bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lysosomal enzyme activities in skeletal muscle of patients with neuromuscular diseases
Authors: Kawai Hisaomi , Yoneda Kenji , Naruo Takako , Nishida Yoshihiko , Kashiwagi Setsuko , Kunishige Makoto , Saito Shiro 
Published: January 2005

AbstractActivities of nine lysosomal enzymes and pH‐dependent isozyme patterns of α‐mannosidase were examined in the skeletal muscle of patients with neuromuscular diseases, and the ratios of these enzyme activities in leukocytes to those in myocytes (L/M ratio) were determined. The activities of enzymes with a high L/M ratio were markedly increased in the muscles of patients with Duchenne muscular dystrophy (DMD), myotonic dystrophy (MyD), or polymyositis (PM). In contrast, those which showed a low L/M ratio were increased in the muscles of amyotrophic lateral sclerosis (ALS) and disuse muscle atrophy (DUA). The isozyme pattern of α‐mannosidase in DMD muscle resembled that in leukocytes, while those in ALS and DUA muscle resembled that in normal muscle. These results may suggest that the increased activity of lysosomal enzymes in the muscles of patients with DMD, MyD, or PM is due primarily to infiltrating leukocytes, while that in patients with ALS or DUA is due to intramyofiber lysosomes. © 1995 John Wiley & Sons, Inc.
An electrophysiological investigation of deglutition in man
Authors: Ertekin Cumhur , Pehlivan Murat , Aydoǧdu Ibrahim , Ertaşl Mustafa , Uludaǧ Burhanettin , Çlelebi Gürbüz , Çlolakoǧlu Zafer , Saǧduyu Ayşle , Yüceyar Nur 
Published: January 2005

AbstractThis article describes a combined electrophysiological and mechanical method used to measure laryngeal movements and related submental EMG activity during swallowing. The mechanical upward and downward movements of the larynx were detected using a piezoelectric sensor while the submental integrated EMG (SM‐EMG) was recorded. Measurements were performed in 29 human subjects. The interval between the onsets of the two sensor signal deflections was used as a measure of the time the larynx remained in its superior position during swallowing. In 10 subjects, the cricopharyngeus muscle (CP) of the upper esophageal spinchter showed a continuous tonic EMG activity except during swallowing. All the parameters measured were influenced by the type and volume of the bolus material. The method presented in this study proved its usefulness in the study of the physiology of deglutition as well as in its objective clinical evaluation in patients with dysphagia.© 1995 John Wiley & Sons, Inc.
Three‐dimensional structure of cat tibialis anterior motor units
Authors: Roy Roland R. , Garfinkel Alan , Ounjian Melinda , Payne Jeremy , Hirahara Alan , Hsu Emmie , Edgerton V. Reggie 
Published: January 2005

AbstractThe motor unit is the basic unit for force production in a muscle. However, the position and shape of the territory of a motor unit within the muscle have not been defined precisely. The territories of five motor units in the cat tibialis anterior muscle were reconstructed three‐dimensionally (3‐D) from tracings of the glycogen‐depleted fibers belonging to each unit. The motor unit territories did not span the entire length of the muscle and their cross‐sectional areas tapered along the proximodistal axis producing a conical shape. In addition, the position of the territory of each unit shifted in an anterior–posterior plane along the longitudinal axis of the muscle, presumably as a consequence of the pinnation of the fibers. The area of the motor unit territory at any given level along the proximodistal axis was highly correlated with the number of fibers within the territory at that level. Connective tissue boundaries (outlining fascicles) appeared to have a strong influence on the shape of the territory, territories showed abrupt changes at connective tissue boundaries as groups of motor unit fibers within a fascicle often terminated together while motor unit fibers in neighboring fascicles did not terminate. It is likely that the mechanical impact of the recruitment of a motor unit is affected by the location and shape of motor units within the same muscle area. Since there is a close relationship between the area of the territory of a motor unit and the number of fibers in the motor unit, while the density of unit fibers remains the same, then the same factor(s) which regulate the number of fibers innervated by a motoneuron may also determine the territory area.© 1995 John Wiley & Sons, Inc.
Thenar motor unit number estimates using the multiple point stimulation technique: Reproducibility studies in als patients and normal subjects
Authors: Felice Kevin J. 
Published: January 2005

AbstractThenar motor unit number estimate (MUNE) reproducibility was assessed in 20 patients with amyotrophic lateral sclerosis (ALS) and 16 normal subjects using the multiple point stimulation (MPS) technique. The MUNE was calculated by dividing the thenar compound muscle action potential negative‐peak (n‐p) area by the mean n‐p area of 10 lowest threshold, all‐or‐nothing, surface‐recorded motor unit action potentials. Two trials (test–retest) were performed by the same examiner either on separate days or on the same day with new electrode placements. The mean test MUNE was 43.4 (SD: 35.9, range: 6–145) for ALS patients and 219.4 (SD: 80.8, range: 122–368) for normal subjects. Test–retest MUNE differences were not significant for ALS patients or normal subjects. The test–retest correlation coefficient (r) was 0.99 for ALS patients and 0.85 for normal subjects. The mean difference between test–retest values was 10% for ALS patients and 17% for normal subjects. Test–retest reproducibility of the thenar MUNE using the MPS technique is high in both ALS patients and normal subjects. The reliability of the MPS technique in estimating motor unit numbers may make it a useful outcome measure in following the course of patients with progressive lower motor neuron disease, especially those enrolled in experimental drug trials.© 1995 John Wiley &Sons, Inc.
Manganese‐enhanced magnetic resonance imaging (MEMRI) of mouse brain development
Authors: Wadghiri Youssef Zaim , Blind Jeffrey A. , Duan Xiaohong , Moreno Clement , Yu Xin , Joyner Alexandra L. , Turnbull Daniel H. 
Published: January 2005

AbstractGiven the importance of genetically modified mice in studies of mammalian brain development and human congenital brain diseases, MRI has the potential to provide an efficient in vivo approach for analyzing mutant phenotypes in the early postnatal mouse brain. The combination of reduced tissue contrast at the high magnetic fields required for mice, and the changing cellular composition of the developing mouse brain make it difficult to optimize MRI contrast in neonatal mouse imaging. We have explored an easily implemented approach for contrast‐enhanced imaging, using systemically administered manganese (Mn) to reveal fine anatomical detail in T1‐weighted MR images of neonatal mouse brains. In particular, we demonstrate the utility of this Mn‐enhanced MRI (MEMRI) method for analyzing early postnatal patterning of the mouse cerebellum. Through comparisons with matched histological sections, we further show that MEMRI enhancement correlates qualitatively with granule cell density in the developing cerebellum, suggesting that the cerebellar enhancement is due to uptake of Mn in the granule neurons. Finally, variable cerebellar defects in mice with a conditional mutation in the Gbx2 gene were analyzed with MEMRI to demonstrate the utility of this method for mutant mouse phenotyping. Taken together, our results indicate that MEMRI provides an efficient and powerful in vivo method for analyzing neonatal brain development in normal and genetically engineered mice. Copyright © 2004 John Wiley & Sons, Ltd.
Amino acid production and translocation in incubated and superfused tissues from the brain
Authors: Jones D. A. , Mc Ilwain H. 
Published: January 2005

AbstractThe content of 12 amino acids in guinea pig cerebral cortical tissues was measured before and after incubation in glucose salines. The incubation caused reltively little change in tissue content, but induced a considerable production and accumulation of amino acids in the incubation medium. The dietarily essential amino acids, found in uncombined form, increased 3 to 6 fold. Glycine and alanine also increased; little change occurred in the quantity of free aspartic and glutamic acids. Amino acids were retained in the tissue in vitro against concentration gradients considerably higher than those estimated to obtain in vivo; by superfusing the tissue, the ratios were further increased. Electrical stimulation of the isolated tissues increased the amino acid accumulating in the medium during incubation, and increased the efflux of radioactive leucine during superfusion. Cycloheximide also increased the efflux of radioactive leucine during superfusion, while colchicine was found to decrease the proportion of total amino acid appearing in superfusates. Reasons are given for considering incubation fluids as artificial extensions of the interstitial fluid of the brain, and for regarding amino acid output from the tissue as a process counterbalancing axoplasmic flow.
Patterns of spontaneous bioelectric activity during maturation in culture of fetal rodent medulla and spinal cord tissues
Authors: Corner Michael A. , Crain Stanley M. 
Published: January 2005

AbstractMicroelectrode recordings in explants of fetal rodent medulla and spinal cord demonstrate that a variety of organotypic temporal patterns of spontaneous bioelectric discharges occur during maturation of these CNS tissues in culture. The spontaneous activities include repetitive barrages of spike potentials, as well as stereotyped slow‐waves. These discharges last up to several sec, and they may occur at regular intervals of the order of 1–10 sec, although activity patterns are often much more irregular. Some explants also show clear periodicity in the recurrence of phases of relative activity and inactivity, with cycle times ranging up to about 10 min. Correlations between the network excitability properties of the CNS tissues and their patterned spontaneous discharges were obtained by electrophysiologic analyses of responses to microelectrode stimulation.These complex, yet stereotyped, spontaneous bioelectric discharge patterns in cultures of organized CNS tissues show remarkable mimicry of rhythmic activities which occur in the embryonic CNS in situ, as determined by electrophysiologic and behavioral motility studies in the intact animal. Organotypic CNS explants provide, therefore, a valuable model system for further analyses of the cellular and molecular mechanisms underlying early development of behavior.
Glutamate uptake by brain slices and its relation to the depolarization of neurones by acidic amino acids
Authors: Balcar V. J. , Johnston G. A. R. 
Published: January 2005

AbstractUptake of L‐glutamate into rat brain slices from media containing either 10−3 or 10−8 M labelled L‐glutamate is not inhibited by (a) excitant amino acids which have an appreciably greater depolarizing action on central neurones than that of L‐glutamate, (b) antagonists of L‐glutamate induced excitation of central neurones, or (c) tetrodotoxin in concentrations which inhibit the sodium ion influx into brain slices produced by L‐glutamate and other excitant amino acids.It is concluded that uptake of L‐glutamate is independent of both the tetrodotoxin‐insensitive depolarization and the tetrodotoxin‐sensitive sodium ion influx induced by L‐glutamate.
The visually evoked defense reflex of the crayfish: Habituation, facilitation, and the influence of picrotoxin
Authors: Glantz Raymon M. 
Published: January 2005

AbstractWhen stimulated with rapidly approaching targets, the crayfish defense reflex exhibited habituation, spontaneous recovery, dishabituation, and stimulus generalization. The rate of habituation increased with stimulus repetition rate over a narrow range of stimulus rates. At the highest repetition rate examined, 20 min, the rate of habituation diminished. After 150 trials at 20 min, responsiveness to subsequent stimuli at lower repetition rates was enhanced. Dishabituation was elicited with mechanical prods to the dorsal thoracic carapace or a 1‐min session of 20\min stimulation. After completion of habituation a 5° shift in the axis of a 10° target resulted in substantial response recovery. Evidence for weak interocular generalization of habituation was also obtained. These results suggest both retinal‐dependent and retinal‐independent sites of habituation. Picrotoxin (2.4 mg\kg body weight) reversed a previously established response habituation and delayed the onset of rehabituation to repetitive stimuli. The effects of picrotoxin suggest the participation an inhibitory mechanism in defense reflex habituation.
Dorsal root recording relevant for mating reflexes in female rats: Identification of receptive fields and effects of peripheral denervation
Authors: Kow Lee‐Ming , Pfaff Donald W. 
Published: January 2005

AbstractCutaneous receptive fields of dorsal roots T11 through S3 in rats were mapped by recording dorsal root multiple unit activity. The receptive fields, having the shape of transverse bands on the skin, are arranged in order according to their dorsal roots, and there are extensive overlaps between adjacent fields. Routes followed by peripheral sensory innervation of skin were also studied by observing effects of various methods of skin denervation on dorsal root responses to cutaneous stimulation. The results are discussed with respect to the somatosensory control of female rat mating reflexes.
The site of anoxic block in the spinal monosynaptic pathway
Authors: Carregal Enrique J. A. 
Published: January 2005

AbstractAsphyxiation of the spinal cord for periods of 2–4 min leads to block of the monosynaptic pathway. At about the same time this blockage takes place, the afferent action potentials fail to invade the presynaptic terminals. Asphyxiation also interferes with the antidromic invasion of motoneurons, and the failure of the antidromic action potentials to invade the motoneuron dendrites coincides with the time of the disappearance of the orthodromic monosynaptic responses. During reoxygenation, both the presynaptic terminals and the dendrites recover their function, or rather their polarization, in a few seconds and yet synaptic transmission reappears only after several minutes. It is postulated that failure of synaptic transmission during asphyxia is due to depolarization of both the presynaptic terminals and the dendrites of the postsynaptic elements. However, repolarization of these elements during reoxygenation, is not sufficient to reestablish synaptic transmission, but recovery of some unidentified biochemical process is apparently necessary.
Dissociation of field potential from neuronal activity in the isolated retina: Failure of the b‐wave with normal ganglion cell response
Authors: Masland Richard H. , Ames Adelbert 
Published: January 2005

AbstractThe b‐wave of the isolated rabbit retina was compared with the ganglion cell response to light before and after modification of the retina's incubating medium. Marked diminution of the b‐wave, with no reduction in ganglion cell response, was observed under three experimental conditions: (1) following a short period of anoxia; (2) following a short period in 0.2 mM Ca++; (3) in a small percentage of preparations, simply as a result of prolonged incubation in control medium. In contrast, a short period in 50 mM K+ led to a parallel fall and parallel recovery of both responses. It is apparent that under selected conditions the field potentials which constitute the b‐wave are poorly correlated with the retina's neural activity.
Integration in the crayfish antennal neuropile: Topographic representation and multiple‐channel coding of mechanoreceptive submodalities
Authors: Taylor Robert C. 
Published: January 2005

Abstract
Response patterns of interneuron populations in the antennal neuropile of the crayfish have been investigated by extracellular recordings made with a single electrode. Mechanical stimuli of the antennae are divided into submodalities and topographically represented. The submodalities include large movements of the entire antenna, directional aspects of movements and vibrations, and vibratory stimulation up to click repetition rates of 100.
Interneuron output is always patterned, ranging from simple bimodal types to complex multimodal patterns that extend over 40 msec. The interneuron output is “noisy” due to short‐ and long‐term fluctuations in sensitivity producing temporal fluctuations in both output probability and output patterns. The response latencies both within and between populations cluster around several fixed latencies.
The axons of a group of neurons, sensitive to the same submodality, are located together and consequently can be recorded with a single electrode. Responses from the interneurons composing a population are similar in response to nonoptimal stimulation, but are synchronized and of high probability to optimal stimulation.
Temperature‐dependence of rapid axonal transport in sympathetic nerves of the rabbit
Authors: Cosens Barry , Thacker David , Brimijoin Stephen 
Published: January 2005

AbstractStop‐flow techniques were used to determine how temperature affected the axonal transport of dopamine‐β‐hydroxylase (DBH) activity in rabbit sciatic nerves in vitro. These nerves were cooled locally to 2°C for 1.5 hr, which caused a sharp peak of DBH activity to accumulate above the cooled region. Accumulated DBH was then allowed to resume migration at various temperatures. From direct measurements of the rate of migration, we found that the axonal transport velocity of DBH was a simple exponential function of temperature between 13°C and 42°C. Over this range of temperatures, the results were well described by the equation: V = 0.546(1.09)T, where V is velocity in mm/hr, and T is temperature in degrees centigrade. The Q10 between 13°C and 42°C was 2.33, and an Arrhenius plot of the natural logarithm of velocity versus the reciprocal of absolute temperature yielded an apparent activation energy of 14.8 kcal. Transport virtually halted when temperature was raised to 47°C, although only about half of the DBH activity disappeared during incubation at this temperature. Another transition occurred at 13°C; below this temperature, velocity fell precipitously. This was not an artifact peculiar to the stop‐flow system since the rate of accumulation of DBH activity proximal to a cold‐block also decreased abruptly when the temperature above the block was reduced below 13°C.
Electrophysiological studies of fetal mouse olfactory bulb explants during development of synaptic functions in culture
Authors: Corrigall William A. , Crain Stanley M. , Bornstein Murray B. 
Published: January 2005

AbstractExplants of 18‐ or 19‐day fetal mouse olfactory bulb have been maintained in culture for periods up to 5 weeks. Compound action potentials can be evoked in the bulb explants by 1 day in vitro, and by 3–4 days, synaptically mediated slow wave discharges can be demonstrated in bicuculline (10−5 M). The capability of the bulb explants to generate these slow‐wave discharges has also been revealed by the introduction of picrotoxin (10−5 M), d‐tubocurarine (10−4 M) and chloride‐free medium, but not of strychnine (up to 3 × 10−5 M). The data indicate early functional development of inhibitory, as well as excitatory, synaptic systems. In addition, the selective and reversible depression of these slow wave potentials by GABA (1–5 × 10−4 M), but not by glycine (up to 3 × 10−3 M), indicates a GABA‐ergic component in the inhibitory network. Single unit extracellular recordings have been obtained from the presumptive mitral cells which, in culture, are spontaneously active even as early as 1–2 days after explantation. Correlative Bodian silver‐impregnations demonstrate the presence of neurons in these explants which resemble typical mitral cells. Studies of mitral cells using paired stimuli suggest the development in vitro of an inhibitory system analogous to that known to suppress the excitability of their in situ counterparts following orthodromic or antidromic activation. These data, as well as the pharmacological sensitivities of the mitral cells in culture to GABA (5 × 10−4 M) and bicuculline (10−5 M), indicate that granule‐to‐mitral synapses may develop characteristic functions in olfactory bulb explants.
Effects of imprinting on lysine uptake and incorporation into protein in chick brain
Authors: Hambley J. W. , Haywood J. , Rose S. P. R. , Bateson P. P. G. 
Published: January 2005

AbstractOne‐day old chicks were exposed for either 30, 60, or 120 min to an imprinting stimulus or kept in darkness in similar conditions. At the end of this time they were injected peripherally with 14C‐lysine and killed 20 min later. The radioactivity of free lysine and that incorporated into protein was measured; incorporation was found to differ between exposed and dark birds only in the anterior part of the forebrain roof after 60‐min treatment (E/D = 1.25). However, more free radioactive lysine was found in all brain regions of exposed birds at this time. When the specific radioactivity of the free lysine (dpm/nmol lysine) was measured there were no differences between the two types of birds, indicating that the incorporation difference was not due to a change in precursor radioactivity. The use of 14C‐2‐aminoisobutyrate confirmed that even with a nonincorporated amino acid pool size changes still occurred. The greater lysine incorporation in anterior forebrain roof was largely restricted to the cytoplasmic soluble fraction.
Functional development in the mauthner cell system of embryos and larvae of the zebra fish
Authors: Eaton Robert C. , Farley R. D. , Kimmel C. B. , Schabtach E. 
Published: January 2005

AbstractIn the embryonic zebra fish as early as 40 hr after fertilization, the Mauthner cells (M‐cells) initiate an escape response, elicited by tactile‐vibrational stimulation. The initial part of this behavior is similar to the acoustic startle reflex seen during the larval stage which begins at 96 hr. The embryonic response is directional and is followed by a series of strong tail flexures which are more pronounced than those during swimming. In the embryo the M‐cell fired at the beginning of the response and rarely fired again during subsequent contractions; in our experiments the M‐cell did not mediate iterative movements of the tail. The M‐cell system is probably involved in evoked hatching behavior, as the tactile response is sufficient to rupture the egg membrane and allow the animal to escape. The M‐cell sometimes fired spontaneously, which suggests that it might function also in spontaneous hatching behavior which occurs in the absence of phasic stimulation. At 48 hr the M‐cell has morphologically mature synapses on its soma and dendrites, but its cytoplasm is relatively undifferentiated; it has few oriented neurofilaments and no distinct axon hillock. During these stages the extracellular M‐spike is longer in duration and smaller in amplitude than at later times when the cell is more mature morphologically. Our data suggest that long‐term inhibitory control of the M‐cell system begins to function at about the time of hatching. At this time the cell is morphologically mature and is richly supplied with synaptic endings over its soma and dendrites.