bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitation of heteroplasmy of mitochondrial trnaLeu(UUR) gene using PCR‐SSCP
Authors: Tanno Yoshinori , Yoneda Makoto , Tanaka Keiko , Tanaka Hajime , Yamazaki Motoyoshi , Nishiawa Masatoyo , Wakabayashi Koichi , Ohama Eisaku , Tsuji Shoji 
Published: January 2005

AbstractWe have devised a novel method for quantitative analysis of the MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes) tRNALeu(UUR) mutation of mitochondrial DNA using a PCR‐SSCP (polymerase chain reaction–single‐strand conformation polymorphism) method, and compared the results obtained using the PCR‐SSCP method with those obtained using other methods including Southern blotting, last one cycle hot PCR, and conventional PCR‐RFLP (restriction fragment length polymorphism). The standard curve obtained using the PCR‐SSCP method is linear, with a correlation coefficient of 0.999; it was determined that this method is more accurate than other methods for quantitative analysis. The PCR‐SSCP method does not require restriction digestions, thereby avoiding potential problems of partial digestions or heteroduplex formation during PCR. The method is quite simple and should have a broad range of application for quantitation of mutant mtDNAs in various mitochondrial encephalo‐myopathies. We applied the method for quantitation of mutant mitochondrial DNA carrying a single base substitution in the tRNALeu(UUR) gene in two autopsied cases of MELAS. In both cases, the mutant mtDNA is abundantly present (82–95%) with little variation among tissues. © 1995 John Wiley & Sons, Inc.
Extracellular space in the central nervous system of the leech, Mooreobdella fervida
Authors: Van Harreveld A. , Khattab F. I. , Steiner Jana 
Published: January 2005

AbstractThe ganglia and connectives of the ventral nerve cord of a leech (Mooreobdella fervida) were subjected to fixation by freeze substitution. This method is believed to preserve the water distribution in the tissue more faithfully than conventional fixation, but has the disadvantage that only the superficial 10 to 15 μU of these structures can be examined. Electron micrographs of this material showed the following differences from nervous tissue fixed by immersion in an osmium tetroxide solution. The lamellae of the packet glia cells were narrower and the extracellular spaces between them were wider than in conventionally fixed material. The cytoplasm of the lamellae was finely granular and lacked the vacuoles which characterize this tissue when fixed by immersion. In the neuropil the nervous elements tended to be separated by glial material which sometimes consisted of a single sheet, but often of several lamellae with rather more extracellular space than in conventionally fixed material. In the connectives thin axons were present in bundles containing little or no glia but surrounded by glial lamellae. The fibers had a rounded appearance and these axon fields showed an appreciable extracellular space. The large axons showed irregular but generally more rounded profiles than in conventionally fixed material. They were usually individually enveloped by glial lamellae with rather ample space between them. In the neuropil and the connective fixed by immersion in OsO4 solutions the extracellular space consisted of the narrow 100 to 150 Å spaces between the tissue elements typical for OsO4 fixed material.
Neurotrophic‐hormonal interaction in the regulation of taste buds in the rat's vallate papilla
Authors: Zalewski Andrew A. 
Published: January 2005

AbstractProlonged treatment of castrated‐male rats with testosterone causes the development of taste buds in abnormal locations in the vallate papilla (i.e., upper surface of the papilla). Since taste buds are morphologically dependent on a trophic factor delivered to them via intact gustatory nerves, investigations of the possible role of testosterone as a trophic agent were undertaken. The effects of testosterone propionate on taste buds were studied in normal male and female, castrated‐male, and male rats in which the taste buds were totally denervated. There was no apparent change in the number, distribution, or appearance of the taste buds normally found in the trench walls of testosterone treated normal or castrated rats. However, in the normal‐male and castrated‐male rats, 1–3 taste buds were found on the top surface of the papilla 6 weeks after treatment. No new buds were seen at 1 or 2 weeks, nor were any seen in hormonally treated females, or in control animals injected with sesame oil alone. Furthermore, testosterone did not maintain old or initiate new taste bud formation in the denervated papilla. Thus, testosterone in the form, doses, and times employed, could not subserve the trophic function of intact gustatory nerves. The results however indicate that new taste bud formation is the result of a nerve–hormone interaction, and not a change induced by castration and subsequent testosterone treatment. Further studies of the nerve–hormone interaction involved in taste bud formation seem indicated.
Divalent cations and electrical properties of cortical cells
Authors: Kelly J. S. , Krnjevic K. , Somjen G. 
Published: January 2005

Abstract1. Ca2+ and Mg2+ have been applied by microiontophoresis, mainly in doses of 20–200 nA, to cortical cells in cats under Dial.2. Both divalent cations had a similar action, causing a sharp but reversible fall in the electrical excitability of neurones.3. Ca2+ was slightly more potent than Mg2+; in small doses the two cations had an additive effect.4. The fall in neuronal excitability was not associated with definite changes in membrane potential or resistance.5. The amounts of Ca2+ and Mg2+ applied did not cause any obvious alteration in synaptic efficiency.6. The membrane properties of unresponsive cells (probably neuroglia) were not markedly altered by the divalent ions, except for an occasional increase in membrane resistance.
Neuromuscular transmission in cultures of adult human and rodent skeletal muscle after innervation in vitro by fetal rodent spinal cord
Authors: Crain Stanley M. , Alfei Laura , Peterson Edith R. 
Published: January 2005

AbstractElectrophysiologic analyses have been carried out on in vitro‐coupled explants of fetal rodent spinal cord and adult skeletal muscle of human as well as rodent origin. The studies demonstrate that characteristic neuromuscular transmission can develop and be maintained in these unusual tissue combinations during long‐term culture.After coupling periods of 2–7 weeks in vitro, selective stimulation of spinal cord evokes widespread coordinated contractions in the muscle tissue. Simultaneous microelectrode recordings of cord and muscle responses to local cord, or ventral root, stimuli show that muscle action potentials (and contractions) generally occur with latencies of several msec after onset of cord discharges. Similar temporal relations are often seen during spontaneous rhythmic discharges of the coupled cord and muscle tissues. Long series of repetitive discharges, at 2–5 sec intervals, may occur synchronously between these cord and muscle explants, in response to single cord (or dorsal‐root ganglion) stimuli, and they may also appear spontaneously.d‐Tubocurarine (1–10 μg/ml) selectively and reversibly blocks neuromuscular transmission in these cultures. Eserine accelerates recovery of normal function. Spontaneous repetitive fibrillations of many of the cultured muscle fibers are observed sporadically, and these contractions often continue unabated after block of neuromusclar transmission by d‐tubocurarine. Many of the fibers which show asynchronous fibrillations are probably not innervated (as in denervated muscle in situ). In some cases, however, extracellular as well as intracellular recordings indicate that similar fibrillations may also occur in fibers which are clearly innervated.Repetitive cord and muscle discharges are greatly augmented after introduction of strychnine. Complex rhythmic oscillatory (ca. 10/sec) afterdischarges generated in strychninized cord explants lead to similarly patterned muscle discharges (and contractions), which may also occur, at, times, in normal medium.
Isolation and characterization of membranes from rat cerebral cortex
Authors: McBride W. J. , Mahler H. R. , Moore W. J. , White F. P. 
Published: January 2005

AbstractThe subcellular fractionation of rat cerebral cortex has been extended to an examination of all fractions in the zones comprising synaptosomes (obtained from unlysed crude mitochondrial fractions [P2]) and synaptosomal membrances (from lysed P2), with emphasis on junctional complexes. The parameters investigated included: (a) ultrastructure, (b) marker enzymes, (c) analytical acrylamide‐gel electropherograms for insoluble proteins, (d) rate of incorporation of labeled 3H‐leucine into constituent proteins in slices, and (e) cytochemical localization of carbohydrate‐containing molecules. The results of these studies have provided the first stage for an analysis of the structure and dynamic chemistry of synaptic systems in the rat brain.
The cholinergic nature of the cercal nerve‐giant fiber synapse in the sixth abdominal ganglion of the American cockroach, Periplaneta americana (L.)
Authors: Shankland D. L. , Rose J. A. , Donniger C. 
Published: January 2005

AbstractThe effects of cholinergic drugs on transmission at the cercal nervegiant fiber synapse in the desheathed sixth abdominal ganglion of the American cockroach, Periplaneta americana (L.) were evaluated.When due consideration was given to slow diffusion rates of drugs into the ganglion, and to the enzymic hydrolysis of exogenously applied choline esters by endogenous cholinesterase, the synapse was found to respond in ways consistent with cholinergic transmission. Botulinus toxin, magnesium, and hemicholinium‐3, all working presynaptically blocked transmission. Atropine, D‐tubocurarine, and hexamethonium produced non‐depolarizing blockade at concentrations of 10−7 M or 10−6 M. Atropine and d‐tubocurarine also blocked the action of exogenously applied acetylcholine. Postsynaptic responses were obtained from acetylcholine (10−7 M), acetyl ß‐methyl choline (10−8 M), and nicotine (10−8 M).The results were discussed with respect to criteria which have been proposed for the indentification of transmitters. It was concluded that considering all of the information available on the cercal nerve‐giant fiber synapse, the transmitter is almost certainly Ach.
The relation of cerebral dominance and handedness to visual evoked potentials
Authors: Gott Peggy S. , Boyarsky Louis L. 
Published: January 2005

AbstractEvoked responses can be characterized with respect to latency and amplitude.The latency of the evoked response depends upon whether the person is right‐handed or left‐handed. In right‐handed subjects, the left (dominant) hemisphere has a longer latency than the right when used as a direct hemisphere. Similarly, when the so‐called dominant (right) hemisphere of left‐handed subjects is used as the direct hemisphere it shows a longer latency than when the non‐dominant hemisphere is used. This has been interpreted as an indication that a longer processing time is required in cortical or subcortical systems.Another asymmetry in response occurs with respect to amplitude. While right‐handed persons show no difference in the amplitude of the response between right (direct) and left (direct) hemispheres, this is not so for left‐handed individuals in whom the response of the right (so‐called dominant) hemisphere is larger when used as the direct hemisphere.The responses from left‐ and right‐handed people were compared to one another. The left (dominant) hemisphere of right‐handed persons has a longer latency than the left (non‐dominant) hemisphere of the left‐handed person. Similarly, the latency of the responses from the right (dominant) hemisphere of the left‐handed subjects is longer than that from the right (non‐dominant) hemisphere of right‐handed subjects.The amplitude of responses recorded from the right (dominant) hemisphere of left‐handed people appears to be larger in general than those from the right (non‐dominant) hemisphere of right‐handed people, but the data were not statistically significant.
Evoked potentials in the central auditory system of alert porpoises to their own and artificial sounds
Authors: Bullock Theodore H. , Ridgway Sam H. 
Published: January 2005

Abstract
A series of 8 experiments is reported in which arrays of 7 or more electrodes on an axis were implanted stereotaxically in Tursiops truncatus. From 1 to 3 of the electrodes were in or near the inferior colliculus or lateral lemniscus.
A total of 39 electrodes out of 130 proved to be responsive to suitable acoustic stimuli. Nine of these lay above the tentorium, 30 in the midbrain above the ventral tegmentum.
The typical midbrain evoked potential is specialized for ultrasonic, ultrabrief, fast rising, closely spaced sounds like the echolocating clicks. It has a short latency and the main deflection is less than 1 ms wide. No potential is evoked if the frequency is below 5 kHz or the rise time above 5 ms.
The typical midbrain evoked potential is specialized for ultrasonic, ultrabrief, fast rising, closely spaced sounds like the echolocating clicks. It has a short latency and the main deflection is less than 1 ms wide. No potential is evoked if the frequency is below 5 kHz or the rise time above 5 ms.
At several cerebral loci a different response was found: long latency, long duration, slowly recovering potentials evoked by frequencies below 5 kHz whether fast or slowly rising. The cerebral “whistle” sensitive loci are probably in the posterolateral temporal cortex.
A few loci at about the tentorial level, probably rostral and lateral to the inferior colliculus gave intermediate or mixed response with some features of each of the previous 2 types.
Implanted, cooperating porpoises were trained to give series of clicks of echolocating types. These evoked potentials like those to artificial tone bursts. Often the highest intensity voluntary clicks evoked quite modest potentials and a much weaker form of click gave maximal potentials. Important differences in click composition are inferred.
Artificial echoes show more rapid recovery following the porpoise's own click than following an artificial conditioning tone burst of equal evoking power.
It has proven practicable to place electrodes with reasonable accuracy, to combine computerized electrophysiological analysis with trained behavior and to maintain chronic implants for at least a month in porpoises. Opportunities for improvements in technique are emphasized.
Transport of radioactivity derived from labeled N‐acetylglucosamine in mammalian motor axons
Authors: Held Irene , Young I. James 
Published: January 2005

AbstractThe distribution of radioactivity in L7 ventral roots after microinjection of N‐acetyl‐3H‐glucosamine into the L7 segment of the feline neuraxis was examined under several conditions; i.e., the isotope was injected before and after ligation of the roots and various periods were allowed for uptake. The results indicated a transport of radiolabeled macromolecular material in both slow and fast components of axoplasmic flow.Further characterization of the nature of the transported, macromolecular material revealed that more than half of the radioactivity was non‐ultrafilterable even after pronase digestion, only 2% of this activity was incorporated into acidic glycosaminoglycans and the remaining activity was probably derived from glycoproteins.
Zonal centrifugation and flotation– fractionation of MSD mutant mouse brain
Authors: Day Eugene D. , Mickey Don D. , Rigsbee Lewis C. , Meier Hans 
Published: January 2005

AbstractZonal centrifuge and flotation–fractionation profile analysis of neonatal mouse brain homogenates in iso‐osmotic Ficoll–sucrose density–gradients demonstrates the presence of four light density fractions. In msd neurological mutant mice with a myelin‐synthesizing deficiency syndrome, the bands appear to be relatively normal until after the 10th day of postnatal brain development. With the onset of visible neurological symptoms after the 11th day, the four density bands begin to disappear from the zonal profiles and are all but absent at the time of death at about the 21st postnatal day. In normal littermates of the mutants, the bands persist with age and intensify. Although their identities remain unknown, the top three identify by their density with adult myelin and the fourth with the lighter of two adult synaptosome fractions. Mixtures of brain homogenates between mutant and normal littermates give rise to zonal and banding profiles intermediate between the separate profiles but somewhat less than their average in intensity.
Characterization of fast and slow transported proteins in dorsal root and sciatic nerve of cat
Authors: Sabri M. I. , Ochs S. 
Published: January 2005

AbstractLabeled components, carried by axoplasmic transport into the cat dorsal roots and sciatic nerves following injection of 3H‐leucine into the lumbar seventh (L7) dorsal root ganglia, were studied. The pattern of activity present in the subcellular fractions was similar for the two branches of the ganglion neurons entering the nerve and the dorsal root.Fractionation of the proteins present in the high speed supernatant fraction shows that slow transport carries a major proportion of high molecular weight soluble proteins. Further fractination of the soluble proteins with Sephadex G‐200 showed labeled activity present in three peaks: Ia, proteins of 480,000 M. W., lb, proteins of 60,000–120,000 M. W. containing colchicine binding (microtubular) protein, and peak II polypeptides, 5,000–10,000 M. W.Isoelectrofocusing of la proteins gave three peaks at pl 4.0, 4.05, and 4.15, and of lb proteins gave peaks at pl 4.0, 4.45, and 4.8 with several minor peaks also present. A gradual shift in pl values of the labeled proteins from acidic to neutral pH was seen from 3 hr to 7 days after the injections.A small amount of soluble proteins and some free leucine is carried down by fast transport, which is characterized by a high amount of activity in the particulate component. A comparison of the distribution of labeled incorporation in the crest and plateau region of fast transported materials showed a somewhat smaller percentage of activity in the small particulate fraction in the plateau, with more labeling of the soluble fraction and with no free leucine present.The results are in conformity with the concept of a compartmentalization of incorporated proteins in the cell body from which materials of somewhat different compositions later enter the axon for transport.
Neural mechanisms underlying behavior in the locust Schistocerca gregaria III. Topography of limb motorneurons in the metathoracic ganglion
Authors: Burrows Malcolm , Hoyle Graham 
Published: January 2005

AbstractSomata of 26 of the motorneurons situated on the right side of the metathoracis ganglion of the locust S. gregaria were identified by correlating their electrical activity with extracellularly or intracellularly recorded muscle potentials evoked either reflexly or by direct elctrical stimulation of the somata through the recording microelectrode. The neurons identified included most of those innervating the major leg muscles. Each neuron occupies a relatively fixed site on the ventral surface of the ganglion. The identified neurons were filled with procion yellow, the ganglia fixed and photographed as whole mounts, and then serially sectioned to determine the three dimensional topography of the major dendrites and the pathway of the axons through the neuropil. The topographical features of individual motorneurons were sufficiently characteristic to permit identification, Nevertheless, it was not found possible to classify the neurons on the basis of branching pattern. There is no relation between location in the ganglion and the muscle innervated, but locomotor motorneurons are clustered togethers in anterior, ventral, and lateral pockets.
The neuronal basis of behavior in Tritonia. I. Functional organization of the central nervous system
Authors: Willows A. O. D. , Dorsett D. A. , Hoyle G. 
Published: January 2005

AbstractAn account is presented of the brain (paired cerebral, pleural, and pedal ganglia) of the nudibranch mollusc Tritonia diomedia. The major efferent nerve fibers are related to their nerve cell bodies and their functional roles identified as far as possible. The channels of sesory input relating to some of these neurons are given so as to provide an overall view of the organization of the brain.A standardized system of abbreviation and notation for the central ganglia, nerve trunks, and gaint somata is proposed. The system of references is intended to provide a guide to the location in the ganglia of many of the smaller neurons of which the functional attributes are known, but which cannot be consistently recognized on visual criteria alone. A system of rectangular coordinates is proposed which is applied to the natural outline of the ganglia. In addition, a system of cell notation is described which is independent of the co‐ordinates used to define the position of the cell on the grid. Cell which by reason of their size, pigmentation, characteristic location and physiological attributes are consistently recognizable from animal to animal are numbered. Two principles were followed in numbering cells; (i) the series begins at unity in each ganglion; (ii) cell homologues in opposite ganglia are given the same number, but distinguished by prefixing the abbreviation for the ganglion in which they occur. It is considered that the system will facilitate the exchange of information between workers on the same species, and also benefit the comparison of neural organization of behavior in closely related forms.The brain is organized in an almost exactly bilaterally symmetrical manner. There are a few bilateral neural pathways, but the major functional routes are ipsilateral. A few motorneurons, which are uniquely identifiable anatomically, cause unique, discrete movements. Others are in small groups sharing overlapping or similar functions.
Transport of sulfate in the rabbit's brain
Authors: Hollingsworth Jillian G. , Davson H. 
Published: January 2005

AbstractThe possibility that, in the rabbit, sulfate is actively transported across the choroid plexuses was investigated by ventriculo‐cisternal perfusion in the absence and presence of carrier. No evidence for this could be found.Penetration of sulfate from blood to brain and CSF was measured in the intact animal equilibration was very slow, indicating the presence of high barriers for this solute, but the low steady‐state level in the brain, approached in these experiments, was quite consistent with slow passive permeability aacross the barriers, with free exchange between extracellular fluid and CSF. The clearance of another slowly penetrating solute, creatinine, from the perfusion fluid during ventriculo‐cisternal perfusion was comparabl with that of sulfate.
Neurite development in vitro: II. The role of microfilaments and microtubules in dibutyryl adenosine 3′,5′‐cyclic monophosphate and nerve growth factor stimulated maturation
Authors: Roisen Fred J. , Murphy Richard A. 
Published: January 2005

AbstractDibutyryl cyclic AMP (DBC) and Nerve Growth Factor (NGF) have both been shown to enhance in vitro neuronal maturation in embryonic sensory ganglia. Since microfilaments and microtubules are known to be involved in neurite elongation, embryonic chick dorsal root ganglia have been treated with cytochalasin B and colcemid in the presence of these growth promoters (DBC or NGF). Established 48‐hr cultures show drastic neurite retraction when treated with either inhibitor. The treatment of cultures with DBC or NGF in the presence of colcemid reverses the inhibitive effects and normal elongation occurs. The growth stimulators, however, are unable to effectively reverse the action of cytochalasin B. These data suggest that increased microtubule assembly is involved in DBC and NGF stimulation of neurite elongation, and hence provide further support for the suggestion that cyclic AMP mediates some of the actions of NGF.