed, but over a period of months this area recovers visually driven activity. The retinotopic map in the recovered area is altered, shifting its representation to the portion of retina immediately surrounding the lesion. This effectively shrinks the representation of the lesioned area of retina, and expands the representation of the lesion surround. To determine the loci along the visual pathway at which the reorganization takes place, we compared the course of topographic alterations in the primary visual cortex and dorsal lateral geniculate nucleus (LGN) of cats and monkeys. At a time when the cortical reorganization is complete, the silent area of LGN persists, indicating that changes in cortical topography are due to alterations that are intrinsic to the cortex. To explore the participation of thalamocortical afferents in the reorganization, we injected a series of retrogradely transported fluorescent tracers into reorganized and surrounding cortex of each animal. Our results show that the thalamocortical arbors do not extend beyond their normal lateral territory and that this physical dimension is insufficient to account for the reorganization. We suggest that the long-range intrinsic horizontal connections are a likely source of visual input into the reorganized cortical area. PMID:7891124

  15. Neural Representations of Natural and Scrambled Movies Progressively Change from Rat Striate to Temporal Cortex

    PubMed Central

    Vinken, Kasper; Van den Bergh, Gert; Vermaercke, Ben; Op de Beeck, Hans P.

    2016-01-01

    In recent years, the rodent has come forward as a candidate model for investigating higher level visual abilities such as object vision. This view has been backed up substantially by evidence from behavioral studies that show rats can be trained to express visual object recognition and categorization capabilities. However, almost no studies have investigated the functional properties of rodent extrastriate visual cortex using stimuli that target object vision, leaving a gap compared with the primate literature. Therefore, we recorded single-neuron responses along a proposed ventral pathway in rat visual cortex to investigate hallmarks of primate neural object representations such as preference for intact versus scrambled stimuli and category-selectivity. We presented natural movies containing a rat or no rat as well as their phase-scrambled versions. Population analyses showed increased dissociation in representations of natural versus scrambled stimuli along the targeted stream, but without a clear preference for natural stimuli. Along the measured cortical hierarchy the neural response seemed to be driven increasingly by features that are not V1-like and destroyed by phase-scrambling. However, there was no evidence for category selectivity for the rat versus nonrat distinction. Together, these findings provide insights about differences and commonalities between rodent and primate visual cortex. PMID:27146315

  16. Testosterone enhances C-14 2-deoxyglucose uptake by striated muscle. [sex hormones and muscle

    NASA Technical Reports Server (NTRS)

    Toop, J.; Max, S. R.

    1982-01-01

    The effect of testosterone propionate (TP) on C-14 2-deoxyglucose (C-14 2DG) uptake was studied in the rat levator ani muscle in vivo using the autoradiographic technique. Following a delay of 1 to 3 h after injecting TP, the rate of C-14 2DG uptake in experimental animals began to increase and continued to increase for at least 20 h. The label, which corresponds to C-14 2-deoxyglucose 6-phosphate, as demonstrated by chromatographic analysis of muscle extracts, was uniformly distributed over the entire muscle and was predominantly in muscle fibers, although nonmuscular elements were also labeled. The 1 to 3 h time lag suggests that the TP effect may be genomic, acting via androgen receptors, rather than directly on muscle membranes. Acceleration of glucose uptake may be an important early event in the anabolic response of the rat levator ani muscle to androgens.

  17. Modulation of the cytosolic androgen receptor in striated muscle by sex steroids

    NASA Technical Reports Server (NTRS)

    Rance, N. E.; Max, S. R.

    1984-01-01

    The effects of orchiectomy (GDX) and of subsequent administration of testosterone propionate (TP) or 17(beta)-estradiol (E2) on the maximum binding (Bmax) and apparent Kd of the cytosolic androgen receptor in levator ani (LA) and skeletal muscles of adult male Sprague-Dawley rats are investigated experimentally. The results are presented in graphs and discussed. In LA, BMAX is found to rise from a control level of 2.5 fmol/mg protein to 280, 600, 478, and 133 percent of control at 12 h, 14 d, 30 d, and 44 d after GDX, respectively, while Kd increased only insignificantly (from 680 to 960 fM); Bmax is held at control levels for 6 h by cycloheximide given at GDX, is unaffected by TP given at 30 d, and is further increased (by 480 percent at 44 d) by administration of E2 at 30 d. Bmax in skeletal muscles is found to increase to 139, 212, 220, and 158 percent of control at 12 h, 14 d, 30 d, and 44 d, respectively; Bmax is returned to control at 44 d by TP at 30 d but is not affected by E2. The effect of E2 in LA is attributed to either induction of the cytosolic receptor or a decreased rate of receptor degradation.

  18. Effects of different activity and inactivity paradigms on myosin heavy chain gene expression in striated muscle

    NASA Technical Reports Server (NTRS)

    Baldwin, K. M.; Haddad, F.

    2001-01-01

    The goal of this mini-review is to summarize findings concerning the role that different models of muscular activity and inactivity play in altering gene expression of the myosin heavy chain (MHC) family of motor proteins in mammalian cardiac and skeletal muscle. This was done in the context of examining parallel findings concerning the role that thyroid hormone (T(3), 3,5,3'-triiodothyronine) plays in MHC expression. Findings show that both cardiac and skeletal muscles of experimental animals are initially undifferentiated at birth and then undergo a marked level of growth and differentiation in attaining the adult MHC phenotype in a T(3)/activity level-dependent fashion. Cardiac MHC expression in small mammals is highly sensitive to thyroid deficiency, diabetes, energy deprivation, and hypertension; each of these interventions induces upregulation of the beta-MHC isoform, which functions to economize circulatory function in the face of altered energy demand. In skeletal muscle, hyperthyroidism, as well as interventions that unload or reduce the weight-bearing activity of the muscle, causes slow to fast MHC conversions. Fast to slow conversions, however, are seen under hypothyroidism or when the muscles either become chronically overloaded or subjected to intermittent loading as occurs during resistance training and endurance exercise. The regulation of MHC gene expression by T(3) or mechanical stimuli appears to be strongly regulated by transcriptional events, based on recent findings on transgenic models and animals transfected with promoter-reporter constructs. However, the mechanisms by which T(3) and mechanical stimuli exert their control on transcriptional processes appear to be different. Additional findings show that individual skeletal muscle fibers have the genetic machinery to express simultaneously all of the adult MHCs, e.g., slow type I and fast IIa, IIx, and IIb, in unique combinations under certain experimental conditions. This degree of heterogeneity among the individual fibers would ensure a large functional diversity in performing complex movement patterns. Future studies must now focus on 1) the signaling pathways and the underlying mechanisms governing the transcriptional/translational machinery that control this marked degree of plasticity and 2) the morphological organization and functional implications of the muscle fiber's capacity to express such a diversity of motor proteins.

  19. Critical current density measurement of striated multifilament-coated conductors using a scanning Hall probe microscope

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Fen; Kochat, Mehdi; Majkic, Goran; Selvamanickam, Venkat

    2016-08-01

    In this paper the authors succeeded in measuring the critical current density ({J}{{c}}) of multifilament-coated conductors (CCs) with thin filaments as low as 0.25 mm using the scanning hall probe microscope (SHPM) technique. A new iterative method of data analysis is developed to make the calculation of {J}{{c}} for thin filaments possible, even without a very small scan distance. The authors also discussed in detail the advantage and limitation of the iterative method using both simulation and experiment results. The results of the new method correspond well with the traditional fast Fourier transform method where this is still applicable. However, the new method is applicable for the filamentized CCs in much wider measurement conditions such as with thin filament and a large scan distance, thus overcoming the barrier for application of the SHPM technique on {J}{{c}} measurement of long filamentized CCs with narrow filaments.

  20. A region of the myosin rod important for interaction with paramyosin in Caenorhabditis elegans striated muscle.

    PubMed Central

    Hoppe, P E; Waterston, R H

    2000-01-01

    The precise arrangement of molecules within the thick filament, as well as the mechanisms by which this arrangement is specified, remains unclear. In this article, we have exploited a unique genetic interaction between one isoform of myosin heavy chain (MHC) and paramyosin in Caenorhabditis elegans to probe the molecular interaction between MHC and paramyosin in vivo. Using chimeric myosin constructs, we have defined a 322-residue region of the MHC A rod critical for suppression of the structural and motility defects associated with the unc-15(e73) allele. Chimeric constructs lacking this region of MHC A either fail to suppress, or act as dominant enhancers of, the e73 phenotype. Although the 322-residue region is required for suppression activity, our data suggest that sequences along the length of the rod also play a role in the isoform-specific interaction between MHC A and paramyosin. Our genetic and cell biological analyses of construct behavior suggest that the 322-residue region of MHC A is important for thick filament stability. We present a model in which this region mediates an avid interaction between MHC A and paramyosin in parallel arrangement in formation of the filament arms. PMID:11014812

  1. The formation and regression of synapses during the re-innervation of axolotl striated muscles.

    PubMed Central

    Bennett, M R; Raftos, J

    1977-01-01

    1. A study has been made of the formation and regression of synapses formed by spinal nerves 16 and 17 in axolotl hind-limb flexor muscles following the severing of nerve 16, using histological, ultrastructural and electrophysiological techniques. 2. Axolotl hind-limb flexor myofibres possessed 'en plaque' end-plates from either spinal nerve 16 or 17 or both at intervals of about 1000 micronm along their length; the myofibre's length constant was about 700 micronm allowing electrophysiological observations of at least two of these synapses during a single impalement; transmitter release at these synapses could be described by binomial statistics and in a given set of ionic conditions the binomial statistic parameter n was directly proportional to the size of the nerve terminals whilst the binomial statistic parameter p was invariant to changes in nerve terminal size. 3. The distribution of synapses formed by spinal nerves 16 and 17 in different sectors of the axolotl hind-limb flexor muscles was determined from a study of evoked end-plate potentials; the middle and proximal sectors of the flexor muscles contained myofibres which received an innervation from nerve 16 only, whereas the sectors surrounding these contained myofibres innervated either by nerve 16 or nerve 17 or by both nerves. 4. Six days following the severing of spinal nerve 16, evoked transmitter release from the synapses formed by this nerve had failed; transmission was subsequently recorded at a few synapses formed by nerve 17 in the middle and proximal sectors of the flexor muscles which are not normally innervated by this nerve and these synapses had a low n; during the succeeding four weeks the value of n at the synapses increased to a size about 70% that of the terminals normally formed by nerve 16 at these sites. 5. Four weeks after severing nerve 16, myofibres which possessed synapses formed by nerve 17 also possessed synapses from re-innervating nerve 16 and these were sometimes formed at the same synaptic sites as those occupied by nerve 17. 6. In the subsequent sixteen weeks, the n value of synapses formed by nerve 17 declined whilst the n values of synapses formed by re-innervating nerve 16 on the same myofibres matured to their control size. 7. It is suggested that on severing nerve 16 collateral sprouting of nearby intact nerve 17 occurs and these collateral sprouts innervate the denervated synaptic sites, although the sprouts arenot as well matched to the denervated synaptic sites as are the original nerve terminals; thus if nerve 16 returns it preferentially forms synapses at its original synaptic sites, and the collateral synapses formed by nerve 17 regress. Images Plate 1 Plate 2 PMID:191597

  2. Triclosan impairs excitation-contraction coupling and Ca2+ dynamics in striated muscle.

    PubMed

    Cherednichenko, Gennady; Zhang, Rui; Bannister, Roger A; Timofeyev, Valeriy; Li, Ning; Fritsch, Erika B; Feng, Wei; Barrientos, Genaro C; Schebb, Nils H; Hammock, Bruce D; Beam, Kurt G; Chiamvimonvat, Nipavan; Pessah, Isaac N

    2012-08-28

    Triclosan (TCS), a high-production-volume chemical used as a bactericide in personal care products, is a priority pollutant of growing concern to human and environmental health. TCS is capable of altering the activity of type 1 ryanodine receptor (RyR1), but its potential to influence physiological excitation-contraction coupling (ECC) and muscle function has not been investigated. Here, we report that TCS impairs ECC of both cardiac and skeletal muscle in vitro and in vivo. TCS acutely depresses hemodynamics and grip strength in mice at doses ≥12.5 mg/kg i.p., and a concentration ≥0.52 μM in water compromises swimming performance in larval fathead minnow. In isolated ventricular cardiomyocytes, skeletal myotubes, and adult flexor digitorum brevis fibers TCS depresses electrically evoked ECC within ∼10-20 min. In myotubes, nanomolar to low micromolar TCS initially potentiates electrically evoked Ca(2+) transients followed by complete failure of ECC, independent of Ca(2+) store depletion or block of RyR1 channels. TCS also completely blocks excitation-coupled Ca(2+) entry. Voltage clamp experiments showed that TCS partially inhibits L-type Ca(2+) currents of cardiac and skeletal muscle, and [(3)H]PN200 binding to skeletal membranes is noncompetitively inhibited by TCS in the same concentration range that enhances [(3)H]ryanodine binding. TCS potently impairs orthograde and retrograde signaling between L-type Ca(2+) and RyR channels in skeletal muscle, and L-type Ca(2+) entry in cardiac muscle, revealing a mechanism by which TCS weakens cardiac and skeletal muscle contractility in a manner that may negatively impact muscle health, especially in susceptible populations. PMID:22891308

  3. Cortical connections of striate and extrastriate visual areas in tree shrews.

    PubMed

    Lyon, D C; Jain, N; Kaas, J H

    1998-11-01

    The ipsilateral and contralateral cortical connections of visual cortex of tree shrews (Tupaia belangeri) were investigated by placing restricted injections of fluorochrome tracers, wheat germ agglutinin-horseradish peroxidase, or biotinylated dextran amine into area 17 (V1), area 18 (V2), or the adjoining temporal dorsal area (TD). As previously reported, V1 was characterized by a widespread, patchy pattern of intrinsic connections; ipsilateral connections with V2, TD, and to a lesser extent, other areas of the temporal cortex; and contralateral connections with V1, V2, and TD. A surface-view of the myelin pattern in V1 revealed a patchwork of light and dark module-like regions. The ipsilateral connections with V2 and TD were roughly topographic, whereas heterotopic locations in V1 were callosally connected. Injections in V2 labeled as much as one third of V2 in a patchy pattern, and portions of ipsilateral V1 and TD in roughly topographic patterns. In addition, connections with several other visual areas in the temporal lobe were revealed. Contralaterally, most of the label was in V2, with some in V1 and TD. Injections in TD demonstrated connections within the region, and with adjoining portions of the temporal cortex, V2, and V1. There were sparse connections with an oval of densely myelinated cortex, which we have termed the temporal inferior area (TI). Callosal connections were concentrated in TD, but also included V2. The results provide further evidence for modular organizations within V1 and V2, and reveal for the first time the complete patterns of cortical connections of V2 and TD. The results are consistent with the proposal that at least three visual areas, the temporal anterior area, TA, the temporal dorsal area, TD, and the temporal posterior area, TP, exist along the rostrolateral border of V2 in tree shrews; suggest visual involvement of at least three other areas, the temporal inferior area, TI, the temporal anterior lateral area, and the temporal posterior inferior area located more ventrally in the temporal cortex; and fortify the conclusion that TD is the likely homologue of the middle temporal visual area of primates. Because tree shrews are considered close relatives of primates, the evidence for several visual areas along the border of V2 is more compatible with theories that propose a series of visual areas along V2 in primates, rather than a single visual area, V3. PMID:9802703

  4. [Ultrastructural changes in transverse striated muscles under the influence of space flight factors].

    PubMed

    Pozdniakov, O M; Babakova, L L; Demorzhi, M S

    1988-12-01

    The influence of space flight (on the biosatellite "Kosmos-1667") on muscles (diaphragmatic, soleus, gastrocnemius) was studied by electron microscope. Muscles had destructive and atrophic changes. The rate of changes was maximal in m. soleus, minimal in the diaphragmatic m. However, some regeneration was found demonstrating the reversibility of changes. PMID:2974735

  5. Electron microscopical and histochemical studies on the transverse striated muscles of birds after prolonged hypokinesis

    NASA Technical Reports Server (NTRS)

    Belak, M.; Kocisova, J.; Marcanik, J.; Boda, K.; Skarda, R.

    1981-01-01

    Studies of the gastrocnemius muscle were carried out in 4 month old cockerels of the laying hybrid after hypokinesis lasting 15 and 30 days. It was found that restricted movement resulted in dystrophic changes of myotibrils, enlargement of the sarcoplasmic reticulum and oedem of interfibrillar spaces. Histochemical studies revealed focuses of increased activity of non-specific esterase, decreased activity of dehydrogenase of lactic acid and a positive reaction of acid phosphatase.

  6. Thermal dependence of force-velocity relation of lamprey live striated muscle fibres.

    PubMed

    Sobol, C V; Nasledov, G A

    1994-06-01

    The thermal dependence of the force-velocity relation (P - V) in thin (20-40 fibres) live twitch muscle bundles from suction apparatus of lamprey by force-clamp method was investigated. The P - V relation was hyperbolic and Hill's constants were as follows: a/P0 was 0.13 +/- 0.01 and 0.08 +/- 0.01 (mean +/- S.E.M.), b was 0.46 +/- 0.02 and 0.65 +/- 0.03 at 8 degrees C and 18 degrees C, respectively. The maximal isometric tension (P0) was about 100 mN/mm2 at 8 degrees C, 18 degrees C, and 22 degrees C. After the temperature was switched from 8 degrees C to 18 degrees C, the dependence of P0 on incubation time was observed. The maximal power output determined from P - V relation using Hill's equation was 0.062 +/- 0.002 and 0.056 +/- 0.001 at 8 degrees C and 18 degrees C, respectively. The maximal velocities of shortening (V0) were 3.9 +/- 0.1 L0/s and 7.2 +/- 0.2 L0/s at 8 degrees C and 18 degrees C, respectively. Q10 for V0 in this range of temperatures was 1.86. a/P0 and power output were about 2 times lower than those reported in literature for other animals. In general, the thermal dependence of the parameters studied was similar to those reported for fish muscles and skinned lamprey muscles, P0 being relatively independent, V0 highly dependent, and a/P0 inversely dependent on temperature. PMID:7835682

  7. Spatial summation in the receptive fields of simple cells in the cat's striate cortex.

    PubMed Central

    Movshon, J A; Thompson, I D; Tolhurst, D J

    1978-01-01

    1. We have examined the responses of simple cells in the cat's atriate cortex to visual patterns that were designed to reveal the extent to which these cells may be considered to sum light-evoked influences linearly across their receptive fields. We used one-dimensional luminance-modulated bars and grating as stimuli; their orientation was always the same as the preferred orientation of the neurone under study. The stimuli were presented on an oscilloscope screen by a digital computer, which also accumulated neuronal responses and controlled a randomized sequence of stimulus presentations. 2. The majority of simple cells respond to sinusoidal gratings that are moving or whose contrast is modulated in time in a manner consistent with the hypothesis that they have linear spatial summation. Their responses to moving gratings of all spatial frequencies are modulated in synchrony with the passage of the gratings' bars across their receptive fields, and they do not produce unmodulated responses even at the highest spatial frequencies. Many of these cells respond to temporally modulated stationary gratings simply by changing their response amplitude sinusoidally as the spatial phase of the grating the grating is varied. Nonetheless, their behavior appears to indicate linear spatial summation, since we show in an Appendix that the absence of a 'null' phase in a visual neurone need not indicate non-linear spatial summation, and further that a linear neurone lacking a 'null' phase should give responses of the form that we have observed in this type of simple cell. 3. A minority of simple cells appears to have significant non-linearities of spatial summation. These neurones respond to moving gratings of high spatial frequency with a partially or totally unmodulated elevation of firing rate. They have no 'null' phases when tested with stationary gratings, and reveal their non-linearity by giving responses to gratings of some spatial phases that are composed partly or wholly of even harmonics of the stimulus frequency ('on-off' responses). 4. We compared simple receptive fields with their sensitivity to sinusoidal gratings of different spatial frequencies. Qualitatively, the most sensitive subregions of simple cells' receptive fields are roughly the same width as the individual bars of the gratings to which they are most sensitive. Quantitatively, their receptive field profiles measured with thin stationary lines, agree well with predicted profiles derived by Fourier synthesis of their spatial frequency tuning curves. PMID:722589

  8. Morphology and histology of chimpanzee primary visual striate cortex indicate that brain reorganization predated brain expansion in early hominid evolution.

    PubMed

    Holloway, Ralph L; Broadfield, Douglas C; Yuan, Michael S

    2003-07-01

    Human brain evolution is characterized by an overall increase in brain size, cerebral reorganization, and cerebral lateralization. It is generally understood when brain enlargement occurred during human evolution. However, issues concerning cerebral reorganization and hemispheric lateralization are more difficult to determine from brain endocasts, and they are topics of considerable debate. One region of the cerebral cortex that may represent the earliest evidence for brain reorganization is the primary visual cortex (PVC), or area 17 of Brodmann. In nonhuman primates, this region is larger in volume (demarcated anteriorly by the lunate sulcus), and extends further rostrally than it does in modern humans. In early hominid fossil (Australopithecus) endocasts, this region appears to occupy a smaller area compared to that in nonhuman primates. Some have argued that the brain first underwent size expansion prior to reorganization, while others maintain that reorganization predated brain expansion. To help resolve this question, we provide a description of two male, common chimpanzee (Pan troglodytes) brains, YN77-111 and YN92-115, which clearly display a more posterior lunate sulcal morphology than seen in other chimpanzees. These data show that neurogenetic variability exists in chimpanzees, and that significant differences in organization (e.g., a reduced PVC) can predate brain enlargement. While the human brain has experienced numerous expansion and reorganization events throughout evolution, the data from these two chimpanzees offer significant support for the hypothesis that the neurogenetic basis for brain reorganization was present in our early fossil ancestors (i.e., the australopithecines) prior to brain enlargement. PMID:12808644

  9. A Study of a Striated Positive Column after Ethanol Impurity Injection in an Air DC Glow Discharge

    NASA Astrophysics Data System (ADS)

    Berzak, Laura; Post Zwicker, Andrew

    2003-04-01

    In a glow discharge when ethanol (CH3CH2OH) was injected, a series of atypical striations formed through the positive column. When the pressure decreased as the ethanol evaporated and was evacuated by the vacuum pump, this behavior decayed away until only an anode glow or normal discharge remained. Varying interelectrode spacings and quantities of ethanol yielded similar patterns. The typical evolution as the pressure decreased consisted of a visible traveling wave traveling from the anode to the cathode followed by numerous, thin ( 1.6 mm) striations evenly spaced down the entire length of the positive column. These, shifted back toward the anode and transformed into bent striations with the tip of the 'V' pointing toward the cathode, and finally, the 'V' striations grouped into fours and took on the appearance of beats. The unusual 'V' striations may be due in part to a contraction of the column, causing the equipotential surfaces to shift from smooth convex to the observed striation shape. The conditions for this contraction effect include a nonlinearly increasing dependence of electron production rate on electron density and a bulk recombination rate higher than that at the tube walls. Visible emission spectra indicated the presence of carbon monoxide (CO), signifying that the striations are due to not only vibrational excitation of the ethanol molecule but also to decomposition and subsequent excitation of the decomposition products as well. One possible mechanism of decomposition is the formation of a radical cation from the ethanol molecule and the ensuing loss of a proton to yield formaldehyde; this then would follow an analogous decomposition to produce carbon monoxide. Thus, there may exist additional charged species which can then contribute to the unique observations. Further analysis, if possible, will include higher temporal resolution spectroscopy and a detailed model of the positive column under these specific conditions.

  10. Striated perineal muscles: location of autonomic, sensory, and somatic neurons projecting to the male pig bulbospongiosus muscle.

    PubMed

    Botti, Maddalena; Ragionieri, Luisa; Gazza, Ferdinando; Acone, Franca; Bo Minelli, Luisa; Panu, Rino

    2009-11-01

    The location, number, and size of the neurons innervating the bulbospongiosus muscle (BSM) were studied in male pigs, by means of Fast Blue (FB) retrograde transport. After injection of FB into the left BSM, labeled neurons were found bilaterally in the L2-S4 sympathetic trunk ganglia (STGs), in the caudal mesenteric ganglia (CMGs), in the microganglia of the pelvic plexus (PGs), in a dorsolateral area with respect to the central canal of S1-S3 segments of the spinal cord (SC) and in the S1-S4 ipsilateral and S2-S3 contralateral spinal ganglia (SGs). The mean number of labeled FB cells was 3,122 +/- 1,968 in STGs, 979 +/- 667 in CMGs, 108 +/- 104 in PGs, 89 +/- 39 in SC and 77 +/- 23 in SGs. The area of the multipolar neurons was 852 +/- 22 microm(2) in the STGs, 878 +/- 23 microm(2) in the CMGs and 922 +/- 31 microm(2) in the PGs. The multipolar SC neurons had an area of 1,057 +/- 38 microm(2), while pseudounipolar SG cells had dimensions of 2,281 +/- 129 microm(2). Our research enables us to highlight two peculiarities regarding the innervation of the boar BSM: the very high number of labeled autonomic neurons and the particular localization of the motor somatic nucleus. PMID:19718716

  11. Force generation and shift of mass between myosin and actin in skinned striated muscle fibres at low calcium concentrations.

    PubMed

    Schiereck, P; van Heijst, B G; Jansen, P M; Schiereck, J; van der Leun, M; Bras, W; de Beer, E L

    1998-01-01

    Skinned muscle fibres from the gracilis muscle of the rabbit were used to record small angle X-ray diffraction spectra under various contractile conditions. The intracellular calcium concentration, expressed as pCa, was varied between 8.0 and 5.74. Equatorial diffraction spectra were fitted by a function consisting of five Gaussian curves and a hyperbola to separate the (1.0), (1.1), (2.0), (2.1) and Z-line diffraction peaks. The hyperbola was used to correct for residual scattering in the preparation. The ratio between the intensities of the (1.1) and (1.0) peaks was defined as the relative transfer of mass between myosin and actin, due to crossbridge formation after activation by calcium. The relation between the ratio and the relative force of the fibre (normalized to the force at pCa 5.74 and sarcomere length 2.0 microns) was linear. At high pCa (from pCa 6.34 to 8.0) no active force was observed, while the ratio still decreased. Sarcomere length was recorded by laser diffraction. The laser diffraction patterns did not show changes in sarcomere length due to activation in the high pCa range (between 8.0 and 6.34). From these results the conclusion is drawn that crossbridge movement occurs even at subthreshold calcium concentrations in the cell, when no active force is exerted. Since no force is generated this movement may be related to crossbridges in the weakly bound state. PMID:9791940

  12. Some relations between changes in the linear electrical properties of striated muscle fibers and changes in ultrastructure.

    PubMed

    Freygang, W H; Rapoport, S I; Peachey, L D

    1967-11-01

    Some of the linear electrical properties of frog sartorius muscle have been investigated in Ringer's fluid and in a Ringer fluid made hypertonic by the addition of sucrose or NaCl. Electrical constants were determined from measurements of the phase angle of the admittance of a fiber for an applied alternating current, from measurements of the voltage induced by an inward pulse of current, and from measurements of the conduction velocity of the action potential and the time constant of its foot. The dilation of the transverse tubular system induced by the sucrose hypertonic Ringer fluid was correlated with the change in the electrical constants. From this it is concluded that a two time constant equivalent circuit for the membrane, as proposed by Falk and Fatt, is in good agreement with our results. Both the area of the membrane of the transverse tubular system, and the capacity (c(e)) attributed to it, increased in the sucrose hypertonic Ringer fluid. The resistance r(e), which is in series with c(e), did not fall when the transverse tubular system was dilated and probably is not located in that system. PMID:6063689

  13. Preserved striate cortex is not sufficient to support the McCollough effect: evidence from two patients with cerebral achromatopsia.

    PubMed

    Mullin, Caitlin R; Démonet, Jean François; Kentridge, Robert W; Heywood, Charles A; Goodale, Melvyn A; Steeves, Jennifer K E

    2009-01-01

    The McCollough effect (ME) is a colour aftereffect contingent on pattern orientation. This effect is generally thought to be mediated by primary visual cortex (V1) although this has remained the subject of some debate. To determine whether V1 is in fact sufficient to subserve the ME, we compared McCollough adaptation in controls to adaptation in two patients with damage to ventrotemporal cortex, resulting in achromatopsia, but who have spared V1. Each of these patients has some residual colour abilities of which he is unaware. Participants performed a 2AFC orientation-discrimination task for pairs of oblique and vertical/horizontal gratings both before and after adaptation to red/green oblique induction gratings. Successful ME induction would manifest itself as an improvement in oblique-orientation discrimination owing to the additional colour cue after adaptation. Indeed, in controls oblique grating discrimination improved post-adaptation. Further, a subdivision of our control group demonstrated successful ME induction despite a lack of conscious awareness of the added colour cue, indicating that conscious colour awareness is not required for ME induction. The patients, however, did not show improvement in oblique-orientation discrimination, indicating a lack of ME induction. This suggests that V1 must be connected to higher cortical colour areas to drive ME induction. PMID:20192125

  14. Multi-Tasking Role of the Mechanosensing Protein Ankrd2 in the Signaling Network of Striated Muscle

    PubMed Central

    Mittempergher, Lorenza; Campanaro, Stefano; Martinelli, Valentina C.; Mouly, Vincent; Valle, Giorgio; Kojic, Snezana; Faulkner, Georgine

    2011-01-01

    Background Ankrd2 (also known as Arpp) together with Ankrd1/CARP and DARP are members of the MARP mechanosensing proteins that form a complex with titin (N2A)/calpain 3 protease/myopalladin. In muscle, Ankrd2 is located in the I-band of the sarcomere and moves to the nucleus of adjacent myofibers on muscle injury. In myoblasts it is predominantly in the nucleus and on differentiation shifts from the nucleus to the cytoplasm. In agreement with its role as a sensor it interacts both with sarcomeric proteins and transcription factors. Methodology/Principal Findings Expression profiling of endogenous Ankrd2 silenced in human myotubes was undertaken to elucidate its role as an intermediary in cell signaling pathways. Silencing Ankrd2 expression altered the expression of genes involved in both intercellular communication (cytokine-cytokine receptor interaction, endocytosis, focal adhesion, tight junction, gap junction and regulation of the actin cytoskeleton) and intracellular communication (calcium, insulin, MAPK, p53, TGF-β and Wnt signaling). The significance of Ankrd2 in cell signaling was strengthened by the fact that we were able to show for the first time that Nkx2.5 and p53 are upstream effectors of the Ankrd2 gene and that Ankrd1/CARP, another MARP member, can modulate the transcriptional ability of MyoD on the Ankrd2 promoter. Another novel finding was the interaction between Ankrd2 and proteins with PDZ and SH3 domains, further supporting its role in signaling. It is noteworthy that we demonstrated that transcription factors PAX6, LHX2, NFIL3 and MECP2, were able to bind both the Ankrd2 protein and its promoter indicating the presence of a regulatory feedback loop mechanism. Conclusions/Significance In conclusion we demonstrate that Ankrd2 is a potent regulator in muscle cells affecting a multitude of pathways and processes. PMID:22016770

  15. The increase in non-cross-bridge forces after stretch of activated striated muscle is related to titin isoforms.

    PubMed

    Cornachione, Anabelle S; Leite, Felipe; Bagni, Maria Angela; Rassier, Dilson E

    2016-01-01

    Skeletal muscles present a non-cross-bridge increase in sarcomere stiffness and tension on Ca(2+) activation, referred to as static stiffness and static tension, respectively. It has been hypothesized that this increase in tension is caused by Ca(2+)-dependent changes in the properties of titin molecules. To verify this hypothesis, we investigated the static tension in muscles containing different titin isoforms. Permeabilized myofibrils were isolated from the psoas, soleus, and heart ventricle from the rabbit, and tested in pCa 9.0 and pCa 4.5, before and after extraction of troponin C, thin filaments, and treatment with the actomyosin inhibitor blebbistatin. The myofibrils were tested with stretches of different amplitudes in sarcomere lengths varying between 1.93 and 3.37 μm for the psoas, 2.68 and 4.21 μm for the soleus, and 1.51 and 2.86 μm for the ventricle. Using gel electrophoresis, we confirmed that the three muscles tested have different titin isoforms. The static tension was present in psoas and soleus myofibrils, but not in ventricle myofibrils, and higher in psoas myofibrils than in soleus myofibrils. These results suggest that the increase in the static tension is directly associated with Ca(2+)-dependent change in titin properties and not associated with changes in titin-actin interactions. PMID:26405100

  16. Two Biological Active Fractions Isolated from Buthotus schach (BS)Scorpion Venom Examined on Striated Muscle Preparation, In-vitro

    PubMed Central

    Vatanpour, Hossein; Ahmadi, Farhad; Zare Mirakabadi, Abbas; Jalali, Amir

    2012-01-01

    Buthotus schach is one of the most dangerous scorpions in tropical part of Iran. The effects of its crude venom at 1, 3, 10 μg/mL and its obtained fractions by gel filtrations were investigated on neuromuscular transmission. CBC and MHD indirectly and directly stimulated preparations techniques were used to study their possible pre or post junctional activities. At 3 and 10 μg/mL (not at 1 μg/mL), BS venom caused initiall increase in twitch height followed by blockage due to large contraction that responded gradually at the same time. Contracture responses to exogenous Ach (1-2 mM, 30 sec) and Carb (30-40 μM, 60 sec) in the presence of the venom were not increased which does show no anticholinstrease effects. Furthermore Contracture response to KCl (20-40 mM, 30 sec) does changed exposure to venom in CBC preparations. On the other hand the effects of the venom in response to directly stimulated preparations was shallower than in indirect stimulated preparations. So in agreement with KCL response BS venom affects mostly prejunctionally to facilitate the neurotransmitter release rather than postjunctionally effects. To access bioactive components, seven fractions were collected by gel filtrations techniques. Among the fractions F6, LD50=21 μg < F4, LD50= 35.5 μg < Venom LD50= 84 μg per mice were more toxic respectively. Both fractions show the same effects but stronger than venom on twitch height responses in indirectly stimulated CBC preparations. Finally, according to our results venom as well as fractions F4 and F6 act mostly prejunctionally on Ach release. More attempt is carrying out to study their effects on ion channel activities. PMID:24250518

  17. Visual responses of neurones in the second visual area of flying foxes (Pteropus poliocephalus) after lesions of striate cortex

    PubMed Central

    Funk, Agnes P; Rosa, Marcello G P

    1998-01-01

    The first (V1) and second (V2) cortical visual areas exist in all mammals. However, the functional relationship between these areas varies between species. While in monkeys the responses of V2 cells depend on inputs from V1, in all non-primates studied so far V2 cells largely retain responsiveness to photic stimuli after destruction of V1.We studied the visual responsiveness of neurones in V2 of flying foxes after total or partial lesions of the primary visual cortex (V1). The main finding was that visual responses can be evoked in the region of V2 corresponding, in visuotopic co-ordinates, to the lesioned portion of V1 (‘lesion projection zone’; LPZ).The visuotopic organization of V2 was not altered by V1 lesions.The proportion of neurones with strong visual responses was significantly lower within the LPZs (31.5 %) than outside these zones, or in non-lesioned control hemispheres (> 70 %). LPZ cells showed weak direction and orientation bias, and responded consistently only at low spatial and temporal frequencies.The data demonstrate that the functional relationship between V1 and V2 of flying foxes resembles that observed in non-primate mammals. This observation contrasts with the ‘primate-like’ characteristics of the flying fox visual system reported by previous studies. PMID:9806999

  18. Promiscuous Actions of Small Molecule Inhibitors of the Protein Kinase D-Class IIa HDAC Axis in Striated Muscle

    PubMed Central

    Lemon, Douglas D.; Harrison, Brooke C.; Horn, Todd R.; Stratton, Matthew S.; Ferguson, Bradley S.; Wempe, Michael F.; McKinsey, Timothy A.

    2015-01-01

    PKD-mediated phosphorylation of class IIa HDACs frees the MEF2 transcription factor to activate genes that govern muscle differentiation and growth. Studies of the regulation and function of this signaling axis have involved MC1568 and Gö-6976, which are small molecule inhibitors of class IIa HDAC and PKD catalytic activity, respectively. We describe unanticipated effects of these compounds. MC1568 failed to inhibit class IIa HDAC catalytic activity in vitro, and exerted divergent effects on skeletal muscle differentiation compared to a bona fide inhibitor of these HDACs. In cardiomyocytes, Gö-6976 triggered calcium signaling and activated stress-inducible kinases. Based on these findings, caution is warranted when employing MC1568 and Gö-6976 as pharmacological tool compounds to assess functions of class IIa HDACs and PKD. PMID:25816750

  19. Myocyte nuclear factor, a novel winged-helix transcription factor under both developmental and neural regulation in striated myocytes.

    PubMed Central

    Bassel-Duby, R; Hernandez, M D; Yang, Q; Rochelle, J M; Seldin, M F; Williams, R S

    1994-01-01

    A sequence motif (CCAC box) within an upstream enhancer region of the human myoglobin gene is essential for transcriptional activity in both cardiac and skeletal muscle. A cDNA clone, myocyte nuclear factor (MNF), was isolated from a murine expression library on the basis of sequence-specific binding to the myoglobin CCAC box motif and was found to encode a novel member of the winged-helix or HNF-3/fork head family of transcription factors. Probes based on this sequence identify two mRNA species that are upregulated during myocyte differentiation, and antibodies raised against recombinant MNF identify proteins of approximately 90, 68, and 65 kDa whose expression is regulated following differentiation of myogenic cells in culture. In addition, the 90-kDa form of MNF is phosphorylated and is upregulated in intact muscles subjected to chronic motor nerve stimulation, a potent stimulus to myoglobin gene regulation. Amino acid residues 280 to 389 of MNF demonstrate 35 to 89% sequence identity to the winged-helix domain from other known members of this family, but MNF is otherwise divergent. A proline-rich amino-terminal region (residues 1 to 206) of MNF functions as a transcriptional activation domain. These studies provide the first evidence that members of the winged-helix family of transcription factors have a role in myogenic differentiation and in remodeling processes of adult muscles that occur in response to physiological stimuli. Images PMID:8007964

  20. Response of the JAK-STAT pathway to mammalian hibernation in 13-lined ground squirrel striated muscle.

    PubMed

    Logan, Samantha M; Tessier, Shannon N; Tye, Joann; Storey, Kenneth B

    2016-03-01

    Over the course of the torpor-arousal cycle, hibernators must make behavioral, physiological, and molecular rearrangements in order to keep a very low metabolic rate and retain organ viability. 13-lined ground squirrels (Ictidomys tridecemlineatus) remain immobile during hibernation, and although the mechanisms of skeletal muscle survival are largely unknown, studies have shown minimal muscle loss in hibernating organisms. Additionally, the ground squirrel heart undergoes cold-stress, reversible cardiac hypertrophy, and ischemia-reperfusion without experiencing fatal impairment. This study examines the role of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway in the regulation of cell stress in cardiac and skeletal muscles, comparing euthermic and hibernating ground squirrels. Immunoblots showed a fivefold decrease in JAK3 expression during torpor in skeletal muscle, along with increases in STAT3 and 5 phosphorylation and suppressors of cytokine signaling-1 (SOCS1) protein levels. Immunoblots also showed coordinated increases in STAT1, 3 and 5 phosphorylation and STAT1 inhibitor protein expression in cardiac muscle during torpor. PCR analysis revealed that the activation of these pro-survival signaling cascades did not result in coordinate changes in downstream genes such as anti-apoptotic B-cell lymphoma-2 (Bcl-2) family gene expression. Overall, these results indicate activation of the JAK-STAT pathway in both cardiac and skeletal muscles, suggesting a response to cellular stress during hibernation. PMID:26885984

  1. The cruciform model of striate generation of the early VEP, re-illustrated, not revoked: a reply to Ales et al. (2013).

    PubMed

    Kelly, Simon P; Vanegas, M Isabel; Schroeder, Charles E; Lalor, Edmund C

    2013-11-15

    Here we summarize the points raised in our dialog with Ales and colleagues on the cortical generators of the early visual evoked potential (VEP), and offer observations on the results of additional simulations that were run in response to our original comment. For small stimuli placed at locations in the upper and lower visual field for which the human VEP has been well characterized, simulated scalp projections of each of the visual areas V1, V2 and V3 invert in polarity. However, the empirically measured, earliest VEP component, "C1," matches the simulated V1 generators in terms of polarity and topography, but not the simulated V2 and V3 generators. We thus conclude that, 1) consistent with the title of Ales et al. (2010a), polarity inversion on its own is not a sufficient criterion for inferring neuroelectric sources in primary visual cortex; but 2) inconsistent with additional claims made in Ales et al. (2010a), the simulated topographies provide additional evidence for - not against - the tenet that the C1 component is generated in V1. PMID:23735259

  2. Cardinal difference between the orientation-selective retinal ganglion cells projecting to the fish tectum and the orientation-selective complex cells of the mammalian striate cortex.

    PubMed

    Damjanović, Ilija; Maximova, Elena; Maximov, Paul; Maximov, Vadim

    2012-06-01

    Responses from two types of orientation-selective units of retinal origin were recorded extracellularly from their axon terminals in the medial sublaminae of tectal retinorecipient layer of immobilized cyprinid fish Carassius gibelio. Excitatory and inhibitory interactions in the receptive field were analyzed with two narrow stripes of optimal orientation flashing synchronously, one in the center and the other in different parts of the periphery. The general pattern of results was that the influence of the remote peripheral stripe was inhibitory, irrespective of the polarity of each stripe (light or dark). In this regard, the orientation-selective ganglion cells of the fish retina differ from the classical orientation-selective complex cells of the mammalian cortex, where the remote paired stripes of the opposite polarity (one light and one dark) interact in a facilitatory fashion. The consequence of these differences may be a weaker lateral inhibition in the latter case in response to stimulation by periodic gratings, which may contribute to a better spatial frequency tuning in the visual cortex. PMID:22744823

  3. Filament lattice of frog striated muscle. Radial forces, lattice stability, and filament compression in the A-band of relaxed and rigor muscle.

    PubMed Central

    Millman, B M; Irving, T C

    1988-01-01

    Repulsive pressure in the A-band filament lattice of relaxed frog skeletal muscle has been measured as a function of interfilament spacing using an osmotic shrinking technique. Much improved chemical skinning was obtained when the muscles were equilibrated in the presence of EGTA before skinning. The lattice shrank with increasing external osmotic pressure. At any specific pressure, the lattice spacing in relaxed muscle was smaller than that of muscle in rigor, except at low pressures where the reverse was found. The lattice spacing was the same in the two states at a spacing close to that found in vivo. The data were consistent with an electrostatic repulsion over most of the pressure range. For relaxed muscle, the data lay close to electrostatic pressure curves for a thick filament charge diameter of approximately 26 nm, suggesting that charges stabilizing the lattice are situated about midway along the thick filament projections (HMM-S1). At low pressures, observed spacings were larger than calculated, consistent with the idea that thick filament projections move away from the filament backbone. Under all conditions studied, relaxed and rigor, at short and very long sarcomere lengths, the filament lattice could be modeled by assuming a repulsive electrostatic pressure, a weak attractive pressure, and a radial stiffness of the thick filaments (projections) that differed between relaxed and rigor conditions. Each thick filament projection could be compressed by approximately 5 or 2.6 nm requiring a force of 1.3 or 80 pN for relaxed and rigor conditions respectively. PMID:3264728

  4. K201 (JTV519) is a Ca2+-Dependent Blocker of SERCA and a Partial Agonist of Ryanodine Receptors in Striated Muscle.

    PubMed

    Darcy, Yuanzhao L; Diaz-Sylvester, Paula L; Copello, Julio A

    2016-08-01

    K201 (JTV-519) may prevent abnormal Ca(2+) leak from the sarcoplasmic reticulum (SR) in the ischemic heart and skeletal muscle (SkM) by stabilizing the ryanodine receptors (RyRs; RyR1 and RyR2, respectively). We tested direct modulation of the SR Ca(2+)-stimulated ATPase (SERCA) and RyRs by K201. In isolated cardiac and SkM SR microsomes, K201 slowed the rate of SR Ca(2+) loading, suggesting potential SERCA block and/or RyR agonism. K201 displayed Ca(2+)-dependent inhibition of SERCA-dependent ATPase activity, which was measured in microsomes incubated with 200, 2, and 0.25 µM Ca(2+) and with the half-maximal K201 inhibitory doses (IC50) estimated at 130, 19, and 9 µM (cardiac muscle) and 104, 13, and 5 µM (SkM SR). K201 (≥5 µM) increased RyR1-mediated Ca(2+) release from SkM microsomes. Maximal K201 doses at 80 µM produced ∼37% of the increase in SkM SR Ca(2+) release observed with the RyR agonist caffeine. K201 (≥5 µM) increased the open probability (Po) of very active ("high-activity") RyR1 of SkM reconstituted into bilayers, but it had no effect on "low-activity" channels. Likewise, K201 activated cardiac RyR2 under systolic Ca(2+) conditions (∼5 µM; channels at Po ∼0.3) but not under diastolic Ca(2+) conditions (∼100 nM; Po < 0.01). Thus, K201-induced the inhibition of SR Ca(2+) leak found in cell-system studies may relate to potentially potent SERCA block under resting Ca(2+) conditions. SERCA block likely produces mild SR depletion in normal conditions but could prevent SR Ca(2+) overload under pathologic conditions, thus precluding abnormal RyR-mediated Ca(2+) release. PMID:27235390

  5. Beyond Discourse? Using Deleuze and Guattari's Schizoanalysis to Explore Affective Assemblages, Heterosexually Striated Space, and Lines of Flight Online and at School

    ERIC Educational Resources Information Center

    Ringrose, Jessica

    2011-01-01

    This paper explores how Deleuze and Guattari's philosophical concepts extend and elaborate discursive and psychoanalytic interpretations of qualitative research findings. Analyzing data from a UK research project exploring young people's engagements with Social Networking Sites (SNSs), Deleuze and Guattari's schizoanalytic method is drawn upon to…

  6. The effects of Duvernoy's gland secretion from the xenodontine colubrid Philodryas olfersii on striated muscle and the neuromuscular junction: partial characterization of a neuromuscular fraction.

    PubMed

    Prado-Franceschi, J; Hyslop, S; Cogo, J C; Andrade, A L; Assakura, M; Cruz-Höfling, M A; Rodrigues-Simioni, L

    1996-04-01

    The effect of Philodryas olfersii Duvernoy's secretion was studied in vivo in mice and chicks as well as in the mouse phrenic nerve-diaphragm and the chick biventer cervicis preparations. The whole secretion (20-40 micrograms/ml) increased the creatine kinase (CK) levels in mice but had no effect on the mouse phrenic nerve-diaphragm preparation. In the chick, the secretion caused head drop and paresia as well as irreversible blockade of the twitch-tension evoked by indirect stimulation in the chick biventer cervicis preparation (50% paralysis in 34.5 +/- 2.7 min, n = 4). The secretion also caused muscle contracture (30% of the maximal twitch-tension generated) after a latency of nearly 9 min. Following fractionation on a Superose 12 FPLC column, the neuromuscular activity was recovered in the high mol. wt fraction (Peak I). At a concentration of 10 micrograms/ml in the chick biventer cervicis preparation, Peak I caused 50% paralysis within 18.5 +/- 3.0 min (n = 4), and evoked a strong contracture (70% of the maximal twitch-tension generated). The contractile responses of the chick preparation to ACh and KCL were partially blocked (90%) by the whole secretion and totally blocked by Peak I. CK release was increased by the whole secretion but not by Peak I. The whole secretion also produced various degrees of muscle cell lysis and extensive widening of the intercellular spaces. The latter showed a loosely arranged membranous network. In general, Peak I caused only minor morphological alterations compared with the whole secretion, although these were still significantly different from those observed in the control preparations. The changes principally involved hypercontraction of the muscle fibers. Based on the above results, we conclude that Peak I contains the factor(s) responsible for the in vitro effects on neuromuscular transmission, whereas the direct myotoxic effect is apparently caused by at least one other component of the Duvernoy's secretion. PMID:8735245

  7. Characterization of a myotoxin from the Duvernoy's gland secretion of the xenodontine colubrid Philodryas olfersii (green snake): effects on striated muscle and the neuromuscular junction.

    PubMed

    Prado-Franceschi, J; Hyslop, S; Cogo, J C; Andrade, A L; Assakura, M T; Reichl, A P; Cruz-Höfling, M A; Rodrigues-Simioni, L

    1998-10-01

    A myotoxin has been isolated from the Duvernoy's gland (DG) secretion of the xenodontine colubrid Philodrvas olfersii (green snake) by gel filtration on Sephadex G-100 SF. Under non-reducing and reducing conditions in SDS-PAGE, the myotoxin migrates as a single band with a mol. wt. of 20000. The toxin has 182 amino acid residues (approximately 20% acidic), a pI of 4.8 and a blocked N-terminal. In the chick biventer cervicis preparation, P. olfersii myotoxin partially blocks potassium-evoked contractures without affecting either the twitch-tension resulting from indirect stimulation or the contractures evoked by acetylcholine. Both the DG secretion and the myotoxin increase the serum creatine kinase (CK) levels of mice and stimulate the release of CK from the biventer cervicis preparation in a dose- and time-dependent manner. The varying degrees of muscle cell lysis and extensive widening of the intercellular spaces caused by the DG secretion are reproduced by the myotoxin, with the exception that in the latter the partial or total loss of transverse muscle striations is restricted to the muscle periphery. This myotoxin is the first such protein to be characterized from a DG secretion. PMID:9723839

  8. Insights into the internal structure and formation of striated fault surfaces of oceanic detachments from in situ observations (13°20'N and 13°30'N, Mid-Atlantic Ridge)

    NASA Astrophysics Data System (ADS)

    Escartin, J.; Bonnemains, D.; Mevel, C.; Cannat, M.; Petersen, S.; Augustin, N.; Bezos, A.; Chavagnac, V.; Choi, Y.; Godard, M.; Haaga, K.; Hamelin, C.; Ildefonse, B.; Jamieson, J. W.; John, B. E.; Leleu, T.; MacLeod, C. J.; Massot-Campos, M.; Nomikou, P.; Olive, J. A. L.; Paquet, M.; Rommevaux, C.; Rothenbeck, M.; Steinführer, A.; Tominaga, M.; Triebe, L.; Andreani, M.; Garcia, R.; Campos, R.

    2014-12-01

    Oceanic detachment faults (ODs) are known to play a significant role in oceanic crustal accretion along slow-spreading ridges, and many display a poorly understood corrugated fault surface. The ODEMAR cruise (Nov-Dec'14) studied the 13°20'N and 13°30'N ODs along the Mid-Atlantic Ridge via extensive microbathymetric surveys with AUV ABYSS (GEOMAR), combined with geological observations and sampling using ROV VICTOR (IFREMER). The 13°20'N OD is largely intact, with an undisrupted corrugated surface. An abrupt, continuous moat where the OD emerges from the seafloor sloping at ~12-18° continuously sheds rubble onto the OD fault plane, blanketing it. An apron surrounds the detachment dipping ~10-14° towards volcanic rift valley floor thus forming a thin wedge above the active OD fault, which uplifts hangingwall material. In contrast, the 13°30'N OD is cut by recent high-angle faults, and is likely inactive. The OD fault is well exposed along these recent high angle fault scarps, and along mass wasting scarps. The OD fault displays individual microbathymetric lineations throughout the >150 m of fault zone thickness, that are traced up to ~2 km in the spreading direction. Flanks of individual lineations display fault planes extending ~20-100 m laterally with well-developed, extension-parallel striae. At 13°20'N. These fault surfaces are primarily basalt fault breccias and minor serpentinite. At 13°30'N the scarps cutting the detachment system reveal highly heterogeneous deformation, with phacoidal blocks of undeformed peridotite, gabbro, and basalt enclosed in anastomosing shear zones. Basalt often shows greenschist grade alteration, and is only present in the upper 50 m of the OD fault zone. In detail, OD faults are characterized by anastomosing zones of localized, strongly anisotropic deformation at different scales (m to km), bounding bodies of largely undeformed rock (basalt, gabbro, peridotite) elongated in the extension direction. Hangingwall material (basalt and dolerite) gets reworked into the fault zone in the green schist facies and effectively accreted to the footwall, both as fault breccia and as large blocks within the fault. Such fine-scale, in situ observations provide unprecedented insights into the three-dimensional and heterogeneous strain localization at OD fault zones.

  9. Shatter Cones in Basalt: A Natural Example from the Vista Alegre Impact Structure, Brazil

    NASA Astrophysics Data System (ADS)

    Pittarello, L.; Nestola, F.; Viti, C.; Crósta, A. P.; Koeberl, C.

    2015-09-01

    Shatter cones, formed in fine-grained basalt in the Vista Alegre impact structure (Brazil), exhibit cataclastic layers sub-parallel to the striated surfaces and a continuous melt rock film, investigated with TEM, decorating the striated surface.

  10. Skeletal muscle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are approximately 650-850 muscles in the human body these include skeletal (striated), smooth and cardiac muscle. The approximation is based on what some anatomists consider separate muscle or muscle systems. Muscles are classified based on their anatomy (striated vs. smooth) and if they are v...

  11. Hand-Held Model of a Sarcomere to Illustrate the Sliding Filament Mechanism in Muscle Contraction

    ERIC Educational Resources Information Center

    Jittivadhna, Karnyupha; Ruenwongsa, Pintip; Panijpan, Bhinyo

    2009-01-01

    From our teaching of the contractile unit of the striated muscle, we have found limitations in using textbook illustrations of sarcomere structure and its related dynamic molecular physiological details. A hand-held model of a striated muscle sarcomere made from common items has thus been made by us to enhance students' understanding of the…

  12. Types of muscle tissue (image)

    MedlinePlus

    The 3 types of muscle tissue are cardiac, smooth, and skeletal. Cardiac muscle cells are located in the walls of the heart, appear striated, and are under involuntary control. Smooth muscle fibers are located in walls of hollow ...

  13. Types of muscle tissue (image)

    MedlinePlus

    ... appear striated, and are under involuntary control. Smooth muscle fibers are located in walls of hollow visceral organs, ... shaped, and are also under involuntary control. Skeletal muscle fibers occur in muscles which are attached to the ...

  14. Shatter Cones from the MEMIN Impact Experiments

    NASA Astrophysics Data System (ADS)

    Wilk, J.; Kenkmann, T.

    2015-09-01

    We recovered shatter cone fragments from the MEMIN cratering experiments in sandstone, quartzite and limestone blocks. We analyzed the conical to hyperboloid, curved and striated fracture surfaces with SEM, WLI and produced µm-accurate 3D models.

  15. Formation of Shatter Cones in the MEMIN Impact Experiments

    NASA Astrophysics Data System (ADS)

    Wilk, J.; Kenkmann, T.

    2015-07-01

    We recovered shatter cone fragments from the MEMIN cratering experiments in sandstone, quartzite and limestone blocks. We analyzed the conical to hyperboloid, curved and striated fracture surfaces with SEM, WLI and produced µm-accurate 3D models.

  16. Toolmark identification of a mattock to a clod of soil from a grave.

    PubMed

    Clark, Michael D

    2011-01-01

    At a recent bushland gravesite that contained a deceased male, a clod of soil displaying a striated toolmark was collected during the excavation of the grave. This clod was preserved, and the mark was cast using Mikrosil™. Shovels and a mattock, which had been discarded by the suspects, were subsequently found at another location. A toolmark comparison identified the hoe end of the mattock head as having produced the striated toolmark. PMID:20735700

  17. Host Chemical Footprints Induce Host Sex Discrimination Ability in Egg Parasitoids

    PubMed Central

    Peri, Ezio; Frati, Francesca; Salerno, Gianandrea; Conti, Eric; Colazza, Stefano

    2013-01-01

    Trissolcus egg parasitoids, when perceiving the chemical footprints left on a substrate by pentatomid host bugs, adopt a motivated searching behaviour characterized by longer searching time on patches were signals are present. Once in contact with host chemical footprints, Trissolcus wasps search longer on traces left by associated hosts rather than non-associated species, and, in the former case, they search longer on traces left by females than males. Based on these evidences, we hypothesized that only associated hosts induce the ability to discriminate host sex in wasps. To test this hypothesis we investigated the ability of Trissolcus basalis, T. brochymenae, and Trissolcus sp. to distinguish female from male Nezara viridula, Murgantia histrionica, and Graphosoma semipunctatum footprints. These three pentatomid bugs were selected according to variable association levels. Bioassays were conducted on filter paper sheets, and on Brassica oleracea (broccoli) leaves. The results confirmed our hypothesis showing that wasps spent significantly more time on female rather than male traces left by associated hosts on both substrates. No differences were observed in the presence of traces left by non-associated hosts. The ecological consequences for parasitoid host location behaviour are discussed. PMID:24244417

  18. Proteomics Unveils Fibroblast-Cardiomyocyte Lactate Shuttle and Hexokinase Paradox in Mouse Muscles.

    PubMed

    Rakus, Dariusz; Gizak, Agnieszka; Wiśniewski, Jacek R

    2016-08-01

    Quantitative mapping, given in biochemically interpretable units such as mol per mg of total protein, of tissue-specific proteomes is prerequisite for the analysis of any process in cells. We applied label- and standard-free proteomics to characterize three types of striated muscles: white, red, and cardiac muscle. The analysis presented here uncovers several unexpected and novel features of striated muscles. In addition to differences in protein expression levels, the three muscle types substantially differ in their patterns of basic metabolic pathways and isoforms of regulatory proteins. Importantly, some of the conclusions drawn on the basis of our results, such as the potential existence of a "fibroblast-cardiomyocyte lactate shuttle" and the "hexokinase paradox" point to the necessity of reinterpretation of some basic aspects of striated muscle metabolism. The data presented here constitute a powerful database and a resource for future studies of muscle physiology and for the design of pharmaceutics for the treatment of muscular disorders. PMID:27302655

  19. Translational control of tropomyosin expression in vertebrate hearts.

    PubMed

    Dube, Dipak K; McLean, Matthew D; Dube, Syamalima; Poiesz, Bernard J

    2014-09-01

    The tropomyosin (TM) gene family produces a set of related TM proteins with important functions in striated and smooth muscle, and nonmuscle cells. In vertebrate striated muscle, the thin filament consists largely of actin, TM, the troponin (Tn) complex (Tn-I, Tn-C and Tn-T), and tropomodulin (Tmod) and is responsible for mediating Ca(2+) control of muscle contraction and relaxation. There are four known genes (designated as TPM1, TPM2, TPM3, and TPM4) for TM in vertebrates. The four TM genes generate a multitude of tissue- and developmental-specific isoforms through the use of different promoters, alternative mRNA splicing, different 3'-end mRNA processing and tissue-specific translational control. In this review, we have focused mainly on the regulation of TM expression in striated muscles, primarily in vertebrate hearts with special emphasis on translational control using mouse and Mexican axolotl animal models. PMID:25125172

  20. Chronic Sarcocystis infections in slaughtered cattle.

    PubMed

    Saito, M; Mizusawa, K; Itagaki, H

    1993-10-01

    Parasitological, histopathological and immunohistochemical examinations were carried out on three slaughtered cattle with many nodules in all the striated muscles. At necropsy, many yellowish green rice-grain sized nodules including cheesy contents were observed in all the striated muscles. Histopathologically the nodules were granuloma principally consisting of eosinophiles. No Sarcocystis cysts nor bradyzoites were found in the nodules, but intact sarcocysts were found in the normal tissues surrounding the nodules. The central necrotic focus of nodules showed intense positive responses against anti-Sarcocystis cruzi rabbit serum by immunohistochemical examination. From the above findings the slaughtered cattle were diagnosed as chronic sarcocystiasis. PMID:8286527

  1. Nomads with Maps: Musical Connections in a Glocalized World

    ERIC Educational Resources Information Center

    Richerme, Lauren Kapalka

    2013-01-01

    This article presents the author's views on the concepts of the philosophers Deleuze and Guattari on striated (sedentary) space and smooth (mobile) space, asserting that "nomads" can move freely about their space. She relates these concepts to music education, incorporating Deleuze and Guattari's concept of mapping as it…

  2. Improving Generalisation Skills in a Neural Network on the Basis of Neurophysiological Data

    ERIC Educational Resources Information Center

    Mermillod, M.; Chauvin, A.; Guyader, N.

    2005-01-01

    The distribution of striate cortex cells exhibits a maximum number of cells tuned to vertical and horizontal orientations (Mansfield, 1974). This was interpreted as an adaptation of the visual system to the presence in the visual environment of greater amounts of vertical and horizontal information compared to information from other orientations…

  3. Two distinct myosin II populations coordinate ovulatory contraction of the myoepithelial sheath in the Caenorhabditis elegans somatic gonad

    PubMed Central

    Ono, Kanako; Ono, Shoichiro

    2016-01-01

    The myoepithelial sheath in the somatic gonad of the nematode Caenorhabditis elegans has nonstriated contractile actomyosin networks that produce highly coordinated contractility for ovulation of mature oocytes. Two myosin heavy chains are expressed in the myoepithelial sheath, which are also expressed in the body-wall striated muscle. The troponin/tropomyosin system is also present and essential for ovulation. Therefore, although the myoepithelial sheath has smooth muscle–like contractile apparatuses, it has a striated muscle–like regulatory mechanism through troponin/tropomyosin. Here we report that the myoepithelial sheath has a distinct myosin population containing nonmuscle myosin II isoforms, which is regulated by phosphorylation and essential for ovulation. MLC-4, a nonmuscle myosin regulatory light chain, localizes to small punctate structures and does not colocalize with large, needle-like myosin filaments containing MYO-3, a striated-muscle myosin isoform. RNA interference of MLC-4, as well as of its upstream regulators, LET-502 (Rho-associated coiled-coil forming kinase) and MEL-11 (a myosin-binding subunit of myosin phosphatase), impairs ovulation. Expression of a phosphomimetic MLC-4 mutant mimicking a constitutively active state also impairs ovulation. A striated-muscle myosin (UNC-54) appears to provide partially compensatory contractility. Thus the results indicate that the two spatially distinct myosin II populations coordinately regulate ovulatory contraction of the myoepithelial sheath. PMID:26864628

  4. Subcortical Modulation of Spatial Attention Including Evidence that the Sprague Effect Extends to Man

    ERIC Educational Resources Information Center

    Weddell, Rodger A.

    2004-01-01

    The Sprague effect is well-established--small tectal lesions restore visual orientation in the hemianopic field of animals with extensive unilateral geniculo-striate lesions. Studies of human midbrain visual functions are rare. This man with a midbrain tumour developed left-neglect through subsequent right frontal damage. Bilateral orientation…

  5. Early visual cortical responses produced by checkerboard pattern stimulation.

    PubMed

    Shigihara, Yoshihito; Hoshi, Hideyuki; Zeki, Semir

    2016-07-01

    Visual evoked potentials have been traditionally triggered with flash or reversing checkerboard stimuli and recorded with electroencephalographic techniques, largely but not exclusively in clinical or clinically related settings. They have been crucial in determining the healthy functioning or otherwise of the visual pathways up to and including the cerebral cortex. They have typically given early response latencies of 100ms, the source of which has been attributed to V1, with the prestriate cortex being secondarily activated somewhat later. On the other hand, magnetoencephalographic studies using stimuli better tailored to the physiology of individual, specialized, visual areas have given early latencies of <50ms with the sources localized in both striate (V1) and prestriate cortex. In this study, we used the reversing checkerboard pattern as a stimulus and recorded cortical visual evoked magnetic fields with magnetoencephalography, to establish whether very early responses can be traced to (estimated) in both striate and prestriate cortex, since such a demonstration would enhance considerably the power of this classical approach in clinical investigations. Our results show that cortical responses evoked by checkerboard patterns can be detected before 50ms post-stimulus onset and that their sources can be estimated in both striate and prestriate cortex, suggesting a strong parallel input from the sub-cortex to both striate and prestriate divisions of the visual cortex. PMID:27083528

  6. New evidence for mid-Pliocene-early Pleistocene glaciation in the northern Patagonian Andes Argentina

    SciTech Connect

    Stephens, G.C.; Evenson, E.B.; Rabassa, J.

    1985-01-01

    Mount Tronador is an extinct, glacially eroded strato-volcano located in the northern Patagonian Andes. With a summit elevation of 3556 m, Mount Tronador lies mostly above the present regional snowline (2000 m) and is largely covered by extensive snow fields and glaciers. The rocks of Mount Tronador comprise the Tronador Formation, a 2000 m thick sequence of interlayered basalts, andesites, ignimbrites, agglomerates, volcanic mudflows and lahars. This volcanic edifice is built on an erosional land surface of Tertiary age. Three K-Ar dates from the Tronador Formation yield radiometric ages of 3.2, 0.34 and 0.18 m.y. Striated clasts have been found included in several large glacial boulders derived from volcanic mudflows and lahars of the Tronador Fm. These boulders have been eroded by the Rio Manso Glacier and deposited in its Neoglacial moraines. The lahar boulders themselves contain pebbles and boulders of andesitic rocks in a vitroclastic matrix of pyroclastic origin. The striated clasts are well-rounded, shaped and polished, and the striations can be traced beneath the volcanic matrix. Thus these striated clasts represent a pre-Holocene cycle of glaciation. Mercer (1976) and Ciesielski (1982) document glaciations from southern Patagonia (2.1-3.5 m.y.) and from the southwestern Atlantic (2.1-3.9 m.y.) respectively. The discovery of striated clasts in lahars and mudflows of the Tronador Fm. indicates the existence of a heretofore undocumented Pliocene-Pleistocene glaciation in northern Patagonia.

  7. Smoothness and Striation in Digital Learning Spaces

    ERIC Educational Resources Information Center

    Bayne, Sian

    2004-01-01

    It is Deleuze & Guattari's description of smooth and striated cultural spaces (Deleuze & Guattari, 1988) which informs this exploration of pedagogical alternatives within the learning environments of cyberspace. Digital spaces work to constitute subject and text in ways which are distinct, and it is awareness of this distinctiveness which must…

  8. Two distinct myosin II populations coordinate ovulatory contraction of the myoepithelial sheath in the Caenorhabditis elegans somatic gonad.

    PubMed

    Ono, Kanako; Ono, Shoichiro

    2016-04-01

    The myoepithelial sheath in the somatic gonad of the nematodeCaenorhabditis eleganshas nonstriated contractile actomyosin networks that produce highly coordinated contractility for ovulation of mature oocytes. Two myosin heavy chains are expressed in the myoepithelial sheath, which are also expressed in the body-wall striated muscle. The troponin/tropomyosin system is also present and essential for ovulation. Therefore, although the myoepithelial sheath has smooth muscle-like contractile apparatuses, it has a striated muscle-like regulatory mechanism through troponin/tropomyosin. Here we report that the myoepithelial sheath has a distinct myosin population containing nonmuscle myosin II isoforms, which is regulated by phosphorylation and essential for ovulation. MLC-4, a nonmuscle myosin regulatory light chain, localizes to small punctate structures and does not colocalize with large, needle-like myosin filaments containing MYO-3, a striated-muscle myosin isoform. RNA interference of MLC-4, as well as of its upstream regulators, LET-502 (Rho-associated coiled-coil forming kinase) and MEL-11 (a myosin-binding subunit of myosin phosphatase), impairs ovulation. Expression of a phosphomimetic MLC-4 mutant mimicking a constitutively active state also impairs ovulation. A striated-muscle myosin (UNC-54) appears to provide partially compensatory contractility. Thus the results indicate that the two spatially distinct myosin II populations coordinately regulate ovulatory contraction of the myoepithelial sheath. PMID:26864628

  9. Uncoupling activity of the anthelmintic oxyclozanide in rodents

    PubMed Central

    Veenendaal, G.H.; De Waal, M.J.

    1974-01-01

    The uncoupling activity of oxyclozanide in warm blooded animals has been studied in whole animals, isolated tissue in vitro and on mitochondrial preparations. The onset of post mortem rigidity in mice and rats is accelerated and a contracture of striated muscle is produced. Oxyclozanide (1 μM) stimulated rat liver mitochondrial respiration and stimulated an ATP-ase activity. PMID:4277750

  10. The Development of Luminance- and Texture-Defined Form Perception during the School-Aged Years

    ERIC Educational Resources Information Center

    Bertone, Armando; Hanck, Julie; Guy, Jacalyn; Cornish, Kim

    2010-01-01

    The objective of the present study was to assess the development of luminance- and texture-defined static form perception in school-aged children. This was done using an adapted Landolt-C technique where C-optotypes were defined by either luminance or texture information, the latter necessitating extra-striate neural processing to be perceived.…

  11. Biofeedback for Developing Self-Control of Tension and Stress in One's Hierarchy of Psychological States.

    ERIC Educational Resources Information Center

    Cassel, Russell

    1985-01-01

    Describes six stage hierarchial patterns in the development of self-control through biofeedback. The stages include Skeletal and Striated Muscle Tension; Visceral Involvement-Anxiety Neuroses; Chronic Physiological Dysfunctioning; Decision Making Competency; Twilight Learning-Permissive Concentration; and Autogenic Feedback Training. (BL)

  12. Revision of the Genus Corallomycetella with Corallonectria gen. nov. for C. jatrophae (Nectriaceae, Hypocreales)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Corallomycetella (Ascomycota, Sordariomycetes, Hypocreales, Nectriaceae) has been defined to include red nectrioid fungi associated with rhizomorphs in nature and culture. With the recent collection of an unusual specimen having striated ascospores, the genus was re-examined using this and...

  13. Heidenhain variant of Creutzfeldt-Jakob disease: An autopsy study from India.

    PubMed

    Kher, Monica; Rao, Medha Y; Acharya, P T; Mahadevan, Anita; Shankar, S K

    2009-01-01

    Prion diseases are rare, progressive and fatal neurodegenerative diseases characterized by long incubation period and short clinical course. We present a rare case of Heidenhain variant of Creutzfeldt-Jakob disease, occurring in a 55-year-old lady presenting with dementia, cortical blindness, and myoclonic jerks. She succumbed to the disease within 8 weeks of onset of symptoms. MRI revealed hyperintense signals on T2WI and fluid attenuated inversion recovery (FLAIR) images in basal ganglia and fronto-temporal and parietal cortex, sparing thalamus, striate cortex and globus pallidum. Abundant abnormal prion protein deposits (PrP(sc)) were detected in caudate, putamen, thalamus, cingulate and striate cortex, in comparison to frontal and parietal cortex while no deposits were found in globus pallidum. MRI changes did not correlate with degree of spongy change, gliosis or prion protein deposition. The cause for abnormal signal changes in MRI and FLAIR images remains unclear. PMID:20151011

  14. Detyrosinated microtubules modulate mechanotransduction in heart and skeletal muscle

    PubMed Central

    Kerr, Jaclyn P.; Robison, Patrick; Shi, Guoli; Bogush, Alexey I.; Kempema, Aaron M.; Hexum, Joseph K.; Becerra, Natalia; Harki, Daniel A.; Martin, Stuart S.; Raiteri, Roberto; Prosser, Benjamin L.; Ward, Christopher W.

    2015-01-01

    In striated muscle, X-ROS is the mechanotransduction pathway by which mechanical stress transduced by the microtubule network elicits reactive oxygen species. X-ROS tunes Ca2+ signalling in healthy muscle, but in diseases such as Duchenne muscular dystrophy (DMD), microtubule alterations drive elevated X-ROS, disrupting Ca2+ homeostasis and impairing function. Here we show that detyrosination, a post-translational modification of α-tubulin, influences X-ROS signalling, contraction speed and cytoskeletal mechanics. In the mdx mouse model of DMD, the pharmacological reduction of detyrosination in vitro ablates aberrant X-ROS and Ca2+ signalling, and in vivo it protects against hallmarks of DMD, including workload-induced arrhythmias and contraction-induced injury in skeletal muscle. We conclude that detyrosinated microtubules increase cytoskeletal stiffness and mechanotransduction in striated muscle and that targeting this post-translational modification may have broad therapeutic potential in muscular dystrophies. PMID:26446751

  15. Mapping of functional activity in brain with /sup 18/F-fluoro-deoxyglucose

    SciTech Connect

    Alavi, A.; Reivich, M.; Greenberg, J.; Hand, P.; Rosenquist, A.; Rintelmann, W.; Christman, D.; Fowler, J.; Goldman, A.; MacGregor, R.; Wolf, A.

    1981-01-01

    The efficacy of using the /sup 18/F-fluoro-deoxyglucose (/sup 18/F-DG) for measuring regional cerebral glucose utilization in man during functional activation is demonstrated. Normal male volunteers subjected to sensory stimuli (visual, auditory, tactile) exhibited focal increases in glucose metabolism in response to the stimulus. Unilateral visual hemifield stimulation caused the contralateral striate cortex to become more active metabolically than the striate cortex ipsilateral to the stimulated hemifield. Similarly, stroking of the fingers and hand of one arm with a brush produced an increase in metabolism in the contralateral postcentral gyrus compared to the homologous ipsilateral region. The auditory stimulus, which consisted of monaural listening to either a meaningful or nonmeaningful story, caused an increase in glucose metabolism in the right temporal cortex independent of which ear was stimulated. These results demonstrate that the /sup 18/F-DG technique is capable of providing functional maps in vivo in the human brain.

  16. Sarcocystis fayeri-Induced Granulomatous and Eosinophilic Myositis in 2 Related Horses.

    PubMed

    Herd, H R; Sula, M M; Starkey, L A; Panciera, R J; Johnson, E M; Snider, T A; Holbrook, T C

    2015-11-01

    This report describes 2 genetically related paint mares, case Nos. 1 and 2, presented to the Oklahoma State University Boren Veterinary Medical Teaching Hospital for chronic weight loss and abnormal gait, respectively. Notable findings in both cases included marked persistent eosinophilia and multiple intramuscular lateral thoracic masses. Histologic examination of masses revealed eosinophilic, centrally necrotic granulomas and marked eosinophilic myositis. Granulomas in case No. 1 also contained intralesional Sarcocystis sp material, and adjacent muscle fibers contained intact protozoal cysts. Case No. 1 developed severe refractory muscle pain and recurrent esophageal dysphagia. At necropsy, disseminated, grossly visible granulomas were present throughout all examined striated muscles. Nested polymerase chain reaction of the 18S rRNA gene revealed >99% homology with Sarcocystis fayeri. Sarcocystis spp are apicomplexan protozoa that infect striated muscle of many omnivorous species, typically without inciting clinical disease. Sarcocystosis should be considered a rare cause of granulomatous eosinophilic myositis and choke in horses. PMID:25957356

  17. Anatomic basis for the continence-preserving radical retropubic prostatectomy.

    PubMed

    Steiner, M S

    2000-02-01

    The technique of continence-preserving anatomic radical retropubic prostatectomy focuses on the preservation of the following anatomic components of the external striated urethral sphincteric complex: (1) the entire circumference of the rhabdosphincter musculature, (2) the periurethral fascial investments (the pubourethral ligaments anterolaterally and median fibrous raphe posteriorly), and (3) the innervation of both the rhabdosphincter by way of the intrapelvic branch of the pudendal nerve (somatic) and the mucosal and smooth muscle components by way of the urethral branch of the inferior hypogastric plexus (autonomic). The clinical impact of preserving the external striated urethral sphincter and its innervation by performing a continence preserving anatomic retropubic prostatectomy is a shorter time to achieve urinary continence. PMID:10719925

  18. Season related ultrastructural features of the parotid, submandibular and von Ebner's glands in hibernating bats.

    PubMed

    Azzali, G; Grandi, D

    1996-08-01

    The parotid, submandibular and the von Ebner's salivary glands of hibernating insectivorous bats (Pipistrellus pipistrellus, Rhinolophus f. e. and Eptesicus serotinus) were studied by transmission electron microscopy and by histochemical methods during various seasons of the year. We report the seasonal ultrastructural changes that occur in the cytoplasmic organelles and the secretory granules of the serous and mucous cells and in the intercalated and striated ducts of the major glands. It previously has been hypothesized that the heterogeneity of the inclusions in the serous granules is closely related to the varying seasonal levels of proteinaceous and glycidic constituents. Lymphatic vessels are present only in the perivascular and periductal connective tissue. Morphofunctional and comparative studies seem to confirm a relationship between secretory activity and nutritional status as well as a likely involvement of the intercalated and striated ducts in determining the composition of the saliva. PMID:8874091

  19. Electron microscopy of the intestine of the African lungfish, Protopterus aethiopicus.

    PubMed

    Purkerson, M L; Jarvis, J U; Luse, S A; Dempsey, E W

    1975-05-01

    Electron microscopic observations are reported on the intestine of the African lungfish, Protopterus aethiopicus. The lungfish has a spiral valve rather than a true stomach. Segments of mucosa from this area reveal, by transmission microscopy, that most cells have distinct striated borders with parallel microvilli. Fibrils within the core of the microvilli extend deeply into the cytoplasm. Microvilli on the surface of goblet cells are less regularly arranged than those of absorptive cells. Interspersed among the cells with striated borders are cells, similar in cytologic appearance except that they are covered with tufts of kinetocilia. By transmission electron microscopy, abnormal cilia having one complete complement of microtubules plus incomplete sets from other cilia which share some of the peripheral doublets of the complete cilium are enclosed by a single membrane. Cilia are usual in the intestine of many lower forms but ordinarily absent in higher vertebrates. Their functional significance in this primitive fish is unknown. PMID:1155792

  20. Incidental finding of a microsporidian parasite from an AIDS patient.

    PubMed Central

    McDougall, R J; Tandy, M W; Boreham, R E; Stenzel, D J; O'Donoghue, P J

    1993-01-01

    Light microscopic examination of feces from a human immunodeficiency virus-positive patient with chronic diarrhea, anorexia, and lethargy revealed the presence of numerous refractile bodies resembling microsporidian spores. They were subsequently identified as belonging to the genus Nosema on the basis of their ultrastructural characteristics. However, the microsporidia were enclosed within striated muscle cells, suggesting that they were probably ingested in food; thus, this represented an incidental finding rather than a true infection. Images PMID:8432833

  1. Visual reactions in a case of long-lasting cortical blindness

    PubMed Central

    Braak, J. W. G. Ter; Schenk, V. W. D.; Vliet, A. G. M. Van

    1971-01-01

    A case is described of long-lasting cortical blindness in a 71 year old man showing no other visual reactions than pupillary narrowing to light and (only after some months) optokinetic nystagmus of the `passive' type. Necropsy demonstrated total bilateral destruction of the striate area of the cortex caused by bilateral softening in the territory of the posterior cerebral artery, and nearly total loss of ganglion cells in both lateral geniculate bodies. Images

  2. Gene regulation, alternative splicing, and posttranslational modification of troponin subunits in cardiac development and adaptation: a focused review

    PubMed Central

    Sheng, Juan-Juan; Jin, Jian-Ping

    2014-01-01

    Troponin plays a central role in regulating the contraction and relaxation of vertebrate striated muscles. This review focuses on the isoform gene regulation, alternative RNA splicing, and posttranslational modifications of troponin subunits in cardiac development and adaptation. Transcriptional and posttranscriptional regulations such as phosphorylation and proteolysis modifications, and structure-function relationships of troponin subunit proteins are summarized. The physiological and pathophysiological significances are discussed for impacts on cardiac muscle contractility, heart function, and adaptations in health and diseases. PMID:24817852

  3. Permian Triassic palynofloral transition in Chintalapudi area, Godavari Graben, Andhra Pradesh, India

    NASA Astrophysics Data System (ADS)

    Jha, Neerja; Chary, M. Basava; Aggarwal, Neha

    2012-10-01

    The entire 606 m-thick sedimentary sequence in borecore MCP-7 from Chintalapudi area, Chintalapudi sub-basin has been lithologically designated as Kamthi Formation. However, the palynological investigation revealed five distinct palynoassemblages, which essentially fall under two groups, one group (Palynoassemblage-I, II and III) having dominance of striate disaccates along with presence of some stratigraphically significant taxa, belongs to Late Permian (Raniganj) palynoflora, while the other group (Palynoassemblages IV and V) shows sharp decline in percentage of characteristic taxa of first group, i.e., striate disaccates, and consequent rise or dominance of taeniate and cingulate cavate spores, belongs to Early Triassic (Panchet) palynoflora. Palynoassemblage-I, II and III (Group I) are characterized by dominance of striate disaccates chiefly, Striatopodocarpites spp. and Faunipollenites spp. along with presence of rare but stratigraphically significant taxa, viz., Gondisporites raniganjensis, Falcisporites nuthaliensis, Klausipollenites schaubergeri, Chordasporites sp., Striomonosaccites, ovatus, Crescentipollenites multistriatus, Verticipollenites debiles, Strotersporites crassiletus, Guttulapollenites hannonicus, G. gondwanensis, Hamiapollenites insolitus, Corisaccites alutus, Lunatisporites ovatus, Weylandites spp. and Vitreisporites pallidus. Palynoassemblage-I is distinguished by significant presence of Densipollenites spp. while Palynoassemblage-II shows significant presence of Crescentipollenites spp. and Palynoassemblage-III differs from the above two assemblages in having significant presence of Guttulapollenites hannonicus. Palynoassemblage-IV (Group II) is characterized by high percentage of taeniate disaccates chiefly Lunatisporites spp., while Palynoassemblage-V (Group II) is characterized by cingulate-cavate trilete spores chiefly, Lundbladispora spp. and Densoisporites spp. Striate disaccates show a sharp decline in these two assemblages. In

  4. Titin: central player of hypertrophic signaling and sarcomeric protein quality control.

    PubMed

    Kötter, Sebastian; Andresen, Christian; Krüger, Martina

    2014-11-01

    The giant sarcomeric protein titin has multiple important functions in striated muscle cells. Due to its gigantic size, its central position in the sarcomere and its elastic I-band domains, titin is a scaffold protein that is important for sarcomere assembly, and serves as a molecular spring that defines myofilament distensibility. This review focuses on the emerging role of titin in mechanosensing and hypertrophic signaling, and further highlights recent evidence that links titin to sarcomeric protein turnover. PMID:25205716

  5. Mullerian adenosarcoma of the cervix with heterologous elements and sarcomatous overgrowth

    PubMed Central

    Pinto, Karen R.

    2016-01-01

    Cervical adenosarcomas are exceedingly infrequent tumors that occur most often in women of reproductive age. Adenosarcomas comprise benign epithelial elements and malignant stromal elements. The malignant stromal elements can either be homologous, such as fibroblasts or smooth muscle, or heterologous, like cartilage, striated muscle, or bone. We report a case of adenosarcoma of the cervix with heterologous elements and sarcomatous overgrowth in a 38-year-old woman. PMID:26722175

  6. Muscle as a “Mediator“ of Systemic Metabolism

    PubMed Central

    Baskin, Kedryn K.; Winders, Benjamin R.; Olson, Eric N.

    2015-01-01

    Skeletal and cardiac muscles play key roles in the regulation of systemic energy homeostasis and display remarkable plasticity in their metabolic responses to caloric availability and physical activity. In this Perspective we discuss recent studies highlighting transcriptional mechanisms that govern systemic metabolism by striated muscles. We focus on the participation of the Mediator complex in this process, and suggest that tissue-specific regulation of Mediator subunits impacts metabolic homeostasis. PMID:25651178

  7. Gravity and the cells of gravity receptors in mammals

    NASA Astrophysics Data System (ADS)

    Ross, M. D.

    Two new findings, that crystals located in the inner ear gravity receptors of mammals have the internal organization requisite for the piezoelectric property, and that sensory hair cells of these same receptors possess contractile-appearing striated organelles, have prompted the author to model mammalian gravity receptors in the ear on the principles of piezoelectricity and bioenergetics. This model is presented and a brief discussion of its implications for the possible effects of weightlessness follows.

  8. Morphological and molecular description of three new species of the cyrtophorid genus Chlamydodon (Ciliophora, Cyrtophoria).

    PubMed

    Pan, Hongbo; Li, Lifang; Al-Rasheid, Khaled A S; Song, Weibo

    2013-01-01

    This study investigates the morphology and molecular characteristics of three new cyrtophorid ciliates isolated from China seas: Chlamydodon salinus n. sp., Chlamydodon caudatus n. sp., and Chlamydodon paramnemosyne n. sp. Of these, C. salinus n. sp. differs from its congeners through a combination of body size, a cross-striated band that is not continuous, the presence of 30-34 somatic kineties, 11-15 nematodesmal rods, and 13 contractile vacuoles. Chlamydodon caudatus n. sp., meanwhile, is characterized by having a conspicuous tail, a continuous cross-striated band, 34-40 somatic kineties, about 15 contractile vacuoles, and 20-24 nematodesmal rods. Compared with other Chlamydodon species, the third new one, C. paramnemosyne n. sp., could be identified by its continuous cross-striated band, 16-18 somatic kineties, 5 contractile vacuoles, and 9-12 nematodesmal rods. Based on the sequence of the small subunit (SSU) rRNA gene, the phylogeny of these three new species was analyzed, indicating that they all clustered with other congeners to form a monophyletic assemblage. Based on previous studies and the present work, a brief revision of the genus Chlamydodon is supplied, and a key to aid the identification of Chlamydodon species is given. PMID:23289638

  9. X-Tream: a novel dosimetry system for Synchrotron Microbeam Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Petasecca, M.; Cullen, A.; Fuduli, I.; Espinoza, A.; Porumb, C.; Stanton, C.; Aldosari, A. H.; Bräuer-Krisch, E.; Requardt, H.; Bravin, A.; Perevertaylo, V.; Rosenfeld, A. B.; Lerch, M. L. F.

    2012-07-01

    Microbeam Radiation Therapy (MRT) is a radiation treatment technique under development for inoperable brain tumors. MRT is based on the use of a synchrotron generated X-ray beam with an extremely high dose rate ( ~ 20 kGy/sec), striated into an array of X-ray micro-blades. In order to advance to clinical trials, a real-time dosimeter with excellent spatial resolution must be developed for absolute dosimetry. The design of a real-time dosimeter for such a radiation scenario represents a significant challenge due to the high photon flux and vertically striated radiation field, leading to very steep lateral dose gradients. This article analyses the striated radiation field in the context of the requirements for temporal dosimetric measurements and presents the architecture of a new dosimetry system based on the use of silicon detectors and fast data acquisition electronic interface. The combined system demonstrates micrometer spatial resolution and microsecond real time readout with accurate sensitivity and linearity over five orders of magnitude of input signal. The system will therefore be suitable patient treatment plan verification and may also be expanded for in-vivo beam monitoring for patient safety during the treatment.

  10. Functional characteristics of the growth factor receptor family and some ligands in the oropharyngeal cavity of the Chukar partridge (Alectoris chukar).

    PubMed

    Saruhan, Berna G; Sağsöz, Hakan; Akbalik, Mehmet E; Erdoğan, Serkan

    2015-01-01

    1. The aim of the present study is to describe, immunohistochemically, the expression and cell type localisation of growth factor receptors and some of their ligands in the oropharyngeal organs of the Chukar partridge. 2. The tissue samples from 10 healthy adult partridges were dissected under ether anaesthesia and then embedded in paraffin following routine histological procedures. The immunoreaction for receptors and ligands of the epidermal growth factor receptor (EGFR)/ligand system was localised in the cell membrane, nucleus and cytoplasm of the luminal and glandular epithelial cells, stromal and striated muscle cells, and vascular endothelial and smooth muscle cells. 3. Variations were observed in the avian oropharyngeal organs. The immunostaining for the erbB1/HER1 (human epidermal growth factor receptor 1) and the EGF (epidermal growth factor) and AREG (Amphiregulin) ligands in the luminal epithelial cells was higher than in the glandular epithelial, stromal and striated muscle cells. However, the immunostaining for erbB3/HER3 (human epidermal growth factor receptor 3) and erbB4/HER4 (human epidermal growth factor receptor 4) were similar in the luminal epithelium, stromal and striated muscle cells. 4. Growth factor receptors and some of their ligands were localised in different cell types in the oropharyngeal organs. We suggest that erbB/HERs (human epidermal growth factor receptors) and their ligands play an important role in proliferation, differentiation, growth, survival and migration of the cells. PMID:26569385

  11. Host preference of the arbovirus vector Culex erraticus (Diptera: Culicidae) at Sonso Lake, Cauca Valley Department, Colombia.

    PubMed

    Mendenhall, I H; Tello, S A; Neira, L A; Castillo, L F; Ocampo, C B; Wesson, D M

    2012-09-01

    Culex erraticus (Dyar & Knab) is a competent vector of Eastern equine encephalitis virus and subtype IC Venezuelan equine encephalitis virus, and both St. Louis encephalitis virus and West Nile virus have been isolated from field-collected specimens. Previous bloodmeal analysis studies have shown this species to be a generalist, feeding on a variety of mammals, birds, reptiles, and amphibians. This behavior can bridge arboviral transmission across different vertebrate groups. Our study examined the host preference of Cx. erraticus at Sonso Lake in Colombia. From July to August 2008, blood-engorged mosquitoes were collected from resting boxes, while vertebrate abundance was determined to calculate host preference. Based on mitochondrial DNA analysis of bloodmeals, birds were the predominant hosts (57.6%), followed by mammals (30.8%), and reptiles (6.7%); 9.5% of the bloodmeals were mixed. The most commonly fed upon species were: limpkin, black-crowned night-heron, striated heron, human, and capybara. Forage ratios showed the least bittern, limpkin, Cocoi heron, striated heron, capybara, and black-crowned night heron were preferred hosts across all vertebrates. Of the available avifauna, the least bittern, limpkin, striated heron, Cocoi heron, and black-crowned night heron were preferred, whereas the bare faced ibis, great egret, snowy egret, and cattle egret were under-used. This study shows that while Cx. erraticus is an opportunistic feeder, using diverse vertebrate hosts in the environment, certain avian species are targeted preferentially for bloodmeals. PMID:23025191

  12. Association of myostatin variants with growth traits of Zhikong scallop ( Chlamys farreri)

    NASA Astrophysics Data System (ADS)

    Fu, Qiang; Guo, Huihui; Feng, Liying; Li, Xue; Zhang, Lingling; Wang, Shi; Hu, Xiaoli; Bao, Zhenmin

    2016-02-01

    Scallop is a popular sea food and an important aquaculture shellfish. Identification of genes and genetic variants relating to scallop growth could benefit high-yielding scallop breeding. Myostatin ( MSTN) is a conservative regulator of muscle growth, and has become one of the most important target genes for genetic improvement of the production of farmed animals. In this study, four single nucleotide polymorphisms (SNPs) were identified in the 5' flanking region of MSTN gene ( CfMSTN) in Zhikong scallop ( Chlamys farreri). The association of these SNPs with scallop growth traits, including shell length, shell height, body weight and striated muscle weight was analyzed. The SNP g-1162Gstriated muscle weight. The TT type scallops showed significantly higher trait values than those of GT type, and the GG type individuals exhibited median values. On the contrary, significantly more CfMSTN transcripts were detected in the striated muscle of GT type scallops than in those of TT and GG type ones. Our results suggested that CfMSTN might regulate the scallop muscle growth negatively, and SNP g-1162G

  13. Mechanical Properties of Respiratory Muscles

    PubMed Central

    Sieck, Gary C.; Ferreira, Leonardo F.; Reid, Michael B.; Mantilla, Carlos B.

    2014-01-01

    Striated respiratory muscles are necessary for lung ventilation and to maintain the patency of the upper airway. The basic structural and functional properties of respiratory muscles are similar to those of other striated muscles (both skeletal and cardiac). The sarcomere is the fundamental organizational unit of striated muscles and sarcomeric proteins underlie the passive and active mechanical properties of muscle fibers. In this respect, the functional categorization of different fiber types provides a conceptual framework to understand the physiological properties of respiratory muscles. Within the sarcomere, the interaction between the thick and thin filaments at the level of cross-bridges provides the elementary unit of force generation and contraction. Key to an understanding of the unique functional differences across muscle fiber types are differences in cross-bridge recruitment and cycling that relate to the expression of different myosin heavy chain isoforms in the thick filament. The active mechanical properties of muscle fibers are characterized by the relationship between myoplasmic Ca2+ and cross-bridge recruitment, force generation and sarcomere length (also cross-bridge recruitment), external load and shortening velocity (cross-bridge cycling rate), and cross-bridge cycling rate and ATP consumption. Passive mechanical properties are also important reflecting viscoelastic elements within sarcomeres as well as the extracellular matrix. Conditions that affect respiratory muscle performance may have a range of underlying pathophysiological causes, but their manifestations will depend on their impact on these basic elemental structures. PMID:24265238

  14. Impact of aging on mitochondrial function in cardiac and skeletal muscle.

    PubMed

    Hepple, R T

    2016-09-01

    Both skeletal muscle and cardiac muscle are subject to marked structural and functional impairment with aging and these changes contribute to the reduced capacity for exercise as we age. Since mitochondria are involved in multiple aspects of cellular homeostasis including energetics, reactive oxygen species signaling, and regulation of intrinsic apoptotic pathways, defects in this organelle are frequently implicated in the deterioration of skeletal and cardiac muscle with aging. On this basis, the purpose of this review is to evaluate the evidence that aging causes dysfunction in mitochondria in striated muscle with a view towards drawing conclusions about the potential of these changes to contribute to the deterioration seen in striated muscle with aging. As will be shown, impairment in respiration and reactive oxygen species emission with aging are highly variable between studies and seem to be largely a consequence of physical inactivity. On the other hand, both skeletal and cardiac muscle mitochondria are more susceptible to permeability transition and this seems a likely cause of the increased recruitment of mitochondrial-mediated pathways of apoptosis seen in striated muscle. The review concludes by examining the role of degeneration of mitochondrial DNA versus impaired mitochondrial quality control mechanisms in the accumulation of mitochondria that are sensitized to permeability transition, whereby the latter mechanism is favored as the most likely cause. PMID:27033952

  15. Chloral hydrate alters the organization of the ciliary basal apparatus and cell organelles in sea urchin embryos

    NASA Technical Reports Server (NTRS)

    Chakrabarti, A.; Schatten, H.; Mitchell, K. D.; Crosser, M.; Taylor, M.

    1998-01-01

    The mitotic inhibitor, chloral hydrate, induces ciliary loss in the early embryo phase of Lytechinus pictus. It causes a breakdown of cilia at the junction of the cilium and the basal body known as the basal plate. This leaves the plasma membrane temporarily unsealed. The basal apparatus accessory structures, consisting of the basal body, basal foot, basal foot cap, striated side arm, and striated rootlet, are either misaligned or disintegrated by treatment with chloral hydrate. Furthermore, microtubules which are associated with the basal apparatus are disassembled. Mitochondria accumulate at the base of cilia - underneath the plasma membrane - and show alterations in their structural organization. The accumulation of mitochondria is observed in 40% of all electron micrograph sections while 60% show the areas mostly devoid of mitochondria. The microvilli surrounding a cilium and striated rootlet remain intact in the presence of chloral hydrate. These results suggest that deciliation in early sea urchin embryos by chloral hydrate is caused by combined effects on the ciliary membrane and on microtubules in the cilia. Furthermore, it is suggested that chloral hydrate can serve as a tool to explore the cytoskeletal mechanisms that are involved in cilia motility in the developing sea urchin embryo.

  16. Muscle-Specific Splicing of a Heterologous Exon Mediated by a Single Muscle-Specific Splicing Enhancer from the Cardiac Troponin T Gene

    PubMed Central

    Cooper, Thomas A.

    1998-01-01

    The chicken cardiac troponin T (cTNT) gene contains a single 30-nucleotide alternative exon that is included in embryonic striated muscle and skipped in the adult. Transient-transfection analysis of cTNT minigenes in muscle and fibroblast cell cultures previously identified four muscle-specific splicing enhancers (MSEs) that promote exon inclusion specifically in embryonic striated muscle cultures. Three MSEs located in the intron downstream from the alternative exon were sufficient for muscle-specific exon inclusion. In the present study, the boundaries of these MSEs were defined by scanning mutagenesis, allowing analysis of individual elements in gain-of-function experiments. Concatamers of MSE2 were necessary and sufficient to promote muscle-specific inclusion of a heterologous exon, indicating that it is a target for muscle-specific regulation. Sequences present in MSE2 are also found in MSE4, suggesting that these two MSEs act in a similar manner. MSE3 appears to be different from MSE2 and MSE4 yet is able to functionally replace both of these elements, demonstrating functional redundancy of elements that are likely to bind different factors. MSE2 and MSE4 each contain a novel sequence motif that is found adjacent to a number of alternative exons that undergo regulated splicing in striated muscle, suggesting a common role for this element in muscle-specific regulation. PMID:9671461

  17. Muscle microanatomy and its changes during contraction: the legacy of William Bowman (1816-1892).

    PubMed

    Frixione, Eugenio

    2006-01-01

    Striated muscle fine structure began to be really understood following a comprehensive survey of the matter carried out by William Bowman in the late 1830s. The publications resulting from such a study, the first of which earned for the author a precocious election as Fellow of the Royal Society, are herewith examined in the context of contemporary views on the subject as well as of their subsequent repercussion and current knowledge today. It is shown that not only Bowman succeeded in establishing the true architecture of striated muscle fibres to the extent possible with the most advanced technology available in his day--explaining and eradicating alternative erroneous concepts in the process--but also in correctly describing the basic microstructural changes associated with contraction. In addition, although unrecognized by him or others at the time, his experiments with muscle provided direct evidence for the existence of a selectively permeable cell membrane--in the present meaning of the word--over half a century before its officially accepted discovery. Yet, in spite of these remarkable advances, Bowman arrived at the conclusion that the structure of striated muscle fibres is essentially irrelevant for the mechanism of contraction. Possible reasons behind Bowman's breakthrough accomplishments as a pioneer of modern muscle research, and his failure to understand their significance for muscle physiology, are discussed. PMID:16465470

  18. Titin and myosin, but not desmin, are linked during myofibrillogenesis in postmitotic mononucleated myoblasts.

    PubMed

    Hill, C S; Duran, S; Lin, Z X; Weber, K; Holtzer, H

    1986-12-01

    Monoclonal antibodies specific for the muscle protein titin have been used in conjunction with muscle-specific antibodies against myofibrillar myosin heavy chains (MHCs) and desmin to study myogenesis in cultured cells. Desmin synthesis is initiated in replicating presumptive myoblasts, whereas the synthesis of titin and MHC is initiated simultaneously in their progeny, the postmitotic, mononucleated myoblasts. Both titin and MHC are briefly localized to nonstriated and thereafter to definitively striated myofibrils. At no stage during myofibrillogenesis is either protein observed as part of a sequence of mini-sarcomeres. Titin antibodies bind to the A-I junction, MHC antibodies to the A bands in nascent, maturing, and mature myofibrils. In contrast, desmin remains distributed as longitudinal filaments until well after the definitive myofibrils have aligned laterally. This tight temporal and topographical linkage between titin and myosin is also observed in postmitotic, mononucleated myoblasts and multinucleated myotubes when myofibrillogenesis is perturbed with Colcemid or taxol. Colcemid induces elongating postmitotic mononucleated myoblasts and multinucleated myotubes to round up and form Colcemid myosacs. The myofibrils that emerge in these rounded cells are deployed in convoluted circles. The time required for their nonstriated myofibrils to transform into striated myofibrils is greatly protracted. Furthermore, as Colcemid induces immense desmin intermediate filament cables, the normal spatial relationships between emerging individual myofibrils is distorted. Despite these disturbances at all stages, the characteristic temporal and spatial relationship observed in normal myofibrils between titin and MHC is observed in myofibrils assembling in Colcemid-treated cells. Newly born postmitotic mononucleated myoblasts, or maturing myotubes, reared in taxol acquire a star-shaped configuration and are induced to assemble "pseudo-striated myofibrils." Pseudo-striated

  19. An unusual parotid gland in the tent-building bat, Uroderma bilobatum: possible correlation of interspecific ultrastructural differences with differences in salivary pH and buffering capacity.

    PubMed

    Nagato, T; Tandler, B; Phillips, C J

    1998-10-01

    The tent-building bat, Uroderma bilobatum, is a small, frugivorous phyllostomid bat with a broad neotropical distribution. Generally found in humid forest, this bat lives in small groups that create daytime "roosts" from large leaves of a variety of tropical plants. Fruit eating engenders a variety of ecological and physiological challenges for bats, some of which could require adaptive features in their salivary glands. The parotid salivary glands of Uroderma bilobatum were prepared for transmission electron microscopy by using methods that have become standard for field work. The parotid gland is extremely unusual in structure. Although the secretory endpieces still produce serous granules with a complex substructure, they are modified into quasi striated ducts. Their basal folds, which are extensive, occasionally harbor some vertically oriented mitochondria, imparting a resemblance to striated ducts. Other evidence for the endpiece origin of these parenchymal components is a well-developed system of intercellular canaliculi, structures that never occur in bona fide striated ducts. The long but sparse intercalated ducts consist of two types of cells, each of which elaborates a modest number of secretory granules of differing substructure. Striated ducts are of conventional morphology, except that a few dark cells shaped like wine glasses are present in their walls. The striated duct cells produce no secretory granules, but their apical cytoplasm may contain some small, empty vesicles. Capillaries lie in longitudinal grooves in the base of the duct cells, an arrangement that might enhance electrolyte exchange. Excretory ducts consist of simple cuboidal epithelium composed of cytologically unspecialized cells that sometimes includes a dark cell. It was concluded that salivary glands could have a major role in adapting species to acquire nutrients from marginal sources, such as tropical fruits, which have a low protein and sodium content. The unusual parotid acinar

  20. Morphological analysis of the urethral muscle of the male pig with relevance to urinary continence and micturition.

    PubMed

    Ragionieri, Luisa; Ravanetti, Francesca; Gazza, Ferdinando; Botti, Maddalena; Ivanovska, Ana; Cacchioli, Antonio

    2016-03-01

    To investigate whether the pig could be considered a suitable model to study lower urinary tract function and dysfunction, the pelvic urethra of 24 slaughtered male pigs were collected, and the associated muscles were macroscopically, histologically and histochemically analyzed. In cross-sections of the urethra, a muscular complex composed of an inner layer of smooth muscle and an outer layer of striated muscle that are not separated by fascial planes was observed. A tunica muscularis, composed of differently oriented smooth muscle bundles, is only evident in the proximal part of the pelvic urethra while, in the remaining part, it contributes to form the prostatic fibromuscular stroma. The striated urethral muscle surrounds the pelvic urethra in a horseshoe-like configuration with a dorsal longitudinal raphe, extending from the bladder neck to the central tendon of perineum. Proximally to the bladder, it is constituted of slow-twitch and fast-twitch myofibers of very small diameter, and embedded in an abundant collagen and elastic fiber net. Moving caudally it is gradually encircled and then completely substituted by larger and compact myofibers, principally presenting circular orientation and fast-twitch histochemical characteristics. So, like in humans, the cranial tract of the muscular system surrounding the pelvic urethra is principally composed of smooth musculature. The striated component cranially may have a role in blocking retrograde ejaculation, while the middle and caudal tracts may facilitate urine and semen flow, and seem especially concerned with the rapid and forceful urethral closure during active continence. Some differences in the morphology and structure between pigs and humans seem due to the different morphology of the 'secondary' sexual organs that develop from the urethral wall and to the different effect of gravity on the mechanics of the urinary system in quadruped and bipedal mammals. PMID:26573248

  1. Involvement of Superoxide Dismutase in Spore Coat Assembly in Bacillus subtilis

    PubMed Central

    Henriques, Adriano O.; Melsen, Lawrence R.; Moran, Charles P.

    1998-01-01

    Endospores of Bacillus subtilis are enclosed in a proteinaceous coat which can be differentiated into a thick, striated outer layer and a thinner, lamellar inner layer. We found that the N-terminal sequence of a 25-kDa protein present in a preparation of spore coat proteins matched that of the Mn-dependent superoxide dismutase (SOD) encoded by the sodA locus. sodA is transcribed throughout the growth and sporulation of a wild-type strain and is responsible for the SOD activity detected in total cell extracts prepared from B. subtilis. Disruption of the sodA locus produced a mutant that lacked any detectable SOD activity during vegetative growth and sporulation. The sodA mutant was not impaired in the ability to form heat- or lysozyme-resistant spores. However, examination of the coat layers of sodA mutant spores revealed increased extractability of the tyrosine-rich outer coat protein CotG. We showed that this condition was not accompanied by augmented transcription of the cotG gene in sporulating cells of the sodA mutant. We conclude that SodA is required for the assembly of CotG into the insoluble matrix of the spore and suggest that CotG is covalently cross-linked into the insoluble matrix by an oxidative reaction dependent on SodA. Ultrastructural analysis revealed that the inner coat formed by a sodA mutant was incomplete. Moreover, the outer coat lacked the characteristic striated appearance of wild-type spores, a pattern that was accentuated in a cotG mutant. These observations suggest that the SodA-dependent formation of the insoluble matrix containing CotG is largely responsible for the striated appearance of this coat layer. PMID:9573176

  2. Ice-flow evolution of the Labrador Sector of the Laurentide Ice Sheet: a review, with new evidence from northern Quebec

    NASA Astrophysics Data System (ADS)

    Veillette, J. J.; Dyke, A. S.; Roy, M.

    1999-07-01

    Outcrops bearing stained, striated facets indicative of north-northeastward moving ice, truncated by unstained, striated facets indicative of various younger flows occur in the Caniapiscau area of north-central Quebec. This is the first report of differential staining of striated facets in the region. We propose that the staining occurred in an ice-free interval of probable interglacial age. This early ice flow probably occurred during ice retreat toward the Quebec highlands. Ice flow and glacial transport data from the southern Hudson Bay and James Bay basins indicate that the next major regional ice flow was toward the northwest and resulted from the expansion of an Early Wisconsinan glacier in the Quebec highlands. The northern part of this flow was diverted northwestward through Hudson Bay, and the southern part southwestward across James Bay, following a progressive counterclockwise rotation of flow. A zone of intersection (ZI) of two major glacier bedform systems, often referred to as the horseshoe-shaped Labrador Ice Divide, represents the head of a large northward convergent ice-flow system that extended to Ungava Bay and beyond. The Ungava flow propagated southward and captured the head of the opposing flow from an outflow centre located east of Caniaspiscau reservoir. We propose that this capture event correlates with the Gold Cove Advance in Ungava Bay and on Baffin Island at about 9900 14C yr BP. It is the largest advance of Quebec-Labrador ice yet proposed for the region. This correlation is based on the relative ice-flow chronology, accommodation of glacial lakes Naskaupi and McLean in the deglaciation sequence, the constraints placed on Last Glacial Maximum (LGM) ice configuration by the postglacial uplift pattern and events in the deep-sea record. Therefore, the Ungava ice-flow pattern is not a relict pre-Wisconsinan glacial landscape as recently proposed.

  3. Substrate & Cell Compliance Effects on Cell Spreading and Differentiation

    NASA Astrophysics Data System (ADS)

    Discher, Dennis; Sheehan, Maureen; Engler, Adam

    2004-03-01

    The stiffness of the substrate that a cell adheres to is emerging as a critically important physical factor in the response of many cell types. The effects are seen with cells on gels as well as cells on cells - highlighting implications for organism development. The basis for the effects lies in the fact that cells literally 'feel' their substrate. Like other anchorage dependent cells, muscle cells feel their substrate and are found in our studies to spread more and organize their cytoskeleton and focal adhesions much more so on rigid glass and stiff substrates than on soft gels. Such spreading is not necessarily physiological or conducive to biological function. Collagen density certainly factors into cell on gel adhesive spreading, with minimal spreading on very low collagen and a weak maximum in cell spreading on intermediate collagen densities. Bell-shaped curves are readily modeled to highlight the coupling between ligand density and substrate stiffness. Most surprising, however, spreading on soft gels is found to be almost independent of adhesive ligand density: even with high collagen densities, the minimal spreading of cells cannot be over-ridden. Remarkably, muscle cells show the strongest tendency to differentiate and striate their acto-myosin on gels that have a stiffness similar to relaxed muscle. Cells gown on top of other cells also show a very strong tendency to striate, even if the underlying cells do not striate; elasticity measurements appear to unify all of the effects. The implications for organismal development as well as cell biological studies can be very important.

  4. Topography and homogeneity of monkey V1 studied through subdurally recorded pattern-evoked potentials.

    PubMed

    Dagnelie, G; Spekreijse, H; van Dijk, B

    1989-12-01

    Using small checkerboard stimulus fields, we have recorded visually evoked potentials (VEPs) in an alert rhesus monkey from an array of 35 electrodes chronically implanted between dura and arachnoid to study mass neuronal activity in striate and peristriate visual cortex. Although the principal purpose of this work was to study in detail cortical mapping in this particular animal for future intracortical recordings, we report here the usefulness of our approach for the non-invasive study of cortical processing, in particular of cortical magnification and receptive-field properties over the central 6 degrees of the visual field. The striate and extrastriate components in the pattern onset VEP both have a double negative-going waveform, with N-P-N peak latencies of 75-100-135 ms and 90-115-160 ms, respectively, for small element sizes and moderate contrasts; latencies may be 5 ms shorter for large element sizes and high contrast. We found little activity at electrode locations over visual areas beyond V2. The waveforms and timing permit some careful speculation concerning intracortical processing and VEP generation. The complex logarithmic form of the retinotopical projection provides a satisfactory model for our data, if a value of 1-1.2 degrees is used for the offset parameter a. Our data suggest that the most abundant receptive-field size in foveal striate cortex has a center diameter of 12'. This size remains constant up to 2 degrees eccentricity, and increases only slowly up to 4 degrees. The smallest receptive-field sizes seem to be independent of eccentricity throughout the central 4 degrees of V1, with a value of 4-8', in agreement with single-cell data reported by Dow et al. (1981) and Van Essen et al. (1984). PMID:2487121

  5. Tectorial Membrane Material Properties in TectaY1870C/+ Heterozygous Mice

    PubMed Central

    Masaki, Kinuko; Ghaffari, Roozbeh; Gu, Jianwen Wendy; Richardson, Guy P.; Freeman, Dennis M.; Aranyosi, A.J.

    2010-01-01

    The solid component of the tectorial membrane (TM) is a porous matrix made up of the radial collagen fibers and the striated sheet matrix. The striated sheet matrix is believed to contribute to shear impedance in both the radial and longitudinal directions, but the molecular mechanisms involved have not been determined. A missense mutation in Tecta, a gene that encodes for the α-tectorin protein in the striated sheet matrix, causes a 60-dB threshold shift in mice with relatively little reduction in outer hair cell amplification. Here, we show that this threshold shift is coupled to changes in shear impedance, response to osmotic pressure, and concentration of fixed charge of the TM. In TectaY1870C/+ mice, the tectorin content of the TM was reduced, as was the content of glycoconjugates reacting with the lectin wheat germ agglutinin. Charge measurements showed a decrease in fixed charge concentration from −6.4±1.4 mmol/L in wild-types to −2.1±0.7 mmol/L in TectaY1870C/+ TMs. TMs from TectaY1870C/+ mice showed little volume change in response to osmotic pressure compared to those of wild-type mice. The magnitude of both radial and longitudinal TM shear impedance was reduced by 10±1.6 dB in TectaY1870C/+ mice. However, the phase of shear impedance was unchanged. These changes are consistent with an increase in the porosity of the TM and a corresponding decrease of the solid fraction. Mechanisms by which these changes can affect the coupling between outer and inner hair cells are discussed. PMID:21081075

  6. Differential effects of temperature and glucose on glycogenolytic enzymes in tissues of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Bolinger, Mark T; Rodnick, Kenneth J

    2014-05-01

    The pathways and regulatory mechanisms of glycogenolysis remain relatively unexplored in non-mammalian vertebrates, especially poikilotherms. We studied the temperature sensitivity and inhibition of glycogenolytic enzymes in liver, ventricle, and white muscle of rainbow trout acclimated to 14 °C. Glycogen phosphorylase (GP) and acid α-glucosidase (GAA) activities were measured in homogenates of tissues at physiological temperatures (4, 14, and 24 °C), and in the presence of allosteric inhibitor, glucose. Higher GP versus GAA activity in all three tissues suggested a predominance of phosphorolytic glycogenolysis over the lysosomal glucosidic pathway. GP activities at 14 °C were ~2-fold higher in the ventricle and white muscle versus the liver and selectively increased by AMP in striated muscle. Conversely, the activities of GAA and lysosomal marker acid phosphatase were 8- to 10-fold higher in the liver compared with the ventricle and white muscle. Thermal sensitivity (Q10) was increased for GP in all tissues below 14 °C and decreased in striated muscle in the absence of AMP above 14 °C. GAA had lower Q10 values than GP below 14 °C, and, unlike GP, Q10s for GAA were not different between tissues or affected by temperature. Both GP (in the absence of AMP) and GAA were inhibited by glucose in a dose-dependent manner, with the lowest IC50 values observed in the white muscle (1.4 and 6.3 mM, respectively). In conclusion, despite comparatively low kinetic potential, lysosomal GAA might facilitate glycogenolysis at colder body temperatures in striated muscle and intracellular glucose could limit phosphorolytic and glucosidic glycogenolysis in multiple tissues of the rainbow trout. PMID:24704523

  7. Note: Effective measurement of retained I(c) in evaluating electromechanical properties of high temperature superconductor tapes by the voltage tap clipping technique.

    PubMed

    Dedicatoria, Marlon J; Bautista, Zhierwinjay; Shin, Hyung-Seop; Sim, Kideok

    2015-08-01

    In this note, the effectiveness of voltage tap clipping technique was assessed in evaluating the electromechanical properties of high temperature superconductor (HTS) tapes in the aspect of practical device applications. In the four-probe transport I(c) measurement, instead of directly soldering the voltage lead wires onto the HTS samples, they were tapped to the sample by either just clipping or soldering them to the clips. This technique facilitated the simultaneous and repeated retained I(c) measurement test for multiple samples. Finally, the critical double bending diameter of HTS tapes and the electrical properties of jointed and striated coated conductor tapes could be easily determined. PMID:26329241

  8. Spontaneous sarcomere dynamics

    NASA Astrophysics Data System (ADS)

    Günther, Stefan; Kruse, Karsten

    2010-12-01

    Sarcomeres are the basic force generating units of striated muscles and consist of an interdigitating arrangement of actin and myosin filaments. While muscle contraction is usually triggered by neural signals, which eventually set myosin motors into motion, isolated sarcomeres can oscillate spontaneously between a contracted and a relaxed state. We analyze a model for sarcomere dynamics, which is based on a force-dependent detachment rate of myosin from actin. Our numerical bifurcation analysis of the spontaneous sarcomere dynamics reveals notably Hopf bifurcations, canard explosions, and gluing bifurcations. We discuss possible implications for experiments.

  9. Visual pathways and psychophysical channels in the primate.

    PubMed

    Lee, Barry B

    2011-01-01

    The main cell systems of the retina that provide input to the striate cortex are now well described, although certain aspects of their anatomy and physiology remain contentious. Under simple stimulus conditions and in a threshold context psychophysical performance can often be assigned to one or other of these systems, and an identification of psychophysical channels with afferent pathways is justifiable. However, results from psychophysical studies using more complex stimulus conditions are more difficult to relate to 'front end' channels, and it is more difficult to separate the physiological contributions of afferent pathways from those of cortical mechanisms, in particular the separation of dorsal and ventral streams. PMID:20724364

  10. The live lattices become visible in coherent synchrotron X-rays

    NASA Astrophysics Data System (ADS)

    Kohn, V.; Rau, C.; Sergienko, P. M.; Snigireva, I.; Snigirev, A.; Vazina, A.

    2005-05-01

    We demonstrate a great potential of the method of phase contrast imaging for a study of muscles and animal organism in normal and pathological states. The method is applied to image biological tissues that have the unique feature of structure-translation symmetry of 0.1-10 μm periodicity. The cross-striated muscle is the most interesting example of such objects. The experiment was done using high-brilliant coherent X-rays, delivered by synchrotron radiation source of third generation (ESRF, Grenoble), and high-resolution 2D-detector.

  11. Tropomyosin exons as models for alternative splicing.

    PubMed

    Gooding, Clare; Smith, Christopher W J

    2008-01-01

    Three of the four mammalian tropomyosin (Tm) genes are alternatively spliced, most commonly by mutually exclusive selection from pairs of internal or 3' end exons. Alternative splicing events in the TPM1, 2 and 3 genes have been analysed experimentally in various levels ofdetail. In particular, mutually exclusive exon pairs in the betaTm (TPM2) and alphaTm (TPM1) genes are among the most intensively studied models for striated and smooth muscle specific alternative splicing, respectively. Analysis of these model systems has provided important insights into general mechanisms and strategies of splicing regulation. PMID:19209811

  12. Mitsugumin 56 (hedgehog acyltransferase-like) is a sarcoplasmic reticulum-resident protein essential for postnatal muscle maturation.

    PubMed

    Van, Bo; Nishi, Miyuki; Komazaki, Shinji; Ichimura, Atsuhiko; Kakizawa, Sho; Nakanaga, Keita; Aoki, Junken; Park, Ki-Ho; Ma, Jianjie; Ueyama, Tomomi; Ogata, Takehiro; Maruyama, Naoki; Takeshima, Hiroshi

    2015-04-28

    Mitsugumin 56 (MG56), also known as the membrane-bound O-acyl-transferase family member hedgehog acyltransferase-like, was identified as a new sarcoplasmic reticulum component in striated muscle. Mg56-knockout mice grew normally for a week after birth, but shortly thereafter exhibited a suckling defect and died under starvation conditions. In the knockout skeletal muscle, regular contractile features were largely preserved, but sarcoplasmic reticulum elements swelled and further developed enormous vacuoles. In parallel, the unfolded protein response was severely activated in the knockout muscle, and presumably disrupted muscle development leading to the suckling failure. Therefore, MG56 seems essential for postnatal skeletal muscle maturation. PMID:25841338

  13. Tropomyosin flexural rigidity and single ca(2+) regulatory unit dynamics: implications for cooperative regulation of cardiac muscle contraction and cardiomyocyte hypertrophy.

    PubMed

    Loong, Campion K P; Badr, Myriam A; Chase, P Bryant

    2012-01-01

    Striated muscle contraction is regulated by dynamic and cooperative interactions among Ca(2+), troponin, and tropomyosin on the thin filament. While Ca(2+) regulation has been extensively studied, little is known about the dynamics of individual regulatory units and structural changes of individual tropomyosin molecules in relation to their mechanical properties, and how these factors are altered by cardiomyopathy mutations in the Ca(2+) regulatory proteins. In this hypothesis paper, we explore how various experimental and analytical approaches could broaden our understanding of the cooperative regulation of cardiac contraction in health and disease. PMID:22493584

  14. Fine structure of the submandibular salivary gland of the venomous short-tailed shrew, Blarina brevicauda Say (Insectivora: Soricidae).

    PubMed

    Carson, K A; Rose, R K

    1993-01-01

    Adult male short-tailed shrews, Blarina brevicauda, (Insectivora: Soricidae) were trapped in Virginia and Pennsylvania, anesthetized, and perfused via the left ventricle of the heart with fixative. The submandibular glands were dissected free and prepared for transmission electron microscopy. The lobular, compound tubuloacinar glands had secretory endpieces consisting of seromucous acini and serous tubules connected to intercalated ducts, granular ducts, striated ducts, and excretory ducts. The general cytology of the submandibular gland of Blarina shared morphological characters with individuals in several other mammalian orders and yet differed in many ways from another Insectivore, the European hedgehog, Erinaceus europaeus. PMID:8398545

  15. ROS and RNS signaling in skeletal muscle: critical signals and therapeutic targets

    PubMed Central

    Michaelson, Luke P; Iler, Colleen; Ward, Christopher W

    2016-01-01

    The health of skeletal muscle is promoted by optimal nutrition and activity/exercise through the activation of molecular signaling pathways. Reactive oxygen species (ROS) or reactive nitrogen species (RNS) have been shown to modulate numerous biochemical processes including glucose uptake, gene expression, calcium signaling and contractility. In pathological conditions, ROS/RNS signaling excess or dysfunction contributes to contractile dysfunction and myopathy in skeletal muscle. Here we provide a brief review of ROS/RNS chemistry and discuss concepts of ROS/RNS signaling and its role in physiological and pathophysiological processes within striated muscle. PMID:24894146

  16. Catalogue of the mite family Tydeidae (Acari: Prostigmata) with the world key to the species.

    PubMed

    Silva, Guilherme Liberato Da; Metzelthin, Maicon Henrique; Silva, Onilda Santos Da; Ferla, Noeli Juarez

    2016-01-01

    Members of the Tydeidae are cosmopolitan, soft-bodied, striated or reticulated mites that are reported to be mainly phytophages, mycophages, pollenophages, insect parasites or scavengers. This catalogue includes 328 species belonging to 30 genera, and their distributions and type habitat. Until now, Brachytydeus comprises the largest number of species with 200, followed by Tydeus, with 50 species, and Pretydeus and Pseudolorryia, with 12 species each. An updated list of the Tydeidae (Acari: Prostigmata), a world key to the species and data on the zoogeographical distribution of the species are presented. PMID:27395702

  17. Solution NMR assignment of the heavy chain complex of the human cardiac myosin regulatory light chain.

    PubMed

    Rostkova, Elena; Gautel, Mathias; Pfuhl, Mark

    2015-04-01

    The regulatory light chain (RLC) of striated and cardiac muscle myosin plays a complex role in muscle function and regulation. Together with the essential light chain it provides stability to the lever arm, which is essential for force generation. Furthermore, phosphorylation and interaction with myosin binding protein C (MyBP-C) suggest an additional role in the regulation of muscle contraction. The former is of particular importance in the heart, where RLC phosphorylation appears to be correlated to the wringing motion of heart contraction. To address these questions and because of a lack of mammalian RLC structures, we initiated an NMR study of the human cardiac regulatory myosin light chain. PMID:24414277

  18. The length-tension curve in muscle depends on lattice spacing

    SciTech Connect

    Williams, C. D.; Salcedo, M. K.; Irving, T. C.; Regnier, M.; Daniel, T. L.

    2013-07-10

    Classic interpretations of the striated muscle length–tension curve focus on how force varies with overlap of thin (actin) and thick (myosin) filaments. New models of sarcomere geometry and experiments with skinned synchronous insect flight muscle suggest that changes in the radial distance between the actin and myosin filaments, the filament lattice spacing, are responsible for between 20% and 50% of the change in force seen between sarcomere lengths of 1.4 and 3.4 µm. Thus, lattice spacing is a significant force regulator, increasing the slope of muscle's force–length dependence.

  19. Structural Phenotyping of Stem Cell-Derived Cardiomyocytes

    PubMed Central

    Pasqualini, Francesco Silvio; Sheehy, Sean Paul; Agarwal, Ashutosh; Aratyn-Schaus, Yvonne; Parker, Kevin Kit

    2015-01-01

    Summary Structural phenotyping based on classical image feature detection has been adopted to elucidate the molecular mechanisms behind genetically or pharmacologically induced changes in cell morphology. Here, we developed a set of 11 metrics to capture the increasing sarcomere organization that occurs intracellularly during striated muscle cell development. To test our metrics, we analyzed the localization of the contractile protein α-actinin in a variety of primary and stem-cell derived cardiomyocytes. Further, we combined these metrics with data mining algorithms to unbiasedly score the phenotypic maturity of human-induced pluripotent stem cell-derived cardiomyocytes. PMID:25733020

  20. A new structural interpretation relating NW Libya to the Hun Graben, western Sirt Basin based on a new paleostress inversion

    NASA Astrophysics Data System (ADS)

    Abdunaser, K. M.; McCaffrey, K. J. W.

    2015-12-01

    The present study is based on fault-slip data (striated fault planes with known sense of slip) measured in outcrops in two structural domains located along the Hun Graben, western Sirt Basin (150 fault-slip data) and the Jifarah Basin and Nafusah Uplift, northwest Libya (200 fault-slip data). Pre-existing field data collected in two previous studies were reprocessed using standard inversion methods in MyFaultTM(v. 1.03) stereonet software, produced by Pangaea Scientific Ltd.

  1. A new geographic and host record for infectious pancreatic necrosis

    USGS Publications Warehouse

    Parisot, T.J.; Yasutake, W.T.; Bressler, V.

    1963-01-01

    The occurrence of infectious pancreatic necrosis in rainbow trout (Salmo gairdneri), brook trout (Salvelinus fontinalis), and cutthroat trout (Salmo clarki) has been experimentally authenticated for the first time in the western United States. The cutthroat trout represents a new host. Brook trout fin tissue culture inoculated with bacteria-free filtrate from the diseased fish tissue showed marked degenerative changes after 24 hours. Chinook salmon (Oncorhynchus tshawytscha), kokanee (O. nerka), and silver salmon (O. kisutch) were not susceptible to the virus when inoculated. Histologically, extensive pancreatic necrosis was observed in the original and experimental materials, but striated muscle hyalinization was detected only in the original material.

  2. Beryllium-10 dating of the duration and retreat of the last pinedale glacial sequence.

    PubMed

    Gosse, J C; Klein, J; Lawn, B; Middleton, R; Evenson, E B

    1995-06-01

    Accurate terrestrial glacial chronologies are needed for comparison with the marine record to establish the dynamics of global climate change during transitions from glacial to interglacial regimes. Cosmogenic beryllium-10 measurements in the Wind River Range indicate that the last glacial maximum (marine oxygen isotope stage 2) was achieved there by 21,700 +/- 700 beryllium-10 years and lasted 5900 years. Ages of a sequence of recessional moraines and striated bedrock surfaces show that the initial deglaciation was rapid and that the entire glacial system retreated 33 kilometers to the cirque basin by 12,100 +/- 500 beryllium-10 years. PMID:17778979

  3. Beryllium-10 dating of the duration and retreat of the last pinedale glacial sequence

    SciTech Connect

    Gosse, J.C. |; Klein, J.; Evenson, E.B.

    1995-06-02

    Accurate terrestrial glacial chronologies are needed for comparison with the marine record to establish the dynamics of global climate change during transitions from glacial to interglacial regimes. Cosmogenic beryllium-10 measurements in the Wind River Range indicate that the last glacial maximum (marine oxygen isotope stage 2) was achieved there by 21,700 {+-} 700 beryllium-10 years and lasted 5900 years. Ages of a sequence of recessional moraines and striated bedrock surfaces show that the initial deglaciation was rapid and that the entire glacial system retreated 33 kilometers to the cirque basin by 12,100 {+-} 500 beryllium-10 years.

  4. Visual pathways and psychophysical channels in the primate

    PubMed Central

    Lee, Barry B

    2011-01-01

    The main cell systems of the retina that provide input to the striate cortex are now well described, although certain aspects of their anatomy and physiology remain contentious. Under simple stimulus conditions and in a threshold context psychophysical performance can often be assigned to one or other of these systems, and an identification of psychophysical channels with afferent pathways is justifiable. However, results from psychophysical studies using more complex stimulus conditions are more difficult to relate to ‘front end’ channels, and it is more difficult to separate the physiological contributions of afferent pathways from those of cortical mechanisms, in particular the separation of dorsal and ventral streams. PMID:20724364

  5. The length–tension curve in muscle depends on lattice spacing

    PubMed Central

    Williams, C. David; Salcedo, Mary K.; Irving, Thomas C.; Regnier, Michael; Daniel, Thomas L.

    2013-01-01

    Classic interpretations of the striated muscle length–tension curve focus on how force varies with overlap of thin (actin) and thick (myosin) filaments. New models of sarcomere geometry and experiments with skinned synchronous insect flight muscle suggest that changes in the radial distance between the actin and myosin filaments, the filament lattice spacing, are responsible for between 20% and 50% of the change in force seen between sarcomere lengths of 1.4 and 3.4 µm. Thus, lattice spacing is a significant force regulator, increasing the slope of muscle's force–length dependence. PMID:23843386

  6. Imaging of Retrochiasmal and Higher Cortical Visual Disorders.

    PubMed

    Tantiwongkosi, Bundhit; Salamon, Noriko

    2015-08-01

    Retrochiasmal visual pathways include optic tracts, lateral geniculate nuclei, optic radiations, and striate cortex (V1). Homonymous hemianopsia and field defect variants with relatively normal visual acuity suggest that the lesions involve retrochiasmal pathways. From V1, visual input is projected to higher visual association areas that are responsible for perception of objects, faces, colors, and orientation. Visual association areas are classified into ventral and dorsal pathways. Damage to the ventral stream results in visual object agnosia, prosopagnosia, and achromatopsia. Balint syndrome, visual inattention, and pure alexia are examples of dorsal stream disorders. Posterior cortical atrophy can involve ventral and dorsal streams, often preceding dementia. PMID:26208417

  7. Background issues for defensive interceptors

    SciTech Connect

    Canavan, G.H.

    1991-03-01

    Mean nuclear backgrounds are large, but are arguably amenable to frame-to-frame subtraction. Striated backgrounds on the sensors for defensive interceptors could, however, cause clutter leak-through, which could make detection and track difficult. Nominal motions and backgrounds give signal to clutter ratios too low to be useful. Clutter leakage due to line-of-sight drift can be reduced by stabilizing the line of sight around the background clutter itself. Current interceptors have detector arrays large enough for operation independent of nuclear backgrounds in their fields of view. 6 refs., 2 figs.

  8. Trichodorus elefjohnsoni n. sp. (Nemata: Trichodoridae) from Undisturbed Appalachian Forest

    PubMed Central

    Bernard, E. C.

    1992-01-01

    A new species of Trichodoridae, Trichodorus elefjohnsoni, is described from undisturbed regions of Great Smoky Mountains National Park, United States. It resembles T. orientalis De Waele &Hashim, 1984, T. persicus De Waele &Sturhan, 1987, and T. taylori De Waele, Mancini, Roca, ' Lamberti, 1982 in arrangement of ventromedian cervical papillae and posterior preanal supplements, but differs by combinations of the following characteristics: body length 516-731 μm; spicule length 33-50 μm, spicules densely striated, constricted medially; vaginal sclerotizations ovate; one pair of lateral body pores near vulva. PMID:19283205

  9. Skeletal muscle disorders associated with inflammatory bowel diseases: occurrence of myositis in a patient with ulcerative colitis and Hashimoto's thyroiditis--case report and review of the literature.

    PubMed

    Paoluzi, Omero Alessandro; Crispino, Pietro; Rivera, Margherita; Iacopini, Federico; Palladini, Dino; Consolazio, Adriana; Paoluzi, Paolo

    2006-07-01

    Ulcerative colitis (UC) and Crohn's disease are inflammatory bowel diseases often associated with extra-intestinal manifestations. Of these, neutrophilic dermatoses and arthropathies are the more frequently observed, while the occurrence of striated muscle disorders, namely, myositis, has been very rarely diagnosed in these kinds of patients. The coexistence of immuno-mediated diseases in patients with inflammatory bowel diseases and myositis suggests a common aetiopathogenetic mechanism underlying these conditions. The present report refers to a rare case of a 51-year-old female with UC and Hashimoto's thyroiditis who developed myositis. PMID:16205931

  10. Requirements for contractility in disordered cytoskeletal bundles

    NASA Astrophysics Data System (ADS)

    Lenz, Martin; Gardel, Margaret L.; Dinner, Aaron R.

    2012-03-01

    Actomyosin contractility is essential for biological force generation, and is well understood in highly organized structures such as striated muscle. Additionally, actomyosin bundles devoid of this organization are known to contract both in vivo and in vitro, which cannot be described by standard muscle models. To narrow down the search for possible contraction mechanisms in these systems, we investigate their microscopic symmetries. We show that contractile behavior requires non-identical motors that generate large-enough forces to probe the nonlinear elastic behavior of F-actin. This suggests a role for filament buckling in the contraction of these bundles, consistent with recent experimental results on reconstituted actomyosin bundles.