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Sample records for channels control cerebellar

  1. Lack of Kinase Regulation of Canonical Transient Receptor Potential 3 (TRPC3) Channel-dependent Currents in Cerebellar Purkinje Cells

    OpenAIRE

    Nelson, Charmaine; Glitsch, Maike D.

    2011-01-01

    Background: TRPC3 channels are inhibited by PKC and PKG, which also induce cerebellar LTD. We investigate if PKC- and PKG-mediated modulation of cerebellar TRPC3 channels contributes to cerebellar LTD.

  2. Sensory mechanisms of balance control in cerebellar disease

    OpenAIRE

    Bunn, L. M.

    2011-01-01

    A wealth of evidence exists to suggest that the cerebellum has an important role in the integration of vestibular, proprioceptive and visual sensory signals. Human bipedal balance depends on sensory integration and balance impairment is a common feature of cerebellar disease. I test the hypothesis that disrupted sensori-motor processing is responsible for balance impairment in cerebellar disease. Balance control in subjects with pure cerebellar disease (SCA6) was compared with matched healthy...

  3. An increased expression of Ca(2+) channel alpha(1A) subunit immunoreactivity in deep cerebellar neurons of rolling mouse Nagoya.

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    Sawada, K; Sakata-Haga, H; Ando, M; Takeda, N; Fukui, Y

    2001-12-01

    Rolling mouse Nagoya (RMN) is an ataxic mutant and carries a mutation in the gene coding for the alpha(1A) subunit of the P/Q-type Ca(2+) channel. We examined the immunohistochemical expression of the alpha(1A) subunit in deep cerebellar nuclei of RMN. The antibody used recognized residues 865-883 of the mouse alpha(1A) subunit not overlapping the altered sequences in RMN. In RMN, many neurons exhibited definite alpha(1A) subunit-staining in the medial nucleus, interposed nucleus, and lateral nucleus of deep cerebellar nuclei. The number of positive neurons in these nuclei was significantly higher in RMN than in controls. Increased expression of the alpha(1A) subunit in deep cerebellar neurons might compensate for the altered function of the P/Q-type Ca(2+) channel of RMN.

  4. Encephalitis due to antibodies to voltage gated potassium channel (VGKC with cerebellar involvement in a teenager

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    Megan M Langille

    2015-01-01

    Full Text Available Encephalitis due to antibodies to voltage gated potassium channel (VGKC typically presents with limbic encephalitis and medial temporal lobe involvement on neuroimaging. We describe a case of 13 year girl female with encephalitis due to antibodies to VGKC with signal changes in the cerebellar dentate nuclei bilaterally and clinical features that suggested predominant cerebellar involvement. These have never been reported previously in the literature. Our case expands the phenotypic spectrum of this rare condition.

  5. Encephalitis due to antibodies to voltage gated potassium channel (VGKC) with cerebellar involvement in a teenager.

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    Langille, Megan M; Desai, Jay

    2015-01-01

    Encephalitis due to antibodies to voltage gated potassium channel (VGKC) typically presents with limbic encephalitis and medial temporal lobe involvement on neuroimaging. We describe a case of 13 year girl female with encephalitis due to antibodies to VGKC with signal changes in the cerebellar dentate nuclei bilaterally and clinical features that suggested predominant cerebellar involvement. These have never been reported previously in the literature. Our case expands the phenotypic spectrum of this rare condition.

  6. [Cerebellar Control of Ocular Movements: Application to the Topographical Diagnosis of Cerebellar Lesions].

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    Hirose, Genjiro

    2016-03-01

    Over the last decade, substantial information on cerebellar oculomotor control has been provided by the use of sophisticated neuroanatomical, neurophysiological, and imaging techniques. We now know that an intact cerebellum is a prerequisite for normal oculomotor performance. This review clarifies the current knowledge on structure-function correlations of the cerebellum in relation to ocular movements and allows them to be applied to topographical diagnosis of cerebellar lesions. The cerebellar regions most closely related to oculomotor function are: (1) the flocculus/paraflocculus for VOR suppression, cancellation, smooth pursuit eye movement and gaze-holding, (2) the nodulus/ventral uvula for velocity storage and low frequency prolonged vestibular response, and (3) the dorsal oculomotor vermis (declive VI, folium VII) and the posterior portion of the fastigial nucleus (fastigial oculomotor region) for saccades and smooth pursuit initiation. Symptomatically, defects in the flocculus/parflocculus cause saccadic pursuit, downbeat nystagmus, and impairments to visual suppression of the VOR. Lesions of the nodulus/uvula reveal as periodic alternating nystagmus. Lesions of the oculomotor vermis and the fastigial nucleus can induce saccadic dysmetria, while fastigial nucleus lesions may also cause ocular flutter/opsoclonus. A detailed knowledge of cerebellar anatomy and the physiology of eye movements enables localization of lesions to specific areas of the cerebellum. PMID:27001776

  7. Emotions and their cognitive control in children with cerebellar tumors.

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    Hopyan, Talar; Laughlin, Suzanne; Dennis, Maureen

    2010-11-01

    A constellation of deficits, termed the cerebellar cognitive affective syndrome (CCAS), has been reported following acquired cerebellar lesions. We studied emotion identification and the cognitive control of emotion in children treated for acquired tumors of the cerebellum. Participants were 37 children (7-16 years) treated for cerebellar tumors (19 benign astrocytomas (AST), 18 malignant medulloblastomas (MB), and 37 matched controls (CON). The Emotion Identification Task investigated recognition of happy and sad emotions in music. In two cognitive control tasks, we investigated whether children could identify emotion in situations in which the emotion in the music and the emotion in the lyrics was either congruent or incongruent. Children with cerebellar tumors identified emotion as accurately and quickly as controls (p > .05), although there was a significant interaction of emotions and group (p sad emotions, and both cerebellar tumor groups were impaired in the cognitive control of emotions (p emotion rather than emotion identification provides some support for a model of the CCAS as a disorder, not so much of emotion as of the regulation of emotion by cognition. PMID:20887648

  8. Cerebellar damage impairs executive control and monitoring of movement generation.

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    Emiliano Brunamonti

    Full Text Available Executive control of motor responses is a psychological construct of the executive system. Several studies have demonstrated the involvement of the cerebral cortex, basal ganglia, and thalamus in the inhibition of actions and monitoring of performance. The involvement of the cerebellum in cognitive function and its functional interaction with basal ganglia have recently been reported. Based on these findings, we examined the hypothesis of cerebellar involvement in executive control by administering a countermanding task in patients with focal cerebellar damage. The countermanding task requires one to make a movement in response to a 'go' signal and to halt it when a 'stop' signal is presented. The duration of the go process (reaction time; RT, the duration of the stop process (stop signal reaction time; SSRT, and their relationship, expressed by a psychometric function, are recorded as measures of executive control. All patients had longer go process duration in general and in particular, as a proactive control, as demonstrated by the increase in RT after erroneously performed stop trials. Further, they were defective in the slope of the psychometric function indicating a difficulty on triggering the stop process, although the SSRT did not differ from controls. Notably, their performance was worse when lesions affected deep cerebellar nuclei. Our results support the hypothesis that the cerebellum regulates the executive control of voluntary actions. We speculate that its activity is attributed to specific cerebellar influence over the cortico-striatal loop.

  9. Cerebellar Control of Locomotion in Health and Disease

    NARCIS (Netherlands)

    M.F. Vinueza Veloz (Maria)

    2015-01-01

    markdownabstract__Abstract__ Modern neuroscience is paving the way for new insight into cerebellar functions including the control of cognitive, autonomic and emotional processes. Yet, how the cerebellum contributes to complex motor behaviors, such as locomotion, is still only partially understood.

  10. Adaptive robotic control driven by a versatile spiking cerebellar network.

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    Casellato, Claudia; Antonietti, Alberto; Garrido, Jesus A; Carrillo, Richard R; Luque, Niceto R; Ros, Eduardo; Pedrocchi, Alessandra; D'Angelo, Egidio

    2014-01-01

    The cerebellum is involved in a large number of different neural processes, especially in associative learning and in fine motor control. To develop a comprehensive theory of sensorimotor learning and control, it is crucial to determine the neural basis of coding and plasticity embedded into the cerebellar neural circuit and how they are translated into behavioral outcomes in learning paradigms. Learning has to be inferred from the interaction of an embodied system with its real environment, and the same cerebellar principles derived from cell physiology have to be able to drive a variety of tasks of different nature, calling for complex timing and movement patterns. We have coupled a realistic cerebellar spiking neural network (SNN) with a real robot and challenged it in multiple diverse sensorimotor tasks. Encoding and decoding strategies based on neuronal firing rates were applied. Adaptive motor control protocols with acquisition and extinction phases have been designed and tested, including an associative Pavlovian task (Eye blinking classical conditioning), a vestibulo-ocular task and a perturbed arm reaching task operating in closed-loop. The SNN processed in real-time mossy fiber inputs as arbitrary contextual signals, irrespective of whether they conveyed a tone, a vestibular stimulus or the position of a limb. A bidirectional long-term plasticity rule implemented at parallel fibers-Purkinje cell synapses modulated the output activity in the deep cerebellar nuclei. In all tasks, the neurorobot learned to adjust timing and gain of the motor responses by tuning its output discharge. It succeeded in reproducing how human biological systems acquire, extinguish and express knowledge of a noisy and changing world. By varying stimuli and perturbations patterns, real-time control robustness and generalizability were validated. The implicit spiking dynamics of the cerebellar model fulfill timing, prediction and learning functions. PMID:25390365

  11. Specific T-type calcium channel isoforms are associated with distinct burst phenotypes in deep cerebellar nuclear neurons

    OpenAIRE

    Molineux, Michael L.; McRory, John E.; McKay, Bruce E.; Hamid, Jawed; Mehaffey, W. Hamish; Rehak, Renata; Snutch, Terrance P; Gerald W Zamponi; Turner, Ray W

    2006-01-01

    T-type calcium channels are thought to transform neuronal output to a burst mode by generating low voltage-activated (LVA) calcium currents and rebound burst discharge. In this study we assess the expression pattern of the three different T-type channel isoforms (Cav3.1, Cav3.2, and Cav3.3) in cerebellar neurons and focus on their potential role in generating LVA spikes and rebound discharge in deep cerebellar nuclear (DCN) neurons. We detected expression of one or more Cav3 channel isoforms ...

  12. Purkinje cell-specific ablation of Cav2.1 channels is sufficient to cause cerebellar ataxia in mice.

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    Todorov, Boyan; Kros, Lieke; Shyti, Reinald; Plak, Petra; Haasdijk, Elize D; Raike, Robert S; Frants, Rune R; Hess, Ellen J; Hoebeek, Freek E; De Zeeuw, Chris I; van den Maagdenberg, Arn M J M

    2012-03-01

    The Cacna1a gene encodes the α(1A) subunit of voltage-gated Ca(V)2.1 Ca(2+) channels that are involved in neurotransmission at central synapses. Ca(V)2.1-α(1)-knockout (α1KO) mice, which lack Ca(V)2.1 channels in all neurons, have a very severe phenotype of cerebellar ataxia and dystonia, and usually die around postnatal day 20. This early lethality, combined with the wide expression of Ca(V)2.1 channels throughout the cerebellar cortex and nuclei, prohibited determination of the contribution of particular cerebellar cell types to the development of the severe neurobiological phenotype in Cacna1a mutant mice. Here, we crossed conditional Cacna1a mice with transgenic mice expressing Cre recombinase, driven by the Purkinje cell-specific Pcp2 promoter, to specifically ablate the Ca(V)2.1-α(1A) subunit and thereby Ca(V)2.1 channels in Purkinje cells. Purkinje cell Ca(V)2.1-α(1A)-knockout (PCα1KO) mice aged without difficulties, rescuing the lethal phenotype seen in α1KO mice. PCα1KO mice exhibited cerebellar ataxia starting around P12, much earlier than the first signs of progressive Purkinje cell loss, which appears in these mice between P30 and P45. Secondary cell loss was observed in the granular and molecular layers of the cerebellum and the volume of all individual cerebellar nuclei was reduced. In this mouse model with a cell type-specific ablation of Ca(V)2.1 channels, we show that ablation of Ca(V)2.1 channels restricted to Purkinje cells is sufficient to cause cerebellar ataxia. We demonstrate that spatial ablation of Ca(V)2.1 channels may help in unraveling mechanisms of human disease.

  13. Anoctamin Calcium-Activated Chloride Channels May Modulate Inhibitory Transmission in the Cerebellar Cortex.

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    Weiping Zhang

    Full Text Available Calcium-activated chloride channels of the anoctamin (alias TMEM16 protein family fulfill critical functions in epithelial fluid transport, smooth muscle contraction and sensory signal processing. Little is known, however, about their contribution to information processing in the central nervous system. Here we examined the recent finding that a calcium-dependent chloride conductance impacts on GABAergic synaptic inhibition in Purkinje cells of the cerebellum. We asked whether anoctamin channels may underlie this chloride conductance. We identified two anoctamin channel proteins, ANO1 and ANO2, in the cerebellar cortex. ANO1 was expressed in inhibitory interneurons of the molecular layer and the granule cell layer. Both channels were expressed in Purkinje cells but, while ANO1 appeared to be retained in the cell body, ANO2 was targeted to the dendritic tree. Functional studies confirmed that ANO2 was involved in a calcium-dependent mode of ionic plasticity that reduces the efficacy of GABAergic synapses. ANO2 channels attenuated GABAergic transmission by increasing the postsynaptic chloride concentration, hence reducing the driving force for chloride influx. Our data suggest that ANO2 channels are involved in a Ca2+-dependent regulation of synaptic weight in GABAergic inhibition. Thus, in balance with the chloride extrusion mechanism via the co-transporter KCC2, ANO2 appears to regulate ionic plasticity in the cerebellum.

  14. Missile guidance law design using adaptive cerebellar model articulation controller.

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    Lin, Chih-Min; Peng, Ya-Fu

    2005-05-01

    An adaptive cerebellar model articulation controller (CMAC) is proposed for command to line-of-sight (CLOS) missile guidance law design. In this design, the three-dimensional (3-D) CLOS guidance problem is formulated as a tracking problem of a time-varying nonlinear system. The adaptive CMAC control system is comprised of a CMAC and a compensation controller. The CMAC control is used to imitate a feedback linearization control law and the compensation controller is utilized to compensate the difference between the feedback linearization control law and the CMAC control. The online adaptive law is derived based on the Lyapunov stability theorem to learn the weights of receptive-field basis functions in CMAC control. In addition, in order to relax the requirement of approximation error bound, an estimation law is derived to estimate the error bound. Then the adaptive CMAC control system is designed to achieve satisfactory tracking performance. Simulation results for different engagement scenarios illustrate the validity of the proposed adaptive CMAC-based guidance law. PMID:15940993

  15. Adaptive control of 2-wheeled balancing robot by cerebellar neuronal network model.

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    Tanaka, Yoshiyuki; Ohata, Yohei; Kawamoto, Tomohiro; Hirata, Yutaka

    2010-01-01

    A new adaptive motor controller was constructed, and tested on the control of a 2-wheeled balancing robot in simulation and real world. The controller consists of a feedback (PD) controller and a cerebellar neuronal network model. The structure of the cerebellar model was configured based upon known anatomical neuronal connection in the cerebellar cortex. Namely it consists of 120 granular (Gr) cells, 1 Golgi cell, 6 basket/stellate cells, and 1 Purkinje (Pk) cell. Each cell is described by a typical artificial neuron model that outputs a weighted sum of inputs after a sigmoidal nonlinear transformation. The 2 components of the proposed controller work in parallel, in a way that the cerebellar model adaptively modifies the synaptic weights between Gr and Pk as in the real cerebellum to minimize the output of the PD controller. We demonstrate that the proposed controller successfully controls a 2-wheeled balancing robot, and the cerebellar model rapidly takes over the PD controller in simulation. We also show that an abrupt load change on the robot, which the PD controller alone cannot compensate for, can be adaptively compensated by the cerebellar model. We further confirmed that the proposed controller can be applied to the control of the robot in real world.

  16. First de novo KCND3 mutation causes severe Kv4.3 channel dysfunction leading to early onset cerebellar ataxia, intellectual disability, oral apraxia and epilepsy

    NARCIS (Netherlands)

    Smets, Katrien; Duarri, Anna; Deconinck, Tine; Ceulemans, Berten; van de Warrenburg, Bart P.; Zuechner, Stephan; Gonzalez, Michael Anthony; Schuele, Rebecca; Synofzik, Matthis; Van der Aa, Nathalie; De Jonghe, Peter; Verbeek, Dineke S.; Baets, Jonathan

    2015-01-01

    Background: Identification of the first de novo mutation in potassium voltage-gated channel, shal-related subfamily, member 3 (KCND3) in a patient with complex early onset cerebellar ataxia in order to expand the genetic and phenotypic spectrum. Methods: Whole exome sequencing in a cerebellar ataxia

  17. Cerebellar control of postural scaling and central set in stance.

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    Horak, F B; Diener, H C

    1994-08-01

    1. The effects of cerebellar deficits in humans on scaling the magnitude of automatic postural responses based on sensory feedback and on predictive central set was investigated. Electromyographic (EMG) and surface reactive torques were compared in patients with anterior lobe cerebellar disorders and in normal healthy adults exposed to blocks of four velocities and five amplitudes of surface translations during stance. Correlations between the earliest postural responses (integrated EMG and initial rate of change of torque) and translation velocity provided a measure of postural magnitude scaling using sensory information from the current displacement. Correlations of responses with translation amplitude provided a measure of scaling dependent on predictive central set based on sequential experience with previous like displacements because the earliest postural responses occurred before completion of the displacements and because scaling to displacement amplitude disappeared when amplitudes were randomized in normal subjects. 2. Responses of cerebellar patients to forward body sway induced by backward surface displacements were hypermetric, that is, surface-reactive torque responses were two to three times larger than normal with longer muscle bursts resulting in overshooting of initial posture. Despite this postural hypermetria, the absolute and relative latencies of agonist muscle bursts at the ankle, knee, and hip were normal in cerebellar patients. 3. Although they were hypermetric, the earliest postural responses of cerebellar patients were scaled normally to platform displacement velocities using somatosensory feedback. Cerebellar patients, however, were unable to scale initial postural response magnitude to expected displacement amplitudes based on prior experience using central set. Randomization of displacement amplitudes eliminated the set effect of amplitude on initial responses in normal subjects, but responses to randomized and blocked trials were not

  18. Direct and indirect spino-cerebellar pathways: shared ideas but different functions in motor control

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    Juan eJiang

    2015-07-01

    Full Text Available The impressive precision of mammalian limb movements relies on internal feedback pathways that convey information about ongoing motor output to cerebellar circuits. The spino-cerebellar tracts (SCT in the cervical, thoracic and lumbar spinal cord have long been considered canonical neural substrates for the conveyance of internal feedback signals. Here we consider the distinct features of an indirect spino-cerebellar route, via the brainstem lateral reticular nucleus (LRN, and the implications of this pre-cerebellar ‘detour’ for the execution and evolution of limb motor control. Both direct and indirect spino-cerebellar pathways signal spinal interneuronal activity to the cerebellum during movements, but evidence suggests that direct SCT neurons are mainly modulated by rhythmic activity, whereas the LRN also receives information from systems active during postural adjustment, reaching and grasping. Thus, while direct and indirect spino-cerebellar circuits can both be regarded as internal copy pathways, it seems likely that the direct system is principally dedicated to rhythmic motor acts like locomotion, while the indirect system also provides a means of pre-cerebellar integration relevant to the execution and coordination of de

  19. Cerebellar output controls generalized spike-and-wave discharge occurrence

    NARCIS (Netherlands)

    L. Kros (Lieke); S.J. Eelkman Rooda; J.K. Spanke (Jochen); P. Alva (Parimala); M. van Dongen (Marijn); A. Karapatis (Athanasios); E.A. Tolner (Else A.); C. Strydis (Christos); N. Davey (Neil); B.H.J. Winkelman (Beerend); M. Negrello (Mario); W. Serdijn (Wouter); V. Steuber (Volker); A.M.J.M. Maagdenberg (Arn); C.I. de Zeeuw (Chris); F.E. Hoebeek (Freek)

    2015-01-01

    textabstractObjective Disrupting thalamocortical activity patterns has proven to be a promising approach to stop generalized spike-and-wave discharges (GSWDs) characteristic of absence seizures. Here, we investigated to what extent modulation of neuronal firing in cerebellar nuclei (CN), which are a

  20. Cerebellar Output Controls Generalized Spike-and-Wave Discharge Occurrence

    NARCIS (Netherlands)

    Kros, L.; Eelkman Rooda, O.H.J.; Spanke, J.K.; Alva, P.; Van Dongen, M.N.; Karapatis, A.; Tolner, E.A.; Strydis, C.; Davey, N.; Winkelman, B.H.J.; Negrello, M.; Serdijn, W.A.; Steuber, V.; Van den Maagdenberg, A.M.J.M.; De Zeeuw, C.I.; Hoebeek, F.E.

    2015-01-01

    Objective Disrupting thalamocortical activity patterns has proven to be a promising approach to stop generalized spike-and-wave discharges (GSWDs) characteristic of absence seizures. Here, we investigated to what extent modulation of neuronal firing in cerebellar nuclei (CN), which are anatomically

  1. Cerebellar output controls generalized spike-and-wave discharge occurrence

    NARCIS (Netherlands)

    Kros, Lieke; Eelkman Rooda, Oscar H J; Spanke, Jochen K; Alva, Parimala; van Dongen, Marijn N; Karapatis, Athanasios; Tolner, Else A; Strydis, Christos; Davey, Neil; Winkelman, Beerend H J; Negrello, Mario; Serdijn, Wouter A; Steuber, Volker; van den Maagdenberg, Arn M J M; De Zeeuw, Chris I; Hoebeek, Freek E

    2015-01-01

    OBJECTIVE: Disrupting thalamocortical activity patterns has proven to be a promising approach to stop generalized spike-and-wave discharges (GSWDs) characteristic of absence seizures. Here, we investigated to what extent modulation of neuronal firing in cerebellar nuclei (CN), which are anatomically

  2. Cerebellar contributions to motor control and language comprehension: searching for common computational principles.

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    Moberget, Torgeir; Ivry, Richard B

    2016-04-01

    The past 25 years have seen the functional domain of the cerebellum extend beyond the realm of motor control, with considerable discussion of how this subcortical structure contributes to cognitive domains including attention, memory, and language. Drawing on evidence from neuroanatomy, physiology, neuropsychology, and computational work, sophisticated models have been developed to describe cerebellar function in sensorimotor control and learning. In contrast, mechanistic accounts of how the cerebellum contributes to cognition have remained elusive. Inspired by the homogeneous cerebellar microanatomy and a desire for parsimony, many researchers have sought to extend mechanistic ideas from motor control to cognition. One influential hypothesis centers on the idea that the cerebellum implements internal models, representations of the context-specific dynamics of an agent's interactions with the environment, enabling predictive control. We briefly review cerebellar anatomy and physiology, to review the internal model hypothesis as applied in the motor domain, before turning to extensions of these ideas in the linguistic domain, focusing on speech perception and semantic processing. While recent findings are consistent with this computational generalization, they also raise challenging questions regarding the nature of cerebellar learning, and may thus inspire revisions of our views on the role of the cerebellum in sensorimotor control. PMID:27206249

  3. Role of synchronous activation of cerebellar purkinje cell ensembles in multi-joint movement control

    NARCIS (Netherlands)

    T.M. Hoogland (Tycho); J.R. de Gruijl (Jornt); L. Witter (Laurens); M.I. Canto (Marcia Irene); C.I. de Zeeuw (Chris)

    2015-01-01

    textabstractIt is a longstanding question in neuroscience how elaborate multi-joint movements are coordinated coherently. Microzones of cerebellar Purkinje cells (PCs) are thought to mediate this coordination by controlling the timing of particular motor domains. However, it remains to be elucidated

  4. Role of Synchronous Activation of Cerebellar Purkinje Cell Ensembles in Multi-joint Movement Control

    NARCIS (Netherlands)

    Hoogland, Tycho M; De Gruijl, Jornt R; Witter, Laurens; Canto, Cathrin B; De Zeeuw, Chris I

    2015-01-01

    It is a longstanding question in neuroscience how elaborate multi-joint movements are coordinated coherently. Microzones of cerebellar Purkinje cells (PCs) are thought to mediate this coordination by controlling the timing of particular motor domains. However, it remains to be elucidated to what ext

  5. An agonist–antagonist cerebellar nuclear system controlling eyelid kinematics during motor learning

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    Raudel eSánchez-Campusano

    2012-03-01

    Full Text Available The presence of two antagonistic groups of deep cerebellar nuclei neurons has been reported as necessary for a proper dynamic control of learned motor responses. Most models of cerebellar function seem to ignore the biomechanical need for a double activation–deactivation system controlling eyelid kinematics, since most of them accept that, for closing the eyelid, only the activation of the orbicularis oculi muscle (via the red nucleus to the facial motor nucleus is necessary, without a simultaneous deactivation of levator palpebrae motoneurons (via unknown pathways projecting to the perioculomotor area. We have analyzed the kinetic neural commands of two antagonistic types of cerebellar posterior interpositus neuron (types A and B, the electromyographic activity of the orbicularis oculi muscle, and eyelid kinematic variables in alert behaving cats during classical eyeblink conditioning, using a delay paradigm. We addressed the hypothesis that the interpositus nucleus can be considered an agonist–antagonist system controlling eyelid kinematics during motor learning. To carry out a comparative study of the kinetic–kinematic relationships, we applied timing and dispersion pattern analyses. We concluded that, in accordance with a dominant role of cerebellar circuits for the facilitation of flexor responses, type A neurons fire during active eyelid downward displacements ─ i.e., during the active contraction of the orbicularis oculi muscle. In contrast, type B neurons present a high tonic rate when the eyelids are wide open, and stop firing during any active downward displacement of the upper eyelid. From a functional point of view, it could be suggested that type B neurons play a facilitative role for the antagonistic action of the levator palpebrae muscle. From an anatomical point of view, the possibility that cerebellar nuclear type B neurons project to the perioculomotor area ─ i.e., more or less directly onto levator palpebrae

  6. Cerebellar-inspired algorithm for adaptive control of nonlinear dielectric elastomer-based artificial muscle

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    Assaf, Tareq; Rossiter, Jonathan M.; Porrill, John

    2016-01-01

    Electroactive polymer actuators are important for soft robotics, but can be difficult to control because of compliance, creep and nonlinearities. Because biological control mechanisms have evolved to deal with such problems, we investigated whether a control scheme based on the cerebellum would be useful for controlling a nonlinear dielectric elastomer actuator, a class of artificial muscle. The cerebellum was represented by the adaptive filter model, and acted in parallel with a brainstem, an approximate inverse plant model. The recurrent connections between the two allowed for direct use of sensory error to adjust motor commands. Accurate tracking of a displacement command in the actuator's nonlinear range was achieved by either semi-linear basis functions in the cerebellar model or semi-linear functions in the brainstem corresponding to recruitment in biological muscle. In addition, allowing transfer of training between cerebellum and brainstem as has been observed in the vestibulo-ocular reflex prevented the steady increase in cerebellar output otherwise required to deal with creep. The extensibility and relative simplicity of the cerebellar-based adaptive-inverse control scheme suggests that it is a plausible candidate for controlling this type of actuator. Moreover, its performance highlights important features of biological control, particularly nonlinear basis functions, recruitment and transfer of training. PMID:27655667

  7. Dual task effect on postural control in patients with degenerative cerebellar disorders

    OpenAIRE

    Jacobi, H.; Alfes, J.; Minnerop, Martina; Konczak, J; Klockgether, T; Timmann, D.

    2015-01-01

    Background The cerebellum plays an important role for balance control and the coordination of voluntary movements. Beyond that there is growing evidence that the cerebellum is also involved in cognitive functions. How ataxic motor symptoms are influenced by simultaneous performance of a cognitive task, however, has rarely been assessed and some of the findings are contradictory. We assessed stance in 20 patients with adult onset degenerative almost purely cerebellar disorders and 20 healthy c...

  8. Studying cerebellar circuits by remote control of selected neuronal types with GABA-A receptors

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    William Wisden

    2009-12-01

    Full Text Available Although GABA-A receptor-mediated inhibition of cerebellar Purkinje cells by molecular layer interneurons (MLIs has been studied intensely on the cellular level, it has remained unclear how this inhibition regulates cerebellum-dependent behaviour. We have implemented two complementary approaches to investigate the function of the MLI-Purkinje cell synapse on the behavioral level. In the first approach we permanently disrupted inhibitory fast synaptic transmission at the synapse by genetically removing the postsynaptic GABA-A receptors from Purkinje cells (PC-Δγ2 mice. We found that chronic disruption of the MLI-Purkinje cell synapse strongly impaired cerebellar learning of the vestibular occular reflex (VOR, presumably by disrupting the temporal patterns of Purkinje cell activity. However, in PC-Δγ2 mice the baseline VOR reflex was only mildly affected; indeed PC-Δγ2 mice showed no ataxia or gait abnormalities suggesting that MLI control of Purkinje cell activity is either not involved in ongoing motor tasks or that the system has found a way to compensate for its loss. To investigate the latter possibility we have developed an alternative genetic technique; we made the MLI-Purkinje cell synapse selectively sensitive to rapid manipulation with the GABAA receptor modulator zolpidem (PC-γ2-swap mice. Minutes after intraperitoneal zolpidem injection, these PC-γ2-swap mice developed severe motor abnormalities, revealing a substantial contribution of the MLI-Purkinje cell synapse to real time motor control. The cell-type selective permanent knockout of synaptic GABAergic input, and the fast reversible modulation of GABAergic input at the same synapse illustrate how pursuing both strategies gives a fuller view.

  9. Training-induced improvements in postural control are accompanied by alterations in cerebellar white matter in brain injured patients

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    David Drijkoningen

    2015-01-01

    Full Text Available We investigated whether balance control in young TBI patients can be promoted by an 8-week balance training program and whether this is associated with neuroplastic alterations in brain structure. The cerebellum and cerebellar peduncles were selected as regions of interest because of their importance in postural control as well as their vulnerability to brain injury. Young patients with moderate to severe TBI and typically developing (TD subjects participated in balance training using PC-based portable balancers with storage of training data and real-time visual feedback. An additional control group of TD subjects did not attend balance training. Mean diffusivity and fractional anisotropy were determined with diffusion MRI scans and were acquired before, during (4 weeks and at completion of training (8 weeks together with balance assessments on the EquiTest® System (NeuroCom which included the Sensory Organization Test, Rhythmic Weight Shift and Limits of Stability protocols. Following training, TBI patients showed significant improvements on all EquiTest protocols, as well as a significant increase in mean diffusivity in the inferior cerebellar peduncle. Moreover, in both training groups, diffusion metrics in the cerebellum and/or cerebellar peduncles at baseline were predictive of the amount of performance increase after training. Finally, amount of training-induced improvement on the Rhythmic Weight Shift test in TBI patients was positively correlated with amount of change in fractional anisotropy in the inferior cerebellar peduncle. This suggests that training-induced plastic changes in balance control are associated with alterations in the cerebellar white matter microstructure in TBI patients.

  10. Cerebellar Degeneration

    Science.gov (United States)

    ... and olivopontocerebellar degeneration, progressive degenerative disorders in which cerebellar degeneration is a key feature Friedreich’s ataxia, and other spinocerebellar ataxias, which are caused by ...

  11. Dendritic Kv3.3 potassium channels in cerebellar purkinje cells regulate generation and spatial dynamics of dendritic Ca2+ spikes.

    Science.gov (United States)

    Zagha, Edward; Manita, Satoshi; Ross, William N; Rudy, Bernardo

    2010-06-01

    Purkinje cell dendrites are excitable structures with intrinsic and synaptic conductances contributing to the generation and propagation of electrical activity. Voltage-gated potassium channel subunit Kv3.3 is expressed in the distal dendrites of Purkinje cells. However, the functional relevance of this dendritic distribution is not understood. Moreover, mutations in Kv3.3 cause movement disorders in mice and cerebellar atrophy and ataxia in humans, emphasizing the importance of understanding the role of these channels. In this study, we explore functional implications of this dendritic channel expression and compare Purkinje cell dendritic excitability in wild-type and Kv3.3 knockout mice. We demonstrate enhanced excitability of Purkinje cell dendrites in Kv3.3 knockout mice, despite normal resting membrane properties. Combined data from local application pharmacology, voltage clamp analysis of ionic currents, and assessment of dendritic Ca(2+) spike threshold in Purkinje cells suggest a role for Kv3.3 channels in opposing Ca(2+) spike initiation. To study the physiological relevance of altered dendritic excitability, we measured [Ca(2+)](i) changes throughout the dendritic tree in response to climbing fiber activation. Ca(2+) signals were specifically enhanced in distal dendrites of Kv3.3 knockout Purkinje cells, suggesting a role for dendritic Kv3.3 channels in regulating propagation of electrical activity and Ca(2+) influx in distal dendrites. These findings characterize unique roles of Kv3.3 channels in dendrites, with implications for synaptic integration, plasticity, and human disease. PMID:20357073

  12. An Adaptive Supervisory Sliding Fuzzy Cerebellar Model Articulation Controller for Sensorless Vector-Controlled Induction Motor Drive Systems

    Directory of Open Access Journals (Sweden)

    Shun-Yuan Wang

    2015-03-01

    Full Text Available This paper presents the implementation of an adaptive supervisory sliding fuzzy cerebellar model articulation controller (FCMAC in the speed sensorless vector control of an induction motor (IM drive system. The proposed adaptive supervisory sliding FCMAC comprised a supervisory controller, integral sliding surface, and an adaptive FCMAC. The integral sliding surface was employed to eliminate steady-state errors and enhance the responsiveness of the system. The adaptive FCMAC incorporated an FCMAC with a compensating controller to perform a desired control action. The proposed controller was derived using the Lyapunov approach, which guarantees learning-error convergence. The implementation of three intelligent control schemes—the adaptive supervisory sliding FCMAC, adaptive sliding FCMAC, and adaptive sliding CMAC—were experimentally investigated under various conditions in a realistic sensorless vector-controlled IM drive system. The root mean square error (RMSE was used as a performance index to evaluate the experimental results of each control scheme. The analysis results indicated that the proposed adaptive supervisory sliding FCMAC substantially improved the system performance compared with the other control schemes.

  13. A New Flatness Pattern Recognition Model Based on Cerebellar Model Articulation Controllers Network

    Institute of Scientific and Technical Information of China (English)

    HE Hai-tao; LI Yan

    2008-01-01

    In the traditional flatness pattern recognition neural network,the topologic configurations need to be rebuilt with a changing width of cold strip.Furthermore,the large learning assignment,slow convergence,and local minimum in the network are observed.Moreover,going by the structure of the tradtional neural network,according to experience,the model is time-consuming and complex.Thus,a new approach of flatness pattern recognition is proposed based on the CMAC (cerebellar model articulation controllers) neural network.The difference in fuzzy distances between samples and the basic patterns is introduced as the input of the CMAC network.Simultaneously,the adequate learning rate is improved in the error correction algorithm of this neural network.The new approach with advantages,such as high learning speed,good generalization,and easy implementation,is efficient and intelligent.The simulation results show that the speed and accuracy of the flatness pattern recognition model are obviously improved.

  14. Cerebellar Hypoplasia

    Science.gov (United States)

    ... disorders that begin in early childhood, such as ataxia telangiectasia. In an infant or young child, symptoms of a disorder that features cerebellar hypoplasia might include floppy muscle tone, developmental or ...

  15. Dysplastic Cerebellar Epilepsy: Complete Seizure Control Following Resection of a Ganglioglioma.

    Science.gov (United States)

    Martins, William Alves; Paglioli, Eliseu; Hemb, Marta; Palmini, Andre

    2016-08-01

    Subcortical epilepsy has been a controversial issue, partially settled by evidence showing seizure generation in hypothalamic hamartomas and also by reports of seizures caused by cerebellar lesions. We report 4-year-old girl with right hemifacial seizures and autonomic phenomena, in whom MRI showed an irregular mass in the right cerebellar peduncle. Despite several unremarkable video-EEG recordings, seizure origin in the lesion was hypothesized. Complete resection was feasible, histopathology showed a ganglioglioma, and she has been seizure free for 3 years. A fine line separates these developmental tumors from focal cortical dysplasia, and the homogeneous presentation of this entity led us to propose the terminology dysplastic cerebellar epilepsy. PMID:26208704

  16. Acute cerebellar ataxia

    Science.gov (United States)

    Cerebellar ataxia; Ataxia - acute cerebellar; Cerebellitis; Post-varicella acute cerebellar ataxia; PVACA ... Acute cerebellar ataxia in children, especially younger than age 3, may occur several weeks after an illness caused by a virus. ...

  17. Control power in perfect controlled teleportation via partially entangled channels

    OpenAIRE

    Li, Xi-Han; Ghose, Shohini

    2014-01-01

    We analyze and evaluate perfect controlled teleportation via three-qubit entangled channels from the point of view of the controller. The key idea in controlled teleportation is that the teleportation is performed only with the participation of the controller. We calculate a quantitative measure of the controller's power and establish a lower bound on the control power required for controlled teleportation. We show that the maximally entangled GHZ state is a suitable channel for controlled te...

  18. [Cerebellar stroke].

    Science.gov (United States)

    Paradowski, Michał; Zimny, Anna; Paradowski, Bogusław

    2015-01-01

    Cerebellar stroke belongs to a group of rare diseases of vascular origin. Cerebellum, supplied by three pairs of arteries (AICA, PICA, SCA) with many anastomoses between them is less susceptible for a stroke, especially ischemic one. Diagnosis of the stroke in this region is harder due to lower sensibility of commonly used CT of the head in case of stroke suspicion. The authors highlight clinical symptoms distinguishing between vascular territories or topographical locations of the stroke, diagnostic procedures, classical and surgical treatment, the most common misdiagnoses are also mentioned. The authors suggest a diagnostic and therapeutic algorithm development, including rtPA treatment criteria for ischemic cerebellar stroke. PMID:26181157

  19. Distributed cerebellar plasticity implements adaptable gain control in a manipulation task: a closed-loop robotic simulation

    Directory of Open Access Journals (Sweden)

    Jesus A Garrido Alcazar

    2013-10-01

    Full Text Available Adaptable gain regulation is at the core of the forward controller operation performed by the cerebro-cerebellar loops and it allows the intensity of motor acts to be finely tuned in a predictive manner. In order to learn and store information about body-object dynamics and to generate an internal model of movement, the cerebellum is thought to employ long-term synaptic plasticity. LTD at the PF-PC synapse has classically been assumed to subserve this function (Marr, 1969. However, this plasticity alone cannot account for the broad dynamic ranges and time scales of cerebellar adaptation. We therefore tested the role of plasticity distributed over multiple synaptic sites (Gao et al., 2012; Hansel et al., 2001 by generating an analog cerebellar model embedded into a control loop connected to a robotic simulator. The robot used a three-joint arm and performed repetitive fast manipulations with different masses along an 8-shape trajectory. In accordance with biological evidence, the cerebellum model was endowed with both LTD and LTP at the PF-PC, MF-DCN and PC-DCN synapses. This resulted in a network scheme whose effectiveness was extended considerably compared to one including just PF-PC synaptic plasticity. Indeed, the system including distributed plasticity reliably self-adapted to manipulate different masses and to learn the arm-object dynamics over a time course that included fast learning and consolidation, along the lines of what has been observed in behavioral tests. In particular, PF-PC plasticity operated as a time correlator between the actual input state and the system error, while MF-DCN and PC-DCN plasticity played a key role in generating the gain controller. This model suggests that distributed synaptic plasticity allows generation of the complex learning properties of the cerebellum. The incorporation of further plasticity mechanisms and of spiking signal processing will allow this concept to be extended in a more realistic

  20. Control of cerebellar granule cell output by sensory-evoked Golgi cell inhibition

    OpenAIRE

    Duguid, Ian; BRANCO, Tiago; Chadderton, Paul; Arlt, Charlotte; Powell, Kate; Häusser, Michael

    2015-01-01

    Understanding how synaptic inhibition regulates sensory responses is a fundamental question in neuroscience. In cerebellar granule cells, sensory stimulation is thought to evoke an excitation–inhibition sequence driven by direct input from mossy fibers and followed by classical disynaptic feed-forward inhibition from nearby Golgi cells. We made, to our knowledge, the first voltage-clamp recordings of sensory-evoked inhibition in granule cells in vivo and show that, surprisingly, sensory-evoke...

  1. Control microprocessor system for charge particle channeling

    International Nuclear Information System (INIS)

    Control microprocessor systems are widely applied not only in designing industrial robots but in providing functioning of different experimental plants. The experiment control system for charge particle channeling has been considered in the paper. Flexibility, relatively low cost and high reliability are advantages of these systems

  2. Automated cerebellar lobule segmentation with application to cerebellar structural analysis in cerebellar disease.

    Science.gov (United States)

    Yang, Zhen; Ye, Chuyang; Bogovic, John A; Carass, Aaron; Jedynak, Bruno M; Ying, Sarah H; Prince, Jerry L

    2016-02-15

    The cerebellum plays an important role in both motor control and cognitive function. Cerebellar function is topographically organized and diseases that affect specific parts of the cerebellum are associated with specific patterns of symptoms. Accordingly, delineation and quantification of cerebellar sub-regions from magnetic resonance images are important in the study of cerebellar atrophy and associated functional losses. This paper describes an automated cerebellar lobule segmentation method based on a graph cut segmentation framework. Results from multi-atlas labeling and tissue classification contribute to the region terms in the graph cut energy function and boundary classification contributes to the boundary term in the energy function. A cerebellar parcellation is achieved by minimizing the energy function using the α-expansion technique. The proposed method was evaluated using a leave-one-out cross-validation on 15 subjects including both healthy controls and patients with cerebellar diseases. Based on reported Dice coefficients, the proposed method outperforms two state-of-the-art methods. The proposed method was then applied to 77 subjects to study the region-specific cerebellar structural differences in three spinocerebellar ataxia (SCA) genetic subtypes. Quantitative analysis of the lobule volumes shows distinct patterns of volume changes associated with different SCA subtypes consistent with known patterns of atrophy in these genetic subtypes. PMID:26408861

  3. Complex partial seizures: cerebellar metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Theodore, W.H.; Fishbein, D.; Deitz, M.; Baldwin, P.

    1987-07-01

    We used positron emission tomography (PET) with (/sup 18/F)2-deoxyglucose to study cerebellar glucose metabolism (LCMRglu) and the effect of phenytoin (PHT) in 42 patients with complex partial seizures (CPS), and 12 normal controls. Mean +/- SD patient LCMRglu was 6.9 +/- 1.8 mg glucose/100 g/min (left = right), significantly lower than control values of 8.5 +/- 1.8 (left, p less than 0.006), and 8.3 +/- 1.6 (right, p less than 0.02). Only four patients had cerebellar atrophy on CT/MRI; cerebellar LCMRglu in these was 5.5 +/- 1.5 (p = 0.054 vs. total patient sample). Patients with unilateral temporal hypometabolism or EEG foci did not have lateralized cerebellar hypometabolism. Patients receiving phenytoin (PHT) at the time of scan and patients with less than 5 years total PHT exposure had lower LCMRglu, but the differences were not significant. There were weak inverse correlations between PHT level and cerebellar LCMRglu in patients receiving PHT (r = -0.36; 0.05 less than p less than 0.1), as well as between length of illness and LCMRglu (r = -0.22; 0.05 less than p less than 0.1). Patients with complex partial seizures have cerebellar hypometabolism that is bilateral and due only in part to the effect of PHT.

  4. Channel adaptive rate control for energy optimization

    Institute of Scientific and Technical Information of China (English)

    BLANCH Carolina; POLLIN Sofie; LAFRUIT Gauthier; EBERLE Wolfgang

    2006-01-01

    Low energy consumption is one of the main challenges for wireless video transmission on battery limited devices. The energy invested at the lower layers of the protocol stack involved in data communication, such as link and physical layer, represent an important part of the total energy consumption. This communication energy highly depends on the channel conditions and on the transmission data rate. Traditionally, video coding is unaware of varying channel conditions. In this paper, we propose a cross-layer approach in which the rate control mechanism of the video codec becomes channel-aware and steers the instantaneous output rate according to the channel conditions to reduce the communication energy. Our results show that energy savings of up to30% can be obtained with a reduction of barely 0.1 dB on the average video quality. The impact of feedback delays is shown to be small. In addition, this adaptive mechanism has low complexity, which makes it suitable for real-time applications.

  5. Sensory prediction or motor control? Application of marr-albus type models of cerebellar function to classical conditioning.

    Science.gov (United States)

    Lepora, Nathan F; Porrill, John; Yeo, Christopher H; Dean, Paul

    2010-01-01

    Marr-Albus adaptive filter models of the cerebellum have been applied successfully to a range of sensory and motor control problems. Here we analyze their properties when applied to classical conditioning of the nictitating membrane response in rabbits. We consider a system-level model of eyeblink conditioning based on the anatomy of the eyeblink circuitry, comprising an adaptive filter model of the cerebellum, a comparator model of the inferior olive and a linear dynamic model of the nictitating membrane plant. To our knowledge, this is the first model that explicitly includes all these principal components, in particular the motor plant that is vital for shaping and timing the behavioral response. Model assumptions and parameters were systematically investigated to disambiguate basic computational capacities of the model from features requiring tuning of properties and parameter values. Without such tuning, the model robustly reproduced a range of behaviors related to sensory prediction, by displaying appropriate trial-level associative learning effects for both single and multiple stimuli, including blocking and conditioned inhibition. In contrast, successful reproduction of the real-time motor behavior depended on appropriate specification of the plant, cerebellum and comparator models. Although some of these properties appear consistent with the system biology, fundamental questions remain about how the biological parameters are chosen if the cerebellar microcircuit applies a common computation to many distinct behavioral tasks. It is possible that the response profiles in classical conditioning of the eyeblink depend upon operant contingencies that have previously prevailed, for example in naturally occurring avoidance movements.

  6. Hopping control channel MAC protocol for opportunistic spectrum access networks

    Institute of Scientific and Technical Information of China (English)

    FU Jing-tuan; JI Hong; MAO Xu

    2010-01-01

    Opportunistic spectrum access (OSA) is considered as a promising approach to mitigate spectrum scarcity by allowing unlicensed users to exploit spectrum opportunities in licensed frequency bands. Derived from the existing channel-hopping multiple access (CHMA) protocol,we introduce a hopping control channel medium access control (MAC) protocol in the context of OSA networks. In our proposed protocol,all nodes in the network follow a common channel-hopping sequence; every frequency channel can be used as control channel and data channel. Considering primary users' occupancy of the channel,we use a primary user (PU) detection model to calculate the channel availability for unlicensed users' access. Then,a discrete Markov chain analytical model is applied to describe the channel states and deduce the system throughput. Through simulation,we present numerical results to demonstrate the throughput performance of our protocol and thus validate our work.

  7. Greater disruption to control of voluntary saccades in autistic disorder than Asperger's disorder: evidence for greater cerebellar involvement in autism?

    Science.gov (United States)

    Stanley-Cary, Chloe; Rinehart, Nicole; Tonge, Bruce; White, Owen; Fielding, Joanne

    2011-03-01

    It remains unclear whether autism and Asperger's disorder (AD) exist on a symptom continuum or are separate disorders with discrete neurobiological underpinnings. In addition to impairments in communication and social cognition, motor deficits constitute a significant clinical feature in both disorders. It has been suggested that motor deficits and in particular the integrity of cerebellar modulation of movement may differentiate these disorders. We used a simple volitional saccade task to comprehensively profile the integrity of voluntary ocular motor behaviour in individuals with high functioning autism (HFA) or AD, and included measures sensitive to cerebellar dysfunction. We tested three groups of age-matched young males with normal intelligence (full scale, verbal, and performance IQ estimates >70) aged between 11 and 19 years; nine with AD, eight with HFA, and ten normally developing males as the comparison group. Overall, the metrics and dynamics of the voluntary saccades produced in this task were preserved in the AD group. In contrast, the HFA group demonstrated relatively preserved mean measures of ocular motricity with cerebellar-like deficits demonstrated in increased variability on measures of response time, final eye position, and movement dynamics. These deficits were considered to be consistent with reduced cerebellar online adaptation of movement. The results support the notion that the integrity of cerebellar modulation of movement may be different in AD and HFA, suggesting potentially differential neurobiological substrates may underpin these complex disorders.

  8. Altered cerebellar feedback projections in Asperger syndrome.

    Science.gov (United States)

    Catani, Marco; Jones, Derek K; Daly, Eileen; Embiricos, Nitzia; Deeley, Quinton; Pugliese, Luca; Curran, Sarah; Robertson, Dene; Murphy, Declan G M

    2008-07-15

    It has been proposed that the biological basis of autism spectrum disorder includes cerebellar 'disconnection'. However, direct in vivo evidence in support of this is lacking. Here, the microstructural integrity of cerebellar white matter in adults with Asperger syndrome was studied using diffusion tensor magnetic resonance tractography. Fifteen adults with Asperger syndrome and 16 age-IQ-gender-matched healthy controls underwent diffusion tensor magnetic resonance imaging. For each subject, tract-specific measurements of mean diffusivity and fractional anisotropy were made within the inferior, middle, superior cerebellar peduncles and short intracerebellar fibres. No group differences were observed in mean diffusivity. However, people with Asperger syndrome had significantly lower fractional anisotropy in the short intracerebellar fibres (pAsperger syndrome. The localised abnormalities in the main cerebellar outflow pathway may prevent the cerebral cortex from receiving those cerebellar feedback inputs necessary for a successful adaptive social behaviour.

  9. Sensory prediction or motor control? Application of Marr-Albus type models of cerebellar function to classical conditioning

    Directory of Open Access Journals (Sweden)

    Nathan F Lepora

    2010-10-01

    Full Text Available Marr-Albus adaptive filter models of the cerebellum have been applied successfully to a range of sensory and motor control problems. Here we analyze their properties when applied to classical conditioning of the nictitating membrane response in rabbits. We consider a system-level model of eyeblink conditioning based on the anatomy of the eyeblink circuitry, comprising an adaptive filter model of the cerebellum, a comparator model of the inferior olive and a linear dynamic model of the nictitating membrane plant. To our knowledge, this is the first model that explicitly includes all these principal components, in particular the motor plant that is vital for shaping and timing the behavioral response. Model assumptions and parameters were systematically investigated to disambiguate basic computational capacities of the model from features requiring tuning of properties and parameter values. Without such tuning, the model robustly reproduced a range of behaviors related to sensory prediction, by displaying appropriate trial-level associative learning effects for both single and multiple stimuli, including blocking and conditioned inhibition. In contrast, successful reproduction of the real-time motor behavior depended on appropriate specification of the plant, cerebellum and comparator models. Although some of these properties appear consistent with the system biology, fundamental questions remain about how the biological parameters are chosen if the cerebellar microcircuit applies a common computation to many distinct behavioral tasks. It is possible that the response profiles in classical conditioning of the eyeblink depend upon operant contingencies that have previously prevailed, for example in naturally occurring avoidance movements.

  10. Cyclostationary signature design for common control channel of cognitive radio

    Institute of Scientific and Technical Information of China (English)

    QI Yuan; PENG Tao; WANG Wen-bo; LUO Shi-feng

    2009-01-01

    Embedding specific signatures in transmitted signals for identifying common control channels of cognitive radio are addressed in research laboratories because availability of the spectrum occupied by the common control channel might change in time. A novel solution to embed a unique cyclostationary signature for the common control channel of cognitive radio is proposed in this article. Based on linear periodically time-variant transformation (LPTV) model, the cyclic autocorrelation expression of the proposed signature is derived, which characterizes its cyclostationarity. Analysis of the cyclostationary signature is presented considering effects of additive white Gaussian noise(AWGN)and multiplath channels. Simulation results illustrating the reliability of signatures are given.

  11. A Multi-channel AC Power Supply Controller

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A multi-channel AC power Supply controler developed recently by us was introdueed briefty in this paper.This controller is a computer controlled multi-electronic-switch device.The controller contains 16 independent channels in a standard box(440W×405D×125H mm).There is an electronic switch in each channel,the rated load power is≤1 kW.The main function of the controller is to set the state of electronic switch(ON/OFF)

  12. Evaluating the Influence of Motor Control on Selective Attention through a Stochastic Model: The Paradigm of Motor Control Dysfunction in Cerebellar Patient

    Directory of Open Access Journals (Sweden)

    Giacomo Veneri

    2014-01-01

    Full Text Available Attention allows us to selectively process the vast amount of information with which we are confronted, prioritizing some aspects of information and ignoring others by focusing on a certain location or aspect of the visual scene. Selective attention is guided by two cognitive mechanisms: saliency of the image (bottom up and endogenous mechanisms (top down. These two mechanisms interact to direct attention and plan eye movements; then, the movement profile is sent to the motor system, which must constantly update the command needed to produce the desired eye movement. A new approach is described here to study how the eye motor control could influence this selection mechanism in clinical behavior: two groups of patients (SCA2 and late onset cerebellar ataxia LOCA with well-known problems of motor control were studied; patients performed a cognitively demanding task; the results were compared to a stochastic model based on Monte Carlo simulations and a group of healthy subjects. The analytical procedure evaluated some energy functions for understanding the process. The implemented model suggested that patients performed an optimal visual search, reducing intrinsic noise sources. Our findings theorize a strict correlation between the “optimal motor system” and the “optimal stimulus encoders.”

  13. Landmark based shape analysis for cerebellar ataxia classification and cerebellar atrophy pattern visualization

    Science.gov (United States)

    Yang, Zhen; Abulnaga, S. Mazdak; Carass, Aaron; Kansal, Kalyani; Jedynak, Bruno M.; Onyike, Chiadi; Ying, Sarah H.; Prince, Jerry L.

    2016-03-01

    Cerebellar dysfunction can lead to a wide range of movement disorders. Studying the cerebellar atrophy pattern associated with different cerebellar disease types can potentially help in diagnosis, prognosis, and treatment planning. In this paper, we present a landmark based shape analysis pipeline to classify healthy control and different ataxia types and to visualize the characteristic cerebellar atrophy patterns associated with different types. A highly informative feature representation of the cerebellar structure is constructed by extracting dense homologous landmarks on the boundary surfaces of cerebellar sub-structures. A diagnosis group classifier based on this representation is built using partial least square dimension reduction and regularized linear discriminant analysis. The characteristic atrophy pattern for an ataxia type is visualized by sampling along the discriminant direction between healthy controls and the ataxia type. Experimental results show that the proposed method can successfully classify healthy controls and different ataxia types. The visualized cerebellar atrophy patterns were consistent with the regional volume decreases observed in previous studies, but the proposed method provides intuitive and detailed understanding about changes of overall size and shape of the cerebellum, as well as that of individual lobules.

  14. Controlled beta-quenching of fuel channels using inert gas

    International Nuclear Information System (INIS)

    The trend towards higher fuel assembly discharge burnups poses new challenges for fuel channels in terms of their dimensional behavior and corrosion resistance. This led AREVA NP to develop a new technique for beta quenching of fuel channels that combines the effect of beta-quenching with the optimization of the microstructure. The first set of fuel channels with these optimized material properties have been placed in the core of a German boiling water reactor (BWR) nuclear power plant in spring of 2004. Some more channels have been sited in the core of a Scandinavian BWR in fall of 2007 to broaden the in-pile experience with these channels. Dimensional stability is the major requirement that is applied to fuel channels. High corrosion resistance and low hydrogen pickup are certainly required as well. However, corrosion and hydrogen pickup are usually not life limiting factors due to the large wall thickness of the material. Since thick layers of oxide may spall off extensively at high burnup and cause increase of the dose rate for the personnel, high corrosion resistance of fuel channels is mandatory. The fuel channels which surround BWR fuel assemblies are exposed to neutron irradiation as well as to loads induced by the reactor coolant flowing through them. These service conditions induce material growth and creep which cause permanent changes in the dimensions of the channels. Especially, fuel channel bow is of certain interest as increased channel bow may lead to some friction with control blades. Fuel channel bow is mainly induced by fluence gradients. However, there may be additional influences such as oxidation and hydrogen uptake to cause increased channel bow. The effect of hydrogen is currently discussed in the nuclear community to explain the unexpected high fuel channel bow that has been observed in some nuclear power plants. (orig.)

  15. Proportional control valves integrated in silicon nitride surface channel technology

    NARCIS (Netherlands)

    Groen, Maarten S.; Groenesteijn, Jarno; Meutstege, Esken; Brookhuis, Robert A.; Brouwer, Dannis M.; Lötters, Joost C.; Wiegerink, Remco J.

    2015-01-01

    We have designed and realized two types of proportional microcontrol valves in a silicon nitride surface channel technology process. This enables on-die integration of flow controllers with other surface channel devices, such as pressure sensors or thermal or Coriolis-based (mass) flow sensors, to o

  16. Ondansetron, a 5-HT3 antagonist, improves cerebellar tremor.

    OpenAIRE

    Rice, G P; Lesaux, J; Vandervoort, P.; Macewan, L; Ebers, G C

    1997-01-01

    It has been previously shown that ondansetron, a 5-HT3 antagonist, can ameliorate vertigo in patients with acute brainstem disorders. A coincidental benefit was the improvement of cerebellar tremor in some patients with both vertigo and tremor. To further evaluate this effect, a placebo controlled, double blind, crossover study was conducted of a single dose of intravenous ondansetron in 20 patients with cerebellar tremor caused by multiple sclerosis, cerebellar degeneration, or drug toxicity...

  17. Synchrony and neural coding in cerebellar circuits

    Directory of Open Access Journals (Sweden)

    Abigail L Person

    2012-12-01

    Full Text Available The cerebellum regulates complex movements and is also implicated in cognitive tasks, and cerebellar dysfunction is consequently associated not only with movement disorders, but also with conditions like autism and dyslexia. How information is encoded by specific cerebellar firing patterns remains debated, however. A central question is how the cerebellar cortex transmits its integrated output to the cerebellar nuclei via GABAergic synapses from Purkinje neurons. Possible answers come from accumulating evidence that subsets of Purkinje cells synchronize their firing during behaviors that require the cerebellum. Consistent with models predicting that coherent activity of inhibitory networks has the capacity to dictate firing patterns of target neurons, recent experimental work supports the idea that inhibitory synchrony may regulate the response of cerebellar nuclear cells to Purkinje inputs, owing to the interplay between unusually fast inhibitory synaptic responses and high rates of intrinsic activity. Data from multiple laboratories lead to a working hypothesis that synchronous inhibitory input from Purkinje cells can set the timing and rate of action potentials produced by cerebellar nuclear cells, thereby relaying information out of the cerebellum. If so, then changing spatiotemporal patterns of Purkinje activity would allow different subsets of inhibitory neurons to control cerebellar output at different times. Here we explore the evidence for and against the idea that a synchrony code defines, at least in part, the input-output function between the cerebellar cortex and nuclei. We consider the literature on the existence of simple spike synchrony, convergence of Purkinje neurons onto nuclear neurons, and intrinsic properties of nuclear neurons that contribute to responses to inhibition. Finally, we discuss factors that may disrupt or modulate a synchrony code and describe the potential contributions of inhibitory synchrony to other motor

  18. The Control of Male Fertility by Spermatozoan Ion Channels

    Science.gov (United States)

    Lishko, Polina V.; Kirichok, Yuriy; Ren, Dejian; Navarro, Betsy; Chung, Jean-Ju

    2014-01-01

    Ion channels control the sperm ability to fertilize the egg by regulating sperm maturation in the female reproductive tract and by triggering key sperm physiological responses required for successful fertilization such as hyperactivated motility, chemotaxis, and the acrosome reaction. CatSper, a pH-regulated, calcium-selective ion channel, and KSper (Slo3) are core regulators of sperm tail calcium entry and sperm hyperactivated motility. Many other channels had been proposed as regulating sperm activity without direct measurements. With the development of the sperm patch-clamp technique, CatSper and KSper have been confirmed as the primary spermatozoan ion channels. In addition, the voltage-gated proton channel Hv1 has been identified in human sperm tail, and the P2X2 ion channel has been identified in the midpiece of mouse sperm. Mutations and deletions in sperm-specific ion channels affect male fertility in both mice and humans without affecting other physiological functions. The uniqueness of sperm ion channels makes them ideal pharmaceutical targets for contraception. In this review we discuss how ion channels regulate sperm physiology. PMID:22017176

  19. Optimal Channel Allocation with Dynamic Power Control in Cellular Networks

    Directory of Open Access Journals (Sweden)

    Xin Wu

    2011-03-01

    Full Text Available Techniques for channel allocation in cellular networks have been an area of intense research interest formany years. An efficient channel allocation scheme can significantly reduce call-blocking and calldroppingprobabilities. Another important issue is to effectively manage the power requirements forcommunication. An efficient power control strategy leads to reduced power consumption and improvedsignal quality. In this paper, we present a novel integer linear program (ILP formulation that jointlyoptimizes channel allocation and power control for incoming calls, based on the carrier-to-interferenceratio (CIR. In our approach we use a hybrid channel assignment scheme, where an incoming call isadmitted only if a suitable channel is found such that the CIR of all ongoing calls on that channel, as wellas that of the new call, will be above a specified value. Our formulation also guarantees that the overallpower requirement for the selected channel will be minimized as much as possible and that no ongoingcalls will be dropped as a result of admitting the new call. We have run simulations on a benchmark 49cell environment with 70 channels to investigate the effect of different parameters such as the desiredCIR. The results indicate that our approach leads to significant improvements over existing techniques.

  20. Metabolic anatomy of paraneoplastic cerebellar degeneration

    International Nuclear Information System (INIS)

    Eleven patients with acquired cerebellar degeneration (10 of whom had paraneoplastic cerebellar degeneration [PCD]) were evaluated using neuropsychological tests and 18F-fluorodeoxyglucose/positron emission tomography to (1) quantify motor, cognitive, and metabolic abnormalities; (2) determine if characteristic alterations in the regional cerebral metabolic rate for glucose (rCMRGlc) are associated with PCD; and (3) correlate behavioral and metabolic measures of disease severity. Eighteen volunteer subjects served as normal controls. Although some PCD neuropsychological test scores were abnormal, these results could not, in general, be dissociated from the effects of dysarthria and ataxia. rCMRGlc was reduced in patients with PCD (versus normal control subjects) in all regions except the brainstem. Analysis of patient and control rCMRGlc data using a mathematical model of regional metabolic interactions revealed two metabolic pattern descriptors, SSF1 and SSF2, which distinguished patients with PCD from normal control subjects; SSF2, which described a metabolic coupling between cerebellum, cuneus, and posterior temporal, lateral frontal, and paracentral cortex, correlated with quantitative indices of cerebellar dysfunction. Our inability to document substantial intellectual impairment in 7 of 10 patients with PCD contrasts with the 50% incidence of dementia in PCD reported by previous investigators. Widespread reductions in PCD rCMRGlc may result from the loss of cerebellar efferents to thalamus and forebrain structures, a reverse cerebellar diaschisis

  1. Regions of KCNQ K+ Channels Controlling Functional Expression

    Directory of Open Access Journals (Sweden)

    Frank eChoveau

    2012-10-01

    Full Text Available KCNQ1-5 α-subunits assemble to form K+ channels that play critical roles in the function of numerous tissues. The channels are tetramers of subunits containing six transmembrane domains. Each subunit consists of a pore region (S5-pore-S6 and a voltage sensor domain (S1-S4. Despite similar structures, KCNQ2 and KCNQ3 homomers yield small current amplitudes compared to other KCNQ homomers and KCNQ2/3 heteromers. Two major mechanisms have been suggested as governing functional expression. The first involves control of channel trafficking to the plasma membrane by the distal part of the C-terminus, containing two coiled-coiled domains, required for channel trafficking and assembly. The proximal half of the C-terminus is the crucial region for channel modulation by signaling molecules such as calmodulin, which may mediate C- and N-terminal interactions. The N-terminus of KCNQ channels has also been postulated as critical for channel surface expression. The second mechanism suggests networks of interactions between the pore helix and the selectivity filter, and between the pore helix and the S6 domain that govern KCNQ current amplitudes. Here, we summarize the role of these different regions in expression of functional KCNQ channels.

  2. File list: InP.Neu.20.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Neu.20.AllAg.Cerebellar_Cortex mm9 Input control Neural Cerebellar Cortex SRX06...2943,SRX1028898,SRX143824,SRX085442,SRX968954,SRX1318104,SRX1318103,SRX685926 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Neu.20.AllAg.Cerebellar_Cortex.bed ...

  3. File list: InP.Neu.05.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Neu.05.AllAg.Cerebellar_Cortex mm9 Input control Neural Cerebellar Cortex SRX06...2943,SRX085442,SRX143824,SRX685926,SRX968954,SRX1318104,SRX1028898,SRX1318103 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Neu.05.AllAg.Cerebellar_Cortex.bed ...

  4. Insights About Channel Width Controls Based on Channel Narrowing Below Dams

    Science.gov (United States)

    Schmidt, J. C.

    2007-12-01

    All channels narrow under conditions of flood reduction, such as downstream from dams, but the magnitude of narrowing is highly variable. Channel width changes on 61 dam-impacted reaches covering more than 4000 km of six large rivers of the western United States (Missouri, Rio Grande, Colorado, Trinity, Snake, Deschutes) were reviewed in an extensive literature search, supplemented by field studies on the Rio Grande, Colorado River and its tributaries, and Snake River. These studies demonstrate that narrowing occurs under conditions of post-dam sediment deficit and surplus, indicating that the primary control on width is not sediment mass balance. However, channel width changes are not related to flood reduction in a simple way, such as would be predicted by downstream hydraulic geometry relations. Narrowing is of larger magnitude on rivers with large suspended sediment loads, and is less obvious on gravel-bed rivers in sediment surplus. Narrowing occurs where beds incise and where this is not the case. Narrowing occurs in the presence or absence of invasive, woody riparian vegetation. Large-scale channel organization, such as distinguishing between meandering and debris-fan affected channels, has a strong effect on the magnitude of narrowing, primarily because the mechanism of narrowing differs between these major channel types. We examined channels whose post-dam 2-yr flood is as little as 0.20 times the pre-dam flood and where channel width narrowed by as much as 0.15 times of the pre- dam width. Field studies were based on extensive analysis of historical data as well an dendrogeomorphic interpretation of floodplain sediments.

  5. Optimal control problems related to the navigation channel engineering

    Institute of Scientific and Technical Information of China (English)

    朱江; 曾庆存; 郭冬建; 刘卓

    1997-01-01

    The navigation channel engineering poses optimal control problems of how to find the optimal way of engineering such that the water depth of the channel is maximum under certain budget constraint, or the cost of me en-gineering is minimum while certain goals are achieved. These are typical control problems of distributed system gov erned by hydraulic/sedimentation models. The problems and methods of solutions are discussed Since the models, usually complicated, are nonlinear, they can be solved by solving a series of linear problems For linear problems the solutions are given. Thus the algorithms are simplified.

  6. Reactive Power Control of Single-Stage Three-Phase Photovoltaic System during Grid Faults Using Recurrent Fuzzy Cerebellar Model Articulation Neural Network

    Directory of Open Access Journals (Sweden)

    Faa-Jeng Lin

    2014-01-01

    Full Text Available This study presents a new active and reactive power control scheme for a single-stage three-phase grid-connected photovoltaic (PV system during grid faults. The presented PV system utilizes a single-stage three-phase current-controlled voltage-source inverter to achieve the maximum power point tracking (MPPT control of the PV panel with the function of low voltage ride through (LVRT. Moreover, a formula based on positive sequence voltage for evaluating the percentage of voltage sag is derived to determine the ratio of the injected reactive current to satisfy the LVRT regulations. To reduce the risk of overcurrent during LVRT operation, a current limit is predefined for the injection of reactive current. Furthermore, the control of active and reactive power is designed using a two-dimensional recurrent fuzzy cerebellar model articulation neural network (2D-RFCMANN. In addition, the online learning laws of 2D-RFCMANN are derived according to gradient descent method with varied learning-rate coefficients for network parameters to assure the convergence of the tracking error. Finally, some experimental tests are realized to validate the effectiveness of the proposed control scheme.

  7. Oculomotor studies of cerebellar function in autism.

    Science.gov (United States)

    Nowinski, Caralynn V; Minshew, Nancy J; Luna, Beatriz; Takarae, Yukari; Sweeney, John A

    2005-11-15

    Histopathological, neuroimaging and genetic findings indicate cerebellar abnormalities in autism, but the extent of neurophysiological dysfunction associated with those findings has not been systematically examined. Suppression of intrusive saccades (square wave jerks) and the ability to sustain eccentric gaze, two phenomena requiring intact cerebellar function, were examined in 52 high-functioning individuals with autism and 52 age- and IQ-matched healthy subjects during visual fixation of static central and peripheral targets. Rates of intrusive saccades were not increased in autism during visual fixation, and foveopetal ocular drift was also not increased when subjects held an eccentric gaze. The absence of gross disturbances of visual fixation associated with cerebellar disease in individuals with autism, such as increased square wave jerk rates and foveopetal drift when holding eccentric gaze, indicates that the functional integrity of cerebellar--brainstem networks devoted to oculomotor control is preserved in autism despite reported anatomic variations. However, increased amplitude of intrusive saccades and reduced latency of target refixation after intrusive saccades were observed in individuals with autism, especially when subjects maintained fixation of remembered target locations without sensory guidance. The atypical metrics of intrusive saccades that were observed may be attributable to faulty functional connectivity in cortico-cerebellar networks. PMID:16214219

  8. Cerebellar motor dysfunction in schizophrenia and psychosis risk: the importance of regional cerebellar analysis approaches

    Directory of Open Access Journals (Sweden)

    Jessica A Bernard

    2014-11-01

    Full Text Available Motor abnormalities in individuals with schizophrenia and those at-risk for psychosis are well documented. An accumulating body of work has also highlighted motor abnormalities related to cerebellar dysfunction in schizophrenia including eye-blink conditioning, timing, postural control, and motor learning. We have also recently found evidence for motor dysfunction in individuals at ultra high-risk for psychosis (1–3. This is particularly relevant as the cerebellum is thought to be central to the cognitive dysmetria model of schizophrenia, and these overt motor signs may point to more general cerebellar dysfunction in the etiology of psychotic disorders. While studies have provided evidence indicative of motor cerebellar dysfunction in at-risk populations and in schizophrenia, findings with respect to the cerebellum have been mixed. One factor potentially contributing to these mixed results is the whole-structure approach taken when investigating the cerebellum. In non-human primates there are distinct closed-loop circuits between the cerebellum, thalamus, and brain with motor and non-motor cortical regions. Recent human neuroimaging has supported this finding and indicates that there is a cerebellar functional topography (4, and this information is being missed with whole-structure approaches. Here, we review cerebellar motor dysfunction in individuals with schizophrenia and those at-risk for psychosis. We also discuss cerebellar abnormalities in psychosis, and the cerebellar functional topography. Because of the segregated functional regions of the cerebellum, we propose that it is important to look at the structure regionally in order to better understand its role in motor dysfunction in these populations. This is analogous to approaches taken with the basal ganglia, where each region is considered separately. Such an approach is necessary to better understand cerebellar pathophysiology on a macro-structural level with respect to the

  9. Cerebellar anatomy as applied to cerebellar microsurgical resections

    Directory of Open Access Journals (Sweden)

    Alejandro Ramos

    2012-06-01

    Full Text Available OBJECTIVE: To define the anatomy of dentate nucleus and cerebellar peduncles, demonstrating the surgical application of anatomic landmarks in cerebellar resections. METHODS: Twenty cerebellar hemispheres were studied. RESULTS: The majority of dentate nucleus and cerebellar peduncles had demonstrated constant relationship to other cerebellar structures, which provided landmarks for surgical approaching. The lateral border is separated from the midline by 19.5 mm in both hemispheres. The posterior border of the cortex is separated 23.3 mm from the posterior segment of the dentate nucleus; the lateral one is separated 26 mm from the lateral border of the nucleus; and the posterior segment of the dentate nucleus is separated 25.4 mm from the posterolateral angle formed by the junction of lateral and posterior borders of cerebellar hemisphere. CONCLUSIONS: Microsurgical anatomy has provided important landmarks that could be applied to cerebellar surgical resections.

  10. Performance of Downlink UTRAN LTE under Control Channel Constraints

    DEFF Research Database (Denmark)

    López Villa, Dimas; Úbeda Castellanos, Carlos; Kovács, István Z.;

    2008-01-01

    Dynamic time-frequency domain packet scheduling algorithms in the shared channel of downlink orthogonal Frequency Division Multiple Access (OFDMA) systems have been shown to achieve high multi-user diversity scheduling gains. However, the flexibility is obtained at the cost of additional control ...

  11. Cerebellar disorders: clinical/radiologic findings and modern imaging tools.

    Science.gov (United States)

    Manto, Mario; Habas, Christophe

    2016-01-01

    Cerebellar disorders, also called cerebellar ataxias, comprise a large group of sporadic and genetic diseases. Their core clinical features include impaired control of coordination and gait, as well as cognitive/behavioral deficits usually not detectable by a standard neurologic examination and therefore often overlooked. Two forms of cognitive/behavioral syndromes are now well identified: (1) the cerebellar cognitive affective syndrome, which combines an impairment of executive functions, including planning and working memory, deficits in visuospatial skills, linguistic deficiencies such as agrammatism, and inappropriate behavior; and (2) the posterior fossa syndrome, a very acute form of cerebellar cognitive affective syndrome occurring essentially in children. Sporadic ataxias include stroke, toxic causes, immune ataxias, infectious/parainfectious ataxias, traumatic causes, neoplasias and paraneoplastic syndromes, endocrine disorders affecting the cerebellum, and the so-called "degenerative ataxias" (multiple system atrophy, and sporadic adult-onset ataxias). Genetic ataxias include mainly four groups of disorders: autosomal-recessive cerebellar ataxias, autosomal-dominant ataxias (spinocerebellar ataxias and episodic ataxias), mitochondrial disorders, and X-linked ataxias. In addition to biochemical studies and genetic tests, brain imaging techniques are a cornerstone for the diagnosis, clinicoanatomic correlations, and follow-up of cerebellar ataxias. Modern radiologic tools to assess cerebellar ataxias include: functional imaging studies, magnetic resonance spectroscopy, volumetric studies, and tractography. These complementary methods provide a multimodal appreciation of the whole long-range cerebellar network functioning, and allow the extraction of potential biomarkers for prognosis and rating level of recovery after treatment. PMID:27432679

  12. Neural correlates of impaired emotional face recognition in cerebellar lesions.

    Science.gov (United States)

    Adamaszek, Michael; Kirkby, Kenneth C; D'Agata, Fedrico; Olbrich, Sebastian; Langner, Sönke; Steele, Christopher; Sehm, Bernhard; Busse, Stefan; Kessler, Christof; Hamm, Alfons

    2015-07-10

    Clinical and neuroimaging data indicate a cerebellar contribution to emotional processing, which may account for affective-behavioral disturbances in patients with cerebellar lesions. We studied the neurophysiology of cerebellar involvement in recognition of emotional facial expression. Participants comprised eight patients with discrete ischemic cerebellar lesions and eight control patients without any cerebrovascular stroke. Event-related potentials (ERP) were used to measure responses to faces from the Karolinska Directed Emotional Faces Database (KDEF), interspersed in a stream of images with salient contents. Images of faces augmented N170 in both groups, but increased late positive potential (LPP) only in control patients without brain lesions. Dipole analysis revealed altered activation patterns for negative emotions in patients with cerebellar lesions, including activation of the left inferior prefrontal area to images of faces showing fear, contralateral to controls. Correlation analysis indicated that lesions of cerebellar area Crus I contribute to ERP deviations. Overall, our results implicate the cerebellum in integrating emotional information at different higher order stages, suggesting distinct cerebellar contributions to the proposed large-scale cerebral network of emotional face recognition. PMID:25912431

  13. 1st International Conference on Hydraulic Design in Water Resources Engineering : Channels and Channel Control Structures

    CERN Document Server

    1984-01-01

    The development of water resources has proceeded at an amazing speed around the world in the last few decades. The hydraulic engineer has played his part: in constructing much larger artificial channels than ever before, larger and more sophisticated control structures, and systems of irrigation, drainage and water supply channels in which the flow by its nature is complex and unsteady requiring computer-based techniques at both the design and operation stage. It seemed appropriate to look briefly at some of the developments in hydraulic design resulting from this situation. Hence the idea of the Conference was formed. The Proceedings of the Conference show that hydraulic engineers have been able to acquire a very substantial base of design capability from the experience of the period referred to. The most outstanding development to have occurred is in the combination of physical and mathematical modelling, which in hydraulic engineering has followed a parallel path to that in other branches of engineering sc...

  14. The Secreted Protein C1QL1 and Its Receptor BAI3 Control the Synaptic Connectivity of Excitatory Inputs Converging on Cerebellar Purkinje Cells

    Directory of Open Access Journals (Sweden)

    Séverine M. Sigoillot

    2015-02-01

    Full Text Available Precise patterns of connectivity are established by different types of afferents on a given target neuron, leading to well-defined and non-overlapping synaptic territories. What regulates the specific characteristics of each type of synapse, in terms of number, morphology, and subcellular localization, remains to be understood. Here, we show that the signaling pathway formed by the secreted complement C1Q-related protein C1QL1 and its receptor, the adhesion-GPCR brain angiogenesis inhibitor 3 (BAI3, controls the stereotyped pattern of connectivity established by excitatory afferents on cerebellar Purkinje cells. The BAI3 receptor modulates synaptogenesis of both parallel fiber and climbing fiber afferents. The restricted and timely expression of its ligand C1QL1 in inferior olivary neurons ensures the establishment of the proper synaptic territory for climbing fibers. Given the broad expression of C1QL and BAI proteins in the developing mouse brain, our study reveals a general mechanism contributing to the formation of a functional brain.

  15. IgG from Amyotrophic Lateral Sclerosis Patients Increases Current Through P-Type Calcium Channels in Mammalian Cerebellar Purkinje Cells and in Isolated Channel Protein in Lipid Bilayer

    Science.gov (United States)

    Llinas, R.; Sugimori, M.; Cherksey, B. D.; Smith, R. Glenn; Delbono, O.; Stefani, E.; Appel, S.

    1993-12-01

    The effect of the IgG from amyotrophic lateral sclerosis (ALS) patients was tested on the voltage-dependent barium currents (IBa) in mammalian dissociated Purkinje cells and in isolated P-type calcium channels in lipid bilayers. Whole cell clamp of Purkinje cells demonstrates that ALS IgG increases the amplitude of IBa without modifying their voltage kinetics. This increased IBa could be blocked by a purified nonpeptide toxin from Agelenopsis aperta venom (purified funnel-web spider toxin) or by a synthetic polyamine analog (synthetic funnel-web spider toxin) and by a peptide toxin from the same spider venom, ω-Aga-IVA. Similar results were obtained on single-channel recordings from purified P channel protein. The addition of ALS IgG increased single-channel IBa open time without affecting slope conductance. The results described above were not seen with normal human IgG nor with boiled ALS IgG. It is concluded that ALS IgG enhances inward current through P-type calcium channels. Since P-type Ca2+ channels are present in motoneuron axon terminals, we propose that the enhanced calcium current triggered by ALS IgG may contribute to neuronal damage in ALS.

  16. Engineering prokaryotic channels for control of mammalian tissue excitability

    Science.gov (United States)

    Nguyen, Hung X.; Kirkton, Robert D.; Bursac, Nenad

    2016-01-01

    The ability to directly enhance electrical excitability of human cells is hampered by the lack of methods to efficiently overexpress large mammalian voltage-gated sodium channels (VGSC). Here we describe the use of small prokaryotic sodium channels (BacNav) to create de novo excitable human tissues and augment impaired action potential conduction in vitro. Lentiviral co-expression of specific BacNav orthologues, an inward-rectifying potassium channel, and connexin-43 in primary human fibroblasts from the heart, skin or brain yields actively conducting cells with customizable electrophysiological phenotypes. Engineered fibroblasts (‘E-Fibs') retain stable functional properties following extensive subculture or differentiation into myofibroblasts and rescue conduction slowing in an in vitro model of cardiac interstitial fibrosis. Co-expression of engineered BacNav with endogenous mammalian VGSCs enhances action potential conduction and prevents conduction failure during depolarization by elevated extracellular K+, decoupling or ischaemia. These studies establish the utility of engineered BacNav channels for induction, control and recovery of mammalian tissue excitability. PMID:27752065

  17. Sediment control - an appropriate solution for small irrigation channels

    International Nuclear Information System (INIS)

    Sediment control is one of the key factors considered prior to the design of an irrigation channel. When the channel takes off from its headworks, its slope is usually smaller than that of the parent stream to obtain required head. If the sediment load is heavy then the channel can not maintain equilibrium since the high influx can not be transported fully due to its small gradient. This results in the deposition of part incoming sediment in the channel itself. A typical irrigation intake suitable for small schemes, which consists of a simple settling basin with double orifice: one at the inlet from the river and the other at the outlet to the canal. The basin is provided with a side spill weir near its downstream end, to discharge flows in excess of the maximum canal capacity. This paper deals with the experimental study of such an arrangement. Different flows were run covering a range of levels in the river, from minimum to flood flows to check the hydraulic performance of the layout and in particular to study its effectiveness in settling sediment at low flows and avoiding excessive sediment input to the canal during flood. (author)

  18. A toolbox to visually explore cerebellar shape changes in cerebellar disease and dysfunction

    Science.gov (United States)

    Abulnaga, S. Mazdak; Yang, Zhen; Carass, Aaron; Kansal, Kalyani; Jedynak, Bruno M.; Onyike, Chiadi U.; Ying, Sarah H.; Prince, Jerry L.

    2016-03-01

    The cerebellum plays an important role in motor control and is also involved in cognitive processes. Cerebellar function is specialized by location, although the exact topographic functional relationship is not fully understood. The spinocerebellar ataxias are a group of neurodegenerative diseases that cause regional atrophy in the cerebellum, yielding distinct motor and cognitive problems. The ability to study the region-specific atrophy patterns can provide insight into the problem of relating cerebellar function to location. In an effort to study these structural change patterns, we developed a toolbox in MATLAB to provide researchers a unique way to visually explore the correlation between cerebellar lobule shape changes and function loss, with a rich set of visualization and analysis modules. In this paper, we outline the functions and highlight the utility of the toolbox. The toolbox takes as input landmark shape representations of subjects' cerebellar substructures. A principal component analysis is used for dimension reduction. Following this, a linear discriminant analysis and a regression analysis can be performed to find the discriminant direction associated with a specific disease type, or the regression line of a specific functional measure can be generated. The characteristic structural change pattern of a disease type or of a functional score is visualized by sampling points on the discriminant or regression line. The sampled points are used to reconstruct synthetic cerebellar lobule shapes. We showed a few case studies highlighting the utility of the toolbox and we compare the analysis results with the literature.

  19. All-optical control of electron trapping in plasma channels

    Science.gov (United States)

    Kalmykov, Serguei Y.; Shadwick, Bradley A.; Davoine, Xavier

    2013-10-01

    Generation of background-free, polychromatic electron beams using laser plasma acceleration in longitudinally uniform, mm-length dense plasma channels is demonstrated. Periodic self-injection and acceleration transfers up to 10 percents of the drive pulse energy to several 100-pC charge, GeV-scale-energy electron bunches, each having a few-percent energy spread. Negative chirp of the broad-bandwidth (up to 400 nm), few-Joule-energy driver reduces the nonlinear frequency red-shift, preventing rapid self-steepening of the pulse, whereas the channel suppresses diffraction of the pulse leading edge. The pulse thus remains uncompressed through electron dephasing, strongly reducing unwanted continuous injection. As a bonus, delayed self-compression of the driver extends the dephasing length, boosting electron energy to the GeV level. The number of the quasi-monoenergetic bunches, their charge, energy, and energy separation can be controlled by varying the channel radius and the acceleration length, whereas accumulation of the noise (viz. continuously injected charge) is prevented by the proper dispersion control via negative chirp of the pulse. These clean polychromatic beams can drive tunable, multi-color gamma-ray Compton sources. Supported by the U.S. DOE Grant DE-SC0008382, NSF Grant PHY-1104683, and DOD AFOSR Grant FA9550-11-1-0157. The CALDER-Circ simulations were performed using HPC resources of GENCI-CCRT and GENCI-CINES (grant 2013-057027).

  20. On a multi-channel transportation loss system with controlled input and controlled service

    Directory of Open Access Journals (Sweden)

    Jewgeni Dshalalow

    1987-01-01

    Full Text Available A multi-channel loss queueing system is investigated. The input stream is a controlled point process. The service in each of m parallel channels depends on the state of the system at certain moments of time when input and service may be controlled. To obtain explicitly the limiting distribution of the main process (Zt (the number of busy channels in equilibrium, an auxiliary three dimensional process with two additional components (one of them is a semi-Markov process is treated as semi-regenerative process. An optimization problem is discussed. Simple expressions for an objective function are derived.

  1. A microfluidic abacus channel for controlling the addition of droplets.

    Science.gov (United States)

    Um, Eujin; Park, Je-Kyun

    2009-01-21

    This paper reports the first use of the abacus-groove structure to handle droplets in a wide microchannel, with no external forces integrated to the system other than the pumps. Microfluidic abacus channels are demonstrated for the sequential addition of droplets at the desired location. A control channel which is analogous to biasing in electronics can also be used to precisely determine the number of added droplets, when all other experimental conditions are fixed including the size of the droplets and the frequency of droplet-generation. The device allows programmable and autonomous operations of complex two-phase microfluidics as well as new applications for the method of analysis and computations in lab-on-a-chip devices.

  2. Consensus Paper: Neuroimmune Mechanisms of Cerebellar Ataxias

    OpenAIRE

    Mitoma, Hiroshi; Adhikari, Keya; Aeschlimann, Daniel; Chattopadhyay, Partha; Hadjivassiliou, Marios; Hampe, Christiane S.; Honnorat, Jérôme; Joubert, Bastien; Kakei, Shinji; Lee, Jongho; Manto, Mario; Matsunaga, Akiko; Mizusawa, Hidehiro; Nanri, Kazunori; Shanmugarajah, Priya

    2015-01-01

    In the last few years, a lot of publications suggested that disabling cerebellar ataxias may develop through immune-mediated mechanisms. In this consensus paper, we discuss the clinical features of the main described immune-mediated cerebellar ataxias and address their presumed pathogenesis. Immune-mediated cerebellar ataxias include cerebellar ataxia associated with anti-GAD antibodies, the cerebellar type of Hashimoto’s encephalopathy, primary autoimmune cerebellar ataxia, gluten ataxia, Mi...

  3. 4-aminopyridine reverses ataxia and cerebellar firing deficiency in a mouse model of spinocerebellar ataxia type 6.

    Science.gov (United States)

    Jayabal, Sriram; Chang, Hui Ho Vanessa; Cullen, Kathleen E; Watt, Alanna J

    2016-01-01

    Spinocerebellar ataxia type 6 (SCA6) is a devastating midlife-onset autosomal dominant motor control disease with no known treatment. Using a hyper-expanded polyglutamine (84Q) knock-in mouse, we found that cerebellar Purkinje cell firing precision was degraded in heterozygous (SCA6(84Q/+)) mice at 19 months when motor deficits are observed. Similar alterations in firing precision and motor control were observed at disease onset at 7 months in homozygous (SCA6(84Q/84Q)) mice, as well as a reduction in firing rate. We further found that chronic administration of the FDA-approved drug 4-aminopyridine (4-AP), which targets potassium channels, alleviated motor coordination deficits and restored cerebellar Purkinje cell firing precision to wildtype (WT) levels in SCA6(84Q/84Q) mice both in acute slices and in vivo. These results provide a novel therapeutic approach for treating ataxic symptoms associated with SCA6. PMID:27381005

  4. Contribution of cerebellar sensorimotor adaptation to hippocampal spatial memory.

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste Passot

    Full Text Available Complementing its primary role in motor control, cerebellar learning has also a bottom-up influence on cognitive functions, where high-level representations build up from elementary sensorimotor memories. In this paper we examine the cerebellar contribution to both procedural and declarative components of spatial cognition. To do so, we model a functional interplay between the cerebellum and the hippocampal formation during goal-oriented navigation. We reinterpret and complete existing genetic behavioural observations by means of quantitative accounts that cross-link synaptic plasticity mechanisms, single cell and population coding properties, and behavioural responses. In contrast to earlier hypotheses positing only a purely procedural impact of cerebellar adaptation deficits, our results suggest a cerebellar involvement in high-level aspects of behaviour. In particular, we propose that cerebellar learning mechanisms may influence hippocampal place fields, by contributing to the path integration process. Our simulations predict differences in place-cell discharge properties between normal mice and L7-PKCI mutant mice lacking long-term depression at cerebellar parallel fibre-Purkinje cell synapses. On the behavioural level, these results suggest that, by influencing the accuracy of hippocampal spatial codes, cerebellar deficits may impact the exploration-exploitation balance during spatial navigation.

  5. Consensus Paper: Revisiting the Symptoms and Signs of Cerebellar Syndrome.

    Science.gov (United States)

    Bodranghien, Florian; Bastian, Amy; Casali, Carlo; Hallett, Mark; Louis, Elan D; Manto, Mario; Mariën, Peter; Nowak, Dennis A; Schmahmann, Jeremy D; Serrao, Mariano; Steiner, Katharina Marie; Strupp, Michael; Tilikete, Caroline; Timmann, Dagmar; van Dun, Kim

    2016-06-01

    The cerebellum is involved in sensorimotor operations, cognitive tasks and affective processes. Here, we revisit the concept of the cerebellar syndrome in the light of recent advances in our understanding of cerebellar operations. The key symptoms and signs of cerebellar dysfunction, often grouped under the generic term of ataxia, are discussed. Vertigo, dizziness, and imbalance are associated with lesions of the vestibulo-cerebellar, vestibulo-spinal, or cerebellar ocular motor systems. The cerebellum plays a major role in the online to long-term control of eye movements (control of calibration, reduction of eye instability, maintenance of ocular alignment). Ocular instability, nystagmus, saccadic intrusions, impaired smooth pursuit, impaired vestibulo-ocular reflex (VOR), and ocular misalignment are at the core of oculomotor cerebellar deficits. As a motor speech disorder, ataxic dysarthria is highly suggestive of cerebellar pathology. Regarding motor control of limbs, hypotonia, a- or dysdiadochokinesia, dysmetria, grasping deficits and various tremor phenomenologies are observed in cerebellar disorders to varying degrees. There is clear evidence that the cerebellum participates in force perception and proprioceptive sense during active movements. Gait is staggering with a wide base, and tandem gait is very often impaired in cerebellar disorders. In terms of cognitive and affective operations, impairments are found in executive functions, visual-spatial processing, linguistic function, and affective regulation (Schmahmann's syndrome). Nonmotor linguistic deficits including disruption of articulatory and graphomotor planning, language dynamics, verbal fluency, phonological, and semantic word retrieval, expressive and receptive syntax, and various aspects of reading and writing may be impaired after cerebellar damage. The cerebellum is organized into (a) a primary sensorimotor region in the anterior lobe and adjacent part of lobule VI, (b) a second sensorimotor

  6. File list: InP.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Neu.50.AllAg.Cerebellar_granule_neurons mm9 Input control Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  7. File list: InP.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Neu.05.AllAg.Cerebellar_granule_neurons mm9 Input control Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  8. File list: InP.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Neu.10.AllAg.Cerebellar_granule_neurons mm9 Input control Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  9. File list: InP.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Neu.20.AllAg.Cerebellar_granule_neurons mm9 Input control Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  10. Cerebellar blood flow in methylmercury poisoning (Minamata disease)

    International Nuclear Information System (INIS)

    We looked at regional cerebellar blood flow in patients with Minamata disease (MD) using technetium-99 m ethyl cysteinate dimer (99m-Tc-ECD). We carried out single-photon emission computed tomography (SPECT) on 15 patients with MD (eight men, seven women, aged 51-78 years, mean 70.5 years) and 11 control subjects (eight men, three women, aged 62-80 years, mean 72.5 years). Regional blood flow was measured in the superior, middle, and inferior portions of the cerebellar hemispheres, and the frontal, temporal and occipital cerebral lobes. The degree of cerebellar atrophy was assessed on MRI. There were significant differences in regional blood flow in all parts of the cerebellum between patients and control, but no significant decrease was observed in the cerebrum. Blood flow was lower in the inferior cerebellum than in the other parts. Even in patients without cerebellar atrophy, flow was significantly decreased regional blood flow in the inferior part. (orig.)

  11. Changes in a cerebellar peduncle lesion in a patient with Dandy-Walker malformation A diffusion tensor imaging study

    Institute of Scientific and Technical Information of China (English)

    Ah Young Lee; Sung Ho Jang; Sang Seok Yeo; Ensil Lee; Yun Woo Cho; Su Min Son

    2013-01-01

    We report a patient with severe ataxia due to Dandy-Walker malformation, who showed functional recovery over 10 months corresponding to a change in a cerebellar peduncle lesion. A 20-month-old female patient who was diagnosed with Dandy-Walker syndrome and six age- and sex-matched healthy control subjects were enrolled. The superior cerebellar peduncle, the middle cerebellar peduncle, and the inferior cerebellar peduncle were evaluated using fractional anisotropy and the apparent diffusion coefficient. The patients' functional ambulation category was 0 at the initial visit, but improved to 2 at the follow-up evaluation, and Berg's balance scale score also improved from 0 to 7. Initial diffusion tensor tractography revealed that the inferior cerebellar peduncle was not detected, that the fractional anisotropy of the superior cerebellar peduncle and middle cerebellar peduncle decreased by two standard deviations below, and that the apparent diffusion coefficient increased by two standard deviations over normal control values. However, on follow-up diffusion tensor tractography, both inferior cerebellar peduncles could be detected, and the fractional anisotropy of superior cerebellar peduncle increased to within two standard deviations of normal controls. The functional improvement in this patient appeared to correspond to changes in these cerebellar peduncles. We believe that evaluating cerebellar peduncles using diffusion tensor imaging is useful in cases when a cerebellar peduncle lesion is suspected.

  12. Oxidative Stress in Autism: Elevated Cerebellar 3-nitrotyrosine Levels

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Sajdel-Sulkowska

    2008-01-01

    Full Text Available It has been suggested that oxidative stress and/or mercury compounds play an important role in the pathophysiology of autism. This study compared for the first time the cerebellar levels of the oxidative stress marker 3-nitrotyrosine (3-NT, mercury (Hg and the antioxidant selenium (Se levels between control and autistic subjects. Tissue homogenates were prepared in the presence of protease inhibitors from the frozen cerebellar tissue of control (n=10; mean age, 15.5 years; mean PMI, 15.5 hours and autistic (n=9; mean age 12.1 years; mean PMI, 19.3 hours subjects. The concentration of cerebellar 3-NT, determined by ELISA, in controls ranged from 13.69 to 49.04 pmol g-1 of tissue; the concentration of 3-NT in autistic cases ranged from 3.91 to 333.03 pmol g-1 of tissue. Mean cerebellar 3-NT was elevated in autism by 68.9% and the increase was statistically significant (p=0.045. Cerebellar Hg, measured by atomic absorption spectrometry ranged from 0.9 to 35 pmol g-1 tissue in controls (n=10 and from 3.2 to 80.7 pmol g-1 tissue in autistic cases (n=9; the 68.2% increase in cerebellar Hg was not statistically significant. However, there was a positive correlation between cerebellar 3-NT and Hg levels (r=0.7961, p=0.0001. A small decrease in cerebellar Se levels in autism, measured by atomic absorption spectroscopy, was not statistically significant but was accompanied by a 42.9% reduction in the molar ratio of Se to Hg in the autistic cerebellum. While preliminary, the results of the present study add elevated oxidative stress markers in brain to the growing body of data reflecting greater oxidative stress in autism.

  13. Fast Control Channel Decoding for LTE UE Power Saving

    DEFF Research Database (Denmark)

    Lauridsen, Mads; Jensen, Anders Riis; Mogensen, Preben

    2012-01-01

    This work examines the energy saving potential of powering down RRC_connected but unscheduled User Equipment (UE). The idea is to power down energy consuming circuits in RF and BB, when it is determined by Fast Control Channel Decoding (FCCD) that the UE is not scheduled to receive downlink data...... and an evaluation of how the relation affects power consumption. The FCCD method can complement DRX sleep mode since it is applicable when the signal is too aperiodic or fast switching for DRX....

  14. Control system devices : architectures and supply channels overview.

    Energy Technology Data Exchange (ETDEWEB)

    Trent, Jason; Atkins, William Dee; Schwartz, Moses Daniel; Mulder, John C.

    2010-08-01

    This report describes a research project to examine the hardware used in automated control systems like those that control the electric grid. This report provides an overview of the vendors, architectures, and supply channels for a number of control system devices. The research itself represents an attempt to probe more deeply into the area of programmable logic controllers (PLCs) - the specialized digital computers that control individual processes within supervisory control and data acquisition (SCADA) systems. The report (1) provides an overview of control system networks and PLC architecture, (2) furnishes profiles for the top eight vendors in the PLC industry, (3) discusses the communications protocols used in different industries, and (4) analyzes the hardware used in several PLC devices. As part of the project, several PLCs were disassembled to identify constituent components. That information will direct the next step of the research, which will greatly increase our understanding of PLC security in both the hardware and software areas. Such an understanding is vital for discerning the potential national security impact of security flaws in these devices, as well as for developing proactive countermeasures.

  15. Verbal Memory Impairments in Children after Cerebellar Tumor Resection

    Directory of Open Access Journals (Sweden)

    Matthew P. Kirschen

    2008-01-01

    Full Text Available This study was designed to investigate cerebellar lobular contributions to specific cognitive deficits observed after cerebellar tumor resection. Verbal working memory (VWM tasks were administered to children following surgical resection of cerebellar pilocytic astrocytomas and age-matched controls. Anatomical MRI scans were used to quantify the extent of cerebellar lobular damage from each patient's resection. Patients exhibited significantly reduced digit span for auditory but not visual stimuli, relative to controls, and damage to left hemispheral lobule VIII was significantly correlated with this deficit. Patients also showed reduced effects of articulatory suppression and this was correlated with damage to the vermis and hemispheral lobule IV/V bilaterally. Phonological similarity and recency effects did not differ overall between patients and controls, but outlier patients with abnormal phonological similarity effects to either auditory or visual stimuli were found to have damage to hemispheral lobule VIII/VIIB on the left and right, respectively. We postulate that damage to left hemispheral lobule VIII may interfere with encoding of auditory stimuli into the phonological store. These data corroborate neuroimaging studies showing focal cerebellar activation during VWM paradigms, and thereby allow us to predict with greater accuracy which specific neurocognitive processes will be affected by a cerebellar tumor resection.

  16. Controlling epithelial sodium channels with light using photoswitchable amilorides

    Science.gov (United States)

    Schönberger, Matthias; Althaus, Mike; Fronius, Martin; Clauss, Wolfgang; Trauner, Dirk

    2014-08-01

    Amiloride is a widely used diuretic that blocks epithelial sodium channels (ENaCs). These heterotrimeric transmembrane proteins, assembled from β, γ and α or δ subunits, effectively control water transport across epithelia and sodium influx into non-epithelial cells. The functional role of δβγENaC in various organs, including the human brain, is still poorly understood and no pharmacological tools are available for the functional differentiation between α- and δ-containing ENaCs. Here we report several photoswitchable versions of amiloride. One compound, termed PA1, enables the optical control of ENaC channels, in particular the δβγ isoform, by switching between blue and green light, or by turning on and off blue light. PA1 was used to modify functionally δβγENaC in amphibian and mammalian cells. We also show that PA1 can be used to differentiate between δβγENaC and αβγENaC in a model for the human lung epithelium.

  17. Anomalous Cerebellar Anatomy in Chinese Children with Dyslexia.

    Science.gov (United States)

    Yang, Ying-Hui; Yang, Yang; Chen, Bao-Guo; Zhang, Yi-Wei; Bi, Hong-Yan

    2016-01-01

    The cerebellar deficit hypothesis for developmental dyslexia claims that cerebellar dysfunction causes the failures in the acquisition of visuomotor skills and automatic reading and writing skills. In people with dyslexia in the alphabetic languages, the abnormal activation and structure of the right or bilateral cerebellar lobes have been identified. Using a typical implicit motor learning task, however, one neuroimaging study demonstrated the left cerebellar dysfunction in Chinese children with dyslexia. In the present study, using voxel-based morphometry, we found decreased gray matter volume in the left cerebellum in Chinese children with dyslexia relative to age-matched controls. The positive correlation between reading performance and regional gray matter volume suggests that the abnormal structure in the left cerebellum is responsible for reading disability in Chinese children with dyslexia. PMID:27047403

  18. Anomalous cerebellar anatomy in Chinese children with dyslexia

    Directory of Open Access Journals (Sweden)

    Ying-Hui eYang

    2016-03-01

    Full Text Available The cerebellar deficit hypothesis for developmental dyslexia (DD claims that cerebellar dysfunction causes the failures in the acquisition of visuomotor skills and automatic reading and writing skills. In people with dyslexia in the alphabetic languages, the abnormal activation and structure of the right or bilateral cerebellar lobes have been identified. Using a typical implicit motor learning task, however, one neuroimaging study demonstrated the left cerebellar dysfunction in Chinese children with dyslexia. In the present study, using voxel-based morphometry, we found decreased gray matter volume in the left cerebellum in Chinese children with dyslexia relative to age-matched controls. The positive correlation between reading performance and regional gray matter volume suggests that the abnormal structure in the left cerebellum is responsible for reading disability in Chinese children with dyslexia.

  19. Presynaptic calcium signalling in cerebellar mossy fibres

    Directory of Open Access Journals (Sweden)

    Louiza B Thomsen

    2010-02-01

    Full Text Available Whole-cell recordings were obtained from mossy fibre terminals in adult turtles in order to characterize the basic membrane properties. Calcium imaging of presynaptic calcium signals was carried out in order to analyse calcium dynamics and presynaptic GABA B inhibition. A TTX-sensitive fast Na+ spike faithfully followed repetitive depolarizing pulses with little change in spike duration or amplitude, while a strong outward rectification dominated responses to long-lasting depolarizations. High-threshold calcium spikes were uncovered following addition of potassium channel blockers. Calcium imaging using Calcium-Green dextran revealed a stimulus-evoked all-or-none tetrodotoxin (TTX -sensitive calcium signal in simple and complex rosettes. All compartments of a complex rosette were activated during electrical activation of the mossy fibre, while individual simple and complex rosettes along an axon appeared to be isolated from one another in terms of calcium signalling. CGP55845 application showed that GABA B receptors mediated presynaptic inhibition of the calcium signal over the entire firing frequency range of mossy fibres. A paired-pulse depression of the calcium signal lasting more than one second affected burst firing in mossy fibres; this paired-pulse depression was reduced by GABA B antagonists. While our results indicated that a presynaptic rosette electrophysiologically functioned as a unit, topical GABA application showed that calcium signals in the branches of complex rosettes could be modulated locally, suggesting that cerebellar glomeruli may be dynamically sub-compartmentalized due to ongoing inhibition mediated by Golgi cells. This could provide a fine-grained control of mossy fibre-granule cell information transfer and synaptic plasticity within a mossy fibre rosette.

  20. Single-Walled Carbon Nanotubes Acting as Controllable Transport Channels

    Institute of Scientific and Technical Information of China (English)

    HUANG Bo-Da; XIA Yue-Yuan; ZHAO Ming-Wen; LI Feng; LIU Xiang-Dong; JI Yan-Ju; SONG Chen; TAN Zhen-Yu; LIU Hui

    2004-01-01

    @@ The motion and equilibrium distribution of water molecules adsorbed inside neutral and negatively charged singlewalled carbon nanotubes (SWNTs) have been studied using molecular dynamics simulations (MDSs) at room temperature based on CHARMM (Chemistry at HARvard Molecular Mechanics) potential parameters. We find that water molecules have a conspicuous electropism phenomenon and regular tubule patterns inside and outside the charged tube wall. The analyses of the motion behaviour of water molecules in the radial and axial directions show that by charging the SWNT, the adsorption efficiency is greatly enhanced, and the electric field produced by the charged SWNTs prevents water molecules from flowing out of the nanotube. However, water molecules can travel through the neutral SWNT in a fluctuating manner. This indicates that by electrically charging and uncharging the SWNTs, one can control the adsorption and transport behaviour of polar molecules in SWNTs for using as a stable storage medium or long transport channels. The transport velocity can be tailored by changing the charge on the SWNTs, which may have a further application as modulatable transport channels.

  1. LQG Control Approach to Gaussian Broadcast Channels with Feedback

    CERN Document Server

    Ardestanizadeh, Ehsan; Franceschetti, Massimo

    2011-01-01

    A code for communication over the k-receiver additive white Gaussian noise broadcast channel with feedback is presented and analyzed using tools from the theory of linear quadratic Gaussian optimal control. It is shown that the performance of this code depends on the noise correlation at the receivers and it is related to the solution of a discrete algebraic Riccati equation. For the case of independent noises, the sum rate achieved by the proposed code, satisfying average power constraint P, is characterized as 1/2 log (1+P*phi), where the coefficient "phi" in the interval [1,k] quantifies the power gain due to the presence of feedback. When specialized to the case of two receivers, this includes a previous result by Elia and strictly improves upon the code of Ozarow and Leung. When the noises are correlated, the pre-log of the sum-capacity of the broadcast channel with feedback can be strictly greater than one. It is established that for all noise covariance matrices of rank r the pre-log of the sum capacit...

  2. Development of General Cerebellar Cognitive Module Used for Robot Motor Control%用于机器人运动控制的通用小脑认知模块的构建

    Institute of Scientific and Technical Information of China (English)

    张少白; 周宁宁

    2012-01-01

    The researches on cerebellar model and sensory-motor system have gradually become an important direction in the field of robot technology. But it is not an ideal method to construct a special cerebellar model for every control task. Base on motor control theory,this paper has developed a general cerebellar cognitive module (GCCM) incorporating all major cell types and connections. GCCM learns to produce a desired output for a given context. As such its function is determined by how its inputs and outputs are connected in the system that it is embedded in. As a result, the GCCM can be used for different sensori-motor coordination control tasks in robot system. The simulation results show that the embedded cerebellar model allows stable and robust control of fast reaching movements if it combines detection of the trajectory errors at the spinal cord level with memory traces in the cerebellum.%用具有神经生理学性质的小脑模型实现对机器人系统各种不同感觉协调运动的控制,这是当前机器人控制领域的一个研究热点.但针对一种控制任务就要构建一种对应的小脑模型,这种方式效率很不理想.文中以运动控制为基础,构建了一种包括所有主要细胞类型及其连接的通用小脑认知模块(General Cerebellum Cognitive Module,GCCM).对给定的背景知识,GCCM能够通过学习生成理想输出,因而,可用于各种不同的机器人感觉运动控制任务.仿真实验证明,通过将脊髓层次上的轨迹误差检测与小脑中的记忆轨迹结合起来,嵌入的GCCM控制系统能对快速手臂延伸运动进行精确的鲁棒控制.

  3. Sleep disorders in cerebellar ataxias

    Directory of Open Access Journals (Sweden)

    José L. Pedroso

    2011-04-01

    Full Text Available Cerebellar ataxias comprise a wide range of etiologies leading to central nervous system-related motor and non-motor symptoms. Recently, a large body of evidence has demonstrated a high frequency of non-motor manifestations in cerebellar ataxias, specially in autosomal dominant spinocerebellar ataxias (SCA. Among these non-motor dysfunctions, sleep disorders have been recognized, although still under or even misdiagnosed. In this review, we highlight the main sleep disorders related to cerebellar ataxias focusing on REM sleep behavior disorder (RBD, restless legs syndrome (RLS, periodic limb movement in sleep (PLMS, excessive daytime sleepiness (EDS, insomnia and sleep apnea.

  4. Light and electron microscopic localization of GABAA-receptors on cultured cerebellar granule cells and astrocytes using immunohistochemical techniques

    DEFF Research Database (Denmark)

    Hansen, G H; Hösli, E; Belhage, B;

    1991-01-01

    GABAA-receptors were localized in explant cultures of rat cerebellum and in dissociated primary cultures of rat cerebellar granule cells and rat cerebellar astrocytes using the monoclonal antibody bd-17 directed against the beta-subunit of the GABAA/benzodiazepine/chloride channel complex...... of GABAA-receptors was observed in the plasma membrane of both the cell bodies and processes in dissociated primary cultures of cerebellar granule cells using an indirect preembedding immunogold staining technique which in contrast to the classical PAP technique allows quantitative estimations...... in dissociated primary cultures of cerebellar astrocytes....

  5. Abnormal cerebellar volume in acute and remitted major depression.

    Science.gov (United States)

    Depping, Malte S; Wolf, Nadine D; Vasic, Nenad; Sambataro, Fabio; Hirjak, Dusan; Thomann, Philipp A; Wolf, Robert C

    2016-11-01

    Abnormal cortical volume is well-documented in patients with major depressive disorder (MDD), but cerebellar findings have been heterogeneous. It is unclear whether abnormal cerebellar structure relates to disease state or medication. In this study, using structural MRI, we investigated cerebellar volume in clinically acute (with and without psychotropic treatment) and remitted MDD patients. High-resolution structural MRI data at 3T were obtained from acute medicated (n=29), acute unmedicated (n=14) and remitted patients (n=16). Data from 29 healthy controls were used for comparison purposes. Cerebellar volume was investigated using cerebellum-optimized voxel-based analysis methods. Patients with an acute MDD episode showed increased volume of left cerebellar area IX, and this was true for both medicated and unmedicated individuals (pbrain functional network with known relevance to core depressive symptom expression, exhibits abnormal volume in patients independent of clinical severity or medication. Thus, the data imply a possible trait marker of the disorder. However, given bilaterality and an association with clinical scores at least in remitted patients, the current findings raise the possibility that cerebellar volume may be reflective of successful treatment as well. PMID:27321187

  6. Oxidative injury in multiple sclerosis cerebellar grey matter.

    Science.gov (United States)

    Kemp, Kevin; Redondo, Juliana; Hares, Kelly; Rice, Claire; Scolding, Neil; Wilkins, Alastair

    2016-07-01

    Cerebellar dysfunction is a significant contributor to disability in multiple sclerosis (MS). Both white matter (WM) and grey matter (GM) injury occurs within MS cerebellum and, within GM, demyelination, inflammatory cell infiltration and neuronal injury contribute to on-going pathology. The precise nature of cerebellar GM injury is, however, unknown. Oxidative stress pathways with ultimate lipid peroxidation and cell membrane injury occur extensively in MS and the purpose of this study was to investigate these processes in MS cerebellar GM. Post-mortem human cerebellar GM from MS and control subjects was analysed immunohistochemically, followed by semi-quantitative analysis of markers of cellular injury, lipid peroxidation and anti-oxidant enzyme expression. We have shown evidence for reduction in myelin and neuronal markers in MS GM, coupled to an increase in expression of a microglial marker. We also show that the lipid peroxidation product 4-hydroxynonenal co-localises with myelin and its levels negatively correlate to myelin basic protein levels. Furthermore, superoxide dismutase (SOD1 and 2) enzymes, localised within cerebellar neurons, are up-regulated, yet the activation of subsequent enzymes responsible for the detoxification of hydrogen peroxide, catalase and glutathione peroxidase are relatively deficient. These studies provide evidence for oxidative injury in MS cerebellar GM and further help define disease mechanisms within the MS brain. PMID:27086975

  7. Controls on plan-form evolution of submarine channels

    Science.gov (United States)

    Imran, J.; Mohrig, D. C.

    2014-12-01

    Vertically aggrading sinuous channels constitute a basic building block of modern submarine fans and the greater continental slope. Interpretation of seismically imaged channels reveals a significant diversity in internal architecture, as well as important similarities and differences in the evolution of submarine channels relative to better studied rivers. Many submarine channel cross sections possess a 'gull wing' shape. Successive stacking of such channels demonstrates that systematic bank erosion is not required in order for lateral migration to occur. The lateral shift of such aggrading channels, however, is expected to be much less dynamic than in the case of terrestrial rivers. Recent high-resolution 3D seismic data from offshore Angola and an upstream segment of the Bengal Submarine Fan show intensely meandering channels that experience considerable lateral shifting during periods of active migration within submarine valleys. The cross sections of the actively migrating channels are similar to meandering river channels characterized by an outer cut-bank and inner-bank accretion. In submarine channels, the orientation of the secondary flow can be river-like or river-reverse depending on the channel gradient, cross sectional shape, and the adaptation length of the channel bend. In river channels, a single circulation cell commonly occupies the entire channel relief, redistributing the bed-load sediment across the channel, and influencing the thread of high velocity and thus the plan-form evolution of the channel. In submarine environments, the height of the circulation cell will be significantly smaller than channel relief, thus leading to development of lower relief point bars from bed-load transport. Nevertheless these "underfit" bars may play an important role in plan-form evolution of submarine channels. In rivers and submarine channels, the inclined surface accretion can be constructed via pure bed-load, suspended-load, or a combination of both transport

  8. A general method for selecting quantum channel for bidirectional controlled state teleportation and other schemes of controlled quantum communication

    Science.gov (United States)

    Thapliyal, Kishore; Verma, Amit; Pathak, Anirban

    2015-12-01

    Recently, a large number of protocols for bidirectional controlled state teleportation (BCST) have been proposed using n-qubit entangled states (nin {5,6,7}) as quantum channel. Here, we propose a general method of selecting multiqubit (n>4) quantum channels suitable for BCST and show that all the channels used in the existing protocols of BCST can be obtained using the proposed method. Further, it is shown that the quantum channels used in the existing protocols of BCST form only a negligibly small subset of the set of all the quantum channels that can be constructed using the proposed method to implement BCST. It is also noted that all these quantum channels are also suitable for controlled bidirectional remote state preparation. Following the same logic, methods for selecting quantum channels for other controlled quantum communication tasks, such as controlled bidirectional joint remote state preparation and controlled quantum dialogue, are also provided.

  9. Metastatic cerebellar tumor of papillary thyroid carcinoma mimicking cerebellar hemangioblastoma

    OpenAIRE

    Ideguchi, Makoto; Nishizaki, Takafumi; Ikeda, Norio; Nakano, Shigeki; Okamura, Tomomi; Fujii, Natsumi; Kimura, Tokuhiro; Ikeda, Eiji

    2016-01-01

    Introduction Well-differentiated papillary thyroid carcinoma generally (PTC) have a favorable prognosis. This metastasis is rare in the central nervous system. Brain metastasis has a relatively poor prognosis. We present a rare case of cerebellar metastasis, one that mimics a solid type cerebellar hemangioblastoma and because of which it was very hard to reach accurate preoperative diagnosis. Accurate diagnosis was challenging because of the similar imaging and histopathological findings for ...

  10. Memory consolidation in the cerebellar cortex.

    Directory of Open Access Journals (Sweden)

    Daniel O Kellett

    Full Text Available Several forms of learning, including classical conditioning of the eyeblink, depend upon the cerebellum. In examining mechanisms of eyeblink conditioning in rabbits, reversible inactivations of the control circuitry have begun to dissociate aspects of cerebellar cortical and nuclear function in memory consolidation. It was previously shown that post-training cerebellar cortical, but not nuclear, inactivations with the GABAA agonist muscimol prevented consolidation but these findings left open the question as to how final memory storage was partitioned across cortical and nuclear levels. Memory consolidation might be essentially cortical and directly disturbed by actions of the muscimol, or it might be nuclear, and sensitive to the raised excitability of the nuclear neurons following the loss of cortical inhibition. To resolve this question, we simultaneously inactivated cerebellar cortical lobule HVI and the anterior interpositus nucleus of rabbits during the post-training period, so protecting the nuclei from disinhibitory effects of cortical inactivation. Consolidation was impaired by these simultaneous inactivations. Because direct application of muscimol to the nuclei alone has no impact upon consolidation, we can conclude that post-training, consolidation processes and memory storage for eyeblink conditioning have critical cerebellar cortical components. The findings are consistent with a recent model that suggests the distribution of learning-related plasticity across cortical and nuclear levels is task-dependent. There can be transfer to nuclear or brainstem levels for control of high-frequency responses but learning with lower frequency response components, such as in eyeblink conditioning, remains mainly dependent upon cortical memory storage.

  11. Autosomal recessive cerebellar ataxias

    Directory of Open Access Journals (Sweden)

    Palau Francesc

    2006-11-01

    Full Text Available Abstract Autosomal recessive cerebellar ataxias (ARCA are a heterogeneous group of rare neurological disorders involving both central and peripheral nervous system, and in some case other systems and organs, and characterized by degeneration or abnormal development of cerebellum and spinal cord, autosomal recessive inheritance and, in most cases, early onset occurring before the age of 20 years. This group encompasses a large number of rare diseases, the most frequent in Caucasian population being Friedreich ataxia (estimated prevalence 2–4/100,000, ataxia-telangiectasia (1–2.5/100,000 and early onset cerebellar ataxia with retained tendon reflexes (1/100,000. Other forms ARCA are much less common. Based on clinicogenetic criteria, five main types ARCA can be distinguished: congenital ataxias (developmental disorder, ataxias associated with metabolic disorders, ataxias with a DNA repair defect, degenerative ataxias, and ataxia associated with other features. These diseases are due to mutations in specific genes, some of which have been identified, such as frataxin in Friedreich ataxia, α-tocopherol transfer protein in ataxia with vitamin E deficiency (AVED, aprataxin in ataxia with oculomotor apraxia (AOA1, and senataxin in ataxia with oculomotor apraxia (AOA2. Clinical diagnosis is confirmed by ancillary tests such as neuroimaging (magnetic resonance imaging, scanning, electrophysiological examination, and mutation analysis when the causative gene is identified. Correct clinical and genetic diagnosis is important for appropriate genetic counseling and prognosis and, in some instances, pharmacological treatment. Due to autosomal recessive inheritance, previous familial history of affected individuals is unlikely. For most ARCA there is no specific drug treatment except for coenzyme Q10 deficiency and abetalipoproteinemia.

  12. Cerebellar Malformations and Cognitive Disdorders

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2007-10-01

    Full Text Available The behavioral developmental profile of 27 children and adults (17 males and 10 females with congenital cerebellar malformations was determined in a clinical, neuroradiological and neuropsychological study at the Scientific Institute 'E Medea', University of Milano, Italy.

  13. Analysis and Application of Covert Channels of Internet Control Message Protocol

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xueguang; ZHANG Huanguo

    2006-01-01

    Based on the analysis of the covert channel's working mechanism of the internet control message protocol (ICMP) in internet protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6), the ICMP covert channel's algorithms of the IPv4 and IPv6 are presented, which enable automatic channeling upon IPv4/v6 nodes with non-IPv4-compatible address, and the key transmission is achieved by using this channel in the embedded Internet terminal. The result shows that the covert channel's algorithm, which we implemented if, set correct, the messages of this covert channel might go through the gateway and enter the local area network.

  14. Redox control of calcium channels: from mechanisms to therapeutic opportunities.

    Science.gov (United States)

    Hool, Livia C; Corry, Ben

    2007-04-01

    Calcium plays an integral role in cellular function. It is a well-recognized second messenger necessary for signaling cellular responses, but in excessive amounts can be deleterious to function, causing cell death. The main route by which calcium enters the cytoplasm is either from the extracellular compartment or internal addistores via calcium channels. There is good evidence that calcium channels can respond to pharmacological compounds that reduce or oxidize thiol groups on the channel protein. In addition, reactive oxygen species such as hydrogen peroxide and superoxide that can mediate oxidative pathology also mediate changes in channel function via alterations of thiol groups. This review looks at the structure and function of calcium channels, the evidence that changes in cellular redox state mediate changes in channel function, and the role of redox modification of channels in disease processes. Understanding how redox modification of the channel protein alters channel structure and function is providing leads for the design of therapeutic interventions that target oxidative stress responses.

  15. Cell volume and membrane stretch independently control K+ channel activity

    DEFF Research Database (Denmark)

    Bomholtz, Sofia Hammami; Willumsen, Niels J; Olsen, Hervør L;

    2009-01-01

    A number of potassium channels including members of the KCNQ family and the Ca(2+) activated IK and SK, but not BK, are strongly and reversibly regulated by small changes in cell volume. It has been argued that this general regulation is mediated through sensitivity to changes in membrane stretch....... To test this hypothesis we have studied the regulation of KCNQ1 and BK channels after expression in Xenopus oocytes. Results from cell-attached patch clamp studies (approximately 50 microm(2) macropatches) in oocytes expressing BK channels demonstrate that the macroscopic volume-insensitive BK current...... was not affected by membrane stretch. The results indicate that (1) activation of BK channels by local membrane stretch is not mimicked by membrane stress induced by cell swelling, and (2) activation of KCNQ1 channels by cell volume increase is not mediated by local tension in the cell membrane. We conclude...

  16. Cannabinoid Control of Learning and Memory through HCN Channels.

    Science.gov (United States)

    Maroso, Mattia; Szabo, Gergely G; Kim, Hannah K; Alexander, Allyson; Bui, Anh D; Lee, Sang-Hun; Lutz, Beat; Soltesz, Ivan

    2016-03-01

    The mechanisms underlying the effects of cannabinoids on cognitive processes are not understood. Here we show that cannabinoid type-1 receptors (CB1Rs) control hippocampal synaptic plasticity and spatial memory through the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels that underlie the h-current (Ih), a key regulator of dendritic excitability. The CB1R-HCN pathway, involving c-Jun-N-terminal kinases (JNKs), nitric oxide synthase, and intracellular cGMP, exerts a tonic enhancement of Ih selectively in pyramidal cells located in the superficial portion of the CA1 pyramidal cell layer, whereas it is absent from deep-layer cells. Activation of the CB1R-HCN pathway impairs dendritic integration of excitatory inputs, long-term potentiation (LTP), and spatial memory formation. Strikingly, pharmacological inhibition of Ih or genetic deletion of HCN1 abolishes CB1R-induced deficits in LTP and memory. These results demonstrate that the CB1R-Ih pathway in the hippocampus is obligatory for the action of cannabinoids on LTP and spatial memory formation. PMID:26898775

  17. Abnormal cerebellar volume in acute and remitted major depression.

    Science.gov (United States)

    Depping, Malte S; Wolf, Nadine D; Vasic, Nenad; Sambataro, Fabio; Hirjak, Dusan; Thomann, Philipp A; Wolf, Robert C

    2016-11-01

    Abnormal cortical volume is well-documented in patients with major depressive disorder (MDD), but cerebellar findings have been heterogeneous. It is unclear whether abnormal cerebellar structure relates to disease state or medication. In this study, using structural MRI, we investigated cerebellar volume in clinically acute (with and without psychotropic treatment) and remitted MDD patients. High-resolution structural MRI data at 3T were obtained from acute medicated (n=29), acute unmedicated (n=14) and remitted patients (n=16). Data from 29 healthy controls were used for comparison purposes. Cerebellar volume was investigated using cerebellum-optimized voxel-based analysis methods. Patients with an acute MDD episode showed increased volume of left cerebellar area IX, and this was true for both medicated and unmedicated individuals (pvolume. In remitted, but not in acutely ill patients, area IX volume was significantly associated with measures of depression severity, as assessed by the Hamilton Depression Rating Scale (HAMD). In addition, area IX volume in remitted patients was significantly related to the duration of antidepressant treatment. In acutely ill patients, no significant relationships were established using clinical variables, such as HAMD, illness or treatment duration and number of depressive episodes. The data suggest that cerebellar area IX, a non-motor region that belongs to a large-scale brain functional network with known relevance to core depressive symptom expression, exhibits abnormal volume in patients independent of clinical severity or medication. Thus, the data imply a possible trait marker of the disorder. However, given bilaterality and an association with clinical scores at least in remitted patients, the current findings raise the possibility that cerebellar volume may be reflective of successful treatment as well.

  18. Design and Implementation of an Underlay Control Channel for Cognitive Radios

    Energy Technology Data Exchange (ETDEWEB)

    Daryl Wasden; Hussein Moradi; Behrouz Farhang-Boroujeny

    2012-11-01

    Implementation of any cognitive radio network requires an effective control channel that can operate under various modes of activity from the primary users. This paper reports the design and implementation of a filter bank multicarrier spread spectrum (FBMC-SS) system for use as the control channel in cognitive radio networks. The proposed design is based on a filtered multitone (FMT) implementation. Carrier and timing acquisition and tracking methods as well as a blind channel estimation method are developed for the proposed control channel. We also report an implementation of the proposed FBMC-SS system on a hardware platform; a FlexRIO FPGA module from National Instruments.

  19. A Beacon Transmission Power Control Algorithm Based on Wireless Channel Load Forecasting in VANETs.

    Directory of Open Access Journals (Sweden)

    Yuanfu Mo

    Full Text Available In a vehicular ad hoc network (VANET, the periodic exchange of single-hop status information broadcasts (beacon frames produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing and preventing channel congestion. In this study, the primary factors that influence wireless channel loading are selected to construct the KF-BCLF, which is a channel load forecasting algorithm based on a recursive Kalman filter and employs multiple regression equation. By pre-adjusting the transmission power based on the forecasted channel load, the channel load was kept within a predefined range; therefore, channel congestion was prevented. Based on this method, the CLF-BTPC, which is a transmission power control algorithm, is proposed. To verify KF-BCLF algorithm, a traffic survey method that involved the collection of floating car data along a major traffic road in Changchun City is employed. By comparing this forecast with the measured channel loads, the proposed KF-BCLF algorithm was proven to be effective. In addition, the CLF-BTPC algorithm is verified by simulating a section of eight-lane highway and a signal-controlled urban intersection. The results of the two verification process indicate that this distributed CLF-BTPC algorithm can effectively control channel load, prevent channel congestion, and enhance the stability and robustness of wireless beacon transmission in a vehicular network.

  20. A Beacon Transmission Power Control Algorithm Based on Wireless Channel Load Forecasting in VANETs.

    Science.gov (United States)

    Mo, Yuanfu; Yu, Dexin; Song, Jun; Zheng, Kun; Guo, Yajuan

    2015-01-01

    In a vehicular ad hoc network (VANET), the periodic exchange of single-hop status information broadcasts (beacon frames) produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing and preventing channel congestion. In this study, the primary factors that influence wireless channel loading are selected to construct the KF-BCLF, which is a channel load forecasting algorithm based on a recursive Kalman filter and employs multiple regression equation. By pre-adjusting the transmission power based on the forecasted channel load, the channel load was kept within a predefined range; therefore, channel congestion was prevented. Based on this method, the CLF-BTPC, which is a transmission power control algorithm, is proposed. To verify KF-BCLF algorithm, a traffic survey method that involved the collection of floating car data along a major traffic road in Changchun City is employed. By comparing this forecast with the measured channel loads, the proposed KF-BCLF algorithm was proven to be effective. In addition, the CLF-BTPC algorithm is verified by simulating a section of eight-lane highway and a signal-controlled urban intersection. The results of the two verification process indicate that this distributed CLF-BTPC algorithm can effectively control channel load, prevent channel congestion, and enhance the stability and robustness of wireless beacon transmission in a vehicular network.

  1. A Beacon Transmission Power Control Algorithm Based on Wireless Channel Load Forecasting in VANETs.

    Science.gov (United States)

    Mo, Yuanfu; Yu, Dexin; Song, Jun; Zheng, Kun; Guo, Yajuan

    2015-01-01

    In a vehicular ad hoc network (VANET), the periodic exchange of single-hop status information broadcasts (beacon frames) produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing and preventing channel congestion. In this study, the primary factors that influence wireless channel loading are selected to construct the KF-BCLF, which is a channel load forecasting algorithm based on a recursive Kalman filter and employs multiple regression equation. By pre-adjusting the transmission power based on the forecasted channel load, the channel load was kept within a predefined range; therefore, channel congestion was prevented. Based on this method, the CLF-BTPC, which is a transmission power control algorithm, is proposed. To verify KF-BCLF algorithm, a traffic survey method that involved the collection of floating car data along a major traffic road in Changchun City is employed. By comparing this forecast with the measured channel loads, the proposed KF-BCLF algorithm was proven to be effective. In addition, the CLF-BTPC algorithm is verified by simulating a section of eight-lane highway and a signal-controlled urban intersection. The results of the two verification process indicate that this distributed CLF-BTPC algorithm can effectively control channel load, prevent channel congestion, and enhance the stability and robustness of wireless beacon transmission in a vehicular network. PMID:26571042

  2. Selection an Optimal Control Channel for STATCOM-Based Stabilizers to Damp Inter-Area Oscillation

    Directory of Open Access Journals (Sweden)

    A. Samanfar

    2014-01-01

    Full Text Available In static synchronous compensator (STATCOM a controllable AC voltage is generated by a voltage-source converter. There are two control channels for controlling of magnitude and phase of the voltage. When these devices are used for damping inter-are oscillations in multi-machine power systems, a damping stabilizer can be applied for both channels. In this paper, a method by quadratic mathematical programming has been presented to design of the damping stabilizer. By this method, the effect of the stabilizer in both control channels of the STATCOM on damping of inter-area oscillations has been assessed. Obtained results on a 2-area 4-machine power system shows that a STATCOM-based stabilizer in the phase control channel is more effective for damping inter-area oscillations than that of the magnitude control channel.

  3. Ion channels that control fertility in mammalian spermatozoa.

    Science.gov (United States)

    Navarro, Betsy; Kirichok, Yuriy; Chung, Jean-Ju; Clapham, David E

    2008-01-01

    Whole-cell voltage clamp of mammalian spermatozoa was first achieved in 2006. This technical advance, combined with genetic deletion strategies, makes unambiguous identification of sperm ion channel currents possible. This review summarizes the ion channel currents that have been directly measured in mammalian sperm, and their physiological roles in fertilization. The predominant currents are a Ca2+-selective current requiring expression of the 4 mCatSper genes, and a rectifying K+ current with properties most similar to mSlo3. Intracellular alkalinization activates both channels and induces hyperactivated motility.

  4. Medium Access Control for Opportunistic Concurrent Transmissions under Shadowing Channels

    Directory of Open Access Journals (Sweden)

    Seung Min Hur

    2009-06-01

    Full Text Available We study the problem of how to alleviate the exposed terminal effect in multihop wireless networks in the presence of log-normal shadowing channels. Assuming node location information, we propose an extension of the IEEE 802.11 MAC protocol that schedules concurrent transmissions in the presence of log-normal shadowing, thus mitigating the exposed terminal problem and improving network throughput and delay performance. We observe considerable improvements in throughput and delay achieved over the IEEE 802.11 MAC under various network topologies and channel conditions in ns-2 simulations, which justify the importance of considering channel randomness in MAC protocol design for multihop wireless networks.

  5. Cognition and Emotion in Cerebellar Disorders

    Science.gov (United States)

    ... FREQUENTLY ASKED QUESTIONS ABOUT... Cognition and Emotion in Cerebellar Disorders Are problems in the areas of cognition and ... active investigation. Why is this important for the ataxia patient? Cerebellar patients and families generally find it helpful to ...

  6. Familial cerebellar ataxia and diabetes insipidus.

    OpenAIRE

    Robinson, I C; O'Malley, B P; Young, I D

    1988-01-01

    Two sisters are reported who both developed partial cranial diabetes insipidus in their 4th decade, followed by progressive cerebellar ataxia. This appears to be the first report of cerebellar ataxia and diabetes insipidus occurring together as a genetic entity.

  7. Active control for drag reduction in turbulent channel flow: the opposition control schemes revisited

    Science.gov (United States)

    Wang, Yin-Shan; Huang, Wei-Xi; Xu, Chun-Xiao

    2016-10-01

    The opposition control schemes first proposed by Choi et al (1994 J. Fluid Mech. 262 75) employing wall-normal (v) and spanwise (w) velocity are revisited in the present study by performing direct numerical simulation to turbulent channel flow at R{e}τ = 180. Special attention is paid to the combined control, in which the wall-normal and spanwise velocities are imposed at the wall just instantaneously opposite to those at a small distance to the wall. In comparison to the v- and w-controls, combined-control could achieve the best drag reduction rate and control efficiency, with the greatest suppression of turbulence intensities. The influence of control on the statistical properties of vortices is scrutinized. By control, the numbers of vortices with every circulation and radius apparently decrease at the same normal location near the wall, while the vortex radius scaled by the actual wall-friction velocity almost remains the same. The streamwise vortices and the induced Reynolds shear stress undergo the greatest suppression by combined control. It is shown that combined control achieves a better efficacy, attributed to the co-work of the mechanisms of the v- and w-controls. At a higher Reynolds number R{e}τ = 1000, combined control is also more effective than v- and w-controls. The better suppression effect on the outer large scales is the primary reason for the larger drag reduction rate in combined control.

  8. Does cerebellar neuronal integrity relate to cognitive ability?

    International Nuclear Information System (INIS)

    Full text: Magnetic resonance spectroscopy (MRS) allows the non-invasive measurement of metabolite levels in the brain. One of these is N-acetylaspartate (NA), a molecule found solely in neurones, synthesised there by mitochondria. This compound can be considered as a marker of 1) neuronal density and 2) neuronal mitochondria function. We recently completed a joint MRS and neuropsychological investigation of Williams-Beuren syndrome (WBS), a rare (1/20,000) autosomal dominant disorder caused by a deletion which includes the elastin locus and LIM-kinase. The syndrome has an associated behavioural and cognitive profile which includes hyperactivity, hyperacusis and excessive sociability. Spatial skills are severely affected, while verbal skills are left relatively intact Our investigation showed loss of NA from the cerebellum in WBS compared with normal controls, with the subject population as a whole displaying a continuum of cerebellar NA concentration. Ability at cognitive tests, including the Weschler IQ scale and various verbal and spatial tests, was shown to correlate significantly and positively with the concentration of NA in the cerebellum. This finding can be interpreted in one of two ways: 1. Our sampling of cerebellar metabolite levels represents a 'global' sampling of total brain neuronal density and, as such, is independent of cerebellar integrity. 2. Cerebellar neuronal integrity is associated with performance at cognitive tests. If the latter interpretation is shown to be the case, it will have important implications for our current understanding of cerebellar function. Copyright (1998) Australian Neuroscience Society

  9. Cerebellar networks with the cerebral cortex and basal ganglia.

    Science.gov (United States)

    Bostan, Andreea C; Dum, Richard P; Strick, Peter L

    2013-05-01

    The dominant view of cerebellar function has been that it is exclusively concerned with motor control and coordination. Recent findings from neuroanatomical, behavioral, and imaging studies have profoundly changed this view. Neuroanatomical studies using virus transneuronal tracers have demonstrated that cerebellar output reaches vast areas of the neocortex, including regions of prefrontal and posterior parietal cortex. Furthermore, it has recently become clear that the cerebellum is reciprocally connected with the basal ganglia, which suggests that the two subcortical structures are part of a densely interconnected network. Taken together, these findings elucidate the neuroanatomical substrate for cerebellar involvement in non-motor functions mediated by the prefrontal and posterior parietal cortex, as well as in processes traditionally associated with the basal ganglia. PMID:23579055

  10. Logical Link Control and Channel Scheduling for Multichannel Underwater Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jun Li

    2012-08-01

    Full Text Available With recent developments in terrestrial wireless networks and advances in acoustic communications, multichannel technologies have been proposed to be used in underwater networks to increase data transmission rate over bandwidth-limited underwater channels. Due to high bit error rates in underwater networks, an efficient error control technique is critical in the logical link control (LLC sublayer to establish reliable data communications over intrinsically unreliable underwater channels. In this paper, we propose a novel protocol stack architecture featuring cross-layer design of LLC sublayer and more efficient packetto- channel scheduling for multichannel underwater sensor networks. In the proposed stack architecture, a selective-repeat automatic repeat request (SR-ARQ based error control protocol is combined with a dynamic channel scheduling policy at the LLC sublayer. The dynamic channel scheduling policy uses the channel state information provided via cross-layer design. It is demonstrated that the proposed protocol stack architecture leads to more efficient transmission of multiple packets over parallel channels. Simulation studies are conducted to evaluate the packet delay performance of the proposed cross-layer protocol stack architecture with two different scheduling policies: the proposed dynamic channel scheduling and a static channel scheduling. Simulation results show that the dynamic channel scheduling used in the cross-layer protocol stack outperforms the static channel scheduling. It is observed that, when the dynamic channel scheduling is used, the number of parallel channels has only an insignificant impact on the average packet delay. This confirms that underwater sensor networks will benefit from the use of multichannel communications.

  11. Adaptive Four-Channel Neuro-Fuzzy Control of a Master-Slave Robot

    Directory of Open Access Journals (Sweden)

    Watcharin Po-Ngaen

    2013-03-01

    Full Text Available In bilateral control of tele‐manipulation based on a conventional approach, there are deficiencies in stability robustness and manoeuvrability against variations in the dynamics of the master input device and the task environment. In this study, an adaptive four‐channel neuro‐fuzzy bilateral control scheme is proposed. To evaluate whether the proposed algorithm is a suitable technique for improving the robustness and manoeuvrability of tele‐robot implementation, four‐channel neuro‐fuzzy and classical bilateral control frameworks have been investigated in a simulation experiment. Distinct bilateral control schemes in the form of four‐channel intelligent control and the classic form of position–force and position‐position have been implemented and compared using a one degree of freedom (DOF master‐slave system. The experimental results show that the application of a four‐channel neuro‐fuzzy control strategy effectively improves the overall performance.

  12. Cultures of Cerebellar Granule Neurons

    OpenAIRE

    sprotocols

    2014-01-01

    Authors: Parizad M. Bilimoria and Azad Bonni1 Corresponding author ([]()) ### INTRODUCTION Primary cultures of granule neurons from the post-natal rat cerebellum provide an excellent model system for molecular and cell biological studies of neuronal development and function. The cerebellar cortex, with its highly organized structure and few neuronal subtypes, offers a well-characterized neural circuitry. Many fundamental insight...

  13. Language Impairment in Cerebellar Ataxia

    NARCIS (Netherlands)

    van Gaalen, Judith; de Swart, Bert J. M.; Oostveen, Judith; Knuijt, Simone; van de Warrenburg, Bart P. C.; Kremer, Berry (H. ) P. H.

    2014-01-01

    Background: Several studies have suggested that language impairment can be observed in patients with cerebellar pathology. The aim of this study was to investigate language performance in patients with spinocerebellar ataxia type 6 (SCA6). Methods: We assessed speech and language in 29 SCA6 patients

  14. Speech Prosody in Cerebellar Ataxia

    Science.gov (United States)

    Casper, Maureen A.; Raphael, Lawrence J.; Harris, Katherine S.; Geibel, Jennifer M.

    2007-01-01

    Persons with cerebellar ataxia exhibit changes in physical coordination and speech and voice production. Previously, these alterations of speech and voice production were described primarily via perceptual coordinates. In this study, the spatial-temporal properties of syllable production were examined in 12 speakers, six of whom were healthy…

  15. Is a Cerebellar Deficit the Underlying Cause of Reading Disabilities?

    Science.gov (United States)

    Irannejad, Shahrzad; Savage, Robert

    2012-01-01

    This study investigated whether children with dyslexia differed in their performance on reading, phonological, rapid naming, motor, and cerebellar-related tasks and automaticity measures compared to reading age (RA)-matched and chronological age (CA)-matched control groups. Participants were 51 children attending mainstream English elementary…

  16. Intracellular correlates of acquisition and long-term memory of classical conditioning in Purkinje cell dendrites in slices of rabbit cerebellar lobule HVI.

    Science.gov (United States)

    Schreurs, B G; Gusev, P A; Tomsic, D; Alkon, D L; Shi, T

    1998-07-15

    Intradendritic recordings in Purkinje cells from a defined area in parasaggital slices of cerebellar lobule HVI, obtained after rabbits were given either paired (classical conditioning) or explicitly unpaired (control) presentations of tone and periorbital electrical stimulation, were used to assess the nature and duration of conditioning-specific changes in Purkinje cell dendritic membrane excitability. We found a strong relationship between the level of conditioning and Purkinje cell dendritic membrane excitability after initial acquisition of the conditioned response. Moreover, conditioning-specific increases in Purkinje cell excitability were still present 1 month after classical conditioning. Although dendritically recorded membrane potential, input resistance, and amplitude of somatic and dendritic spikes were not different in cells from paired or control animals, the size of a potassium channel-mediated transient hyperpolarization was significantly smaller in cells from animals that received classical conditioning. In slices of lobule HVI obtained from naive rabbits, the conditioning-related increases in membrane excitability could be mimicked by application of potassium channel antagonist tetraethylammonium chloride, iberiotoxin, or 4-aminopyridine. However, only 4-aminopyridine was able to reduce the transient hyperpolarization. The pharmacological data suggest a role for potassium channels and, possibly, channels mediating an IA-like current, in learning-specific changes in membrane excitability. The conditioning-specific increase in Purkinje cell dendritic excitability produces an afterhyperpolarization, which is hypothesized to release the cerebellar deep nuclei from inhibition, allowing conditioned responses to be elicited via the red nucleus and accessory abducens motorneurons.

  17. Processing of Positive and Negative Feedback in Patients with Cerebellar Lesions.

    Science.gov (United States)

    Rustemeier, Martina; Koch, Benno; Schwarz, Michael; Bellebaum, Christian

    2016-08-01

    It is well accepted that the cerebellum plays a crucial role in the prediction of the sensory consequences of movements. Recent findings of altered error processing in patients with selective cerebellar lesions led to the hypothesis that feedback processing and feedback-based learning might be affected by cerebellar damage as well. Thus, the present study investigated learning from and processing of positive and negative feedback in 12 patients with selective cerebellar lesions and healthy control subjects. Participants performed a monetary feedback learning task. The processing of positive and negative feedback was assessed by means of event-related potentials (ERPs) during the learning task and during a separate task in which the frequencies of positive and negative feedback were balanced. Patients did not show a general learning deficit compared to controls. Relative to the control group, however, patients with cerebellar lesions showed significantly higher ERP difference wave amplitudes (rewards-losses) in a time window between 250 and 450 ms after feedback presentation, possibly indicating impaired outcome prediction. The analysis of the original waveforms suggested that patients and controls primarily differed in their pattern of feedback-related negativity and P300 amplitudes. Our results add to recent findings on altered performance monitoring associated with cerebellar damage and demonstrate, for the first time, alterations of feedback processing in patients with cerebellar damage. Unaffected learning performance appears to suggest that chronic cerebellar lesions can be compensated in behaviour. PMID:26208703

  18. Aperiodic Linear Networked Control Considering Variable Channel Delays: Application to Robots Coordination (+ supplementary file)

    NARCIS (Netherlands)

    Santos, C.; Espinosa, F.; Santiso, E.; Mazo, M.

    2015-01-01

    One of the main challenges in wireless cyber-physical systems is to reduce the load of the communication channel while preserving the control performance. In this way, communication resources are liberated for other applications sharing the channel bandwidth. The main contribution of this work is th

  19. A Fairness-Based Access Control Scheme to Optimize IPTV Fast Channel Changing

    Directory of Open Access Journals (Sweden)

    Junyu Lai

    2014-01-01

    Full Text Available IPTV services are typically featured with a longer channel changing delay compared to the conventional TV systems. The major contributor to this lies in the time spent on intraframe (I-frame acquisition during channel changing. Currently, most widely adopted fast channel changing (FCC methods rely on promptly transmitting to the client (conducting the channel changing a retained I-frame of the targeted channel as a separate unicasting stream. However, this I-frame acceleration mechanism has an inherent scalability problem due to the explosions of channel changing requests during commercial breaks. In this paper, we propose a fairness-based admission control (FAC scheme for the original I-frame acceleration mechanism to enhance its scalability by decreasing the bandwidth demands. Based on the channel changing history of every client, the FAC scheme can intelligently decide whether or not to conduct the I-frame acceleration for each channel change request. Comprehensive simulation experiments demonstrate the potential of our proposed FAC scheme to effectively optimize the scalability of the I-frame acceleration mechanism, particularly in commercial breaks. Meanwhile, the FAC scheme only slightly increases the average channel changing delay by temporarily disabling FCC (i.e., I-frame acceleration for the clients who are addicted to frequent channel zapping.

  20. The mechanosensory calcium-selective ion channel: key component of a plasmalemmal control centre?

    Science.gov (United States)

    Pickard, B. G.; Ding, J. P.

    1993-01-01

    Mechanosensory calcium-selective ion channels probably serve to detect not only mechanical stress but also electrical, thermal, and diverse chemical stimuli. Because all stimuli result in a common output, most notably a shift in second messenger calcium concentration, the channels are presumed to serve as signal integrators. Further, insofar as second messenger calcium in turn gives rise to mechanical, electrical, and diverse chemical changes, the channels are postulated to initiate regulatory feedbacks. It is proposed that the channels and the feedback loops play a wide range of roles in regulating normal plant function, as well as in mediating disturbance of normal function by environmental stressors and various pathogens. In developing evidence for the physiological performance of the channel, a model for a cluster of regulatory plasmalemmal proteins and cytoskeletal elements grouped around a set of wall-to-membrane and transmembrane linkers has proved useful. An illustration of how the model might operate is presented. It is founded on the demonstration that several xenobiotics interfere both with normal channel behaviour and with gravitropic reception. Accordingly, the first part of the illustration deals with how the channels and the control system within which they putatively operate might initiate gravitropism. Assuming that gravitropism is an asymmetric expression of growth, the activities of the channels and the plasmalemmal control system are extrapolated to account for regulation of both rate and allometry of cell expansion. Finally, it is discussed how light, hormones, redox agents and herbicides could in principle affect growth via the putative plasmalemmal control cluster or centre.

  1. Control works in debris-flow channels: influence on morphology and sediment transfer

    Science.gov (United States)

    Marchi, L.

    2012-04-01

    Extensive torrent control works, such as grade-control dams, debris basins, deflecting walls, etc. have been implemented in the European Alps since the last decades of 19th century. These structural measures, aimed at stabilizing channels and to control sediment transport, are also widespread in Japan and are increasingly present in other mountain regions. As debris flows are one of the most destructive processes in steep mountain channels, hydraulic works are often intended to attenuate debris-flow hazard. Multi-temporal aerial photos and historic records permit evaluating the long term effects of torrent control works on the morphological settings of the channels and the delivery of sediment. The experience arising from over one century of torrent control works in debris-flow channels of the Alps permits also to improve the management of steep headwater catchments. A basic issue in the management of debris-flow channels is the recognition of success versus failure of engineering control works. Successful debris-flow control works provide benchmarks for further implementations, whereas the failure in reducing debris-flow hazard may lead to refinements in planning and design of control works or to the choice of preferring non-structural measures for coping with debris flows. Data from historical archives on debris-flow occurrence and on the performance of control works are the basic sources of information for these analyses. Moreover, when dealing with hydraulic structures for debris-flow control, it should be reminded that the artificial morphology resulting from the construction of check dams provides only a temporary stability to the channel and adjacent banks. This stresses the importance of evaluating the state of conservation and the effectiveness of control works and implies the need for their careful and continuous maintenance. Inventories of hydraulic structures, coupled with detailed data on catchment and channel topography, sediment sources and supply

  2. Dual-channel near-field control by polarizations using isotropic and inhomogeneous metasurface

    Science.gov (United States)

    Wan, Xiang; Cai, Ben Geng; Li, Yun Bo; Cui, Tie Jun

    2015-11-01

    We propose a method for dual-channel near-field manipulations by designing isotropic but inhomogeneous metasurfaces. As example, we present a dual-channel near-field focusing metasurface device. When the device is driven by surface waves from different channels on the metasurface, the near fields will be focused at the same spatial point with different polarizations. Conversely, if a linearly polarized source is radiated at the spatial focal point, different channels will be evoked on the metasurface controlled by polarization. We fabricated and measured the metasurface device in the microwave frequency. Well agreements between the simulation and measurement results are observed. The proposed method exhibits great flexibility in controlling the surface waves and spatial waves simultaneously. It is expected that the proposed method and dual-channel device will facilitate the manipulation of near electromagnetic or optical waves in different frequency regimes.

  3. Groundwater, biogeomorphic succession and controls on river channel pattern

    Science.gov (United States)

    Bätz, N.; Colombini, P.; Cherubini, P.; Lane, S. N.

    2015-12-01

    Strong feedbacks between river braiding and vegetation processes are now well-recognised. Recently, this has been illustrated in the notion of biogeomorphic succession, the transition from pioneer vegetation establishment to a fully-developed floodplain forest ecosystem. This succession also results in important vegetation-mediated feedbacks, through bank stabilisation and the capture of organic matter and fine sediments, stimulating soil formation and further enhancing the succession process itself. However, there are few studies that have addressed what this succession might mean for the evolution of channel planform, and almost no studies that have considered how this succession rates might be mediated by groundwater. The latter is a key concern for gravel-bed rivers with low water retention capacity. Here, we present results from a 2 km length of braiding-wandering river system in Switzerland (Allondon River). We show that the spatio-temporal dynamics of the groundwater table drives the biogeomorphic succession process at different rates, leading to very different river channel pattern responses. In the upper braiding-anastomosing part of the reach, the groundwater table is deeper. Here, dendrochronological data show that rates of pioneer vegetation growth are strongly dependent upon groundwater table fluctuations. Bank resistance modelling shows that vegetation-reinforcement of bank resistance is below its maximum. In the meandering lower part of the reach, with a mature floodplain forest, tree growth rates are independent of groundwater fluctuations, because trees can almost always access the higher groundwater table. Bank resistance is at its maximum. Through time, in response to disturbance frequency, the meandering tendency has migrated upstream. Thus, our results suggest that groundwater access modulates biogeomorphic succession processes in ways that determine the resultant river channel pattern.

  4. Fault tolerant model predictive control of open channels

    OpenAIRE

    Horváth, Klaudia; Blesa Izquierdo, Joaquim; Duviella, Eric; Chuquet, Karine

    2014-01-01

    Automated control of water systems (irrigation canals, navigation canals, rivers etc.) relies on the measured data. The control action is calculated, in case of feedback controller, directly from the on-line measured data. If the measured data is corrupted, the calculated control action will have a different effect than it is desired. Therefore, it is crucial that the feedback controller receives good quality measurement data. On-line fault detection techniques can be applied in order to dete...

  5. Flatness-based control of open-channel flow in an irrigation canal using SCADA

    OpenAIRE

    Rabbani, T.; Munier, S.; Dorchies, D.; Malaterre, P.O.; Bayen, A.; Litrico, X.

    2009-01-01

    Open channels are used to distribute water to large irrigated areas. In these systems, ensuring timely water delivery is essential to reduce operational water losses. This article derives a method for open-loop control of open channel flow, based on the Hayami model, a parabolic partial differential equation resulting from a simplification of the Saint-Venant equations. The open-loop control is represented as infinite series using differential flatness. Experimental results show the effective...

  6. Cerebellar ataxia and functional genomics : Identifying the routes to cerebellar neurodegeneration

    NARCIS (Netherlands)

    Smeets, C J L M; Verbeek, D S

    2014-01-01

    Cerebellar ataxias are progressive neurodegenerative disorders characterized by atrophy of the cerebellum leading to motor dysfunction, balance problems, and limb and gait ataxia. These include among others, the dominantly inherited spinocerebellar ataxias, recessive cerebellar ataxias such as Fried

  7. Oral administration of PF-01247324, a subtype-selective Nav1.8 blocker, reverses cerebellar deficits in a mouse model of multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Shannon D Shields

    Full Text Available Cerebellar symptoms significantly diminish quality of life in patients with multiple sclerosis (MS. We previously showed that sodium channel Nav1.8, although normally restricted to peripheral somatosensory neurons, is upregulated in the cerebellum in MS, and that Nav1.8 expression is linked to ataxia and MS-like symptoms in mice. Furthermore, intracerebroventricular administration of the Nav1.8 blocker A-803467 temporarily reversed electrophysiological and behavioral manifestations of disease in a mouse MS model; unfortunately A-803467 is not orally bioavailable, diminishing the potential for translation to human patients. In the present study, we assessed the effect of per os (p.o. dosing of a new orally bioavailable Nav1.8-selective blocker, PF-01247324, in transgenic mice expressing Nav1.8 in Purkinje neurons, and in wildtype mice in the experimental autoimmune encephalomyelitis (EAE model. PF-01247324 was administered by oral gavage at 1000 mg/kg; control groups received an equal volume of vehicle. Behavioral assays of motor coordination, grip strength, and ataxia were performed. We observed significant improvements in motor coordination and cerebellar-like symptoms in mice that received PF-01247324 compared to control littermates that received vehicle. These preclinical proof-of-concept data suggest that PF-01247324, its derivatives, or other Nav1.8-selective blockers merit further study for providing symptomatic therapy for cerebellar dysfunction in MS and related disorders.

  8. Control system of magnetic optical element power supplies for some beam channels

    International Nuclear Information System (INIS)

    The control system of the magnetic optical element power supplies for some beam channels of the IHEP accelerator, based on the micro-computer ''Elektronika-60'' and its software are described. The remote control is supplied with three Multidrop Serial Busses (31 consumer per bus). The number of controlled elements can be increased by adding one or more serial busses

  9. Signal processing by T-type calcium channel interactions in the cerebellum

    Directory of Open Access Journals (Sweden)

    Jordan D.T. Engbers

    2013-11-01

    Full Text Available T-type calcium channels of the Cav3 family are unique among voltage-gated calcium channels due to their low activation voltage, rapid inactivation, and small single channel conductance. These special properties allow Cav3 calcium channels to regulate neuronal processing in the subthreshold voltage range. Here, we review two different subthreshold ion channel interactions involving Cav3 channels and explore the ability of these interactions to expand the functional roles of Cav3 channels. In cerebellar Purkinje cells, Cav3 and intermediate conductance calcium-activated potassium (IKCa channels form a novel complex which creates a low voltage-activated, transient outward current capable of suppressing temporal summation of excitatory postsynaptic potentials (EPSPs. In large diameter neurons of the deep cerebellar nuclei, Cav3-mediated calcium current (IT and hyperpolarization-activated cation current (IH are activated during trains of IPSPs. These currents have distinct, and yet synergistic, roles in the subthreshold domain with IT generating a rebound burst and IH controlling first spike latency and rebound spike precision. However, by shortening the membrane time constant the membrane returns towards resting value at a faster rate, allowing IH to increase the efficacy of IT, and increase the range of burst frequencies that can be generated. The net effect of Cav3 channels thus depends on the channels with which they are paired. When expressed in a complex with a KCa channel, Cav3 channels reduce excitability when processing excitatory inputs. If functionally coupled with an HCN channel, the depolarizing effect of Cav3 channels is accentuated, allowing for efficient inversion of inhibitory inputs to generate a rebound burst output. Therefore, signal processing relies not only on the activity of individual subtypes of channels but also on complex interactions between ion channels whether based on a physical complex or by indirect effects on

  10. Signal processing by T-type calcium channel interactions in the cerebellum.

    Science.gov (United States)

    Engbers, Jordan D T; Anderson, Dustin; Zamponi, Gerald W; Turner, Ray W

    2013-11-27

    T-type calcium channels of the Cav3 family are unique among voltage-gated calcium channels due to their low activation voltage, rapid inactivation, and small single channel conductance. These special properties allow Cav3 calcium channels to regulate neuronal processing in the subthreshold voltage range. Here, we review two different subthreshold ion channel interactions involving Cav3 channels and explore the ability of these interactions to expand the functional roles of Cav3 channels. In cerebellar Purkinje cells, Cav3 and intermediate conductance calcium-activated potassium (IKCa) channels form a novel complex which creates a low voltage-activated, transient outward current capable of suppressing temporal summation of excitatory postsynaptic potentials (EPSPs). In large diameter neurons of the deep cerebellar nuclei, Cav3-mediated calcium current (I T) and hyperpolarization-activated cation current (I H) are activated during trains of inhibitory postsynaptic potentials. These currents have distinct, and yet synergistic, roles in the subthreshold domain with I T generating a rebound burst and I H controlling first spike latency and rebound spike precision. However, by shortening the membrane time constant the membrane returns towards resting value at a faster rate, allowing I H to increase the efficacy of I T and increase the range of burst frequencies that can be generated. The net effect of Cav3 channels thus depends on the channels with which they are paired. When expressed in a complex with a KCa channel, Cav3 channels reduce excitability when processing excitatory inputs. If functionally coupled with an HCN channel, the depolarizing effect of Cav3 channels is accentuated, allowing for efficient inversion of inhibitory inputs to generate a rebound burst output. Therefore, signal processing relies not only on the activity of individual subtypes of channels but also on complex interactions between ion channels whether based on a physical complex or by indirect

  11. Signal processing by T-type calcium channel interactions in the cerebellum

    Science.gov (United States)

    Engbers, Jordan D. T.; Anderson, Dustin; Zamponi, Gerald W.; Turner, Ray W.

    2013-01-01

    T-type calcium channels of the Cav3 family are unique among voltage-gated calcium channels due to their low activation voltage, rapid inactivation, and small single channel conductance. These special properties allow Cav3 calcium channels to regulate neuronal processing in the subthreshold voltage range. Here, we review two different subthreshold ion channel interactions involving Cav3 channels and explore the ability of these interactions to expand the functional roles of Cav3 channels. In cerebellar Purkinje cells, Cav3 and intermediate conductance calcium-activated potassium (IKCa) channels form a novel complex which creates a low voltage-activated, transient outward current capable of suppressing temporal summation of excitatory postsynaptic potentials (EPSPs). In large diameter neurons of the deep cerebellar nuclei, Cav3-mediated calcium current (IT) and hyperpolarization-activated cation current (IH) are activated during trains of inhibitory postsynaptic potentials. These currents have distinct, and yet synergistic, roles in the subthreshold domain with IT generating a rebound burst and IH controlling first spike latency and rebound spike precision. However, by shortening the membrane time constant the membrane returns towards resting value at a faster rate, allowing IH to increase the efficacy of IT and increase the range of burst frequencies that can be generated. The net effect of Cav3 channels thus depends on the channels with which they are paired. When expressed in a complex with a KCa channel, Cav3 channels reduce excitability when processing excitatory inputs. If functionally coupled with an HCN channel, the depolarizing effect of Cav3 channels is accentuated, allowing for efficient inversion of inhibitory inputs to generate a rebound burst output. Therefore, signal processing relies not only on the activity of individual subtypes of channels but also on complex interactions between ion channels whether based on a physical complex or by indirect

  12. Microfluidic Induced Controllable Microdroplets Assembly in Confined Channels

    Directory of Open Access Journals (Sweden)

    Juan Wang

    2015-09-01

    Full Text Available We report on the microfluidic induced monodispersed microdroplet generation and assembly in confined microchannels. Two and three dimensional close-packed droplet lattices were obtained in microfluidic devices by adjusting the channel geometry, the fluidic flow rates and the monodispersed droplet size. The droplet packing was mainly caused by the volumetric effect and capillarity in confined microchannels. Polymerizable fluids were also investigated to demonstrate the effect of fluidic properties on the microdroplet generation and assembly, which could find interesting applications in the future. This approach would be helpful to fundamentally understand the mechanism of self-assembly process of particles in confined microstructures, and practically be applied in sensing and energy storage devices.

  13. Ferrofluid magnetoviscous control of wall flow channeling in porous media

    Institute of Scientific and Technical Information of China (English)

    Fa(ic)al Larachi; Damien Desvigne

    2007-01-01

    We analyzed the phenomenon of ferrofluid magnetoviscosity in high-permeability wall-region non-magnetic porous media of the Müller kind.After upscaling the pore-level ferrohydrodynamic model, we obtained a simplified volume-average zero-order axisymmetric model for non-Darcy non-turbulent flow of steady-state isothermal incompressible Newtonian ferrofluids through a porous medium experiencing external constant bulk-flow oriented gradient magnetic field, ferrofluid self-consistent demagnetizing field and induced magnetic field in the solid. The model was explored in contexts plagued by wall flow maldistribution due to low column-to-particle diameter ratios. It was shown that for proper magnetic field arrangement, wall channeling can be reduced by inflating wall flow resistance through magnetovisco-thickening and Kelvin body force density which reroute a fraction of wall flow towards bed core.

  14. Cerebellar medulloblastoma presenting with skeletal metastasis

    OpenAIRE

    Barai Sukanta; Bandopadhayaya G; Julka P; Dhanapathi H; Haloi A; Seith A

    2004-01-01

    Medulloblastomas are highly malignant brain tumours, but only rarely produce skeletal metastases. No case of medulloblastoma has been documented to have produced skeletal metastases prior to craniotomy or shunt surgery. A 21-year-old male presented with pain in the hip and lower back with difficulty in walking of 3 months′ duration. Signs of cerebellar dysfunction were present hence a diagnosis of cerebellar neoplasm or skeletal tuberculosis with cerebellar abscess formation was consid...

  15. Crossed cerebral - cerebellar diaschisis : MRI evaluation.

    Directory of Open Access Journals (Sweden)

    Chakravarty A

    2002-07-01

    Full Text Available MRI, done later in life, in two patients with infantile hemiplegia syndrome showed significant volume loss in the cerebellar hemisphere contralateral to the side of the affected cerebrum. The cerebellar volume loss seemed to correlate with the degree of volume loss in the contralateral cerebral hemisphere. These observations provide morphological evidence of the phenomenon of crossed cerebral-cerebellar diaschisis (CCD. Functional neuroimaging studies in support of the concept of CCD has been critically reviewed.

  16. Autosomal recessive cerebellar ataxias : the current state of affairs

    NARCIS (Netherlands)

    Vermeer, S.; van de Warrenburg, B. P. C.; Willemsen, M. A. A. P.; Cluitmans, M.; Scheffer, H.; Kremer, B. P.; Knoers, N. V. A. M.

    2011-01-01

    Among the hereditary ataxias, autosomal recessive cerebellar ataxias (ARCAs) encompass a diverse group of rare neurodegenerative disorders in which a cerebellar syndrome is the key clinical feature. The clinical overlap between the different cerebellar ataxias, the occasional atypical phenotypes, an

  17. A review on synchronous CDMA systems: optimum overloaded codes, channel capacity, and power control

    Directory of Open Access Journals (Sweden)

    Hosseini Seyed Amirhossein

    2011-01-01

    Full Text Available Abstract This paper is a tutorial review on important issues related to code-division multiple-access (CDMA systems such as channel capacity, power control, and optimum codes; specifically, we consider optimum overloaded codes that achieve errorless transmission in the absence of noise for the binary and nonbinary cases. A survey of lower and upper bounds for the sum channel capacity of such systems is given in the presence and absence of channel noise. The asymptotic results for the channel capacity are also investigated. The channel capacity, errorless transmission codes, and power estimation for near-far effects are also explored. The emphasis of this tutorial review is on the overloaded CDMA systems.

  18. A heme-binding domain controls regulation of ATP-dependent potassium channels.

    Science.gov (United States)

    Burton, Mark J; Kapetanaki, Sofia M; Chernova, Tatyana; Jamieson, Andrew G; Dorlet, Pierre; Santolini, Jérôme; Moody, Peter C E; Mitcheson, John S; Davies, Noel W; Schmid, Ralf; Raven, Emma L; Storey, Nina M

    2016-04-01

    Heme iron has many and varied roles in biology. Most commonly it binds as a prosthetic group to proteins, and it has been widely supposed and amply demonstrated that subtle variations in the protein structure around the heme, including the heme ligands, are used to control the reactivity of the metal ion. However, the role of heme in biology now appears to also include a regulatory responsibility in the cell; this includes regulation of ion channel function. In this work, we show that cardiac KATP channels are regulated by heme. We identify a cytoplasmic heme-binding CXXHX16H motif on the sulphonylurea receptor subunit of the channel, and mutagenesis together with quantitative and spectroscopic analyses of heme-binding and single channel experiments identified Cys628 and His648 as important for heme binding. We discuss the wider implications of these findings and we use the information to present hypotheses for mechanisms of heme-dependent regulation across other ion channels.

  19. Crossed cerebellar hyperperfusion in brain perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Jinnouchi, Seishi; Nagamachi, Shigeki; Nishii, Ryuuichi; Futami, Shigemi; Tamura, Shozo [Miyazaki Medical Coll., Kiyotake (Japan); Kawai, Keiichi

    2000-10-01

    Crossed cerebellar diaschisis is a well-known brain SPECT finding in stroke patients. Few reports, however, have described supratentorial and contralateral cerebellar hyperperfusion (crossed cerebellar hyperperfusion, CCH). We assessed the incidence of CCH in 33 patients with cerebral hyperperfusion. Brain SPECT showed CCH in five patients out of 20 epilepsy and three of 13 patients with acute encephalitis. These eight patients with CCH had recent epileptic attack. CCH was found in ECD SPECT as well as HM-PAO. The contralateral cerebellar activity correlated with the cerebral activity in patients with CCH. CCH would have a relation with supratentrial hyperfunction in epilepsy and acute encephalitis. (author)

  20. [Peripheral neuropathies associated with hereditary cerebellar ataxias].

    Science.gov (United States)

    Anheim, M; Tranchant, C

    2011-01-01

    Inherited cerebellar ataxias constitute a complicated and heterogeneous group of neurodegenerative disorders affecting the cerebellum and/or spinocerebellar tract, spinal cord and peripheral nerves. A peripheral neuropathy is frequently seen in inherited cerebellar ataxias although it rarely reveals the disease. Moreover, the peripheral neuropathy is helpful for the diagnostic procedure and contributes to the functional prognosis of the disease. Thus, electroneuromyography is essential in the algorithm for the diagnosis of inherited cerebellar ataxias, as well as brain MRI (looking especially for cerebellar atrophy) and the assessment of several biomarkers (alpha-foetoprotein, vitamin E, albumin, LDL cholesterol, lactic acid, phytanic acid).

  1. Grip-load force coordination in cerebellar patients.

    Science.gov (United States)

    Serrien, D J; Wiesendanger, M

    1999-09-01

    The study examined the anticipatory grip force modulations to load force changes during a drawer-opening task. An impact force was induced by a mechanical stop which abruptly arrested movement of the pulling hand. In performing this task, normal subjects generated a typical grip force profile characterized by an initial force impulse related to drawer movement onset, followed by a ramp-like grip force increase prior to the impending load perturbation. Finally, a reactive response was triggered by the impact. In patients with bilateral cerebellar dysfunction, the drawer-opening task was performed with an alternative control strategy. During pulling, grip force was increased to a high (overestimated) default level. The latter suggests that cerebellar patients were unable to adjust and to scale precisely the grip force according to the load force. In addition, the latency between impact and reactive activity was prolonged in the patients, suggesting an impaired cerebellar transmission of the long-latency responses. In conclusion, these data demonstrate the involvement of cerebellar circuits in both proactive and reactive mechanisms in view of predictable load perturbations during manipulative behavior. PMID:10473743

  2. Mapping the development of cerebellar Purkinje cells in zebrafish.

    Science.gov (United States)

    Hamling, Kyla R; Tobias, Zachary J C; Weissman, Tamily A

    2015-11-01

    The cells that comprise the cerebellum perform a complex integration of neural inputs to influence motor control and coordination. The functioning of this circuit depends upon Purkinje cells and other cerebellar neurons forming in the precise place and time during development. Zebrafish provide a useful platform for modeling disease and studying gene function, thus a quantitative metric of normal zebrafish cerebellar development is key for understanding how gene mutations affect the cerebellum. To begin to quantitatively measure cerebellar development in zebrafish, we have characterized the spatial and temporal patterning of Purkinje cells during the first 2 weeks of development. Differentiated Purkinje cells first emerged by 2.8 days post fertilization and were spatially patterned into separate dorsomedial and ventrolateral clusters that merged at around 4 days. Quantification of the Purkinje cell layer revealed that there was a logarithmic increase in both Purkinje cell number as well as overall volume during the first 2 weeks, while the entire region curved forward in an anterior, then ventral direction. Purkinje cell dendrites were positioned next to parallel fibers as early as 3.3 days, and Purkinje cell diameter decreased significantly from 3.3 to 14 days, possibly due to cytoplasmic reappropriation into maturing dendritic arbors. A nearest neighbor analysis showed that Purkinje cells moved slightly apart from each other from 3 to 14 days, perhaps spreading as the organized monolayer forms. This study establishes a quantitative spatiotemporal map of Purkinje cell development in zebrafish that provides an important metric for studies of cerebellar development and disease.

  3. Neural correlates of cerebellar-mediated timing during finger tapping in children with fetal alcohol spectrum disorders

    Directory of Open Access Journals (Sweden)

    Lindie du Plessis

    2015-01-01

    Conclusions: The four cerebellar areas activated by the controls more during rhythmic than non-rhythmic tapping have been implicated in the production of timed responses in several previous studies. These data provide evidence linking binge-like drinking during pregnancy to poorer function in cerebellar regions involved in timing and somatosensory processing needed for complex tasks requiring precise timing.

  4. Fetal MRI and antenatal diagnosis of unilateral cerebellar hypoplasia

    OpenAIRE

    Houda El Mhabrech; Ahmed Zrig; Chiraz Hafsa

    2015-01-01

    Focal cerebellar hypoplasia is restricted to one cerebellar hemisphere or to the vermis. Prenatal diagnosis of unilateral cerebellar hypoplasia is possible by the use of ultrasound and MRI. Familiarity with the prenatal MRI findings is essential to recognize cerebellar pathologies accurately and prospectively. We present US and MRI findings in a fetus with cerebellar malformation at 20 weeks gestation. The goal of our case report is to present the fetal MRI findings of unilateral cerebellar h...

  5. Dissociation of locomotor and cerebellar deficits in a murine Angelman syndrome model.

    Science.gov (United States)

    Bruinsma, Caroline F; Schonewille, Martijn; Gao, Zhenyu; Aronica, Eleonora M A; Judson, Matthew C; Philpot, Benjamin D; Hoebeek, Freek E; van Woerden, Geeske M; De Zeeuw, Chris I; Elgersma, Ype

    2015-11-01

    Angelman syndrome (AS) is a severe neurological disorder that is associated with prominent movement and balance impairments that are widely considered to be due to defects of cerebellar origin. Here, using the cerebellar-specific vestibulo-ocular reflex (VOR) paradigm, we determined that cerebellar function is only mildly impaired in the Ube3am-/p+ mouse model of AS. VOR phase-reversal learning was singularly impaired in these animals and correlated with reduced tonic inhibition between Golgi cells and granule cells. Purkinje cell physiology, in contrast, was normal in AS mice as shown by synaptic plasticity and spontaneous firing properties that resembled those of controls. Accordingly, neither VOR phase-reversal learning nor locomotion was impaired following selective deletion of Ube3a in Purkinje cells. However, genetic normalization of αCaMKII inhibitory phosphorylation fully rescued locomotor deficits despite failing to improve cerebellar learning in AS mice, suggesting extracerebellar circuit involvement in locomotor learning. We confirmed this hypothesis through cerebellum-specific reinstatement of Ube3a, which ameliorated cerebellar learning deficits but did not rescue locomotor deficits. This double dissociation of locomotion and cerebellar phenotypes strongly suggests that the locomotor deficits of AS mice do not arise from impaired cerebellar cortex function. Our results provide important insights into the etiology of the motor deficits associated with AS. PMID:26485287

  6. Cerebellar and pontine tegmental hypermetabolism in miller-fisher syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Kyrong; Kim, Ji Soo; Lee, Won Woo; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    Miller Fisher syndrome (MFS) has been considered as a variant of Guillain-Barre syndrome (GBS), a type of acute immune neuropathies involving peripheral nerve system. Unlike GBS, presence of cerebellar type ataxia and supranuclear ophthalmioplesia in MFS suggests additional involvement of the central nervous system. To determine involvement of the central nervous system in MFS, we investigated the cerebral metabolic abnormalities in patients with MFS using FDG PET. Nine patients who were diagnosed as MFS based on acute ophthalmoplegia, ataxia, and areflexia without other identifiable causes participated in this study. In six patients, serum antibodies possibly related with symptom of MFS (anti- GQ1b or anti-GM1) were detected at the time of the study. With the interval of 25 26 days (range: 3-83 days) from the symptom on set, brain FDG PET were underwent in patients and compared with those from healthy controls. In group analysis comparing with healthy controls, FDG PET of patients revealed increased metabolism in the bilateral cerebellar hemispheres and vermis, and the thalamus. In contrast, the occipital cortex showed decreased metabolism. Individual analyses disclosed hypermetabolism in the cerebellar vermis or hemispheres in 5, and in the pontine tegmentum in 2 of the 9 patients. We also found that the cerebellar vermian hypermetabolism was inversely correlated with the interval between from the symptom on set to PET study. Moreover, follow-up PET of a patient demonstrated that cerebellar hypermetabolism decreased markedly with an improvement of the ophthalmoplegia and ataxia. These findings indicate an involvement of the central nervous system in MFS and suggest an antibody-associated acute inflammatory process as a mechanism of this disorder.

  7. Filtering random matrices: the effect of incomplete channel control in multiple scattering.

    Science.gov (United States)

    Goetschy, A; Stone, A D

    2013-08-01

    We present an analytic random matrix theory for the effect of incomplete channel control on the measured statistical properties of the scattering matrix of a disordered multiple-scattering medium. When the fraction of the controlled input channels, m1, and output channels, m2, is decreased from unity, the density of the transmission eigenvalues is shown to evolve from the bimodal distribution describing coherent diffusion, to the distribution characteristic of uncorrelated Gaussian random matrices, with a rapid loss of access to the open eigenchannels. The loss of correlation is also reflected in an increase in the information capacity per channel of the medium. Our results have strong implications for optical and microwave experiments on diffusive scattering media. PMID:23971574

  8. NUMERICAL SIMULATION OF ICE CONTROL EFFECT OF SOLAR ENERGY ON TIBETAN CHANNELS

    Institute of Scientific and Technical Information of China (English)

    AN Rui-dong; CHEN Ming-qian; LI Ran; Banjiuciren; SHI Yun-qiang

    2007-01-01

    With the Tanghe Diversion Channel in Tibet as an example, the theoretical study on the ice control effect of the solar sacks was conducted based on the previous study. The numerical simulation method was adopted and a one-dimensional numerical model for ice crystal in diversion channels in high-altitude cold regions was developed in this article. The heat transfer through the air-water interface and the mass transfer between ice and water were considered in the model. The model was validated by the field observation data on the diversion channel of the Tanghe Hydropower Station. The results show that the ice control effect of the solar sacks is obvious in the channel with large mass flow rate in the high-altitude cold regions.

  9. Aperiodic Linear Networked Control Considering Variable Channel Delays: Application to Robots Coordination

    Directory of Open Access Journals (Sweden)

    Carlos Santos

    2015-05-01

    Full Text Available One of the main challenges in wireless cyber-physical systems is to reduce the load of the communication channel while preserving the control performance. In this way, communication resources are liberated for other applications sharing the channel bandwidth. The main contribution of this work is the design of a remote control solution based on an aperiodic and adaptive triggering mechanism considering the current network delay of multiple robotics units. Working with the actual network delay instead of the maximum one leads to abandoning this conservative assumption, since the triggering condition is fixed depending on the current state of the network. This way, the controller manages the usage of the wireless channel in order to reduce the channel delay and to improve the availability of the communication resources. The communication standard under study is the widespread IEEE 802.11g, whose channel delay is clearly uncertain. First, the adaptive self-triggered control is validated through the TrueTime simulation tool configured for the mentioned WiFi standard. Implementation results applying the aperiodic linear control laws on four P3-DX robots are also included. Both of them demonstrate the advantage of this solution in terms of network accessing and control performance with respect to periodic and non-adaptive self-triggered alternatives.

  10. Deficits in reflexive covert attention following cerebellar injury.

    Science.gov (United States)

    Striemer, Christopher L; Cantelmi, David; Cusimano, Michael D; Danckert, James A; Schweizer, Tom A

    2015-01-01

    Traditionally the cerebellum has been known for its important role in coordinating motor output. Over the past 15 years numerous studies have indicated that the cerebellum plays a role in a variety of cognitive functions including working memory, language, perceptual functions, and emotion. In addition, recent work suggests that regions of the cerebellum involved in eye movements also play a role in controlling covert visual attention. Here we investigated whether regions of the cerebellum that are not strictly tied to the control of eye movements might also contribute to covert attention. To address this question we examined the effects of circumscribed cerebellar lesions on reflexive covert attention in a group of patients (n = 11) without any gross motor or oculomotor deficits, and compared their performance to a group of age-matched controls (n = 11). Results indicated that the traditional RT advantage for validly cued targets was significantly smaller at the shortest (50 ms) SOA for cerebellar patients compared to controls. Critically, a lesion overlap analysis indicated that this deficit in the rapid deployment of attention was linked to damage in Crus I and Crus II of the lateral cerebellum. Importantly, both cerebellar regions have connections to non-motor regions of the prefrontal and posterior parietal cortices-regions important for controlling visuospatial attention. Together, these data provide converging evidence that both lateral and midline regions of the cerebellum play an important role in the control of reflexive covert visual attention. PMID:26300756

  11. Deficits in reflexive covert attention following cerebellar injury.

    Directory of Open Access Journals (Sweden)

    Christopher eStriemer

    2015-08-01

    Full Text Available Traditionally the cerebellum has been known for its important role in coordinating motor output. Over the past fifteen years numerous studies have indicated that the cerebellum plays a role in a variety of cognitive functions including working memory, language, perceptual functions, and emotion. In addition, recent work suggests that regions of the cerebellum involved in eye movements also play a role in controlling covert visual attention. Here we investigated whether regions of the cerebellum that are not strictly tied to the control of eye movements might also contribute to covert attention. To address this question we examined the effects of circumscribed cerebellar lesions on reflexive covert attention in a group of patients (n=11 without any gross motor or oculomotor deficits, and compared their performance to a group of age-matched controls (n=11. Results indicated that the traditional RT advantage for validly cued targets was significantly smaller at the shortest (50ms SOA for cerebellar patients compared to controls. Critically, a lesion overlap analysis indicated that this deficit in the rapid deployment of attention was linked to damage in Crus I and Crus II of the lateral cerebellum. Importantly, both cerebellar regions have connections to non-motor regions of the prefrontal and posterior parietal cortices – regions important for controlling visuospatial attention. Together, these data provide converging evidence that both lateral and midline regions of the cerebellum play an important role in the control of reflexive covert visual attention.

  12. Cognitive planning deficit in patients with cerebellar atrophy.

    Science.gov (United States)

    Grafman, J; Litvan, I; Massaquoi, S; Stewart, M; Sirigu, A; Hallett, M

    1992-08-01

    We compared the performance of 12 patients with cerebellar atrophy (CA) and 12 normal controls matched for age and education on the Tower of Hanoi, a nine-problem task that requires cognitive planning. CA patients performed significantly worse than controls on this task despite no difference in planning and between-move pause times. A reanalysis of the data using just the subgroup of patients with pure cerebellar cortical atrophy (CCA) (N = 9) replicated the above results and also showed that CCA patients had significantly increased planning times compared with controls. Neither age, sex, education level, severity of dementia, word fluency, response time, memory, nor visuomotor procedural learning predicted CA or CCA performance. This deficit in cognitive planning suggests a functional link between the cerebellum, basal ganglia, and the frontal lobe concerning specific cognitive processes. However, the exact role of the cerebellum in cognitive planning remains undetermined. PMID:1641142

  13. A novel adaptive joint power control algorithm with channel estimation in a CDMA cellular system

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Joint power control has advantages of multi-user detection and power control; and it can combat the multi-access interference and the near-far problem. A novel adaptive joint power control algorithm with channel estimation in a CDMA cellular system was designed. Simulation results show that the algorithm can control the power not only quickly but also precisely with a time change. The method is useful for increasing system capacity.

  14. Unsteady transonic flow control around an airfoil in a channel

    Science.gov (United States)

    Hamid, Md. Abdul; Hasan, A. B. M. Toufique; Ali, Mohammad; Mitsutake, Yuichi; Setoguchi, Toshiaki; Yu, Shen

    2016-04-01

    Transonic internal flow around an airfoil is associated with self-excited unsteady shock wave oscillation. This unsteady phenomenon generates buffet, high speed impulsive noise, non-synchronous vibration, high cycle fatigue failure and so on. Present study investigates the effectiveness of perforated cavity to control this unsteady flow field. The cavity has been incorporated on the airfoil surface. The degree of perforation of the cavity is kept constant as 30%. However, the number of openings (perforation) at the cavity upper wall has been varied. Results showed that this passive control reduces the strength of shock wave compared to that of baseline airfoil. As a result, the intensity of shock wave/boundary layer interaction and the root mean square (RMS) of pressure oscillation around the airfoil have been reduced with the control method.

  15. Long lasting cerebellar alterations after perinatal asphyxia in rats.

    Science.gov (United States)

    Campanille, Verónica; Saraceno, G Ezequiel; Rivière, Stéphanie; Logica, Tamara; Kölliker, Rodolfo; Capani, Francisco; Castilla, Rocío

    2015-07-01

    The developing brain may be particularly vulnerable to injury before, at and after birth. Among possible insults, hypoxia suffered as a consequence of perinatal asphyxia (PA) exhibits the highest incidence levels and the cerebellar circuitry appears to be particularly susceptible, as the cellular makeup and the quantity of inputs change quickly during days and weeks following birth. In this work, we have used a murine model to induce severe global PA in rats at the time of birth. Short-term cerebellar alterations within this PA model have been previously reported but whether such alterations remain in adulthood has not been conclusively determined yet. For this reason, and given the crucial cerebellar role in determining connectivity patterns in the brain, the aim of our work is to unveil long-term cerebellum histomorphology following a PA insult. Morphological and cytological neuronal changes and glial reaction in the cerebellar cortex were analyzed at postnatal 120 (P120) following injury performed at birth. As compared to control, PA animals exhibited: (1) an increase in molecular and granular thickness, both presenting lower cellular density; (2) a disarrayed Purkinje cell layer presenting a higher number of anomalous calbindin-stained cells. (3) focal swelling and marked fragmentation of microtubule-associated protein 2 (MAP-2) in Purkinje cell dendrites and, (4) an increase in glial fibrillary acidic protein (GFAP) expression in Bergmann cells and the granular layer. In conclusion, we demonstrate that PA produces long-term damage in cellular histomorphology in rat cerebellar cortex which could be involved in the pathogenesis of cognitive deficits observed in both animals and humans.

  16. Long lasting cerebellar alterations after perinatal asphyxia in rats.

    Science.gov (United States)

    Campanille, Verónica; Saraceno, G Ezequiel; Rivière, Stéphanie; Logica, Tamara; Kölliker, Rodolfo; Capani, Francisco; Castilla, Rocío

    2015-07-01

    The developing brain may be particularly vulnerable to injury before, at and after birth. Among possible insults, hypoxia suffered as a consequence of perinatal asphyxia (PA) exhibits the highest incidence levels and the cerebellar circuitry appears to be particularly susceptible, as the cellular makeup and the quantity of inputs change quickly during days and weeks following birth. In this work, we have used a murine model to induce severe global PA in rats at the time of birth. Short-term cerebellar alterations within this PA model have been previously reported but whether such alterations remain in adulthood has not been conclusively determined yet. For this reason, and given the crucial cerebellar role in determining connectivity patterns in the brain, the aim of our work is to unveil long-term cerebellum histomorphology following a PA insult. Morphological and cytological neuronal changes and glial reaction in the cerebellar cortex were analyzed at postnatal 120 (P120) following injury performed at birth. As compared to control, PA animals exhibited: (1) an increase in molecular and granular thickness, both presenting lower cellular density; (2) a disarrayed Purkinje cell layer presenting a higher number of anomalous calbindin-stained cells. (3) focal swelling and marked fragmentation of microtubule-associated protein 2 (MAP-2) in Purkinje cell dendrites and, (4) an increase in glial fibrillary acidic protein (GFAP) expression in Bergmann cells and the granular layer. In conclusion, we demonstrate that PA produces long-term damage in cellular histomorphology in rat cerebellar cortex which could be involved in the pathogenesis of cognitive deficits observed in both animals and humans. PMID:26116983

  17. Cerebellar motor learning: are environment dynamics more important than error size?

    OpenAIRE

    Gibo, Tricia L.; Criscimagna-Hemminger, Sarah E.; Okamura, Allison M.; Bastian, Amy J.

    2013-01-01

    Cerebellar damage impairs the control of complex dynamics during reaching movements. It also impairs learning of predictable dynamic perturbations through an error-based process. Prior work suggests that there are distinct neural mechanisms involved in error-based learning that depend on the size of error experienced. This is based, in part, on the observation that people with cerebellar degeneration may have an intact ability to learn from small errors. Here we studied the relative effect of...

  18. The clinical presentation of preterm cerebellar haemorrhage

    NARCIS (Netherlands)

    G.M. Ecury-Goossen (Ginette); J. Dudink (Jeroen); M. Leguin (Maarten); M. Feijen-Roon (Monique); S. Horsch (Sandra); P. Govaert (Paul)

    2010-01-01

    textabstractThe objective of this study was to evaluate clinical symptoms and findings on cranial ultrasound (CUS) in preterm infants with cerebellar haemorrhage through retrospective analysis of all preterm infants with a postnatal CUS or MRI diagnosis of cerebellar haemorrhage admitted in a tertia

  19. Research Spotlight: What controls the shape of sediment channels in river deltas?

    Science.gov (United States)

    Tretkoff, Ernie

    2011-03-01

    When turbulent, sediment-filled rivers empty into oceans and lakes, the channels often divide repeatedly to form triangular deltas. Some channels, however, travel long distances before bifurcating, creating elongated channels. Understanding how these patterns arise could be useful for designing wetland restoration schemes on river deltas. Seeking to explain the conditions under which elongated channels form, Falcini and Jerolmack considered an analogy with cold filaments in ocean currents, in which high potential vorticity (a measure that combines the rotation of a flow with its thermal gradient) helps a filament hold a coherent structure over long distances. The researchers introduced a model that incorporates sediment concentration and fluid vorticity, to derive a new “potential vorticity” equation that describes sedimentation patterns at the river mouth. Their model shows that a high potential vorticity is needed for the creation of elongated channels, and their comparison to modeling, laboratory, and field studies confirms that potential vorticity is a primary control on channel morphology. The new model could help to understand the shape of the iconic Mississippi River delta and may aid in the design of proposed channel diversions there and in other deltas. (Journal of Geophysical Research-Earth Surface, doi:10.1029/2010JF001802, 2010)

  20. Altered Functional Connectivity of Cognitive-Related Cerebellar Subregions in Well-Recovered Stroke Patients

    Directory of Open Access Journals (Sweden)

    Wei Li

    2013-01-01

    Full Text Available The cerebellum contains several cognitive-related subregions that are involved in different functional networks. The cerebellar crus II is correlated with the frontoparietal network (FPN, whereas the cerebellar IX is associated with the default-mode network (DMN. These two networks are anticorrelated and cooperatively implicated in cognitive control, which may facilitate the motor recovery in stroke patients. In the present study, we aimed to investigate the resting-state functional connectivity (rsFC changes in 25 subcortical ischemic stroke patients with well-recovered global motor function. Consistent with previous studies, the crus II was correlated with the FPN, including the dorsolateral prefrontal cortex (DLPFC and posterior parietal cortex, and the cerebellar IX was correlated with the DMN, including the posterior cingulate cortex/precuneus (PCC/Pcu, medial prefrontal cortex (MPFC, DLPFC, lateral parietal cortices, and anterior temporal cortices. No significantly increased rsFCs of these cerebellar subregions were found in stroke patients, suggesting that the rsFCs of the cognitive-related cerebellar subregions are not the critical factors contributing to the recovery of motor function in stroke patients. The finding of the disconnection in the cerebellar-related cognitive control networks may possibly explain the deficits in cognitive control function even in stroke patients with well-recovered global motor function.

  1. Control of mesoscopic transport by modifying transmission channels in opaque media

    CERN Document Server

    Sarma, Raktim; Liew, Seng Fatt; Guy, Mikhael; Cao, Hui

    2015-01-01

    While controlling particle diffusion in a confined geometry is a popular approach taken by both natural and artificial systems, it has not been widely adopted for controlling light transport in random media, where wave interference effects play a critical role. The transmission eigenchannels determine not only light propagation through the disordered system but also the energy concentrated inside. Here we propose and demonstrate an effective approach to modify these channels, whose structures are considered to be universal in conventional diffusive waveguides. By adjusting the waveguide geometry, we are able to alter the spatial profiles of the transmission eigenchannels significantly and deterministically from the universal ones. In addition, propagating channels may be converted to evanescent channels or vice versa by tapering the waveguide cross-section. Our approach allows to control not only the transmitted and reflected light, but also the depth profile of energy density inside the scattering system. In...

  2. The mechano-activated K+ channels TRAAK and TREK-1 control both warm and cold perception.

    Science.gov (United States)

    Noël, Jacques; Zimmermann, Katharina; Busserolles, Jérome; Deval, Emanuel; Alloui, Abdelkrim; Diochot, Sylvie; Guy, Nicolas; Borsotto, Marc; Reeh, Peter; Eschalier, Alain; Lazdunski, Michel

    2009-05-01

    The sensation of cold or heat depends on the activation of specific nerve endings in the skin. This involves heat- and cold-sensitive excitatory transient receptor potential (TRP) channels. However, we show here that the mechano-gated and highly temperature-sensitive potassium channels of the TREK/TRAAK family, which normally work as silencers of the excitatory channels, are also implicated. They are important for the definition of temperature thresholds and temperature ranges in which excitation of nociceptor takes place and for the intensity of excitation when it occurs. They are expressed with thermo-TRP channels in sensory neurons. TRAAK and TREK-1 channels control pain produced by mechanical stimulation and both heat and cold pain perception in mice. Expression of TRAAK alone or in association with TREK-1 controls heat responses of both capsaicin-sensitive and capsaicin-insensitive sensory neurons. Together TREK-1 and TRAAK channels are important regulators of nociceptor activation by cold, particularly in the nociceptor population that is not activated by menthol.

  3. Cellular and molecular basis of cerebellar development

    Science.gov (United States)

    Martinez, Salvador; Andreu, Abraham; Mecklenburg, Nora; Echevarria, Diego

    2013-01-01

    Historically, the molecular and cellular mechanisms of cerebellar development were investigated through structural descriptions and studying spontaneous mutations in animal models and humans. Advances in experimental embryology, genetic engineering, and neuroimaging techniques render today the possibility to approach the analysis of molecular mechanisms underlying histogenesis and morphogenesis of the cerebellum by experimental designs. Several genes and molecules were identified to be involved in the cerebellar plate regionalization, specification, and differentiation of cerebellar neurons, as well as the establishment of cellular migratory routes and the subsequent neuronal connectivity. Indeed, pattern formation of the cerebellum requires the adequate orchestration of both key morphogenetic signals, arising from distinct brain regions, and local expression of specific transcription factors. Thus, the present review wants to revisit and discuss these morphogenetic and molecular mechanisms taking place during cerebellar development in order to understand causal processes regulating cerebellar cytoarchitecture, its highly topographically ordered circuitry and its role in brain function. PMID:23805080

  4. Cellular and Molecular Basis of Cerebellar Development

    Directory of Open Access Journals (Sweden)

    Salvador eMartinez

    2013-06-01

    Full Text Available Historically, the molecular and cellular mechanisms of cerebellar development were investigated through structural descriptions and studying spontaneous mutations in animal models and humans. Advances in experimental embryology, genetic engineering and neuroimaging techniques render today the possibility to approach the analysis of molecular mechanisms underlying histogenesis and morphogenesis of the cerebellum by experimental designs. Several genes and molecules were identified to be involved in the cerebellar plate regionalization, specification and differentiation of cerebellar neurons, as well as the establishment of cellular migratory routes and the subsequent neuronal connectivity. Indeed, pattern formation of the cerebellum requires the adequate orchestration of both key morphogenetic signals, arising from distinct brain regions, and local expression of specific transcription factors. Thus, the present review wants to revisit and discuss these morphogenetic and molecular mechanisms taking place during cerebellar development in order to understand causal processes regulating cerebellar cytoarchitecture, its highly topographically ordered circuitry and its role in brain function.

  5. Cerebellar stroke-manifesting as mania

    Directory of Open Access Journals (Sweden)

    Venkatesan Jagadesan

    2014-01-01

    Full Text Available Secondary mania resulting from cerebral Cortex are described commonly. But secondary mania produced by cerebellar lesions are relatively uncommon. This case report describes a patient who developed cerebellar stoke and manic features simultaneously. 28 years old male developed giddiness and projectile vomiting. Then he would lie down for about an hour only to find that he could not walk. He became quarrelsome. His Psycho motor activities and speech were increased. He was euphoric and was expressing grandiose ideas. Bender Gestalt Test showed signs of organicity. Score in Young mania relating scale was 32; productivity was low in Rorschach. Neurological examination revealed left cerebellar signs like ataxia and slurring of speech. Computed tomography of brain showed left cerebellar infarct. Relationship between Psychiatric manifestations and cerebellar lesion are discussed.

  6. KATP channels are not essential for pressure-dependent control of renin secretion

    DEFF Research Database (Denmark)

    Jensen, B L; Gambaryan, S; Scholz, H;

    1998-01-01

    This study aimed to investigate the functional role of ATP-sensitive K+ (KATP) channels in the control of renin secretion by renal perfusion pressure. We studied the effect of openers and blockers of KATP-channels on basal- and low-pressure-induced renin secretion from isolated perfused rat kidneys......, all of which suggests that KATP channel openers stimulate renin secretion at the level of JG cells. A decrease in the perfusion pressure from 13.3 to 9.33 kPa (100 mmHg to 70 mmHg) increased renin secretion twofold, and cromakalim further increased renin secretion. At 5.33 kPa (40 mmHg) renin...... pathway that includes a decrease in JG cell calcium. KATP channels are not essentially involved in pressure-sensitive renin secretion....

  7. Differential Modulation of GABAA Receptors Underlies Postsynaptic Depolarization- and Purinoceptor-Mediated Enhancement of Cerebellar Inhibitory Transmission: A Non-Stationary Fluctuation Analysis Study

    Science.gov (United States)

    Ono, Yumie; Saitow, Fumihito; Konishi, Shiro

    2016-01-01

    Cerebellar GABAergic inhibitory transmission between interneurons and Purkinje cells (PCs) undergoes a long-lasting enhancement following different stimulations, such as brief depolarization or activation of purinergic receptors of postsynaptic PCs. The underlying mechanisms, however, are not completely understood. Using a peak-scaled non-stationary fluctuation analysis, we therefore aimed at characterizing changes in the electrophysiological properties of GABAA receptors in PCs of rat cerebellar cortex during depolarization-induced “rebound potentiation (RP)” and purinoceptor-mediated long-term potentiation (PM-LTP), because both RP and PM-LTP likely depend on postsynaptic mechanisms. Stimulation-evoked inhibitory postsynaptic currents (eIPSCs) were recorded from PCs in neonatal rat cerebellar slices. Our analysis showed that postsynaptic membrane depolarization induced RP of eIPSCs in association with significant increase in the number of synaptic GABAA receptors without changing the channel conductance. By contrast, bath application of ATP induced PM-LTP of eIPSCs with a significant increase of the channel conductance of GABAA receptors without affecting the receptor number. Pretreatment with protein kinase A (PKA) inhibitors, H-89 and cAMPS-Rp, completely abolished the PM-LTP. The CaMKII inhibitor KN-62 reported to abolish RP did not alter PM-LTP. These results suggest that the signaling mechanism underlying PM-LTP could involve ATP-induced phosphorylation of synaptic GABAA receptors, thereby resulting in upregulation of the channel conductance by stimulating adenylyl cyclase-PKA signaling cascade, possibly via activation of P2Y11 purinoceptor. Thus, our findings reveal that postsynaptic GABAA receptors at the interneuron-PC inhibitory synapses are under the control of two distinct forms of long-term potentiation linked with different second messenger cascades. PMID:26930485

  8. Differential Modulation of GABAA Receptors Underlies Postsynaptic Depolarization- and Purinoceptor-Mediated Enhancement of Cerebellar Inhibitory Transmission: A Non-Stationary Fluctuation Analysis Study.

    Directory of Open Access Journals (Sweden)

    Yumie Ono

    Full Text Available Cerebellar GABAergic inhibitory transmission between interneurons and Purkinje cells (PCs undergoes a long-lasting enhancement following different stimulations, such as brief depolarization or activation of purinergic receptors of postsynaptic PCs. The underlying mechanisms, however, are not completely understood. Using a peak-scaled non-stationary fluctuation analysis, we therefore aimed at characterizing changes in the electrophysiological properties of GABAA receptors in PCs of rat cerebellar cortex during depolarization-induced "rebound potentiation (RP" and purinoceptor-mediated long-term potentiation (PM-LTP, because both RP and PM-LTP likely depend on postsynaptic mechanisms. Stimulation-evoked inhibitory postsynaptic currents (eIPSCs were recorded from PCs in neonatal rat cerebellar slices. Our analysis showed that postsynaptic membrane depolarization induced RP of eIPSCs in association with significant increase in the number of synaptic GABAA receptors without changing the channel conductance. By contrast, bath application of ATP induced PM-LTP of eIPSCs with a significant increase of the channel conductance of GABAA receptors without affecting the receptor number. Pretreatment with protein kinase A (PKA inhibitors, H-89 and cAMPS-Rp, completely abolished the PM-LTP. The CaMKII inhibitor KN-62 reported to abolish RP did not alter PM-LTP. These results suggest that the signaling mechanism underlying PM-LTP could involve ATP-induced phosphorylation of synaptic GABAA receptors, thereby resulting in upregulation of the channel conductance by stimulating adenylyl cyclase-PKA signaling cascade, possibly via activation of P2Y11 purinoceptor. Thus, our findings reveal that postsynaptic GABAA receptors at the interneuron-PC inhibitory synapses are under the control of two distinct forms of long-term potentiation linked with different second messenger cascades.

  9. CALCULATION METHODS OF OPTIMAL ADJUSTMENT OF CONTROL SYSTEM THROUGH DISTURBANCE CHANNEL

    Directory of Open Access Journals (Sweden)

    I. M. Golinko

    2014-01-01

    Full Text Available In the process of automatic control system debugging the great attention is paid to determining formulas’ parameters of optimal dynamic adjustment of regulators, taking into account the dynamics of Objects control. In most cases the known formulas are oriented on design of automatic control system through channel “input-output definition”. But practically in all continuous processes the main task of all regulators is stabilization of output parameters. The Methods of parameters calculation for dynamic adjustment of regulations were developed. These methods allow to optimize the analog and digital regulators, taking into account minimization of regulated influences. There were suggested to use the fact of detuning and maximum value of regulated influence. As the automatic control system optimization with proportional plus reset controllers on disturbance channel is an unimodal task, the main algorithm of optimization is realized by Hooke – Jeeves method. For controllers optimization through channel external disturbance there were obtained functional dependences of parameters calculations of dynamic proportional plus reset controllers from dynamic characteristics of Object control. The obtained dependences allow to improve the work of controllers (regulators of automatic control on external disturbance channel and so it allows to improve the quality of regulation of transient processes. Calculation formulas provide high accuracy and convenience in usage. In suggested method there are no nomographs and this fact expels subjectivity of investigation in determination of parameters of dynamic adjustment of proportional plus reset controllers. Functional dependences can be used for calculation of adjustment of PR controllers in a great range of change of dynamic characteristics of Objects control.

  10. Channel control ASIC for the CMS hadron calorimeter front end readout module

    International Nuclear Information System (INIS)

    The Channel Control ASIC (CCA) is used along with a custom Charge Integrator and Encoder (QIE) ASIC to digitize signals from the hybrid photo diodes (HPDs) and photomultiplier tubes (PMTs) in the CMS hadron calorimeter. The CCA sits between the QIE and the data acquisition system. All digital signals to and from the QIE pass through the CCA chip. One CCA chip interfaces with two QIE channels. The CCA provides individually delayed clocks to each of the QIE chips in addition to various control signals. The QIE sends digitized PMT or HPD signals and time slice information to the CCA, which sends the data to the data acquisition system through an optical link

  11. Three-Party Controlled Quantum Teleportation with Six-Photon Entangled States via Collective Noise Channel

    International Nuclear Information System (INIS)

    Two three-party controlled quantum teleportation protocols using six-photon entangled states are proposed for circumventing collective noise. It can be performed in collective-dephasing noise or collective-rotation noise with unitary successful probability. Due to the symmetry of the quantum channel, each participant can act as a sender, a receiver or a controller. Moreover, it can be generalized to multiparty controlled teleportation protocols. (authors)

  12. An external sodium ion binding site controls allosteric gating in TRPV1 channels.

    Science.gov (United States)

    Jara-Oseguera, Andres; Bae, Chanhyung; Swartz, Kenton J

    2016-01-01

    TRPV1 channels in sensory neurons are integrators of painful stimuli and heat, yet how they integrate diverse stimuli and sense temperature remains elusive. Here, we show that external sodium ions stabilize the TRPV1 channel in a closed state, such that removing the external ion leads to channel activation. In studying the underlying mechanism, we find that the temperature sensors in TRPV1 activate in two steps to favor opening, and that the binding of sodium to an extracellular site exerts allosteric control over temperature-sensor activation and opening of the pore. The binding of a tarantula toxin to the external pore also exerts control over temperature-sensor activation, whereas binding of vanilloids influences temperature-sensitivity by largely affecting the open/closed equilibrium. Our results reveal a fundamental role of the external pore in the allosteric control of TRPV1 channel gating and provide essential constraints for understanding how these channels can be tuned by diverse stimuli. PMID:26882503

  13. T-Type Calcium Channel: A Privileged Gate for Calcium Entry and Control of Adrenal Steroidogenesis.

    Science.gov (United States)

    Rossier, Michel F

    2016-01-01

    Intracellular calcium plays a crucial role in modulating a variety of functions such as muscle contraction, hormone secretion, gene expression, or cell growth. Calcium signaling has been however shown to be more complex than initially thought. Indeed, it is confined within cell microdomains, and different calcium channels are associated with different functions, as shown by various channelopathies. Sporadic mutations on voltage-operated L-type calcium channels in adrenal glomerulosa cells have been shown recently to be the second most prevalent genetic abnormalities present in human aldosterone-producing adenoma. The observed modification of the threshold of activation of the mutated channels not only provides an explanation for this gain of function but also reminds us on the importance of maintaining adequate electrophysiological characteristics to make channels able to exert specific cellular functions. Indeed, the contribution to steroid production of the various calcium channels expressed in adrenocortical cells is not equal, and the reason has been investigated for a long time. Given the very negative resting potential of these cells, and the small membrane depolarization induced by their physiological agonists, low threshold T-type calcium channels are particularly well suited for responding under these conditions and conveying calcium into the cell, at the right place for controlling steroidogenesis. In contrast, high threshold L-type channels are normally activated by much stronger cell depolarizations. The fact that dihydropyridine calcium antagonists, specific for L-type channels, are poorly efficient for reducing aldosterone secretion either in vivo or in vitro, strongly supports the view that these two types of channels differently affect steroid biosynthesis. Whether a similar analysis is transposable to fasciculata cells and cortisol secretion is one of the questions addressed in the present review. No similar mutations on L-type or T-type channels

  14. T-type calcium channel: a privileged gate for calcium entry and control of adrenal steroidogenesis

    Directory of Open Access Journals (Sweden)

    Michel Florian Rossier

    2016-05-01

    Full Text Available Intracellular calcium plays a crucial role in modulating a variety of functions such as muscle contraction, hormone secretion, gene expression or cell growth. Calcium signaling has been however shown to be more complex than initially thought. Indeed, it is confined within cell microdomains and different calcium channels are associated with different functions, as shown by various channelopathies.Sporadic mutations on voltage-operated L-type calcium channels in adrenal glomerulosa cells have been shown recently to be the second most prevalent genetic abnormalities present in human aldosterone-producing adenoma. The observed modification of the threshold of activation of the mutated channels not only provides an explanation for this gain of function but reminds us on the importance of maintaining adequate electrophysiological characteristics to make channels able to exert specific cellular functions. Indeed, the contribution to steroid production of the various calcium channels expressed in adrenocortical cells is not equal and the reason has been investigated for a long time. Given the very negative resting potential of these cells, and the small membrane depolarization induced by their physiological agonists, low threshold T-type calcium channels are particularly well suited for responding under these conditions and conveying calcium into the cell, at the right place for controlling steroidogenesis. In contrast, high threshold L-type channels are normally activated by much stronger cell depolarizations. The fact that dihydropyridine calcium antagonists, specific for L-type channels, are poorly efficient for reducing aldosterone secretion either in vivo or in vitro, strongly supports the view that these two types of channels differently affect steroid biosynthesis.Whether a similar analysis is transposable to fasciculata cells and cortisol secretion is one of the questions addressed in the present review. No similar mutations on L-type or T

  15. Integrated plasticity at inhibitory and excitatory synapses in the cerebellar circuit

    Directory of Open Access Journals (Sweden)

    Lisa eMapelli

    2015-05-01

    Full Text Available The way long-term potentiation (LTP and depression (LTD are integrated within the different synapses of brain neuronal circuits is poorly understood. In order to progress beyond the identification of specific molecular mechanisms, a system in which multiple forms of plasticity can be correlated with large-scale neural processing is required. In this paper we take as an example the cerebellar network , in which extensive investigations have revealed LTP and LTD at several excitatory and inhibitory synapses. Cerebellar LTP and LTD occur in all three main cerebellar subcircuits (granular layer, molecular layer, deep cerebellar nuclei and correspondingly regulate the function of their three main neurons: granule cells (GrCs, Purkinje cells (PCs and deep cerebellar nuclear (DCN cells. All these neurons, in addition to be excited, are reached by feed-forward and feed-back inhibitory connections, in which LTP and LTD may either operate synergistically or homeostatically in order to control information flow through the circuit. Although the investigation of individual synaptic plasticities in vitro is essential to prove their existence and mechanisms, it is insufficient to generate a coherent view of their impact on network functioning in vivo. Recent computational models and cell-specific genetic mutations in mice are shedding light on how plasticity at multiple excitatory and inhibitory synapses might regulate neuronal activities in the cerebellar circuit and contribute to learning and memory and behavioral control.

  16. Integrated plasticity at inhibitory and excitatory synapses in the cerebellar circuit.

    Science.gov (United States)

    Mapelli, Lisa; Pagani, Martina; Garrido, Jesus A; D'Angelo, Egidio

    2015-01-01

    The way long-term potentiation (LTP) and depression (LTD) are integrated within the different synapses of brain neuronal circuits is poorly understood. In order to progress beyond the identification of specific molecular mechanisms, a system in which multiple forms of plasticity can be correlated with large-scale neural processing is required. In this paper we take as an example the cerebellar network, in which extensive investigations have revealed LTP and LTD at several excitatory and inhibitory synapses. Cerebellar LTP and LTD occur in all three main cerebellar subcircuits (granular layer, molecular layer, deep cerebellar nuclei) and correspondingly regulate the function of their three main neurons: granule cells (GrCs), Purkinje cells (PCs) and deep cerebellar nuclear (DCN) cells. All these neurons, in addition to be excited, are reached by feed-forward and feed-back inhibitory connections, in which LTP and LTD may either operate synergistically or homeostatically in order to control information flow through the circuit. Although the investigation of individual synaptic plasticities in vitro is essential to prove their existence and mechanisms, it is insufficient to generate a coherent view of their impact on network functioning in vivo. Recent computational models and cell-specific genetic mutations in mice are shedding light on how plasticity at multiple excitatory and inhibitory synapses might regulate neuronal activities in the cerebellar circuit and contribute to learning and memory and behavioral control.

  17. Alternative splicing generates a smaller assortment of CaV2.1 transcripts in cerebellar Purkinje cells than in the cerebellum.

    Science.gov (United States)

    Kanumilli, Srinivasan; Tringham, Elizabeth W; Payne, C Elizabeth; Dupere, Jonathan R B; Venkateswarlu, Kanamarlapudi; Usowicz, Maria M

    2006-01-12

    P/Q-type calcium channels control many calcium-driven functions in the brain. The CACNA1A gene encoding the pore-forming CaV2.1 (alpha1A) subunit of P/Q-type channels undergoes alternative splicing at multiple loci. This results in channel variants with different phenotypes. However, the combinatorial patterns of alternative splice events at two or more loci, and hence the diversity of CaV2.1 transcripts, are incompletely defined for specific brain regions and types of brain neurons. Using RT-PCR and splice variant-specific primers, we have identified multiple CaV2.1 transcript variants defined by different pairs of splice events in the cerebellum of adult rat. We have uncovered new splice variations between exons 28 and 34 (some of which predict a premature stop codon) and a new variation in exon 47 (which predicts a novel extended COOH-terminus). Single cell RT-PCR reveals that each individual cerebellar Purkinje neuron also expresses multiple alternative CaV2.1 transcripts, but the assortment is smaller than in the cerebellum. Two of these variants encode different extended COOH-termini which are not the same as those previously reported in Purkinje cells of the mouse. Our patch-clamp recordings show that calcium channel currents in the soma and dendrites of Purkinje cells are largely inhibited by a concentration of omega-agatoxin IVA selective for P-type over Q-type channels, suggesting that the different transcripts may form phenotypic variants of P-type calcium channels in Purkinje cells. These results expand the known diversity of CaV2.1 transcripts in cerebellar Purkinje cells, and propose the selective expression of distinct assortments of CaV2.1 transcripts in different brain neurons and species.

  18. Ferrofluid magnetoviscous control of wall flow channeling in porous media

    Institute of Scientific and Technical Information of China (English)

    Faal; Larachi

    2007-01-01

    [1]Bacri,J.C.,Perzynski,R.,Shliomis,M.I.,& Burde,G.I.(1995).Negative viscosity effect in a magnetic fluid.Physical Review Letters,75(11),2128-2131.[2]Felderhof,B.U.(2001).Flow of a ferrofluid down a tube in an oscillating magnetic field.Physical Review E,64(021508),1-7.[3]Khuzir,P.,Bossis,G.,Bashtovoi,V.,& Volkova,O.(2003).Flow of magnetorheological fluid through porous media.European Journal of Mechanics B/Fluids,22,331-343.[4]McTague,J.P.(1969).Magnetoviscosity of magnetic colloids.Journal of Chemical Physics,51,133-136.[5]Odenbach,S.(2003).Magnetic fluids-Suspensions of magnetic dipoles and their magnetic control.Journal of Physics:Condensed Matter,15,S 1497-S1508.[6]Rinaldi,C.,& Zahn,M.(2002).Effects of spin viscosity on ferrofluid flow profiles in alternating and rotating magnetic fields.Physics of Fluids,14,2847-2870.[7]Rosensweig,R.E.(1997).Ferrohydrodynamics.New York:Dover Publications.[8]Schumacher,K.R.,Sellien,I.,Knoke,G.S.,Cadet,T.,& Finlayson,B.A.(2003).Experiment and simulation of laminar and turbulent ferrofluid pipe flow in an oscillating magnetic field.Physical Review E,67(026308),1-11.[9]Shliomis,M.I.(1972).Effective viscosity of magnetic suspensions.Soviet Physics JETP,34,1291-1294.[10]Whitaker,S.(1999).Theory and applications of transport in porous media.Dordrecht:Kluwer Academic Press.[11]Zeuner,A.,Richter,R.,& Rehberg,I.(1998).Experiments on negative and positive magnetoviscosity in an alternating magnetic field.Physical Review E,58,62876293.

  19. Sustained Reduction of Cerebellar Activity in Experimental Epilepsy

    Directory of Open Access Journals (Sweden)

    Kim Rijkers

    2015-01-01

    Full Text Available Clinical and experimental evidence suggests a role for the cerebellum in seizure control, while no data are available on cerebellar activity between seizures. We hypothesized that interictal regional activity of the deep cerebellar nuclei is reduced in epilepsy and tested this in an animal model by using ΔFosB and cytochrome oxidase (COX (immunohistochemistry. The expression of these two markers of neuronal activity was analysed in the dentate nucleus (DN, interpositus nucleus (IN, and fastigial nucleus (FN of the cerebellum of fully amygdala kindled rats that were sacrificed 48 hours after their last seizure. The DN and FN of kindled rats exhibited 25 to 29% less ΔFosB immunopositive cells than their respective counterpart in sham controls (P<0.05. COX expression in the DN and FN of kindled animals was reduced by 32 to 33% compared to respective control values (P<0.05. These results indicate that an epileptogenic state is characterized by decreased activity of deep cerebellar nuclei, especially the DN and FN. Possible consequences may include a decreased activation of the thalamus, contributing to further seizure spread. Restoration of FN activity by low frequency electrical stimulation is suggested as a possible treatment option in chronic epilepsy.

  20. Control of Ca2+ Influx and Calmodulin Activation by SK-Channels in Dendritic Spines.

    Directory of Open Access Journals (Sweden)

    Thom Griffith

    2016-05-01

    Full Text Available The key trigger for Hebbian synaptic plasticity is influx of Ca2+ into postsynaptic dendritic spines. The magnitude of [Ca2+] increase caused by NMDA-receptor (NMDAR and voltage-gated Ca2+ -channel (VGCC activation is thought to determine both the amplitude and direction of synaptic plasticity by differential activation of Ca2+ -sensitive enzymes such as calmodulin. Ca2+ influx is negatively regulated by Ca2+ -activated K+ channels (SK-channels which are in turn inhibited by neuromodulators such as acetylcholine. However, the precise mechanisms by which SK-channels control the induction of synaptic plasticity remain unclear. Using a 3-dimensional model of Ca2+ and calmodulin dynamics within an idealised, but biophysically-plausible, dendritic spine, we show that SK-channels regulate calmodulin activation specifically during neuron-firing patterns associated with induction of spike timing-dependent plasticity. SK-channel activation and the subsequent reduction in Ca2+ influx through NMDARs and L-type VGCCs results in an order of magnitude decrease in calmodulin (CaM activation, providing a mechanism for the effective gating of synaptic plasticity induction. This provides a common mechanism for the regulation of synaptic plasticity by neuromodulators.

  1. Altered corticomotor-cerebellar integrity in young ataxia telangiectasia patients.

    Science.gov (United States)

    Sahama, Ishani; Sinclair, Kate; Fiori, Simona; Pannek, Kerstin; Lavin, Martin; Rose, Stephen

    2014-09-01

    Magnetic resonance imaging (MRI) research in identifying altered brain structure and function in ataxia-telangiectasia, an autosomal recessive neurodegenerative disorder, is limited. Diffusion-weighted MRI were obtained from 11 ataxia telangiectasia patients (age range, 7-22 years; mean, 12 years) and 11 typically developing age-matched participants (age range, 8-23 years; mean, 13 years). Gray matter volume alterations in patients were compared with those of healthy controls using voxel-based morphometry, whereas tract-based spatial statistics was employed to elucidate white matter microstructure differences between groups. White matter microstructure was probed using quantitative fractional anisotropy and mean diffusivity measures. Reduced gray matter volume in both cerebellar hemispheres and in the precentral-postcentral gyrus in the left cerebral hemisphere was observed in ataxia telangiectasia patients compared with controls (P < 0.05, corrected for multiple comparisons). A significant reduction in fractional anisotropy in the cerebellar hemispheres, anterior/posterior horns of the medulla, cerebral peduncles, and internal capsule white matter, particularly in the left posterior limb of the internal capsule and corona radiata in the left cerebral hemisphere, was observed in patients compared with controls (P < 0.05). Mean diffusivity differences were observed within the left cerebellar hemisphere and the white matter of the superior lobule of the right cerebellar hemisphere (P < 0.05). Cerebellum-localized gray matter changes are seen in young ataxia telangiectasia patients along with white matter tract degeneration projecting from the cerebellum into corticomotor regions. The lack of cortical involvement may reflect early-stage white matter motor pathway degeneration within young patients. PMID:25042086

  2. Control of colloid transport via solute gradients in dead-end channels

    Science.gov (United States)

    Shin, Sangwoo; Um, Eujin; Warren, Patrick; Stone, Howard

    2015-11-01

    Transport of colloids in dead-end channels is involved in widespread applications ranging from drug delivery to geophysical flows. In such geometries, Brownian motion may be considered as the sole mechanism that enables transport of colloidal particles into or out of the channels, which is, unfortunately, an extremely inefficient transport mechanism for microscale particles. Here, we explore the possibility of diffusiophoresis as a means to control the colloid transport by introducing a solute gradient along the dead-end channels. We demonstrate that the transport of colloidal particles into the dead-end channels can be either enhanced or completely prevented via diffusiophoresis. We also observe a size-dependent focusing of the particles where, as the particle size increases, the particles tend to concentrate more, and they tend to reside deeper in the channel. Our findings have implications for all manners of controlled release processes, especially for site-specific drug delivery systems where localized targeting of drugs with minimal dispersion to the non-target is essential.

  3. Clinical characteristics and pathogenesis of cerebellar glioblastoma.

    Science.gov (United States)

    Takahashi, Yoshinobu; Makino, Keishi; Nakamura, Hideo; Hide, Takuichiro; Yano, Shigetoshi; Kamada, Hajime; Kuratsu, Jun-Ichi

    2014-11-01

    Cerebellar glioblastomas (GBMs) are rare, with neither their pathogenesis nor prognosis being completely understood. The present study aimed to clarify the clinical characteristics of cerebellar GBMs by comparison with supratentorial GBMs, focusing particularly on the pathogenesis. The clinical factors between cerebellar (n=10) and supratentorial (n=216) GBMs were compared. Additionally, p53 and epidermal growth factor receptor (EGFR) levels were investigated in six patients by immunostaining as well as the isocitrate dehydrogenase 1 (IDH1) status of five patients by direct sequencing. Eight males and two females participated in the present study, the mean age at diagnosis was 56.6 years and the range 37-75 years. Four patients presented with hydrocephalus and one with brainstem involvement, and two patients were diagnosed with neurofibromatosis type 1. Two patients had previously received radiotherapy, eight patients received postoperative radiotherapy and seven chemotherapy. The mean Karnofsky performance status (KPS) score was lower in patients with cerebellar GBMs compared to those with supratentorial GBM; however, the survival times did not differ between the two groups. All of the cases of six cerebellar GBMs were p53‑positive and EGFR‑negative, as detected by immunostaining, consistent with secondary GBM. However, no IDH1 mutations were detected in any of the five cases of cerebellar GBMs analyzed, indicating that these tumors were not of the secondary type. The KPS score with cerebellar GBMs may be lower due to hydrocephalus, which was ameliorated by surgery but may have impacted the survival rate. It was confirmed that cerebellar GBMs were identical to supratentorial GBMs with respect to its clinical features, with the possible exception of the KPS score. The present study's genetic analyses indicated that cerebellar GBMs may develop via a pathway different from that of either primary or secondary GBM. PMID:25199771

  4. The design of multi-channel pulse amplitude analyzer based on ARM micro controller

    International Nuclear Information System (INIS)

    It introduces the design of multi-channel pulse amplitude analyzer based on embedded ARM micro-controller. The embedded and real-time system μC/OS-II builds up the real-time and stability of the system and advances the integration. (authors)

  5. Short latency cerebellar modulation of the basal ganglia.

    Science.gov (United States)

    Chen, Christopher H; Fremont, Rachel; Arteaga-Bracho, Eduardo E; Khodakhah, Kamran

    2014-12-01

    The graceful, purposeful motion of our body is an engineering feat that remains unparalleled in robotic devices using advanced artificial intelligence. Much of the information required for complex movements is generated by the cerebellum and the basal ganglia in conjunction with the cortex. Cerebellum and basal ganglia have been thought to communicate with each other only through slow, multi-synaptic cortical loops, begging the question as to how they coordinate their outputs in real time. We found that the cerebellum rapidly modulates the activity of the striatum via a disynaptic pathway in mice. Under physiological conditions, this short latency pathway was capable of facilitating optimal motor control by allowing the basal ganglia to incorporate time-sensitive cerebellar information and by guiding the sign of cortico-striatal plasticity. Conversely, under pathological condition, this pathway relayed aberrant cerebellar activity to the basal ganglia to cause dystonia. PMID:25402853

  6. Failure of Fixation Suppression of Spontaneous Nystagmus in Cerebellar Infarction: Frequency, Pattern, and a Possible Structure.

    Science.gov (United States)

    Kim, Hyun-Ah; Yi, Hyon-Ah; Lee, Hyung

    2016-04-01

    To investigate the frequency and pattern of failure of the fixation suppression (FFS) of spontaneous nystagmus (SN) in unilateral cerebellar infarction, and to identify the structure responsible for FFS, 29 patients with acute, mainly unilateral, isolated cerebellar infarction who had SN with a predominantly horizontal component were enrolled in this study. The ocular fixation index (OFI) was defined as the mean slow phase velocity (SPV) of the horizontal component of SN with fixation divided by the mean SPV of the horizontal component of SN without fixation. The OFI from age- and sex-matched patients with vestibular neuritis was calculated and used as the control data. The FFS of SN was only found in less than half (41 %, 12/29) of the patients. Approximately 65 % (n = 7) of the patients with isolated anterior inferior cerebellar artery territory cerebellar infarction showed FFS, whereas only a quarter (n = 3) of the patients with isolated posterior inferior cerebellar artery (PICA) territory cerebellar infarction showed FFS. The proportion of gaze-evoked nystagmus (6/12 [50 %] vs. 2/17 [12 %], p = 0.04) and deficient gain of ipsilesional pursuit (10/12 [83 %] vs. 6/17 [35 %], p = 0.05) was more frequent in the FFS group than in the group without FFS. Lesion subtraction analysis in isolated PICA territory cerebellar infarction revealed that the nodulus was commonly damaged in patients with FFS, compared to that of patients without FFS. Our study shows that FFS of SN due to acute cerebellar infarction is less common than previously thought and the nodulus may be an important structure for the suppression of SN in humans. PMID:26082303

  7. Sonic hedgehog patterning during cerebellar development.

    Science.gov (United States)

    De Luca, Annarita; Cerrato, Valentina; Fucà, Elisa; Parmigiani, Elena; Buffo, Annalisa; Leto, Ketty

    2016-01-01

    The morphogenic factor sonic hedgehog (Shh) actively orchestrates many aspects of cerebellar development and maturation. During embryogenesis, Shh signaling is active in the ventricular germinal zone (VZ) and represents an essential signal for proliferation of VZ-derived progenitors. Later, Shh secreted by Purkinje cells sustains the amplification of postnatal neurogenic niches: the external granular layer and the prospective white matter, where excitatory granule cells and inhibitory interneurons are produced, respectively. Moreover, Shh signaling affects Bergmann glial differentiation and promotes cerebellar foliation during development. Here we review the most relevant functions of Shh during cerebellar ontogenesis, underlying its role in physiological and pathological conditions. PMID:26499980

  8. Pediatric Neurocutaneous Syndromes with Cerebellar Involvement.

    Science.gov (United States)

    Bosemani, Thangamadhan; Huisman, Thierry A G M; Poretti, Andrea

    2016-08-01

    Neurocutaneous syndromes encompasses a broad group of genetic disorders with different clinical, genetic, and pathologic features that share developmental lesions of the skin as well as central and peripheral nervous system. Cerebellar involvement has been shown in numerous types of neurocutaneous syndrome. It may help or be needed for the diagnosis and to explain the cognitive and behavioral phenotype of affected children. This article describes various types of neurocutaneous syndrome with cerebellar involvement. For each neurocutaneous disease or syndrome, clinical features, genetic, neuroimaging findings, and the potential role of the cerebellar involvement is discussed. PMID:27423801

  9. Controlled release of stored optical pulses in an atomic ensemble into two separate photonic channels

    International Nuclear Information System (INIS)

    We report an experiment in which optical pulses stored in an atomic system can be controllably released into two different photonic channels. By controllably turning on the retrieve control pulses at either 795 or 780 nm to read the stored optical pulses in a four-level double Λ-type atomic medium, we can obtain the released probe pulse at 795 or 780 nm, respectively. These readout pulses can be further separated spatially and directed into different optical propagation channels through a grating. Such controlled release of stored optical pulses may extend the capabilities of the quantum information storage technique, and can have applications in multichannel all-optical switching, all-optical routing, quantum information processing, and image storage systems

  10. The CatSper channel controls chemosensation in sea urchin sperm.

    Science.gov (United States)

    Seifert, Reinhard; Flick, Melanie; Bönigk, Wolfgang; Alvarez, Luis; Trötschel, Christian; Poetsch, Ansgar; Müller, Astrid; Goodwin, Normann; Pelzer, Patric; Kashikar, Nachiket D; Kremmer, Elisabeth; Jikeli, Jan; Timmermann, Bernd; Kuhl, Heiner; Fridman, Dmitry; Windler, Florian; Kaupp, U Benjamin; Strünker, Timo

    2015-02-01

    Sperm guidance is controlled by chemical and physical cues. In many species, Ca(2+) bursts in the flagellum govern navigation to the egg. In Arbacia punctulata, a model system of sperm chemotaxis, a cGMP signaling pathway controls these Ca(2+) bursts. The underlying Ca(2+) channel and its mechanisms of activation are unknown. Here, we identify CatSper Ca(2+) channels in the flagellum of A. punctulata sperm. We show that CatSper mediates the chemoattractant-evoked Ca(2+) influx and controls chemotactic steering; a concomitant alkalization serves as a highly cooperative mechanism that enables CatSper to transduce periodic voltage changes into Ca(2+) bursts. Our results reveal intriguing phylogenetic commonalities but also variations between marine invertebrates and mammals regarding the function and control of CatSper. The variations probably reflect functional and mechanistic adaptations that evolved during the transition from external to internal fertilization. PMID:25535245

  11. Cerebellar fMRI Activation Increases with Increasing Working Memory Demands.

    Science.gov (United States)

    Küper, M; Kaschani, P; Thürling, M; Stefanescu, M R; Burciu, R G; Göricke, S; Maderwald, S; Ladd, M E; Hautzel, H; Timmann, D

    2016-06-01

    The aim of the present study was to explore cerebellar contributions to the central executive in n-back working memory tasks using 7-T functional magnetic imaging (fMRI). We hypothesized that cerebellar activation increased with increasing working memory demands. Activations of the cerebellar cortex and dentate nuclei were compared between 0-back (serving as a motor control task), 1-back, and 2-back working memory tasks for both verbal and abstract modalities. A block design was used. Data of 27 participants (mean age 26.6 ± 3.8 years, female/male 12:15) were included in group statistical analysis. We observed that cerebellar cortical activations increased with higher central executive demands in n-back tasks independent of task modality. As confirmed by subtraction analyses, additional bilateral activations following higher executive demands were found primarily in four distinct cerebellar areas: (i) the border region of lobule VI and crus I, (ii) inferior parts of the lateral cerebellum (lobules crus II, VIIb, VIII, IX), (iii) posterior parts of the paravermal cerebellar cortex (lobules VI, crus I, crus II), and (iv) the inferior vermis (lobules VI, VIIb, VIII, IX). Dentate activations were observed for both verbal and abstract modalities. Task-related increases were less robust and detected for the verbal n-back tasks only. These results provide further evidence that the cerebellum participates in an amodal bilateral neuronal network representing the central executive during working memory n-back tasks. PMID:26202670

  12. Multi-motion robots control based on bioelectric signals from single-channel dry electrode.

    Science.gov (United States)

    Shen, Hui-Min; Hu, Liang; Lee, Kok-Meng; Fu, Xin

    2015-02-01

    This article presents a multi-motion control system to help severe disabled people operate an auxiliary appliance using neck-up bioelectric signals measured by a single-channel dry electrode on the forehead. The single-channel dry-electrode multi-motion control system exhibits several practical advantages over its conventional counterparts that use multi-channel wet-electrodes; among the challenges is an effective technique to extract bioelectric features for reliable implementation of multi degrees-of-freedom motion control. Using both time and frequency characteristics of the single-channel dry-electrode measurements, motion commands are derived from multiple feature signals associated with concentration demands and different eye-blink actions for use in a two-level control strategy that has been developed to control predefined multi degrees-of-freedom motion trajectories. Test paradigms were designed to pre-calibrate the users' feature signals to statistically account for individual variances. Experimental trials were then carried out on able-bodied and disabled volunteers to validate the universal applicability of the algorithms. The classification success rates for two different eye-blink feature signals were approximately 95% with an average time of 2.4 s for executing a concentration feature signal. The single-channel dry-electrode-based technique has been validated on a 6-degree-of-freedom robot arm demonstrating its significant potentials to help patients suffering severe motor dysfunctions operate a multi-motion auxiliary appliance in everyday living where the ease of use is a priority.

  13. Nonlinear Control of Tunneling Through an Epsilon-Near-Zero Channel

    CERN Document Server

    Powell, David A; Edwards, Brian; Vakil, Ashkan; Kivshar, Yuri S; Engheta, Nader

    2009-01-01

    The epsilon-near-zero (ENZ) tunneling phenomenon allows full transmission of waves through a narrow channel even in the presence of a strong geometric mismatch. Here we experimentally demonstrate nonlinear control of the ENZ tunneling by an external field, as well as self-modulation of the transmission resonance due to the incident wave. Using a waveguide section near cut-off frequency as the ENZ system, we introduce a diode with tunable and nonlinear capacitance to demonstrate both of these effects. Our results confirm earlier theoretical ideas on using an ENZ channel for dielectric sensing, and their potential applications for tunable slow-light structures.

  14. CT findings in cerebellar hemangioblastomas

    Energy Technology Data Exchange (ETDEWEB)

    Heiss, E.; Albert, F.

    1982-02-01

    The computed tomographic (CT) findings in 16 personal cases of cerebellar hemangioblastomas are presented. Accordings to other reports in the literature, three-quarters of the tumours were cystic, containing a small mural nodule, whereas the others were predominantly solid. By CT scan the cystic tumours were always identified as roundish or oval space-occupying lesions, sharply demarcated from the surrounding tissue. The solid portion of these tumours, projecting into the cystic part, was delineated more precisely by contrast enhancement, but sometimes escaped identification. On the contrary, even after contrast enhancement the predominantly solid tumours could not be clearly identified as hemangioblastomas. Calcification could not be demonstrated. Additional angiographic investigations were imperative in order to establish the diagnosis, besides visualizing further hypervascular nodules of hemangioblastoma, which CT scanning failed to reveal.

  15. Reactive Power Control of Single-Stage Three-Phase Photovoltaic System during Grid Faults Using Recurrent Fuzzy Cerebellar Model Articulation Neural Network

    OpenAIRE

    Faa-Jeng Lin; Kuang-Chin Lu; Hsuan-Yu Lee

    2014-01-01

    This study presents a new active and reactive power control scheme for a single-stage three-phase grid-connected photovoltaic (PV) system during grid faults. The presented PV system utilizes a single-stage three-phase current-controlled voltage-source inverter to achieve the maximum power point tracking (MPPT) control of the PV panel with the function of low voltage ride through (LVRT). Moreover, a formula based on positive sequence voltage for evaluating the percentage of voltage sag is deri...

  16. Control of mesoscopic transport by modifying transmission channels in opaque media

    Science.gov (United States)

    Sarma, Raktim; Yamilov, Alexey; Liew, Seng Fatt; Guy, Mikhael; Cao, Hui

    2015-12-01

    While controlling particle diffusion in a confined geometry is a popular approach taken by both natural and artificial systems, it has not been widely adopted for controlling light transport in random media, where wave interference effects play a critical role. The transmission eigenchannels determine not only light propagation through the disordered system but also the energy concentrated inside. Here, we propose and demonstrate an effective approach to modify these channels, whose structures are considered to be universal in conventional diffusive waveguides. By adjusting the waveguide geometry, we are able to alter the spatial profiles of the transmission eigenchannels significantly and deterministically from the universal ones. In addition, evanescent channels may be converted to propagating channels by gradually increasing the waveguide cross-section. Our approach allows to control not only the transmitted and reflected light, but also the depth profile of energy density inside the scattering system. In particular geometries, perfect reflection channels are created, and their large penetration depth into the turbid medium as well as the complete return of probe light to the input end would greatly benefit sensing and imaging applications. Absorption along with geometry can be further employed for tuning the decay length of energy flux inside the random system, which cannot be achieved in a common waveguide with uniform cross-section. Our approach relies solely on confined geometry and does not require any modification of intrinsic disorder, thus it is applicable to a variety of systems and also to other types of waves.

  17. Marketing channels and control the distribution of products in the meat industry.

    OpenAIRE

    Sidorchuk, Roman

    2010-01-01

    The article deals with the formation of distribution channels in the meat industry. Question of finding channels. Awareness of the problem-added customer value in the channel. The task of shaping the company's own distribution channel products. The procedure of forming a channel of distribution. The main problem in forming their own distribution channel. Prospects of development of different channels

  18. Catchment- and reach-scale controls on the distribution and expectation of geomorphic channel adjustment

    Science.gov (United States)

    Lisenby, Peyton E.; Fryirs, Kirstie A.

    2016-05-01

    Variability in channel function (behavior) can be assessed by characterizing different forms of adjustment over time. Here, historical channel adjustments in three tributary systems of the Lockyer Valley, Southeast Queensland (SEQ) are analyzed in order to evaluate the range of catchment- and reach-scale controls on channel behavior. Over 300 individual adjustments and 13 forms of adjustment were identified over a ˜130 year time span. We measured the width-to-depth ratio (W:D), mean stream power (ω), and basin area (A) at the location of all observed adjustments. The most common forms of adjustment were avulsions, lateral expansion of the channel, and bend adjustments. The tributary systems behave distinctly different from one another according to statistical comparisons between the W:D, ω, and A data for these forms of adjustment. We find that it is possible to develop process domains or typologies for forms of geomorphic adjustment found in the Lockyer Valley. These domains or typologies provide the foundations for synoptic comparisons between catchments and assessing the expectation of channel adjustment (forecasting), which should be included in process-based river management practice.

  19. Environmental Impact Assessment of a Flood Control Channel in Sfax City, Tunisia

    Directory of Open Access Journals (Sweden)

    Noura Dahri

    2014-05-01

    Full Text Available The objective of this study is to evaluate water and sediment quality in the southern branch of a flood control channel in Sfax city, as well as its neighboring sites.  This artificial channel, located 4km away from downtown Sfax, was implemented in 1984 to protect the city against floods. Even though it contributed to reduce the harmful flood effects, this channel also resulted in new environmental problems that may cause a public health threat. Indeed, artificial surfaces pose a greater risk of infection due to bacteria, fungi and other microorganisms. A total of 19 water samples (9 from the channel and 10 from groundwater wells were collected in a dry period and analyzed in the laboratory. Furthermore, 12 sediment samples were taken from the bottom of the channel. Water quality data were used to examine the spatial variability of the different water quality parametrs. The resultant maps revealed an important contamination and illustrated that the degree of contamination differs from one site to another, depending on the distance from the pollution source (industrial, domestic or agricultural activity, the depth of the groundwater table and also the maintenance of the well and its surroundings.

  20. Vascular inward rectifier K+ channels as external K+ sensors in the control of cerebral blood flow.

    Science.gov (United States)

    Longden, Thomas A; Nelson, Mark T

    2015-04-01

    For decades it has been known that external K(+) ions are rapid and potent vasodilators that increase CBF. Recent studies have implicated the local release of K(+) from astrocytic endfeet-which encase the entirety of the parenchymal vasculature-in the dynamic regulation of local CBF during NVC. It has been proposed that the activation of KIR channels in the vascular wall by external K(+) is a central component of these hyperemic responses; however, a number of significant gaps in our knowledge remain. Here, we explore the concept that vascular KIR channels are the major extracellular K(+) sensors in the control of CBF. We propose that K(+) is an ideal mediator of NVC, and discuss KIR channels as effectors that produce rapid hyperpolarization and robust vasodilation of cerebral arterioles. We provide evidence that KIR channels, of the KIR 2 subtype in particular, are present in both the endothelial and SM cells of parenchymal arterioles and propose that this dual positioning of KIR 2 channels increases the robustness of the vasodilation to external K(+), enables the endothelium to be actively engaged in NVC, and permits electrical signaling through the endothelial syncytium to promote upstream vasodilation to modulate CBF.

  1. Dominant geomorphic controls on channel capacity and flood risk in a hydrologically variable fluvial system

    Science.gov (United States)

    Daley, James; Croke, Jacky; Thompson, Chris; Cohen, Tim

    2016-04-01

    Traditionally, particular emphasis has been placed on the hydrological characteristics of rivers to understand the role of channel morphology in flood risk. However, in regions of high hydrological variability, the relationship between channel characteristics and flood conveyance is often highly complex. Consequently in these settings, the applicability of stream discharge or steady-state form-process relationships, may be of less use to understanding flood conveyance. In the subtropical region of southeast Queensland, Australia, rivers are characterized by highly variable flows and entrenched channel morphologies. The latter are such dramatic features, they are termed 'macrochannels'. Following the extreme flood of 2011 in the Lockyer Creek in this region, longitudinal variations in the macrochannel form were found to be a significant factor in flood conveyance. Nine reaches were identified on a basis of flood inundation extent, with significant non-linear changes in channel capacity and discharge, alternating between flood expansion and contraction zones with associated increases and decreases in flood risk. Detailed geomorphic and chronostratigraphic analyses presented here indicate that macrochannel capacity is being strongly influenced by the antecedent bedrock topography, resistant valley-fill and abrupt downstream changes in sediment delivery. A large proportion of the valley fill represents a major Late Pleistocene aggradation phase of fine-grained alluvium that overlies older Pleistocene basal sediments. Subsequent channel incision at 10 ka reoccupied a pre-existing bedrock valley and resistant Pleistocene alluvium imposed substantial controls on the capacity for lateral adjustment. Abrupt changes in sediment supply associated with the location of tributaries provide further evidence for geomorphic controls on macrochannel form and capacity. Identification of the dominant geomorphic factors influencing the overall macrochannel form highlights the relative

  2. Cerebellar mutism: review of the literature

    DEFF Research Database (Denmark)

    Gudrunardottir, Thora; Sehested, Astrid; Juhler, Marianne;

    2011-01-01

    Cerebellar mutism is a common complication of posterior fossa surgery in children. This article reviews current status with respect to incidence, anatomical substrate, pathophysiology, risk factors, surgical considerations, treatment options, prognosis and prevention....

  3. Cerebellar Involvement in Ataxia and Generalized Epilepsy

    NARCIS (Netherlands)

    L. Kros (Lieke)

    2015-01-01

    markdownabstract__Abstract__ The work described in this thesis was performed in order to elucidate the role of different cerebellar modules in ataxia and generalized epilepsy using various techniques including in vivo electrophysiology, optogenetics, pharmacological interventions, immunohistology a

  4. Cell Signaling and Neurotoxicity: 3H-Arachidonic acid release (Phospholipase A2) in cerebellar granule neurons

    Science.gov (United States)

    Cell signaling is a complex process which controls basic cellular activities and coordinates actions to maintain normal cellular homeostasis. Alterations in signaling processes have been associated with neurological diseases such as Alzheimer's and cerebellar ataxia, as well as, ...

  5. Cerebellar mutism: review of the literature

    DEFF Research Database (Denmark)

    Gudrunardottir, Thora; Sehested, Astrid; Juhler, Marianne;

    2011-01-01

    Cerebellar mutism is a common complication of posterior fossa surgery in children. This article reviews current status with respect to incidence, anatomical substrate, pathophysiology, risk factors, surgical considerations, treatment options, prognosis and prevention.......Cerebellar mutism is a common complication of posterior fossa surgery in children. This article reviews current status with respect to incidence, anatomical substrate, pathophysiology, risk factors, surgical considerations, treatment options, prognosis and prevention....

  6. Stereological study of the effects of maternal diabetes on cerebellar cortex development in rat.

    Science.gov (United States)

    Hami, Javad; Vafaei-Nezhad, Saeed; Ghaemi, Kazem; Sadeghi, Akram; Ivar, Ghasem; Shojae, Fatemeh; Hosseini, Mehran

    2016-06-01

    Diabetes during pregnancy is associated with the deficits in balance and motor coordination and altered social behaviors in offspring. In the present study, we have investigated the effect of maternal diabetes and insulin treatment on the cerebellar volume and morphogenesis of the cerebellar cortex of rat neonates during the first two postnatal weeks. Sprague Dawley female rats were maintained diabetic from a week before pregnancy through parturition. At the end of pregnancy, the male offspring euthanized on postnatal days (P) 0, 7, and 14. Cavalieri's principle and fractionator methods were used to estimate the cerebellar volume, the thickness and the number of cells in the different layers of the cerebellar cortex. In spite of P0, there was a significant reduction in the cerebellar volume and the thickness of the external granule, molecular, and internal granule layers between the diabetic and the control animals. In diabetic group, the granular and purkinje cell densities were increased at P0. Moreover, the number of granular and purkinje cells in the cerebellum of diabetic neonates was reduced in comparison with the control group at P7 and P14. There were no significant differences in either the volume and thickness or the number of cells in the different layers of the cerebellar cortex between the insulin-treated diabetic group and controls. Our data indicate that diabetes in pregnancy disrupts the morphogenesis of cerebellar cortex. This dysmorphogenesis may be part of the cascade of events through which diabetes during pregnancy affects motor coordination and social behaviors in offspring. PMID:26842601

  7. Effective reinforcement learning following cerebellar damage requires a balance between exploration and motor noise.

    Science.gov (United States)

    Therrien, Amanda S; Wolpert, Daniel M; Bastian, Amy J

    2016-01-01

    Reinforcement and error-based processes are essential for motor learning, with the cerebellum thought to be required only for the error-based mechanism. Here we examined learning and retention of a reaching skill under both processes. Control subjects learned similarly from reinforcement and error-based feedback, but showed much better retention under reinforcement. To apply reinforcement to cerebellar patients, we developed a closed-loop reinforcement schedule in which task difficulty was controlled based on recent performance. This schedule produced substantial learning in cerebellar patients and controls. Cerebellar patients varied in their learning under reinforcement but fully retained what was learned. In contrast, they showed complete lack of retention in error-based learning. We developed a mechanistic model of the reinforcement task and found that learning depended on a balance between exploration variability and motor noise. While the cerebellar and control groups had similar exploration variability, the patients had greater motor noise and hence learned less. Our results suggest that cerebellar damage indirectly impairs reinforcement learning by increasing motor noise, but does not interfere with the reinforcement mechanism itself. Therefore, reinforcement can be used to learn and retain novel skills, but optimal reinforcement learning requires a balance between exploration variability and motor noise.

  8. Paraneoplastic cerebellar degeneration with anti-Yo antibodies - a review.

    Science.gov (United States)

    Venkatraman, Anand; Opal, Puneet

    2016-08-01

    The ataxic syndrome associated with Anti-Yo antibody, or Purkinje cell cytoplasmic antibody type 1 (PCA1), is the most common variant of paraneoplastic cerebellar degeneration (PCD). The typical presentation involves the subacute development of pancerebellar deficits with a clinical plateau within 6 months. The vast majority of cases have been reported in women with pelvic or breast tumors. Magnetic resonance imaging of the brain is often normal in the early stages, with cerebellar atrophy seen later. The underlying mechanism is believed to be an immunological reaction to cerebellar degeneration-related protein 2 (CDR2), a protein usually found in the cerebellum that is ectopically produced by tumor cells. Although both B- and T-cell abnormalities are seen, there is debate about the relative importance of the autoantibodies and cytotoxic T lymphocytes in the neuronal loss. Cerebrospinal fluid abnormalities, primarily elevated protein, lymphocytic pleocytosis, and oligoclonal bands, are common in the early stages. The low prevalence of this condition has not allowed for large-scale randomized controlled trials. Immunotherapies, such as steroids, intravenous immune globulins, and plasma exchange, have been extensively used in managing this condition, with limited success. Although some reports indicate benefit from antitumor therapies like surgery and chemotherapy, this has not been consistently observed. The prognosis for anti-Yo PCD is almost uniformly poor, with most patients left bedridden. Further studies are required to clarify the pathophysiology and provide evidence-based treatment options. PMID:27606347

  9. Paraneoplastic cerebellar degeneration with anti-Yo antibodies - a review.

    Science.gov (United States)

    Venkatraman, Anand; Opal, Puneet

    2016-08-01

    The ataxic syndrome associated with Anti-Yo antibody, or Purkinje cell cytoplasmic antibody type 1 (PCA1), is the most common variant of paraneoplastic cerebellar degeneration (PCD). The typical presentation involves the subacute development of pancerebellar deficits with a clinical plateau within 6 months. The vast majority of cases have been reported in women with pelvic or breast tumors. Magnetic resonance imaging of the brain is often normal in the early stages, with cerebellar atrophy seen later. The underlying mechanism is believed to be an immunological reaction to cerebellar degeneration-related protein 2 (CDR2), a protein usually found in the cerebellum that is ectopically produced by tumor cells. Although both B- and T-cell abnormalities are seen, there is debate about the relative importance of the autoantibodies and cytotoxic T lymphocytes in the neuronal loss. Cerebrospinal fluid abnormalities, primarily elevated protein, lymphocytic pleocytosis, and oligoclonal bands, are common in the early stages. The low prevalence of this condition has not allowed for large-scale randomized controlled trials. Immunotherapies, such as steroids, intravenous immune globulins, and plasma exchange, have been extensively used in managing this condition, with limited success. Although some reports indicate benefit from antitumor therapies like surgery and chemotherapy, this has not been consistently observed. The prognosis for anti-Yo PCD is almost uniformly poor, with most patients left bedridden. Further studies are required to clarify the pathophysiology and provide evidence-based treatment options.

  10. Hippocampal and cerebellar atrophy in patients with Cushing's disease.

    Science.gov (United States)

    Burkhardt, Till; Lüdecke, Daniel; Spies, Lothar; Wittmann, Linus; Westphal, Manfred; Flitsch, Jörg

    2015-11-01

    OBJECT Cushing's disease (CD) may cause atrophy of different regions of the human brain, mostly affecting the hippocampus and the cerebellum. This study evaluates the use of 3-T MRI of newly diagnosed patients with CD to detect atrophic degeneration with voxel-based volumetry. METHODS Subjects with newly diagnosed, untreated CD were included and underwent 3-T MRI. Images were analyzed using a voxelwise statistical test to detect reduction of brain parenchyma. In addition, an atlas-based volumetric study for regions likely to be affected by CD was performed. RESULTS Nineteen patients with a mean disease duration of 24 months were included. Tumor markers included adrenocorticotropic hormone (median 17.5 pmol/L), cortisol (949.4 nmol/L), and dehydroepiandrosterone sulfate (5.4 μmol/L). The following values are expressed as the mean ± SD. The voxelwise statistical test revealed clusters of significantly reduced gray matter in the hippocampus and cerebellum, with volumes of 2.90 ± 0.26 ml (right hippocampus), 2.89 ± 0.28 ml (left hippocampus), 41.95 ± 4.67 ml (right cerebellar hemisphere), and 42.11 ± 4.59 ml (left cerebellar hemisphere). Healthy control volunteers showed volumes of 3.22 ± 0.25 ml for the right hippocampus, 3.23 ± 0.25 ml for the left hippocampus, 50.87 ± 4.23 ml for the right cerebellar hemisphere, and 50.42 ± 3.97 ml for the left cerebellar hemisphere. CONCLUSIONS Patients with untreated CD show significant reduction of gray matter in the cerebellum and hippocampus. These changes can be analyzed and objectified with the quantitative voxel-based method described in this study.

  11. Investigating the Effects of the Common Control Channel Challenge in Multichannel Cognitive Networks With Hypothetical Spectrum Hole

    Directory of Open Access Journals (Sweden)

    Mthulisi Velempini

    2013-11-01

    Full Text Available Multichannel MAC protocols have become a design choice of wireless access networks as they increase theachievable throughput. However, the implementationof a common control channel has been a challenge.The common control channel challenge has not been investigated in opportunistic networks where theavailability of medium is temporary and unpredictable. The uncertainty of the availability of the channelcoupled with the common control channel challenge makes this area an interesting research topic.Unfortunately, this challenge requires further investigation in Cognitive Radio Ad Hoc Networks(CRAHN, a promising next generation technology. The challenge makes an interesting study in CRAHNgiven the opportunistic access and use of channels.Given a hypothetical spectrum hole of any size coupledwith the implementation of a control channel in a multi-channel environment, how much of good put canberealized and be effectively utilized for data transmission. We investigate the common control channelchallenge in CRAHN through network simulations. Theopportunistic nature of CRAHNs in the presence ofthe common control channel challenge is investigated. The simulation results show that the combinationofthe control channel challenge and the size of the spectrum hole degrade gracefully the network.Furthermore, the size of the spectrum hole has a bearing on good put. The results show that a big holeimproves performance. Unfortunately, the opportunistic attribute of CRAHNs does not guarantee desirablespectrum holes.

  12. Variable structure control for MRAC systems with perturbations in input and output channels

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A design scheme of variable structure model reference control systems using only input and output measurements is presented for the systems with unmodeled dynamics and disturbances in input and output channels. The modeled part of the systems has relative degree greater than one and unknown upper bound of degree. By introducing some auxiliary signals and normalized signals with memory functions and appropriate choice of controller parameters, the developed variable structure controller guarantees the global stability of the closed-loop system and the arbitrarily small tracking error.

  13. Optimal source rate control for adapting VBR video over CBR channels

    Institute of Scientific and Technical Information of China (English)

    Chunwen LI; Peng ZHU

    2006-01-01

    In this paper we discuss the source rate control problem of adapting variable bit-rate (VBR) compressed video over constant bit-rate (CBR) channels. Firstly we formulate it as an optimal control problem of a discrete linear system with state and control constraints. Then we apply the discrete maximum principle to get the optimal solution.Experimental results are given in the end. Compared with traditional algorithms, the proposed algorithm is suitable for the coder with continuous output rates, and can achieve the better solution. Our algorithm can be used in both off-line and on-line coding.

  14. Motor dysfunction in cerebellar Purkinje cell-specific vesicular GABA transporter knockout mice

    Directory of Open Access Journals (Sweden)

    Mikiko eKayakabe

    2014-01-01

    Full Text Available γ-Aminobutyric acid (GABA is a major inhibitory neurotransmitter in the adult mammalian central nervous system and plays modulatory roles in neural development. The vesicular GABA transporter (VGAT is an essential molecule for GABAergic neurotransmission due to its role in vesicular GABA release. Cerebellar Purkinje cells (PCs are GABAergic projection neurons that are indispensable for cerebellar function. To elucidate the significance of VGAT in cerebellar PCs, we generated and characterized PC-specific VGAT knockout (L7-VGAT mice. VGAT mRNAs and proteins were specifically absent in the 40-week-old L7-VGAT PCs. The morphological charactereistics, such as lamination and foliation of the cerebellar cortex, of the L7-VGAT mice were similar to those of the control littermate mice. Moreover, the protein expression levels and patterns of pre- (calbindin and parvalbumin and postsynaptic (GABA-A receptor α1 subunit (GABAARα1 and gephyrin molecules between the L7-VGAT and control mice were similar in the deep cerebellar nuclei that receive PC projections. However, the L7-VGAT mice performed poorly in the accelerating rotarod test and displayed ataxic gait in the footprint test. The L7-VGAT mice also exhibited severer ataxia as VGAT deficits progressed. These results suggest that VGAT in cerebellar Purkinje cells is not essential for the rough maintenance of cerebellar structure, but does play an important role in motor coordination. The L7-VGAT mice are a novel model of ataxia without PC degeneration, and would also be useful for studying the role of Purkinje cells in cognition and emotion.

  15. Channel Control ASIC for the CMS hadron calorimeter front end readout module

    CERN Document Server

    Yarema, R J; Boubekeur, A; Elias, J E; Shaw, T

    2002-01-01

    The Channel Control ASIC (CCA) is used along with a custom Charge Integrator and Encoder (QIE) ASIC to digitize signals from the hybrid photo diodes (HPDs) and photomultiplier tubes (PMTs) in the CMS hadron calorimeter. The CCA sits between the QIE and the data acquisition system. All digital signals to and from the QIE pass through the CCA chip. One CCA chip interfaces with two QIE channels. The CCA provides individually delayed clocks to each of the QIE chips in addition to various control signals. The QIE sends digitized PMT or HPD signals and time slice information to the CCA, which sends the data to the data acquisition system through an optical link. (2 refs) .

  16. Fetal MRI and antenatal diagnosis of unilateral cerebellar hypoplasia

    Directory of Open Access Journals (Sweden)

    Houda El Mhabrech

    2015-03-01

    Full Text Available Focal cerebellar hypoplasia is restricted to one cerebellar hemisphere or to the vermis. Prenatal diagnosis of unilateral cerebellar hypoplasia is possible by the use of ultrasound and MRI. Familiarity with the prenatal MRI findings is essential to recognize cerebellar pathologies accurately and prospectively. We present US and MRI findings in a fetus with cerebellar malformation at 20 weeks gestation. The goal of our case report is to present the fetal MRI findings of unilateral cerebellar hypoplasia, to discuss the value of fetal MRI in the early diagnoses of this malformation and to summarize the current main stream literature concerning the etiology.

  17. Bilateral Cerebellar Cortical Dysplasia without Other Malformations: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jung Seok; Ahn Kook Jin; Kim, Jee Young; Lee, Sun Jin; Park, Jeong Mi [Catholic University Yeouido St. Mary' s Hospital, College of Medicine, Seoul (Korea, Republic of)

    2010-06-15

    Recent advances in MRI have revealed congenital brain malformations and subtle developmental abnormalities of the cerebral and cerebellar cortical architecture. Typical cerebellar cortical dysplasia as a newly categorized cerebellar malformation, has been seen in patients with Fukuyama congenital muscular dystrophy. Cerebellar cortical dysplasia occurs at the embryonic stage and is often observed in healthy newborns. It is also incidentally and initially detected in adults without symptoms. To the best of our knowledge, cerebellar dysplasia without any related disorders is very rare. We describe the MRI findings in one patient with disorganized foliation of both cerebellar hemispheres without a related disorder or syndrome

  18. Description and control of dissociation channels in gas-phase protein complexes

    Science.gov (United States)

    Thachuk, Mark; Fegan, Sarah K.; Raheem, Nigare

    2016-08-01

    Using molecular dynamics simulations of a coarse-grained model of the charged apo-hemoglobin protein complex, this work expands upon our initial report [S. K. Fegan and M. Thachuk, J. Am. Soc. Mass Spectrom. 25, 722-728 (2014)] about control of dissociation channels in the gas phase using specially designed charge tags. Employing a charge hopping algorithm and a range of temperatures, a variety of dissociation channels are found for activated gas-phase protein complexes. At low temperatures, a single monomer unfolds and becomes charge enriched. At higher temperatures, two additional channels open: (i) two monomers unfold and charge enrich and (ii) two monomers compete for unfolding with one eventually dominating and the other reattaching to the complex. At even higher temperatures, other more complex dissociation channels open with three or more monomers competing for unfolding. A model charge tag with five sites is specially designed to either attract or exclude charges. By attaching this tag to the N-terminus of specific monomers, the unfolding of those monomers can be decidedly enhanced or suppressed. In other words, using charge tags to direct the motion of charges in a protein complex provides a mechanism for controlling dissociation. This technique could be used in mass spectrometry experiments to direct forces at specific attachment points in a protein complex, and hence increase the diversity of product channels available for quantitative analysis. In turn, this could provide insight into the function of the protein complex in its native biological environment. From a dynamics perspective, this system provides an interesting example of cooperative behaviour involving motions with differing time scales.

  19. Principal component analysis of cerebellar shape on MRI separates SCA types 2 and 6 into two archetypal modes of degeneration.

    Science.gov (United States)

    Jung, Brian C; Choi, Soo I; Du, Annie X; Cuzzocreo, Jennifer L; Geng, Zhuo Z; Ying, Howard S; Perlman, Susan L; Toga, Arthur W; Prince, Jerry L; Ying, Sarah H

    2012-12-01

    Although "cerebellar ataxia" is often used in reference to a disease process, presumably there are different underlying pathogenetic mechanisms for different subtypes. Indeed, spinocerebellar ataxia (SCA) types 2 and 6 demonstrate complementary phenotypes, thus predicting a different anatomic pattern of degeneration. Here, we show that an unsupervised classification method, based on principal component analysis (PCA) of cerebellar shape characteristics, can be used to separate SCA2 and SCA6 into two classes, which may represent disease-specific archetypes. Patients with SCA2 (n=11) and SCA6 (n=7) were compared against controls (n=15) using PCA to classify cerebellar anatomic shape characteristics. Within the first three principal components, SCA2 and SCA6 differed from controls and from each other. In a secondary analysis, we studied five additional subjects and found that these patients were consistent with the previously defined archetypal clusters of clinical and anatomical characteristics. Secondary analysis of five subjects with related diagnoses showed that disease groups that were clinically and pathophysiologically similar also shared similar anatomic characteristics. Specifically, Archetype #1 consisted of SCA3 (n=1) and SCA2, suggesting that cerebellar syndromes accompanied by atrophy of the pons may be associated with a characteristic pattern of cerebellar neurodegeneration. In comparison, Archetype #2 was comprised of disease groups with pure cerebellar atrophy (episodic ataxia type 2 (n=1), idiopathic late-onset cerebellar ataxias (n=3), and SCA6). This suggests that cerebellar shape analysis could aid in discriminating between different pathologies. Our findings further suggest that magnetic resonance imaging is a promising imaging biomarker that could aid in the diagnosis and therapeutic management in patients with cerebellar syndromes.

  20. Principal component analysis of cerebellar shape on MRI separates SCA types 2 and 6 into two archetypal modes of degeneration.

    Science.gov (United States)

    Jung, Brian C; Choi, Soo I; Du, Annie X; Cuzzocreo, Jennifer L; Geng, Zhuo Z; Ying, Howard S; Perlman, Susan L; Toga, Arthur W; Prince, Jerry L; Ying, Sarah H

    2012-12-01

    Although "cerebellar ataxia" is often used in reference to a disease process, presumably there are different underlying pathogenetic mechanisms for different subtypes. Indeed, spinocerebellar ataxia (SCA) types 2 and 6 demonstrate complementary phenotypes, thus predicting a different anatomic pattern of degeneration. Here, we show that an unsupervised classification method, based on principal component analysis (PCA) of cerebellar shape characteristics, can be used to separate SCA2 and SCA6 into two classes, which may represent disease-specific archetypes. Patients with SCA2 (n=11) and SCA6 (n=7) were compared against controls (n=15) using PCA to classify cerebellar anatomic shape characteristics. Within the first three principal components, SCA2 and SCA6 differed from controls and from each other. In a secondary analysis, we studied five additional subjects and found that these patients were consistent with the previously defined archetypal clusters of clinical and anatomical characteristics. Secondary analysis of five subjects with related diagnoses showed that disease groups that were clinically and pathophysiologically similar also shared similar anatomic characteristics. Specifically, Archetype #1 consisted of SCA3 (n=1) and SCA2, suggesting that cerebellar syndromes accompanied by atrophy of the pons may be associated with a characteristic pattern of cerebellar neurodegeneration. In comparison, Archetype #2 was comprised of disease groups with pure cerebellar atrophy (episodic ataxia type 2 (n=1), idiopathic late-onset cerebellar ataxias (n=3), and SCA6). This suggests that cerebellar shape analysis could aid in discriminating between different pathologies. Our findings further suggest that magnetic resonance imaging is a promising imaging biomarker that could aid in the diagnosis and therapeutic management in patients with cerebellar syndromes. PMID:22258915

  1. Timing and control requirements for a 32-channel AMU-ADC ASIC for the PHENIX detector

    Energy Technology Data Exchange (ETDEWEB)

    Emery, M.S.; Ericson, M.N.; Britton, C.L. Jr. [and others

    1998-02-01

    A custom CMOS Application Specific Integrated Circuit (ASIC) has been developed consisting of an analog memory unit (AMU) has been developed consisting of an analog memory unit (AMU) and analog to digital converter (ADC), both of which have been designed for applications in the PHENIX experiment. This IC consists of 32 pipes of analog memory with 64 cells per pipe. Each pipe also has its own ADC channel. Timing and control signal requirements for optimum performance are discussed in this paper.

  2. Separation of Parkinson's patients in early and mature stages from control subjects using one EOG channel

    DEFF Research Database (Denmark)

    Christensen, Julie A.E.; Frandsen, Rune; Kempfner, Jacob;

    2012-01-01

    different reconstructed detail subbands across all sleep epochs during a whole night of sleep. A subset of features was chosen based on a cross validated Shrunken Centroids Regularized Discriminant Analysis, where the controls were treated as one group and the patients as another. Classification...... reflecting EMG activity. This study demonstrates that both analysis of eye movements during sleep as well as EMG activity measured at the EOG channel hold potential of being biomarkers for Parkinson's disease....

  3. Non-cooperative Feedback Rate Control Game for Channel State Information in Wireless Networks

    OpenAIRE

    Song, Lingyang; Han, Zhu; Zhang, Zhongshan; Jiao, Bingli

    2011-01-01

    It has been well recognized that channel state information (CSI) feedback is of great importance for dowlink transmissions of closed-loop wireless networks. However, the existing work typically researched the CSI feedback problem for each individual mobile station (MS), and thus, cannot efficiently model the interactions among self-interested mobile users in the network level. To this end, in this paper, we propose an alternative approach to investigate the CSI feedback rate control problem i...

  4. Cerebellar Ataxia and Glutamic Acid Decarboxylase Antibodies

    Science.gov (United States)

    Ariño, Helena; Gresa-Arribas, Nuria; Blanco, Yolanda; Martínez-Hernández, Eugenia; Sabater, Lidia; Petit-Pedrol, Mar; Rouco, Idoia; Bataller, Luis; Dalmau, Josep O.; Saiz, Albert; Graus, Francesc

    2016-01-01

    IMPORTANCE Current clinical and immunologic knowledge on cerebellar ataxia (CA) with glutamic acid decarboxylase 65 antibodies (GAD65-Abs) is based on case reports and small series with short-term follow-up data. OBJECTIVE To report the symptoms, additional antibodies, prognostic factors, and long-term outcomes in a cohort of patients with CA and GAD65-Abs. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study and laboratory investigations at a center for autoimmune neurologic disorders among 34 patients with CA and GAD65-Abs, including 25 with long-term follow-up data (median, 5.4 years; interquartile range, 3.1-10.3 years). MAIN OUTCOMES AND MEASURES Analysis of clinicoimmunologic features and predictors of response to immunotherapy. Immunochemistry on rat brain, cultured neurons, and human embryonic kidney cells expressing GAD65, GAD67, α1-subunit of the glycine receptor, and a repertoire of known cell surface autoantigens were used to identify additional antibodies. Twenty-eight patients with stiff person syndrome and GAD65-Abs served as controls. RESULTS The median age of patients was 58 years (range, 33-80 years); 28 of 34 patients (82%) were women. Nine patients (26%) reported episodes of brainstem and cerebellar dysfunction or persistent vertigo several months before developing CA. The clinical presentation was subacute during a period of weeks in 13 patients (38%). Nine patients (26%) had coexisting stiff person syndrome symptoms. Systemic organ-specific autoimmunities (type 1 diabetes mellitus and others) were present in 29 patients (85%). Twenty of 25 patients with long-term follow-up data received immunotherapy (intravenous immunoglobulin in 10 and corticosteroids and intravenous immunoglobulin or other immunosuppressors in 10), and 7 of them (35%) improved. Predictors of clinical response included subacute onset of CA (odds ratio [OR], 0.50; 95% CI, 0.25-0.99; P = .047) and prompt immunotherapy (OR, 0.98; 95% CI, 0.96-0.99; P = .01). Similar

  5. Unfolding of a Temperature-Sensitive Domain Controls Voltage-Gated Channel Activation.

    Science.gov (United States)

    Arrigoni, Cristina; Rohaim, Ahmed; Shaya, David; Findeisen, Felix; Stein, Richard A; Nurva, Shailika Reddy; Mishra, Smriti; Mchaourab, Hassane S; Minor, Daniel L

    2016-02-25

    Voltage-gated ion channels (VGICs) are outfitted with diverse cytoplasmic domains that impact function. To examine how such elements may affect VGIC behavior, we addressed how the bacterial voltage-gated sodium channel (BacNa(V)) C-terminal cytoplasmic domain (CTD) affects function. Our studies show that the BacNa(V) CTD exerts a profound influence on gating through a temperature-dependent unfolding transition in a discrete cytoplasmic domain, the neck domain, proximal to the pore. Structural and functional studies establish that the BacNa(V) CTD comprises a bi-partite four-helix bundle that bears an unusual hydrophilic core whose integrity is central to the unfolding mechanism and that couples directly to the channel activation gate. Together, our findings define a general principle for how the widespread four-helix bundle cytoplasmic domain architecture can control VGIC responses, uncover a mechanism underlying the diverse BacNa(V) voltage dependencies, and demonstrate that a discrete domain can encode the temperature-dependent response of a channel. PMID:26919429

  6. Attitude Control of a Single Tilt Tri-Rotor UAV System: Dynamic Modeling and Each Channel's Nonlinear Controllers Design

    Directory of Open Access Journals (Sweden)

    Juing-Shian Chiou

    2013-01-01

    Full Text Available This paper has implemented nonlinear control strategy for the single tilt tri-rotor aerial robot. Based on Newton-Euler’s laws, the linear and nonlinear mathematical models of tri-rotor UAVs are obtained. A numerical analysis using Newton-Raphson method is chosen for finding hovering equilibrium point. Back-stepping nonlinear controller design is based on constructing Lyapunov candidate function for closed-loop system. By imitating the linguistic logic of human thought, fuzzy logic controllers (FLCs are designed based on control rules and membership functions, which are much less rigid than the calculations computers generally perform. Effectiveness of the controllers design scheme is shown through nonlinear simulation model on each channel.

  7. Stimulus-dependent state transition between synchronized oscillation and randomly repetitive burst in a model cerebellar granular layer.

    Directory of Open Access Journals (Sweden)

    Takeru Honda

    2011-07-01

    Full Text Available Information processing of the cerebellar granular layer composed of granule and Golgi cells is regarded as an important first step toward the cerebellar computation. Our previous theoretical studies have shown that granule cells can exhibit random alternation between burst and silent modes, which provides a basis of population representation of the passage-of-time (POT from the onset of external input stimuli. On the other hand, another computational study has reported that granule cells can exhibit synchronized oscillation of activity, as consistent with observed oscillation in local field potential recorded from the granular layer while animals keep still. Here we have a question of whether an identical network model can explain these distinct dynamics. In the present study, we carried out computer simulations based on a spiking network model of the granular layer varying two parameters: the strength of a current injected to granule cells and the concentration of Mg²⁺ which controls the conductance of NMDA channels assumed on the Golgi cell dendrites. The simulations showed that cells in the granular layer can switch activity states between synchronized oscillation and random burst-silent alternation depending on the two parameters. For higher Mg²⁺ concentration and a weaker injected current, granule and Golgi cells elicited spikes synchronously (synchronized oscillation state. In contrast, for lower Mg²⁺ concentration and a stronger injected current, those cells showed the random burst-silent alternation (POT-representing state. It is suggested that NMDA channels on the Golgi cell dendrites play an important role for determining how the granular layer works in response to external input.

  8. Analyzing the trade-off between multiple memory controllers and memory channels on multi-core processor performance

    Energy Technology Data Exchange (ETDEWEB)

    Sancho Pitarch, Jose Carlos [Los Alamos National Laboratory; Kerbyson, Darren [Los Alamos National Laboratory; Lang, Mike [Los Alamos National Laboratory

    2010-01-01

    Increasing the core-count on current and future processors is posing critical challenges to the memory subsystem to efficiently handle concurrent memory requests. The current trend to cope with this challenge is to increase the number of memory channels available to the processor's memory controller. In this paper we investigate the effectiveness of this approach on the performance of parallel scientific applications. Specifically, we explore the trade-off between employing multiple memory channels per memory controller and the use of multiple memory controllers. Experiments conducted on two current state-of-the-art multicore processors, a 6-core AMD Istanbul and a 4-core Intel Nehalem-EP, for a wide range of production applications shows that there is a diminishing return when increasing the number of memory channels per memory controller. In addition, we show that this performance degradation can be efficiently addressed by increasing the ratio of memory controllers to channels while keeping the number of memory channels constant. Significant performance improvements can be achieved in this scheme, up to 28%, in the case of using two memory controllers with each with one channel compared with one controller with two memory channels.

  9. Genetics Home Reference: autosomal recessive cerebellar ataxia type 1

    Science.gov (United States)

    ... Genetics Home Health Conditions ARCA1 autosomal recessive cerebellar ataxia type 1 Enable Javascript to view the expand/ ... Open All Close All Description Autosomal recessive cerebellar ataxia type 1 ( ARCA1 ) is a condition characterized by ...

  10. Compact Hybrid Subsystem of 16 Channel Optical Demultiplexer, 2x2 Switches, Optical Power Monitors and Control Circuit

    Institute of Scientific and Technical Information of China (English)

    Kenichiro; Takahashi; Toshihiko; Kishimoto; Shintaro; Mouri; Youichi; Hata; Hideaki; Yusa; Mitsuaki; Tamura; Kazuhito; Saito; Hisao; Maki

    2003-01-01

    A compact hybrid subsystem of 16channel optical demultiplexer, 2x2 switches, optical power monitors and control circuit board is developed. The subsystem is able to add or drop arbitrary optical channels and monitor the optical power level by software commands. The size of the subsystem is 170x200x30(mm).

  11. Ethanol affects NMDA receptor signaling at climbing fiber-Purkinje cell synapses in mice and impairs cerebellar LTD

    OpenAIRE

    He, Qionger; Titley, Heather; Grasselli, Giorgio; Piochon, Claire; Hansel, Christian

    2012-01-01

    Ethanol profoundly influences cerebellar circuit function and motor control. It has recently been demonstrated that functional N-methyl-d-aspartate (NMDA) receptors are postsynaptically expressed at climbing fiber (CF) to Purkinje cell synapses in the adult cerebellum. Using whole cell patch-clamp recordings from mouse cerebellar slices, we examined whether ethanol can affect NMDA receptor signaling in mature Purkinje cells. NMDA receptor-mediated currents were isolated by bath application of...

  12. Diffusion tensor imaging parameters' changes of cerebellar hemispheres in Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Mormina, Enricomaria; Arrigo, Alessandro; Granata, Francesca; Anastasi, Giuseppe P.; Gaeta, Michele [University of Messina, Department of Biomedical Science and Morphological and Functional Images, Messina (Italy); Calamuneri, Alessandro; Quartarone, Angelo [University of Messina, Department of Neurosciences, Messina (Italy); Ghilardi, Maria F.; Inglese, Matilde; Di Rocco, Alessandro [Mount Sinai Hospital, New York, NY (United States); Milardi, Demetrio [University of Messina, Department of Biomedical Science and Morphological and Functional Images, Messina (Italy); IRCCS Centro Neurolesi Bonino Pulejo, Messina (Italy)

    2015-03-01

    Studies with diffusion tensor imaging (DTI) analysis have produced conflicting information about the involvement of the cerebellar hemispheres in Parkinson's disease (PD). We, thus, used a new approach for the analysis of DTI parameters in order to ascertain the involvement of the cerebellum in PD. We performed a fiber tract-based analysis of cerebellar peduncles and cerebellar hemispheres in 16 healthy subjects and in 16 PD patients with more than 5 years duration of disease, using a 3T MRI scanner and a constrained spherical deconvolution (CSD) approach for tractographic reconstructions. In addition, we performed statistical analysis of DTI parameters and fractional anisotropy (FA) XYZ direction samplings. We found a statistically significant decrement of FA values in PD patients compared to controls (p < 0.05). In addition, extrapolating and analyzing FA XYZ direction samplings for each patient and each control, we found that this result was due to a stronger decrement of FA values along the Y axis (antero-posterior direction) (p < 0.01); FA changes along X and Z axes were not statistically significant (p > 0.05). We confirmed also no statistically significant differences of FA and apparent diffusion coefficient (ADC) for cerebellar peduncles in PD patients compared to healthy controls. The DTI-based cerebellar abnormalities in PD could constitute an advance in the knowledge of this disease. We demonstrated a statistically significant reduction of FA in cerebellar hemispheres of PD patients compared to healthy controls. Our work also demonstrated that the use of more sophisticated approaches in the DTI parameter analysis could potentially have a clinical relevance. (orig.)

  13. Anomalous Cerebellar Anatomy in Chinese Children with Dyslexia

    OpenAIRE

    Yang, Ying-Hui; Yang, Yang; Chen, Bao-Guo; Zhang, Yi-Wei; Bi, Hong-Yan

    2016-01-01

    The cerebellar deficit hypothesis for developmental dyslexia claims that cerebellar dysfunction causes the failures in the acquisition of visuomotor skills and automatic reading and writing skills. In people with dyslexia in the alphabetic languages, the abnormal activation and structure of the right or bilateral cerebellar lobes have been identified. Using a typical implicit motor learning task, however, one neuroimaging study demonstrated the left cerebellar dysfunction in Chinese children ...

  14. Aberrant cerebellar connectivity in motor and association networks in schizophrenia

    Directory of Open Access Journals (Sweden)

    Ann K. Shinn

    2015-03-01

    Full Text Available Schizophrenia is a devastating illness characterized by disturbances in multiple domains. The cerebellum is involved in both motor and non-motor functions, and the cognitive dysmetria and dysmetria of thought models propose that abnormalities of the cerebellum may contribute to schizophrenia signs and symptoms. The cerebellum and cerebral cortex are reciprocally connected via a modular, closed-loop network architecture, but few schizophrenia neuroimaging studies have taken into account the topographical and functional heterogeneity of the cerebellum. In this study, using a previously defined 17-network cerebral cortical parcellation system as the basis for our functional connectivity seeds, we systematically investigated connectivity abnormalities within the cerebellum of 44 schizophrenia patients and 28 healthy control participants. We found selective alterations in cerebro-cerebellar functional connectivity. Specifically, schizophrenia patients showed decreased cerebro-cerebellar functional connectivity in higher level association networks (ventral attention, salience, control, and default mode networks relative to healthy control participants. Schizophrenia patients also showed increased cerebro-cerebellar connectivity in somatomotor and default mode networks, with the latter showing no overlap with the regions found to be hypoconnected within the same default mode network. Finally, we found evidence to suggest that somatomotor and default mode networks may be inappropriately linked in schizophrenia. The relationship of these dysconnectivities to schizophrenia symptoms, such as neurological soft signs and altered sense of agency, is discussed. We conclude that the cerebellum ought to be considered for analysis in all future studies of network abnormalities in SZ, and further suggest the cerebellum as a potential target for further elucidation, and possibly treatment, of the underlying mechanisms and network abnormalities producing symptoms of

  15. Feedback Power Control Strategies inWireless Sensor Networks with Joint Channel Decoding

    Directory of Open Access Journals (Sweden)

    Fabio Perna

    2009-11-01

    Full Text Available In this paper, we derive feedback power control strategies for block-faded multiple access schemes with correlated sources and joint channel decoding (JCD. In particular, upon the derivation of the feasible signal-to-noise ratio (SNR region for the considered multiple access schemes, i.e., the multidimensional SNR region where error-free communications are, in principle, possible, two feedback power control strategies are proposed: (i a classical feedback power control strategy, which aims at equalizing all link SNRs at the access point (AP, and (ii an innovative optimized feedback power control strategy, which tries to make the network operational point fall in the feasible SNR region at the lowest overall transmit energy consumption. These strategies will be referred to as “balanced SNR” and “unbalanced SNR,” respectively. While they require, in principle, an unlimited power control range at the sources, we also propose practical versions with a limited power control range. We preliminary consider a scenario with orthogonal links and ideal feedback. Then, we analyze the robustness of the proposed power control strategies to possible non-idealities, in terms of residual multiple access interference and noisy feedback channels. Finally, we successfully apply the proposed feedback power control strategies to a limiting case of the class of considered multiple access schemes, namely a central estimating officer (CEO scenario, where the sensors observe noisy versions of a common binary information sequence and the AP’s goal is to estimate this sequence by properly fusing the soft-output information output by the JCD algorithm.

  16. Impaired cerebellar functional connectivity in schizophrenia patients and their healthy siblings

    Directory of Open Access Journals (Sweden)

    Guusje eCollin

    2011-12-01

    Full Text Available The long-standing notion of schizophrenia as a disorder of connectivity is supported by emerging evidence from recent neuroimaging studies, suggesting impairments of both structural and functional connectivity in schizophrenia. However, investigations are generally restricted to supratentorial brain regions, thereby excluding the cerebellum. As increasing evidence suggests that the cerebellum contributes to cognitive and affective processing, aberrant connectivity in schizophrenia may include cerebellar dysconnectivity. Moreover, as schizophrenia is highly heritable, unaffected family members of schizophrenia patients may exhibit similar connectivity profiles. The present study applies resting-state fMRI to determine cerebellar functional connectivity profiles, and the familial component of cerebellar connectivity profiles, in 62 schizophrenia patients and 67 siblings of schizophrenia patients. Compared to healthy control subjects, schizophrenia patients showed impaired functional connectivity between the cerebellum and several left-sided cerebral regions, including the hippocampus, thalamus, middle cingulate gyrus, triangular part of the inferior frontal gyrus, supplementary motor area and lingual gyrus (all p<0.0025, whole brain significant. Importantly, siblings of schizophrenia patients showed several similarities to patients in cerebellar functional connectivity, suggesting that cerebellar dysconnectivity in schizophrenia might be related to familial factors. In conclusion, our findings suggest that dysconnectivity in schizophrenia involves the cerebellum and that this defect may be related to the risk to develop the illness.

  17. Enhancing the Temporal Complexity of Distributed Brain Networks with Patterned Cerebellar Stimulation.

    Science.gov (United States)

    Farzan, Faranak; Pascual-Leone, Alvaro; Schmahmann, Jeremy D; Halko, Mark

    2016-01-01

    Growing evidence suggests that sensory, motor, cognitive and affective processes map onto specific, distributed neural networks. Cerebellar subregions are part of these networks, but how the cerebellum is involved in this wide range of brain functions remains poorly understood. It is postulated that the cerebellum contributes a basic role in brain functions, helping to shape the complexity of brain temporal dynamics. We therefore hypothesized that stimulating cerebellar nodes integrated in different networks should have the same impact on the temporal complexity of cortical signals. In healthy humans, we applied intermittent theta burst stimulation (iTBS) to the vermis lobule VII or right lateral cerebellar Crus I/II, subregions that prominently couple to the dorsal-attention/fronto-parietal and default-mode networks, respectively. Cerebellar iTBS increased the complexity of brain signals across multiple time scales in a network-specific manner identified through electroencephalography (EEG). We also demonstrated a region-specific shift in power of cortical oscillations towards higher frequencies consistent with the natural frequencies of targeted cortical areas. Our findings provide a novel mechanism and evidence by which the cerebellum contributes to multiple brain functions: specific cerebellar subregions control the temporal dynamics of the networks they are engaged in. PMID:27009405

  18. Contribution of plasma membrane Ca2+ ATPase to cerebellar synapse function

    Institute of Scientific and Technical Information of China (English)

    Helena; Huang; Raghavendra; Y; Nagaraja; Molly; L; Garside; Walther; Akemann; Thomas; Knpfel; Ruth; M; Empson

    2010-01-01

    The cerebellum expresses one of the highest levels of the plasma membrane Ca2+ATPase,isoform 2 in the mammalian brain.This highly efficient plasma membrane calcium transporter protein is enriched within the main output neurons of the cerebellar cortex;i.e. the Purkinje neurons(PNs) .Here we review recent evidence,including electrophysiological and calcium imaging approaches using the plasma membrane calcium ATPase 2(PMCA2) knockout mouse,to show that PMCA2 is critical for the physiological control of calcium at cerebellar synapses and cerebellar dependent behaviour.These studies have also revealed that deletionof PMCA2 throughout cerebellar development in the PMCA2 knockout mouse leads to permanent signalling and morphological alterations in the PN dendrites. Whilst these findings highlight the importance of PMCA2 during cerebellar synapse function and development,they also reveal some limitations in the use of the PMCA2 knockout mouse and the need for additional experimental approaches including cell-specific and reversible manipulation of PMCAs.

  19. Crossed cerebellar diaschisis in ischemic stroke

    DEFF Research Database (Denmark)

    Meneghetti, G; Vorstrup, S; Mickey, B;

    1984-01-01

    Seventy measurements of CBF were performed in 12 stroke patients by 133Xe inhalation and a rapidly rotating single photon emission computerized tomograph. CBF was measured every other day during the acute phase and at 2- and 6-month follow-up visits. A persistent contralateral cerebellar blood flow....... It is concluded from this serial study that crossed cerebellar diaschisis is a common finding in completed stroke. It is probably caused by disconnection of the corticopontine pathways, a disconnection that tends to persist. The phenomenon is in fact less variable than the stroke-related CBF changes...

  20. Paraneoplastic cerebellar dysfunction in Hodgkin's lymphoma

    Directory of Open Access Journals (Sweden)

    Kazi Sazzad Manir

    2015-01-01

    Full Text Available Paraneoplastic cerebellar degeneration (PCD is a rare presentation of Hodgkin's Lymphoma (HL manifests as acute/sub-acute nature. We report a case of 21 yr old male presented with acute cerebellar signs along with underlying HL.MRI brain was normal. CSF study was unremarkable. Patient was treated with six cycles of chemotherapy followed by radiotherapy. Neurological manifestations remarkably improved along with complete resolution of underlying HL. Anti-cancer therapy of underlying HL is the main strategy of treating associated PCD.

  1. Robust and Optimal Control of Magnetic Microparticles Inside Fluidic Channels with Time-varying Flow Rates

    Directory of Open Access Journals (Sweden)

    Islam S.M. Khalil

    2016-06-01

    Full Text Available Targeted therapy using magnetic microparticles and nanoparticles has the potential to mitigate the negative side-effects associated with conventional medical treatment. Major technological challenges still need to be addressed in order to translate these particles into in vivo applications. For example, magnetic particles need to be navigated controllably in vessels against flowing streams of body fluid. This paper describes the motion control of paramagnetic microparticles in the flowing streams of fluidic channels with time-varying flow rates (maximum flow is 35 ml.hr-1. This control is designed using a magnetic-based proportional-derivative (PD control system to compensate for the time-varying flow inside the channels (with width and depth of 2 mm and 1.5 mm, respectively. First, we achieve point-to-point motion control against and along flow rates of 4 ml.hr-1, 6 ml.hr-1, 17 ml.hr-1, and 35 ml.hr-1. The average speeds of single microparticle (with average diameter of 100 μm against flow rates of 6 ml.hr-1 and 30 ml.hr-1 are calculated to be 45 μm.s-1 and 15 μm.s-1, respectively. Second, we implement PD control with disturbance estimation and compensation. This control decreases the steady-state error by 50%, 70%, 73%, and 78% at flow rates of 4 ml.hr-1, 6 ml.hr-1, 17 ml.hr-1, and 35 ml.hr-1, respectively. Finally, we consider the problem of finding the optimal path (minimal kinetic energy between two points using calculus of variation, against the mentioned flow rates. Not only do we find that an optimal path between two collinear points with the direction of maximum flow (middle of the fluidic channel decreases the rise time of the microparticles, but we also decrease the input current that is supplied to the electromagnetic coils by minimizing the kinetic energy of the microparticles, compared to a PD control with disturbance compensation.

  2. Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

    Science.gov (United States)

    Bechstein, S.; Petsche, F.; Scheiner, M.; Drung, D.; Thiel, F.; Schnabel, A.; Schurig, Th

    2006-06-01

    Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/√Hz was specially designed for a 304-channel low-Tc dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm × 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm × 4 cm × 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented.

  3. Influence of different structured channels of mesoporous silicate on the controlled ibuprofen delivery

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Lin [Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, 100 PingLeYuan, Chaoyang District, Beijing 100124 (China); Sun, Jihong, E-mail: jhsun@bjut.edu.cn [Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, 100 PingLeYuan, Chaoyang District, Beijing 100124 (China); Zhang, Li; Wang, Jinpeng; Ren, Bo [Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, 100 PingLeYuan, Chaoyang District, Beijing 100124 (China)

    2012-08-15

    The bimodal mesoporous silicas with short random mesoporous channels and MCM-41 with long ordered mesopores were synthesised and modified with 3-(2-aminoethylamino) propyltrimethoxysilane as ibuprofen carriers to study the influence of mesoporous structure on drug delivery property. For further comparing the different mesoporous channels, modified SBA-15 with relative large and long ordered mesopores was also synthesized as drug carriers. The resultant samples were characterized with X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectra, N{sub 2} adsorption-desorption isotherms, thermogravimetric analyses, solid-state {sup 29}Si NMR spectra, elemental analysis, and UV-vis spectra. Meanwhile, the Korsmeyer-Peppas equation f{sub t} = kt{sup n} was employed to analyze the drug release profile and three release mediums including simulated fluid solution, distilled water and simulated gastric fluid were used. The results indicated that the modified BMMs with the bimodal mesopores leaded to the most drug loading amount of 25.0 mg/0.1 g, while the MCM-41 with the long and one-dimensional mesopores had the least loading amount around 20.3 mg/0.1 g. Meanwhile, the easier diffusion behavior of drug molecules in the bimodal mesopore channels of BMMs resulted in relatively faster drug release properties in comparison with MCM-41, while the release time maintained in SBF for about 12 h (release percent was about 90 wt%) and corresponding release constant k obtained from Korsmeyer-Peppas equation was around 4.10. Highlights: Black-Right-Pointing-Pointer BMMs, MCM-41 and SBA-15 with different mesostructure channels were modified with amino groups via post-treatment procedure. Black-Right-Pointing-Pointer Loading and release profiles of ibuprofen in modified BMMs, MCM-41 and SBA-15. Black-Right-Pointing-Pointer BMMs presents more drug loading amount than MCM-41 as well as better controlled release than SBA-15.

  4. NUMERICAL MODELING OF CHANNEL EQUILIBRIUM PROFILE AND ITS EFFECT ON FLOOD CONTROL

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on the morphology of Luoshan-Hankou reach at the middle Yangtze River, the one-dimensional, unsteady flow and sediment transport numerical model was adopted to study the generalized channel equilibrium profile. The variation of the longitudinal equilibrium profile, and the relation with the condition of the inflow water and sediment from the upper reach were analyzed. Meanwhile, the numerical simulation results were compared with the corresponding theoretical results. Finally, the equilibrium longitudinal slope variations and its impact on flood control were analyzed after the sediment transport process has changed.

  5. The Cerebellar Mutism Syndrome and Its Relation to Cerebellar Cognitive Function and the Cerebellar Cognitive Affective Disorder

    Science.gov (United States)

    Wells, Elizabeth M.; Walsh, Karin S.; Khademian, Zarir P.; Keating, Robert F.; Packer, Roger J.

    2008-01-01

    The postoperative cerebellar mutism syndrome (CMS), consisting of diminished speech output, hypotonia, ataxia, and emotional lability, occurs after surgery in up to 25% of patients with medulloblastoma and occasionally after removal of other posterior fossa tumors. Although the mutism is transient, speech rarely normalizes and the syndrome is…

  6. Tutorial on Feedback Control of Flows, Part I: Stabilization of Fluid Flows in Channels and Pipes

    Directory of Open Access Journals (Sweden)

    Ole M. Aamo

    2002-07-01

    Full Text Available The field of flow control has picked up pace over the past decade or so, on the promise of real-time distributed control on turbulent scales being realizable in the near future. This promise is due to the micromachining technology that emerged in the 1980s and developed at an amazing speed through the 1990s. In lab experiments, so called micro-electro-mechanical systems (MEMS that incorporate the entire detection-decision-actuation process on a single chip, have been batch processed in large numbers and assembled into flexible skins for gluing onto body-fluid interfaces for drag reduction purposes. Control of fluid flows span a wide variety of specialities. In Part I of this tutorial, we focus on the problem of reducing drag in channel and pipe flows by stabilizing the parabolic equilibrium profile using boundary feedback control. The control strategics used for this problem include classical control, based on the Nyquist criteria, and various optimal control techniques (H2, H-Infinity, as well as applications of Lyapunov stability theory.

  7. Relaminarisation of Re_{\\tau} = 100 channel flow with globally stabilising linear feedback control

    CERN Document Server

    Sharma, A S; McKeon, B J; Limebeer, D J N L; Koberg, W H; Sherwin, S J; 10.1063/1.3662449

    2013-01-01

    The problems of nonlinearity and high dimension have so far prevented a complete solution of the control of turbulent flow. Addressing the problem of nonlinearity, we propose a flow control strategy which ensures that the energy of any perturbation to the target profile decays monotonically. The controller's estimate of the flow state is similarly guaranteed to converge to the true value. We present a one-time off-line synthesis procedure, which generalises to accommodate more restrictive actuation and sensing arrangements, with conditions for existence for the controller given in this case. The control is tested in turbulent channel flow ($Re_\\tau=100$) using full-domain sensing and actuation on the wall-normal velocity. Concentrated at the point of maximum inflection in the mean profile, the control directly counters the supply of turbulence energy arising from the interaction of the wall-normal perturbations with the flow shear. It is found that the control is only required for the larger-scale motions, sp...

  8. Control of intrabunch dynamics at CERN SPS ring using 3.2 GS/s digital feedback channel

    CERN Document Server

    Rivetta, C; Cesaratto, J M; Dusatko, J; Pivi, M; Pollock, K; Turgut, O; Bartosik, H; Hofle, W; Kotzian, G; Li, K

    2013-01-01

    The feedback control of intra-bunch instabilities driven by electron-cloud or strong head-tail interaction requires bandwidth sufficient to sense the vertical position and apply correction fields to multiple sections of a nanosecondscale bunch. These requirements impose challenges and limits in the design of the feedback channel. We present experimental measurements taken from the CERN SPS machine development studies with an intrabunch feedback channel prototype. The performance of a 3.2 GS/s digital processing system is evaluated, quantifying the effect of noise and limits of the feedback channel in the bunch stability as well as transient and steady state motion of the bunch. The controllers implemented are general purpose 16 tap FIR filters and the impact on the bunch stability of controller parameters are analyzed and quantified. These studies, based on the limited feedback prototype, are crucial to validate reduced models of the system and macroparticle simulation codes, including the feedback channel. T...

  9. Silencing the Majority of Cerebellar Granule Cells Uncovers Their Essential Role in Motor Learning and Consolidation

    Directory of Open Access Journals (Sweden)

    Elisa Galliano

    2013-04-01

    Full Text Available Cerebellar granule cells (GCs account for more than half of all neurons in the CNS of vertebrates. Theoretical work has suggested that the abundance of GCs is advantageous for sparse coding during memory formation. Here, we minimized the output of the majority of GCs by selectively eliminating their CaV2.1 (P/Q-type Ca2+ channels, which mediate the bulk of their neurotransmitter release. This resulted in reduced GC output to Purkinje cells (PCs and stellate cells (SCs as well as in impaired long-term plasticity at GC-PC synapses. As a consequence modulation amplitude and regularity of simple spike (SS output were affected. Surprisingly, the overall motor performance was intact, whereas demanding motor learning and memory consolidation tasks were compromised. Our findings indicate that a minority of functionally intact GCs is sufficient for the maintenance of basic motor performance, whereas acquisition and stabilization of sophisticated memories require higher numbers of normal GCs controlling PC firing.

  10. Ultrasonically detectable cerebellar haemorrhage in preterm infants.

    LENUS (Irish Health Repository)

    McCarthy, Lisa Kenyon

    2011-07-01

    To determine the frequency and pattern of cerebellar haemorrhage (CBH) on routine cranial ultrasound (cUS) imaging in infants of ≤32 weeks gestation, and to investigate how extremely preterm infants with CBH differ from those with severe intraventricular haemorrhage (IVH).

  11. Inverse Stochastic Resonance in Cerebellar Purkinje Cells

    Science.gov (United States)

    Häusser, Michael; Gutkin, Boris S.; Roth, Arnd

    2016-01-01

    Purkinje neurons play an important role in cerebellar computation since their axons are the only projection from the cerebellar cortex to deeper cerebellar structures. They have complex internal dynamics, which allow them to fire spontaneously, display bistability, and also to be involved in network phenomena such as high frequency oscillations and travelling waves. Purkinje cells exhibit type II excitability, which can be revealed by a discontinuity in their f-I curves. We show that this excitability mechanism allows Purkinje cells to be efficiently inhibited by noise of a particular variance, a phenomenon known as inverse stochastic resonance (ISR). While ISR has been described in theoretical models of single neurons, here we provide the first experimental evidence for this effect. We find that an adaptive exponential integrate-and-fire model fitted to the basic Purkinje cell characteristics using a modified dynamic IV method displays ISR and bistability between the resting state and a repetitive activity limit cycle. ISR allows the Purkinje cell to operate in different functional regimes: the all-or-none toggle or the linear filter mode, depending on the variance of the synaptic input. We propose that synaptic noise allows Purkinje cells to quickly switch between these functional regimes. Using mutual information analysis, we demonstrate that ISR can lead to a locally optimal information transfer between the input and output spike train of the Purkinje cell. These results provide the first experimental evidence for ISR and suggest a functional role for ISR in cerebellar information processing. PMID:27541958

  12. Cerebellar liponeurocytoma: a case-report

    Directory of Open Access Journals (Sweden)

    K.V. Sreedhar Babu

    Full Text Available Cerebellar liponeurocytoma is a rare cerebellar neoplasm of adults with advanced neuronal / neurocytic and focal lipomatous differentiation, a low proliferative potential and a favorable clinical prognosis corresponding to World Health Organization grade I or II. Only a few cases have been described in the literature (approximately 20 cases by different names. A 48-years old female, presented with history of headache and dizziness associated with neck pain; restricted neck movements, drop attacks and occasional regurgitation of food since one year. Magnetic resonance imaging disclosed a right cerebellar mass lesion. Gross total resec- tion of the tumour was accomplished through a suboccipital craniotomy. The excised tissue was diagnosed as cerebellar liponeurocytoma, a rare entity, based on histopathological examination and immunohistochemistry. The morphological appearance of this neoplasm can be confused with that of oligodendroglioma, neurocytoma, ependymoma, medulloblastoma, solid hemangioblastoma and metastatic carcinomas etc., with unpredictable prognosis, which require postoperative radiotherapy, hence the importance of accurately diagnosing this rare neoplasm. This tumour should be added to the differential diagnosis of mass lesions of the posterior fossa.

  13. Cerebellar cortical inhibition and classical eyeblink conditioning.

    Science.gov (United States)

    Bao, Shaowen; Chen, Lu; Kim, Jeansok J; Thompson, Richard F

    2002-02-01

    The cerebellum is considered a brain structure in which memories for learned motor responses (e.g., conditioned eyeblink responses) are stored. Within the cerebellum, however, the relative importance of the cortex and the deep nuclei in motor learning/memory is not entirely clear. In this study, we show that the cerebellar cortex exerts both basal and stimulus-activated inhibition to the deep nuclei. Sequential application of a gamma-aminobutyric acid type A receptor (GABA(A)R) agonist and a noncompetitive GABA(A)R antagonist allows selective blockade of stimulus-activated inhibition. By using the same sequential agonist and antagonist methods in behaving animals, we demonstrate that the conditioned response (CR) expression and timing are completely dissociable and involve different inhibitory inputs; although the basal inhibition modulates CR expression, the conditioned stimulus-activated inhibition is required for the proper timing of the CR. In addition, complete blockade of cerebellar deep nuclear GABA(A)Rs prevents CR acquisition. Together, these results suggest that different aspects of the memories for eyeblink CRs are encoded in the cerebellar cortex and the cerebellar deep nuclei.

  14. Inverse Stochastic Resonance in Cerebellar Purkinje Cells.

    Science.gov (United States)

    Buchin, Anatoly; Rieubland, Sarah; Häusser, Michael; Gutkin, Boris S; Roth, Arnd

    2016-08-01

    Purkinje neurons play an important role in cerebellar computation since their axons are the only projection from the cerebellar cortex to deeper cerebellar structures. They have complex internal dynamics, which allow them to fire spontaneously, display bistability, and also to be involved in network phenomena such as high frequency oscillations and travelling waves. Purkinje cells exhibit type II excitability, which can be revealed by a discontinuity in their f-I curves. We show that this excitability mechanism allows Purkinje cells to be efficiently inhibited by noise of a particular variance, a phenomenon known as inverse stochastic resonance (ISR). While ISR has been described in theoretical models of single neurons, here we provide the first experimental evidence for this effect. We find that an adaptive exponential integrate-and-fire model fitted to the basic Purkinje cell characteristics using a modified dynamic IV method displays ISR and bistability between the resting state and a repetitive activity limit cycle. ISR allows the Purkinje cell to operate in different functional regimes: the all-or-none toggle or the linear filter mode, depending on the variance of the synaptic input. We propose that synaptic noise allows Purkinje cells to quickly switch between these functional regimes. Using mutual information analysis, we demonstrate that ISR can lead to a locally optimal information transfer between the input and output spike train of the Purkinje cell. These results provide the first experimental evidence for ISR and suggest a functional role for ISR in cerebellar information processing. PMID:27541958

  15. Improving cerebellar segmentation with statistical fusion

    Science.gov (United States)

    Plassard, Andrew J.; Yang, Zhen; Prince, Jerry L.; Claassen, Daniel O.; Landman, Bennett A.

    2016-03-01

    The cerebellum is a somatotopically organized central component of the central nervous system well known to be involved with motor coordination and increasingly recognized roles in cognition and planning. Recent work in multiatlas labeling has created methods that offer the potential for fully automated 3-D parcellation of the cerebellar lobules and vermis (which are organizationally equivalent to cortical gray matter areas). This work explores the trade offs of using different statistical fusion techniques and post hoc optimizations in two datasets with distinct imaging protocols. We offer a novel fusion technique by extending the ideas of the Selective and Iterative Method for Performance Level Estimation (SIMPLE) to a patch-based performance model. We demonstrate the effectiveness of our algorithm, Non- Local SIMPLE, for segmentation of a mixed population of healthy subjects and patients with severe cerebellar anatomy. Under the first imaging protocol, we show that Non-Local SIMPLE outperforms previous gold-standard segmentation techniques. In the second imaging protocol, we show that Non-Local SIMPLE outperforms previous gold standard techniques but is outperformed by a non-locally weighted vote with the deeper population of atlases available. This work advances the state of the art in open source cerebellar segmentation algorithms and offers the opportunity for routinely including cerebellar segmentation in magnetic resonance imaging studies that acquire whole brain T1-weighted volumes with approximately 1 mm isotropic resolution.

  16. Self-assembled oxide films with tailored nanoscale ionic and electronic channels for controlled resistive switching.

    Science.gov (United States)

    Cho, Seungho; Yun, Chao; Tappertzhofen, Stefan; Kursumovic, Ahmed; Lee, Shinbuhm; Lu, Ping; Jia, Quanxi; Fan, Meng; Jian, Jie; Wang, Haiyan; Hofmann, Stephan; MacManus-Driscoll, Judith L

    2016-01-01

    Resistive switches are non-volatile memory cells based on nano-ionic redox processes that offer energy efficient device architectures and open pathways to neuromorphics and cognitive computing. However, channel formation typically requires an irreversible, not well controlled electroforming process, giving difficulty to independently control ionic and electronic properties. The device performance is also limited by the incomplete understanding of the underlying mechanisms. Here, we report a novel memristive model material system based on self-assembled Sm-doped CeO2 and SrTiO3 films that allow the separate tailoring of nanoscale ionic and electronic channels at high density (∼10(12) inch(-2)). We systematically show that these devices allow precise engineering of the resistance states, thus enabling large on-off ratios and high reproducibility. The tunable structure presents an ideal platform to explore ionic and electronic mechanisms and we expect a wide potential impact also on other nascent technologies, ranging from ionic gating to micro-solid oxide fuel cells and neuromorphics. PMID:27491392

  17. Energy-Efficient Power Control in Multipath CDMA Channels via Large System Analysis

    CERN Document Server

    Buzzi, Stefano; Poor, H Vincent

    2008-01-01

    This paper is focused on the design and analysis of power control procedures for the uplink of multipath code-division-multiple-access (CDMA) channels based on the large system analysis (LSA). Using the tools of LSA, a new decentralized power control algorithm aimed at energy efficiency maximization and requiring very little prior information on the interference background is proposed; moreover, it is also shown that LSA can be used to predict with good accuracy the performance and operational conditions of a large network operating at the equilibrium over a multipath channel, i.e. the power, signal-to-interference-plus-noise ratio (SINR) and utility profiles across users, wherein the utility is defined as the number of bits reliably delivered to the receiver for each energy-unit used for transmission. Additionally, an LSA-based performance comparison among linear receivers is carried out in terms of achieved energy efficiency at the equilibrium. Finally, the problem of the choice of the utility-maximizing tr...

  18. Microinjection in a microfluidic format using flexible and compliant channels and electroosmotic dosage control.

    Science.gov (United States)

    Noori, Arash; Selvaganapathy, P Ravi; Wilson, Joanna

    2009-11-21

    We present a novel PDMS-based microinjection system in a microfluidic format with precise electroosmotic dosage control. The device architecture is fully scalable and enables high-throughput microinjections with integrated pre- and post-processing operations. The injection mechanism greatly simplifies current methods as only a single degree of freedom is required for injections. The injections are performed inside a fully enclosed channel by an integrated microneedle. Actuation of the needle is achieved by the compliant deformation of the channel structure by an external actuator. Reagent transport is achieved using electroosmotic flow (EOF) which provides non-pulsating flow and precise electrical dosage control. The potentials used for injections were between 5 V-25 V. The electrical properties and flow rates for the device were characterized for Zebrafish embryos and Rhodamine B and Methylene blue in pH 10 buffer solution. We also propose a method to enable precise individual dosing of embryos using direct electrical feedback. Additionally, we show that electrical feedback can be used to verify the location of the needle inside the injection target. A preliminary viability study of our device was conducted using Zebrafish (Danio rerio) embryos. The study involved the injection of ultrapure water into the embryos in an E3 buffer, and resulted in embryos that showed normal development at 48 hours. PMID:19865726

  19. Self-assembled oxide films with tailored nanoscale ionic and electronic channels for controlled resistive switching

    Science.gov (United States)

    Cho, Seungho; Yun, Chao; Tappertzhofen, Stefan; Kursumovic, Ahmed; Lee, Shinbuhm; Lu, Ping; Jia, Quanxi; Fan, Meng; Jian, Jie; Wang, Haiyan; Hofmann, Stephan; MacManus-Driscoll, Judith L.

    2016-08-01

    Resistive switches are non-volatile memory cells based on nano-ionic redox processes that offer energy efficient device architectures and open pathways to neuromorphics and cognitive computing. However, channel formation typically requires an irreversible, not well controlled electroforming process, giving difficulty to independently control ionic and electronic properties. The device performance is also limited by the incomplete understanding of the underlying mechanisms. Here, we report a novel memristive model material system based on self-assembled Sm-doped CeO2 and SrTiO3 films that allow the separate tailoring of nanoscale ionic and electronic channels at high density (~1012 inch-2). We systematically show that these devices allow precise engineering of the resistance states, thus enabling large on-off ratios and high reproducibility. The tunable structure presents an ideal platform to explore ionic and electronic mechanisms and we expect a wide potential impact also on other nascent technologies, ranging from ionic gating to micro-solid oxide fuel cells and neuromorphics.

  20. Self-assembled oxide films with tailored nanoscale ionic and electronic channels for controlled resistive switching

    Science.gov (United States)

    Cho, Seungho; Yun, Chao; Tappertzhofen, Stefan; Kursumovic, Ahmed; Lee, Shinbuhm; Lu, Ping; Jia, Quanxi; Fan, Meng; Jian, Jie; Wang, Haiyan; Hofmann, Stephan; MacManus-Driscoll, Judith L.

    2016-01-01

    Resistive switches are non-volatile memory cells based on nano-ionic redox processes that offer energy efficient device architectures and open pathways to neuromorphics and cognitive computing. However, channel formation typically requires an irreversible, not well controlled electroforming process, giving difficulty to independently control ionic and electronic properties. The device performance is also limited by the incomplete understanding of the underlying mechanisms. Here, we report a novel memristive model material system based on self-assembled Sm-doped CeO2 and SrTiO3 films that allow the separate tailoring of nanoscale ionic and electronic channels at high density (∼1012 inch−2). We systematically show that these devices allow precise engineering of the resistance states, thus enabling large on–off ratios and high reproducibility. The tunable structure presents an ideal platform to explore ionic and electronic mechanisms and we expect a wide potential impact also on other nascent technologies, ranging from ionic gating to micro-solid oxide fuel cells and neuromorphics. PMID:27491392

  1. Cerebellar Transcranial Direct Current Stimulation (ctDCS)

    Science.gov (United States)

    Grimaldi, Giuliana; Argyropoulos, Georgios P.; Bastian, Amy; Cortes, Mar; Davis, Nicholas J.; Edwards, Dylan J.; Ferrucci, Roberta; Fregni, Felipe; Galea, Joseph M.; Hamada, Masahi; Manto, Mario; Miall, R. Chris; Morales-Quezada, Leon; Pope, Paul A.; Priori, Alberto; Rothwell, John; Tomlinson, S. Paul; Celnik, Pablo

    2016-01-01

    The cerebellum is critical for both motor and cognitive control. Dysfunction of the cerebellum is a component of multiple neurological disorders. In recent years, interventions have been developed that aim to excite or inhibit the activity and function of the human cerebellum. Transcranial direct current stimulation of the cerebellum (ctDCS) promises to be a powerful tool for the modulation of cerebellar excitability. This technique has gained popularity in recent years as it can be used to investigate human cerebellar function, is easily delivered, is well tolerated, and has not shown serious adverse effects. Importantly, the ability of ctDCS to modify behavior makes it an interesting approach with a potential therapeutic role for neurological patients. Through both electrical and non-electrical effects (vascular, metabolic) ctDCS is thought to modify the activity of the cerebellum and alter the output from cerebellar nuclei. Physiological studies have shown a polarity-specific effect on the modulation of cerebellar–motor cortex connectivity, likely via cerebellar–thalamocortical pathways. Modeling studies that have assessed commonly used electrode montages have shown that the ctDCS-generated electric field reaches the human cerebellum with little diffusion to neighboring structures. The posterior and inferior parts of the cerebellum (i.e., lobules VI-VIII) seem particularly susceptible to modulation by ctDCS. Numerous studies have shown to date that ctDCS can modulate motor learning, and affect cognitive and emotional processes. Importantly, this intervention has a good safety profile; similar to when applied over cerebral areas. Thus, investigations have begun exploring ctDCS as a viable intervention for patients with neurological conditions. PMID:25406224

  2. Cerebellar Information Processing in Relapsing-Remitting Multiple Sclerosis (RRMS

    Directory of Open Access Journals (Sweden)

    E. Lesage

    2010-01-01

    Full Text Available Recent research has characterized the anatomical connectivity of the cortico-cerebellar system – a large and important fibre system in the primate brain. Within this system, there are reciprocal projections between the prefrontal cortex and Crus II of the cerebellar cortex, which both play important roles in the acquisition and execution of cognitive skills. Here, we propose that this system also plays a particular role in sustaining skilled cognitive performance in patients with Relapsing-Remitting Multiple Sclerosis (RRMS, in whom advancing neuropathology causes increasingly inefficient information processing. We scanned RRMS patients and closely matched healthy subjects while they performed the Paced Auditory Serial Addition Test (PASAT, a demanding test of information processing speed, and a control task. This enabled us to localize differences between conditions that change as a function of group (group-by-condition interactions. Hemodynamic activity in some patient populations with CNS pathology are not well understood and may be atypical, so we avoided analysis strategies that rely exclusively on models of hemodynamic activity derived from the healthy brain, using instead an approach that combined a ‘model-free’ analysis technique (Tensor Independent Component Analysis, TICA that was relatively free of such assumptions, with a post-hoc ‘model-based’ approach (General Linear Model, GLM. Our results showed group-by-condition interactions in cerebellar cortical Crus II. We suggest that this area may have in role maintaining performance in working memory tasks by compensating for inefficient data transfer associated with white matter lesions in MS.

  3. In vivo evidence of cerebellar atrophy and cerebral white matter loss in Huntington disease

    DEFF Research Database (Denmark)

    Fennema-Notestine, C; Archibald, S.L.; Jacobsen, M.W.;

    2004-01-01

    OBJECTIVE: To investigate the regional pattern of white matter and cerebellar changes, as well as subcortical and cortical changes, in Huntington disease (HD) using morphometric analyses of structural MRI. METHODS: Fifteen individuals with HD and 22 controls were studied; groups were similar in a...

  4. Distributed cerebellar plasticity implements generalized multiple-scale memory components in real-robot sensorimotor tasks

    Directory of Open Access Journals (Sweden)

    Claudia eCasellato

    2015-02-01

    Full Text Available The cerebellum plays a crucial role in motor learning and it acts as a predictive controller. Modeling it and embedding it into sensorimotor tasks allows us to create functional links between plasticity mechanisms, neural circuits and behavioral learning. Moreover, if applied to real-time control of a neurorobot, the cerebellar model has to deal with a real noisy and changing environment, thus showing its robustness and effectiveness in learning. A biologically inspired cerebellar model with distributed plasticity, both at cortical and nuclear sites, has been used. Two cerebellum-mediated paradigms have been designed: an associative Pavlovian task and a vestibulo-ocular reflex, with multiple sessions of acquisition and extinction and with different stimuli and perturbation patterns. The cerebellar controller succeeded to generate conditioned responses and finely tuned eye movement compensation, thus reproducing human-like behaviors. Through a productive plasticity transfer from cortical to nuclear sites, the distributed cerebellar controller showed in both tasks the capability to optimize learning on multiple time-scales, to store motor memory and to effectively adapt to dynamic ranges of stimuli.

  5. In vivo evidence of cerebellar atrophy and cerebral white matter loss in Huntington disease

    DEFF Research Database (Denmark)

    Fennema-Notestine, C; Archibald, S.L.; Jacobsen, M.W.;

    2004-01-01

    OBJECTIVE: To investigate the regional pattern of white matter and cerebellar changes, as well as subcortical and cortical changes, in Huntington disease (HD) using morphometric analyses of structural MRI. METHODS: Fifteen individuals with HD and 22 controls were studied; groups were similar in age...

  6. Distributed cerebellar plasticity implements generalized multiple-scale memory components in real-robot sensorimotor tasks.

    Science.gov (United States)

    Casellato, Claudia; Antonietti, Alberto; Garrido, Jesus A; Ferrigno, Giancarlo; D'Angelo, Egidio; Pedrocchi, Alessandra

    2015-01-01

    The cerebellum plays a crucial role in motor learning and it acts as a predictive controller. Modeling it and embedding it into sensorimotor tasks allows us to create functional links between plasticity mechanisms, neural circuits and behavioral learning. Moreover, if applied to real-time control of a neurorobot, the cerebellar model has to deal with a real noisy and changing environment, thus showing its robustness and effectiveness in learning. A biologically inspired cerebellar model with distributed plasticity, both at cortical and nuclear sites, has been used. Two cerebellum-mediated paradigms have been designed: an associative Pavlovian task and a vestibulo-ocular reflex, with multiple sessions of acquisition and extinction and with different stimuli and perturbation patterns. The cerebellar controller succeeded to generate conditioned responses and finely tuned eye movement compensation, thus reproducing human-like behaviors. Through a productive plasticity transfer from cortical to nuclear sites, the distributed cerebellar controller showed in both tasks the capability to optimize learning on multiple time-scales, to store motor memory and to effectively adapt to dynamic ranges of stimuli. PMID:25762922

  7. TURBULENT OPEN CHANNEL FLOW SUBJECTED TO THE CONTROL OF A SPANWISE TRAVELING WAVE

    Institute of Scientific and Technical Information of China (English)

    LIU Nan-sheng; WANG Lei; LU Xi-yun

    2009-01-01

    Turbulent open channel flows subjected to the control of a spanwise traveling wave have been investigated by means of Direct Numerical Simulation(DNS).The objective of this study is to reveal the response of the near-wall and surface-influenced turbulence to the spanwise traveling wave control.Three typical frequencies of the spanwise traveling wave,i.e.,high-,middle-and low-frequency,corresponding to the exciting periods at 25,50 and 100,are considered to study the turbulence dynamics in the wall and surface regions.To elucidate the behaviors of turbulence statistics,some typical quantities,including the mean velocity,velocity fluctuations and the structures of turbulence fluctuations,are exhibited and analyzed.

  8. Control of Energy Density inside a Disordered Medium by Coupling to Open or Closed Channels.

    Science.gov (United States)

    Sarma, Raktim; Yamilov, Alexey G; Petrenko, Sasha; Bromberg, Yaron; Cao, Hui

    2016-08-19

    We demonstrate experimentally the efficient control of light intensity distribution inside a random scattering system. The adaptive wave front shaping technique is applied to a silicon waveguide containing scattering nanostructures, and the on-chip coupling scheme enables access to all input spatial modes. By selectively coupling the incident light to the open or closed channels of the disordered system, we not only vary the total energy stored inside the system by a factor of 7.4, but also change the energy density distribution from an exponential decay to a linear decay and to a profile peaked near the center. This work provides an on-chip platform for controlling light-matter interactions in turbid media. PMID:27588875

  9. Control of Energy Density inside a Disordered Medium by Coupling to Open or Closed Channels

    Science.gov (United States)

    Sarma, Raktim; Yamilov, Alexey G.; Petrenko, Sasha; Bromberg, Yaron; Cao, Hui

    2016-08-01

    We demonstrate experimentally the efficient control of light intensity distribution inside a random scattering system. The adaptive wave front shaping technique is applied to a silicon waveguide containing scattering nanostructures, and the on-chip coupling scheme enables access to all input spatial modes. By selectively coupling the incident light to the open or closed channels of the disordered system, we not only vary the total energy stored inside the system by a factor of 7.4, but also change the energy density distribution from an exponential decay to a linear decay and to a profile peaked near the center. This work provides an on-chip platform for controlling light-matter interactions in turbid media.

  10. Fabrication of polydimethylsiloxane (PDMS) nanofluidic chips with controllable channel size and spacing.

    Science.gov (United States)

    Peng, Ran; Li, Dongqing

    2016-10-01

    The ability to create reproducible and inexpensive nanofluidic chips is essential to the fundamental research and applications of nanofluidics. This paper presents a novel and cost-effective method for fabricating a single nanochannel or multiple nanochannels in PDMS chips with controllable channel size and spacing. Single nanocracks or nanocrack arrays, positioned by artificial defects, are first generated on a polystyrene surface with controllable size and spacing by a solvent-induced method. Two sets of optimal working parameters are developed to replicate the nanocracks onto the polymer layers to form the nanochannel molds. The nanochannel molds are used to make the bi-layer PDMS microchannel-nanochannel chips by simple soft lithography. An alignment system is developed for bonding the nanofluidic chips under an optical microscope. Using this method, high quality PDMS nanofluidic chips with a single nanochannel or multiple nanochannels of sub-100 nm width and height and centimeter length can be obtained with high repeatability. PMID:27539019

  11. Control of energy density inside disordered medium by coupling to open or closed channels

    CERN Document Server

    Sarma, Raktim; Petrenko, Sasha; Bromberg, Yaron; Cao, Hui

    2016-01-01

    We demonstrate experimentally an efficient control of light intensity distribution inside a random scattering system. The adaptive wavefront shaping technique is applied to a silicon waveguide containing scattering nanostructures, and the on-chip coupling scheme enables access to all input spatial modes. By selectively coupling the incident light to open or closed channels of the disordered system, we not only vary the total energy stored inside the system by 7.4 times, but also change the energy density distribution from an exponential decay to a linear decay and to a profile peaked near the center. This work provides an on-chip platform for controlling light-matter interactions in turbid media.

  12. Adenosine modulation of [Ca2+]i in cerebellar granular cells: multiple adenosine receptors involved.

    Science.gov (United States)

    Vacas, Javier; Fernández, Mercedes; Ros, Manuel; Blanco, Pablo

    2003-12-01

    Elimination of adenosine by addition of adenosine deaminase (ADA) to the media leads to alterations in intracellular free calcium concentration ([Ca(2+)](i)) in cerebellar granular cells. Adenosine deaminase brings about increases or decreases in [Ca(2+)](i) depending on the previous activation state of the cell. These effects are dependent on the catalytic activity of adenosine deaminase, since its previous catalytic inactivation with Hg(2+) prevents the above-mentioned changes in intracellular calcium. Extracellular calcium is required for the increase in [Ca(2+)](i) promoted by ADA. This rise is insensitive to thapsigargin, but sensitive to micromolar concentrations of Ni(2+). Toxins specific for L, N and P/Q calcium channels do not overtly reduce this effect. N(6)-Cyclopentyl adenosine (CPA), an A(1) receptor agonist, produces a partial reversion of ADA effects, while CGS21680, A(2A)/A(2B) receptor agonist, slightly enhances them. Expression of A(1), A(2A), A(2B) and A(3) adenosine receptor mRNAs was detected in cerebellar granular cell cultures. These results suggest that adenosine modulate [Ca(2+)](i) in cerebellar granule cells through different adenosine receptor subtypes which, at least in part, seem to act through R-type calcium channels.

  13. Development of motor coordination and cerebellar structure in male and female rat neonates exposed to hypergravity

    Science.gov (United States)

    Nguon, K.; Ladd, B.; Baxter, M. G.; Sajdel-Sulkowska, E. M.

    2006-01-01

    We previously reported that the developing rat cerebellum is affected by exposure to hypergravity. In the present study, we explored the hypothesis that the changes in cerebellar structure in hypergravity-exposed rat neonates may affect their motor coordination. Furthermore, we hypothesized that the changes observed at 1.5G will be magnified at higher gravitational loading. To test this hypothesis, we compared motor behavior, cerebellar structure, and protein expression in rat neonates exposed to 1.5 1.75G on a 24-ft centrifuge daily for 22.5 h starting on gestational day (G) 10, through birth on G22/G23 and through postnatal day (P) 21. Exposure to hypergravity impacted the neurodevelopmental process as indicated by: (1) impaired righting response on P3, more than doubling the righting time at 1.75G, and (2) delayed onset of the startle response by one day, from P9 in controls to P10 in hypergravity-exposed pups. Hypergravity exposure resulted in impaired motor functions as evidenced by performance on a rotarod on P21; the duration of the stay on the rotarod recorded for 1.75G pups of both sexes was one tenth that of the stationary control (SC) pups. These changes in motor behavior were associated with cerebellar changes: (1) cerebellar mass on P6 was decreased by 7.5% in 1.5G-exposed male pups, 27.5% in 1.75G-exposed male pups, 17.5% in 1.5G-exposed female pups, and 22.5% in 1.75G female pups and (2) changes in the expression of glial and neuronal proteins. The results of this study suggest that perinatal exposure to hypergravity affects cerebellar development as evidenced by decreased cerebellar mass and altered cerebellar protein expression; cerebellar changes observed in hypergravity-exposed rat neonates are associated with impaired motor behavior. Furthermore, the response to hypergravity appears to be different in male and female neonates. If one accepts that the hypergravity paradigm is a useful animal model with which to predict those biological processes

  14. Speech prosody in Friedreich's and olivo-ponto cerebellar atrophy

    Science.gov (United States)

    Casper, Maureen

    2001-05-01

    A critical issue in the study of speech motor control is the identification of the mechanisms that generate the temporal flow of serially ordered articulatory events. Two staged models of serial ordered events (Lashley, 1951; Lindblom, 1963) claim that time controls events whereas dynamic models predict a relative relation between time and space. Each of these models predicts a different relation between the acoustic measures of formant frequency and segmental duration. The most recent method described herein provides a sensitive index of speech deterioration which is both acoustically robust and phonetically systematic. Both acoustic and magnetic resonance imaging measures were used to describe the speech disturbance in two neurologically distinct groups of cerebellar ataxia: Friedreich's ataxia and olivo-ponto cerebellar ataxia. The speaking task was designed to elicit six different prosodic conditions and four prosodic contrasts. All subjects read the same syllable embedded in a sentence, under six different prosodic conditions. Pair-wise comparisons derived from the six conditions were used to describe (1) final lengthening, (2) phrasal accent, (3) nuclear accent and (4) syllable reduction. An estimate of speech deterioration as determined by individual and normal subects' acoustic values of syllable duration, formant and fundamental frequencies was used in correlation analyses with magnetic resonance imaging ratings.

  15. Efficacy of oxytetracycline hydrochloride bath immersion to control external columnaris disease on walleye and channel catfish fingerlings

    Science.gov (United States)

    Rach, J.J.; Johnson, Aaron H.; Rudacille, J.B.; Schleis, S.M.

    2008-01-01

    The efficacy of oxytetracycline hydrochloride (OTC-HCl) in controlling external columnaris disease caused by Flavobacterium columnare on fingerling walleyes Sander vitreus and channel catfish Ictalurus punctatus was evaluated in two on-site hatchery trials. Microscopic examination of skin scrapings before treatment confirmed the presence of bacteria with characteristics indicative of F. columnare.in separate trials, walleyes (4.4 g) and channel catfish (1.5 g) were exposed to 60-min static bath treatments of OTC-HCl at 0, 10, and 20 mg/L (walleyes) or 0, 10, 20, and 40 mg/L (channel catfish) on three consecutive days. Each treatment regimen was tested in triplicate, and each replicate contained either 30 walleyes or 55 channel catfish. Posttreatment presumptive disease diagnosis indicated that F. columnare was the disease agent causing the mortality in both species of fish. Walleye survival at 10 d posttreatment was greater in the 10- and 20-mg/L treatment groups than in the control group; however, only the 10-mg/L treatment significantly (P < 0.05) increased walleye survival in comparison with controls. In the channel catfish trial, survival at 10 d posttreatment was significantly (P < 0.05) greater for all OTC-HCl treatment groups relative to controls. Results from these trials indicated that OTC-HCl treatments effectively reduced mortality in walleyes (10 mg/L only) and channel catfish infected with F. columnare. ?? Copyright by the American Fisheries Society 2008.

  16. Passivity-Based Output-Feedback Control of Turbulent Channel Flow

    CERN Document Server

    Heins, Peter H; Sharma, Ati S

    2016-01-01

    This paper describes a robust linear time-invariant output-feedback control strategy to reduce turbulent fluctuations, and therefore skin-friction drag, in wall-bounded turbulent fluid flows, that nonetheless gives performance guarantees in the nonlinear turbulent regime. The novel strategy is effective in reducing the supply of available energy to feed the turbulent fluctuations, expressed as reducing a bound on the supply rate to a quadratic storage function. The nonlinearity present in the equations that govern the dynamics of the flow is known to be passive and can be considered as a feedback forcing to the linearised dynamics (a Lur'e decomposition). Therefore, one is only required to control the linear dynamics in order to make the system close to passive. The ten most energy-producing spatial modes of a turbulent channel flow were identified. Passivity-based controllers were then generated to control these modes. The controllers require measurements of streamwise and spanwise wall-shear stress, and the...

  17. New supervised learning theory applied to cerebellar modeling for suppression of variability of saccade end points.

    Science.gov (United States)

    Fujita, Masahiko

    2013-06-01

    A new supervised learning theory is proposed for a hierarchical neural network with a single hidden layer of threshold units, which can approximate any continuous transformation, and applied to a cerebellar function to suppress the end-point variability of saccades. In motor systems, feedback control can reduce noise effects if the noise is added in a pathway from a motor center to a peripheral effector; however, it cannot reduce noise effects if the noise is generated in the motor center itself: a new control scheme is necessary for such noise. The cerebellar cortex is well known as a supervised learning system, and a novel theory of cerebellar cortical function developed in this study can explain the capability of the cerebellum to feedforwardly reduce noise effects, such as end-point variability of saccades. This theory assumes that a Golgi-granule cell system can encode the strength of a mossy fiber input as the state of neuronal activity of parallel fibers. By combining these parallel fiber signals with appropriate connection weights to produce a Purkinje cell output, an arbitrary continuous input-output relationship can be obtained. By incorporating such flexible computation and learning ability in a process of saccadic gain adaptation, a new control scheme in which the cerebellar cortex feedforwardly suppresses the end-point variability when it detects a variation in saccadic commands can be devised. Computer simulation confirmed the efficiency of such learning and showed a reduction in the variability of saccadic end points, similar to results obtained from experimental data.

  18. Compensatory striatal–cerebellar connectivity in mild–moderate Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Alison C. Simioni

    2016-01-01

    Full Text Available Dopamine depletion in the putamen is associated with altered motor network functional connectivity in people with Parkinson's disease (PD, but the functional significance of these changes remains unclear, attributed to either pathological or compensatory mechanisms in different studies. Here, we examined the effects of PD on dorsal caudal putamen functional connectivity, off and on dopamine replacement therapy (DRT, using resting state fMRI. Motor performance was assessed with the Purdue pegboard task. Twenty-one patients with mild–moderate Parkinson's disease were studied twice, once after an overnight DRT washout and once after the administration of a standard dose of levodopa (Sinemet, and compared to 20 demographically-matched healthy control participants. PD patients off DRT showed increased putamen functional connectivity with both the cerebellum (lobule V and primary motor cortex (M1, relative to healthy controls. Greater putamen–cerebellar functional connectivity was significantly correlated with better motor performance, whereas greater putamen–M1 functional connectivity was predictive of poorer motor performance. The administration of levodopa improved motor performance in the PD group, as expected, and reduced putamen–cerebellar connectivity to levels comparable to the healthy control group. The strength of putamen–cerebellar functional connectivity continued to predict motor performance in the PD group while on levodopa. These findings argue that increased putamen–M1 functional connectivity reflects a pathological change, deleterious to motor performance. In contrast, increased putamen–cerebellar connectivity reflects a compensatory mechanism.

  19. Structural basis of control of inward rectifier Kir2 channel gating by bulk anionic phospholipids.

    Science.gov (United States)

    Lee, Sun-Joo; Ren, Feifei; Zangerl-Plessl, Eva-Maria; Heyman, Sarah; Stary-Weinzinger, Anna; Yuan, Peng; Nichols, Colin G

    2016-09-01

    Inward rectifier potassium (Kir) channel activity is controlled by plasma membrane lipids. Phosphatidylinositol-4,5-bisphosphate (PIP2) binding to a primary site is required for opening of classic inward rectifier Kir2.1 and Kir2.2 channels, but interaction of bulk anionic phospholipid (PL(-)) with a distinct second site is required for high PIP2 sensitivity. Here we show that introduction of a lipid-partitioning tryptophan at the second site (K62W) generates high PIP2 sensitivity, even in the absence of PL(-) Furthermore, high-resolution x-ray crystal structures of Kir2.2[K62W], with or without added PIP2 (2.8- and 2.0-Å resolution, respectively), reveal tight tethering of the C-terminal domain (CTD) to the transmembrane domain (TMD) in each condition. Our results suggest a refined model for phospholipid gating in which PL(-) binding at the second site pulls the CTD toward the membrane, inducing the formation of the high-affinity primary PIP2 site and explaining the positive allostery between PL(-) binding and PIP2 sensitivity. PMID:27527100

  20. Integrated design optimization of voltage channel distribution and control voltages for tracking the dynamic shapes of smart plates

    International Nuclear Information System (INIS)

    This paper investigates a control scheme for tracking the dynamic shapes of structures with limited numbers of voltage channels. Integrated design optimization of voltage channel distribution and control parameters for structural dynamic shape control is formulated as an optimization problem with discrete variables and continuous variables coexisting. A two-level optimization method based on a simulated annealing algorithm is proposed. In the first level, the optimum channel distribution is determined by optimizing the objective function which is the optimal value obtained in the second level. The optimum control parameters are obtained by using a sequential linear least-squares algorithm in the second level. The effectiveness of the present design methodology and optimization scheme is then demonstrated through numerical examples for tracking the dynamic shapes of composite plates

  1. Dual-channel near-field control by polarizations using isotropic and inhomogeneous metasurface

    OpenAIRE

    Xiang Wan; Ben Geng Cai; Yun Bo Li; Tie Jun Cui

    2015-01-01

    We propose a method for dual-channel near-field manipulations by designing isotropic but inhomogeneous metasurfaces. As example, we present a dual-channel near-field focusing metasurface device. When the device is driven by surface waves from different channels on the metasurface, the near fields will be focused at the same spatial point with different polarizations. Conversely, if a linearly polarized source is radiated at the spatial focal point, different channels will be evoked on the met...

  2. Sexual dimorphism of the cerebellar vermis in schizophrenia.

    Science.gov (United States)

    Womer, Fay Y; Tang, Yanqing; Harms, Michael P; Bai, Chuan; Chang, Miao; Jiang, Xiaowei; Wei, Shengnan; Wang, Fei; Barch, Deanna M

    2016-10-01

    Converging lines of evidence implicate structural and functional abnormalities in the cerebellum in schizophrenia (SCZ). The cerebellar vermis is of particular interest given its association with clinical symptoms and cognitive deficits in SCZ and its known connections with cortical regions such as the prefrontal cortex. Prior neuroimaging studies have shown structural and functional abnormalities in the vermis in SCZ. In this study, we examined the cerebellar vermis in 50 individuals with SCZ and 54 healthy controls (HC) using a quantitative volumetric approach. All participants underwent high-resolution structural magnetic resonance imaging (MRI). The vermis was manually traced for each participant, and vermis volumes were computed using semiautomated methods. Volumes for total vermis and vermis subregions (anterior and posterior vermis) were analyzed in the SCZ and HC groups. Significant diagnosis-by-sex interaction effects were found in total vermis and vermis subregion analyses. These effects appeared to be driven by significantly decreased posterior vermis volumes in males with SCZ. Exploratory analyses did not reveal significant effects of clinical variables (FEP status, illness duration, and BPRS total score and subscores) on vermis volumes. The findings herein highlight the presence of neural sex differences in SCZ and the need for considering sex-related factors in studying the disorder. PMID:27401530

  3. Deep Learning for Cerebellar Ataxia Classification and Functional Score Regression

    Science.gov (United States)

    Yang, Zhen; Zhong, Shenghua; Carass, Aaron; Ying, Sarah H.; Prince, Jerry L.

    2014-01-01

    Cerebellar ataxia is a progressive neuro-degenerative disease that has multiple genetic versions, each with a characteristic pattern of anatomical degeneration that yields distinctive motor and cognitive problems. Studying this pattern of degeneration can help with the diagnosis of disease subtypes, evaluation of disease stage, and treatment planning. In this work, we propose a learning framework using MR image data for discriminating a set of cerebellar ataxia types and predicting a disease related functional score. We address the difficulty in analyzing high-dimensional image data with limited training subjects by: 1) training weak classifiers/regressors on a set of image subdomains separately, and combining the weak classifier/regressor outputs to make the decision; 2) perturbing the image subdomain to increase the training samples; 3) using a deep learning technique called the stacked auto-encoder to develop highly representative feature vectors of the input data. Experiments show that our approach can reliably classify between one of four categories (healthy control and three types of ataxia), and predict the functional staging score for ataxia. PMID:25553339

  4. HSF1-deficiency affects gait coordination and cerebellar calbindin levels.

    Science.gov (United States)

    Ingenwerth, Marc; Estrada, Veronica; Stahr, Anna; Müller, Hans Werner; von Gall, Charlotte

    2016-09-01

    Heat shock proteins (HSPs) play an important role in cell homeostasis and protect against cell damage. They were previously identified as key players in different ataxia models. HSF1 is the main transcription factor for HSP activation. HSF1-deficient mice (HSF1-/-) are known to have deficiencies in motor control test. However, little is known about effects of HSF1-deficiency on locomotor, especially gait, coordination. Therefore, we compared HSF-deficient (HSF1-/-) mice and wildtype littermates using an automated gait analysis system for objective assessment of gait coordination. We found significant changes in gait parameters of HSF1-/- mice reminiscent of cerebellar ataxia. Immunohistochemical analyses of a cerebellum revealed co-localization of HSF1 and calbindin in Purkinje cells. Therefore, we tested the hypothesis of a potential interconnection between HSF1 and calbindin in Purkinje cells. Calbindin levels were analyzed qualitatively and quantitatively by immunohistochemistry and immunoblotting, respectively. While quantitative PCR revealed no differences in calbindin mRNA levels between HSF1+/+ and HSF1-/- mice, calbindin protein levels, however, were significantly decreased in a cerebellum of HSF1-/- mice. A pathway analysis supports the hypothesis of an interconnection between HSF1 and calbindin. In summary, the targeted deletion of HSF1 results in changes of locomotor function associated with changes in cerebellar calbindin protein levels. These findings suggest a role of HSF1 in regular Purkinje cell calcium homeostasis. PMID:27173427

  5. Combined Base Station Association and Power Control in Multi-channel Cellular Networks

    CERN Document Server

    Singh, Chandramani; Sundaresan, Rajesh

    2011-01-01

    A combined base station association and power control problem is studied for the uplink of multichannel multicell cellular networks, in which each channel is used by exactly one cell (i.e., base station). A distributed association and power update algorithm is proposed and shown to converge to a Nash equilibrium of a noncooperative game. We consider network models with discrete mobiles (yielding an atomic congestion game), as well as a continuum of mobiles (yielding a population game). We find that the equilibria need not be Pareto efficient, nor need they be system optimal. To address the lack of system optimality, we propose pricing mechanisms. It is shown that these mechanisms can be implemented in a distributed fashion.

  6. Multi-channel spark gaps with lamellar control electrodes, their development and application

    International Nuclear Information System (INIS)

    The reviews multichannel (several tens) low-induced (∼ 1 nH) gas-filled gaps (MGL) with lamellar control electrodes rated at ≤ 100 kV operating voltage and up to 100 kA switching current. Switches are designed to obtain nanosecond accuracy of operation delay as to initiating pulse when electrical power safety margin is equal to 100% dictated by pressure (> 0.1 MPa) of a filling gas. One examined electric circuits of initiation of discharge acceleration in MGL, studied transient processes in the mentioned circuits and factors affecting parameters of processes, on delay and rate of break-tougher of gaps. One described the available designs of MGLs, multicable systems of parallel starting of a large number of MGLs and application of 48 four-channel MGLs rated at 50 kV. The mentioned spark gaps are applied in new power linear accelerators of electrons

  7. Modeling the Cerebellar Microcircuit: New Strategies for a Long-Standing Issue

    Science.gov (United States)

    D’Angelo, Egidio; Antonietti, Alberto; Casali, Stefano; Casellato, Claudia; Garrido, Jesus A.; Luque, Niceto Rafael; Mapelli, Lisa; Masoli, Stefano; Pedrocchi, Alessandra; Prestori, Francesca; Rizza, Martina Francesca; Ros, Eduardo

    2016-01-01

    The cerebellar microcircuit has been the work bench for theoretical and computational modeling since the beginning of neuroscientific research. The regular neural architecture of the cerebellum inspired different solutions to the long-standing issue of how its circuitry could control motor learning and coordination. Originally, the cerebellar network was modeled using a statistical-topological approach that was later extended by considering the geometrical organization of local microcircuits. However, with the advancement in anatomical and physiological investigations, new discoveries have revealed an unexpected richness of connections, neuronal dynamics and plasticity, calling for a change in modeling strategies, so as to include the multitude of elementary aspects of the network into an integrated and easily updatable computational framework. Recently, biophysically accurate “realistic” models using a bottom-up strategy accounted for both detailed connectivity and neuronal non-linear membrane dynamics. In this perspective review, we will consider the state of the art and discuss how these initial efforts could be further improved. Moreover, we will consider how embodied neurorobotic models including spiking cerebellar networks could help explaining the role and interplay of distributed forms of plasticity. We envisage that realistic modeling, combined with closed-loop simulations, will help to capture the essence of cerebellar computations and could eventually be applied to neurological diseases and neurorobotic control systems. PMID:27458345

  8. Association of Chiari I malformation and cerebellar ectopia with sensorineural hearing loss.

    Science.gov (United States)

    Haktanir, Alpay; Yücedağ, Fatih; Kaçar, Emre; Ulu, Sahin; Gültekin, Mehmet Ali; Ünlü, Ebru; Bucak, Abdülkadir; Ayçiçek, Abdullah

    2013-07-01

    We aimed to examine the prevalence of cerebellar tonsil ectopia and Chiari 1 malformation in sensorineural hearing loss (SHL) that has, to the best of our knowledge, not been studied previously. Magnetic resonance imaging records of 166 subjects with SHL and 50 controls without known otologic disturbances were included in the study. A tonsils descent more than 2 mm was assumed as cerebellar ectopia, and a descent equal to or more than 5 mm was assumed as Chiari 1 malformation. A tonsil descent group was also formed by summation of both groups. Transverse diameters of bilateral intracranial vertebral arteries and transverse sinuses were also measured, and all parameters were analyzed using appropriate statistics. A significant difference of frequencies of Chiari 1, ectopia, and tonsil descent was detected between patients and controls. In comparison of cerebellar ectopia and Chiari 1 groups, SHL did not show any significant difference. The left lateral sinus diameter showed positive correlation with tonsil descent. There was no significant correlation for the diameters of other vessels. A powerful correlation was detected between SHL and age. In addition, right and vertebral artery diameters showed positive correlations with age. Chiari 1 malformation and cerebellar ectopia showed an association with SHL. These patients should also be evaluated for otologic disturbances. Further high-resolution magnetic resonance imaging studies to explain the exact cause of this currently unknown association seems required.

  9. Hereditary cerebellar ataxia progressively impairs force adaptation during goal-directed arm movements.

    Science.gov (United States)

    Maschke, Matthias; Gomez, Christopher M; Ebner, Timothy J; Konczak, Jürgen

    2004-01-01

    We investigated how humans with hereditary cerebellar degeneration [spinocerebellar ataxia (SCA) type 6 and 8, n = 9] and age- and sex-matched healthy controls (n = 9) adapted goal-directed arm movements to an unknown external force field. We tested whether learning could be generalized to untrained regions in the workspace, an aspect central to the idea of an internal model, and if any learning could be retained. After removal of the force field, SCA patients showed little or no learning-related aftereffects indicating that repeated force-field exposure never led to successful force compensation. In contrast, healthy control subjects quickly adapted their movements to the new force field. The difference in force adaptation was significant for movements to targets that required both the shoulder and elbow joint (P < 0.001). Moreover, the generalization of learned movements to targets outside the learned workspace was prevented by the cerebellar degeneration (P < 0.01). Retention of force adaptation was significantly lower in SCA patients (P = 0.003). The severity of ataxia in SCA patients correlated negatively with the extent of learning (r = -0.84, P = 0.004). Our findings imply that progressive loss of cerebellar function gradually impairs force adaptation. The failure to generalize learning suggests that cerebellar degeneration prevents the formation of an internal representation of the limb dynamics. PMID:13679403

  10. Modeling the Cerebellar Microcircuit: New Strategies for a Long-Standing Issue.

    Science.gov (United States)

    D'Angelo, Egidio; Antonietti, Alberto; Casali, Stefano; Casellato, Claudia; Garrido, Jesus A; Luque, Niceto Rafael; Mapelli, Lisa; Masoli, Stefano; Pedrocchi, Alessandra; Prestori, Francesca; Rizza, Martina Francesca; Ros, Eduardo

    2016-01-01

    The cerebellar microcircuit has been the work bench for theoretical and computational modeling since the beginning of neuroscientific research. The regular neural architecture of the cerebellum inspired different solutions to the long-standing issue of how its circuitry could control motor learning and coordination. Originally, the cerebellar network was modeled using a statistical-topological approach that was later extended by considering the geometrical organization of local microcircuits. However, with the advancement in anatomical and physiological investigations, new discoveries have revealed an unexpected richness of connections, neuronal dynamics and plasticity, calling for a change in modeling strategies, so as to include the multitude of elementary aspects of the network into an integrated and easily updatable computational framework. Recently, biophysically accurate "realistic" models using a bottom-up strategy accounted for both detailed connectivity and neuronal non-linear membrane dynamics. In this perspective review, we will consider the state of the art and discuss how these initial efforts could be further improved. Moreover, we will consider how embodied neurorobotic models including spiking cerebellar networks could help explaining the role and interplay of distributed forms of plasticity. We envisage that realistic modeling, combined with closed-loop simulations, will help to capture the essence of cerebellar computations and could eventually be applied to neurological diseases and neurorobotic control systems. PMID:27458345

  11. Interfacing sensory input with motor output: does the control architecture converge to a serial process along a single channel?

    Directory of Open Access Journals (Sweden)

    Cornelis eVan De Kamp

    2013-05-01

    Full Text Available Modular organisation in control architecture may underlie the versatility of human motor control; but the nature of the interface relating sensory input through task-selection in the space of performance variables to control actions in the space of the elemental variables is currently unknown. Our central question is whether the control architecture converges to a serial process along a single channel? In discrete reaction time experiments, psychologists have firmly associated a serial single channel hypothesis with refractoriness and response selection (psychological refractory period. Recently, we developed a methodology and evidence identifying refractoriness in sustained control of an external single degree-of-freedom system. We hypothesise that multi-segmental whole-body control also shows refractoriness. Eight participants controlled their whole body to ensure a head marker tracked a target as fast and accurately as possible. Analysis showed enhanced delays in response to stimuli with close temporal proximity to the preceding stimulus. Consistent with our preceding work, this evidence is incompatible with control as a linear time invariant process. This evidence is consistent with a single-channel serial ballistic process within the intermittent control paradigm with an intermittent interval of around 0.5 s. A control architecture reproducing intentional human movement control must reproduce refractoriness. Intermittent control is designed to provide computational time for an online optimisation process and is appropriate for flexible adaptive control. For human motor control we suggest that parallel sensory input converges to a serial, single channel process involving planning, selection and temporal inhibition of alternative responses prior to low dimensional motor output. Such design could aid robots to reproduce the flexibility of human control.

  12. Lissencephaly and cerebellar hypoplasia in a goat

    Directory of Open Access Journals (Sweden)

    José Rômulo Soares dos Santos

    2013-10-01

    Full Text Available A case of lissencephaly and cerebellar hypoplasia was observed in a 30-day-old goat. The goat presented with sternal recumbence, absence of a menace response, intention tremors, ataxia, and nystagmus. The goat was euthanized and necropsied after having been hospitalised for eleven days. At necropsy, the surface of the brain was found to be smooth, the cerebral sulci and gyri were absent, and the cerebellum was reduced in size. Histologically, the grey matter and white matter were thicker and thinner than normal in cortices, respectively. The neurons were randomly arranged in the grey matter. In the cerebellum, the layers were disorganised, and cells were heterotopics. The histologic and gross lesions observed in this animal are characteristic of lissencephaly associated with cerebellar hypoplasia. The presence of a single goat affected suggests that the malformation was not of infectious origin and because lissencephaly is a malformation not previously described in goats, it is unlikely this case was inherited.

  13. Isolated rhomboencephalosynapsis – a rare cerebellar anomaly

    International Nuclear Information System (INIS)

    Rhomboencephalosynapsis (RES, RS) is a unique entity usually recognized in infancy based on neuroimaging. Cerebellar fusion and absence of cerebellar vermis is often associated with supratentorial findings. Since now there are about 50 cases described worldwide, with approximately 36 patients diagnosed by MRI. The authors present the first in Poland case of this uncommon malformation and review the literature. The authors describe a 28-month-old-girl with microcephaly and proper psychomotor development. The family history was unrelevant. Based on MRI the congenital malformation of posterior fossa-rhombencephalosynapsis was confirmed Presented patient is a typical example of MRI usefulness especially in patients with RES. RES symptoms are mild and that is why the diagnosis is usually made only in adulthood

  14. Cerebellar ataxia as presenting feature of hypothyroidism.

    Science.gov (United States)

    Kotwal, Suman Kumar; Kotwal, Shalija; Gupta, Rohan; Singh, Jang Bhadur; Mahajan, Annil

    2016-04-01

    Symptoms and signs of the hypothyroidism vary in relation to the magnitude and acuteness of the thyroid hormone deficiency. The usual clinical features are constipation, fatigue, cold intolerance and weight gain. Rarely it can present with neurologic problems like reversible cerebellar ataxia, dementia, peripheral neuropathy, psychosis and coma. Hypothyroidism should be suspected in all cases of ataxia, as it is easily treatable. A 40 year-old male presented with the history facial puffiness, hoarseness of voice and gait-ataxia. Investigations revealed frank primary hypothyroidism. Anti-TPO antibody was positive. Thyroxine was started and patient improved completely within eight weeks. Hypothyroidism can present with ataxia as presenting feature. Hypothyroidism should be considered in all cases of cerebellar ataxia as it is a reversible cause of ataxia. PMID:26886095

  15. A biomimetic DNA-based channel for the ligand-controlled transport of charged molecular cargo across a biological membrane

    Science.gov (United States)

    Burns, Jonathan R.; Seifert, Astrid; Fertig, Niels; Howorka, Stefan

    2016-02-01

    Biological ion channels are molecular gatekeepers that control transport across cell membranes. Recreating the functional principle of such systems and extending it beyond physiological ionic cargo is both scientifically exciting and technologically relevant to sensing or drug release. However, fabricating synthetic channels with a predictable structure remains a significant challenge. Here, we use DNA as a building material to create an atomistically determined molecular valve that can control when and which cargo is transported across a bilayer. The valve, which is made from seven concatenated DNA strands, can bind a specific ligand and, in response, undergo a nanomechanical change to open up the membrane-spanning channel. It is also able to distinguish with high selectivity the transport of small organic molecules that differ by the presence of a positively or negatively charged group. The DNA device could be used for controlled drug release and the building of synthetic cell-like or logic ionic networks.

  16. Cerebellar and cerebral atrophy in trichothiodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hye-Kyung; Sargent, Michael A.; Poskitt, Kenneth J. [British Columbia Children' s Hospital, Department of Radiology, Vancouver, BC (Canada); Prendiville, Julie S. [British Columbia Children' s Hospital, Division of Paediatric Dermatology, Department of Paediatrics, Vancouver, BC (Canada)

    2005-10-01

    Trichothiodystrophy is a rare neuroectodermal disorder of autosomal recessive inheritance that is characterized by brittle hair, nail dysplasia, ichthyosis, mental retardation, and gonadal failure. We describe a female patient whose cranial MRI revealed almost total lack of myelination in the supratentorial white matter, which is similar to the previously described cases. In addition, there was progressive cerebellar and cerebral atrophy, which has not been well documented in association with trichothiodystrophy. (orig.)

  17. Hereditary spastic paraplegia with cerebellar ataxia

    DEFF Research Database (Denmark)

    Nielsen, J E; Johnsen, B; Koefoed, P;

    2004-01-01

    Complex forms of hereditary spastic paraplegia (HSP) are rare and usually transmitted in an autosomal recessive pattern. A family of four generations with autosomal dominant hereditary spastic paraplegia (AD-HSP) and a complex phenotype with variably expressed co-existing ataxia, dysarthria, unip...... relatively decreased regional cerebral blood flow in most of the cerebellum. We conclude that this kindred demonstrates a considerable overlap between cerebellar ataxia and spastic paraplegia, emphasizing the marked clinical heterogeneity of HSP associated with spastin mutations....

  18. Potassium channel and NKCC cotransporter involvement in ocular refractive control mechanisms.

    Directory of Open Access Journals (Sweden)

    Sheila G Crewther

    Full Text Available Myopia affects well over 30% of adult humans globally. However, the underlying physiological mechanism is little understood. This study tested the hypothesis that ocular growth and refractive compensation to optical defocus can be controlled by manipulation of potassium and chloride ion-driven transretinal fluid movements to the choroid. Chicks were raised with +/-10D or zero power optical defocus rendering the focal plane of the eye in front of, behind, or at the level of the retinal photoreceptors respectively. Intravitreal injections of barium chloride, a non-specific inhibitor of potassium channels in the retina and RPE or bumetanide, a selective inhibitor of the sodium-potassium-chloride cotransporter were made, targeting fluid control mechanisms. Comparison of refractive compensation to 5 mM Ba(2+ and 10(-5 M bumetanide compared with control saline injected eyes shows significant change for both positive and negative lens defocus for Ba(2+ but significant change only for negative lens defocus with bumetanide (Rx(SAL(-10D = -8.6 +/- .9 D; Rx(Ba2+(-10D = -2.9 +/- .9 D; Rx(Bum(-10D = -2.9 +/- .9 D; Rx(SAL(+10D = +8.2 +/- .9 D; Rx(Ba2+(+10D = +2.8 +/- 1.3 D; Rx(Bum(+10D = +8.0 +/- .7 D. Vitreous chamber depths showed a main effect for drug conditions with less depth change in response to defocus shown for Ba(2+ relative to Saline, while bumetanide injected eyes showed a trend to increased depth without a significant interaction with applied defocus. The results indicate that both K channels and the NKCC cotransporter play a role in refractive compensation with NKCC blockade showing far more specificity for negative, compared with positive, lens defocus. Probable sites of action relevant to refractive control include the apical retinal pigment epithelium membrane and the photoreceptor/ON bipolar synapse. The similarities between the biometric effects of NKCC inhibition and biometric reports of the blockade of the retinal ON response, suggest a

  19. Computed tomography in hypertensive cerebellar hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Nose, T.; Maki, Y.; Ono, Y.; Yoshizawa, T.; Tsuboi, K. (Tsukuba Univ., Sakura, Ibaraki (Japan))

    1981-11-01

    Fourteen cases of cerebellar hemorrhage were analysed from the point of CT-scan, and the following results were obtained. 1. The number of cases of cerebellar hemorrhage forms 4.4% of that of total intracranial hemorrhage. 2. Most of the cerebellar hematomas extend upward. Downward extension is rare. 3. In acute dead cases hematomas are 5 cm or more in diameter and lie over bilateral hemispheres with the extension to third or fourth ventricles in CT-scans. 4. Slowly progressive cases are detriorated by the secondary hydrocephalus. 5. In mild cases hematomas are 3cm or less in diameter on CT-scans and the hematoma evacuation is not indicated for these cases. 6. The shunt operation alone is sufficient for the life saving of the slowly progressive cases, but the hematoma evacuation is indicated in these cases if the functional prognosis is taken into consideration. 7. Immediate hematoma evacuation together with the ventricular drainage is considered to be effective for the life saving of the acute fulminant cases.

  20. GlyT2+ Neurons in the Lateral Cerebellar Nucleus

    OpenAIRE

    Uusisaari, Marylka; Knöpfel, Thomas

    2009-01-01

    The deep cerebellar nuclei (DCN) are a major hub in the cerebellar circuitry but the functional classification of their neurons is incomplete. We have previously characterized three cell groups in the lateral cerebellar nucleus: large non-GABAergic neurons and two groups of smaller neurons, one of which express green fluorescence protein (GFP) in a GAD67/GFP mouse line and is therefore GABAergic. However, as a substantial number of glycinergic and glycine/GABA co-expressing neurons have been ...

  1. Lacunar thalamic stroke with pure cerebellar and proprioceptive deficits.

    OpenAIRE

    Gutrecht, J A; Zamani, A A; D N Pandya

    1992-01-01

    Case reports of two patients with cerebellar ataxia and proprioceptive sensory loss are presented. MRI of the brain revealed lesions of the ventroposterior part of the thalamus. These patients illustrate clinically the anatomical independence of cerebellar and sensory pathways in the thalamus. We suggest that the ataxic deficit is caused by interruption of cerebellar outflow pathways in the thalamus and not secondary to sensory deafferentation.

  2. A user-friendly wearable single-channel EOG-based human-computer interface for cursor control

    OpenAIRE

    ANG, AMS; Zhang, Z.; Hung, YS; Mak, JNF

    2015-01-01

    This paper presents a novel wearable single-channel electrooculography (EOG) based human-computer interface (HCI) with a simple system design and robust performance. In the proposed system, EOG signals for control are generated from double eye blinks, collected by a commercial wearable device (the NeuroSky MindWave headset), and then converted into a sequence of commands that can control cursor navigations and actions. The EOG-based cursor control system was tested on 8 subjects in indoor or ...

  3. Cerebellar ataxia as the presenting manifestation of Lyme disease.

    Science.gov (United States)

    Arav-Boger, Ravit; Crawford, Thomas; Steere, Allen C; Halsey, Neal A

    2002-04-01

    A 7-year-old boy from suburban Baltimore who presented with cerebellar ataxia and headaches was found by magnetic resonance imaging to have multiple cerebellar enhancing lesions. He had no history of tick exposure. He was initially treated with steroids for presumptive postinfectious encephalitis. Lyme disease was diagnosed 10 weeks later after arthritis developed. Testing of the cerebrospinal fluid obtained at the time cerebellar ataxia was diagnosed revealed intrathecal antibody production to Borrelia burgdorferi. Treatment with intravenous antibiotics led to rapid resolution of persistent cerebellar findings.

  4. Cerebellar Nuclear Neurons Use Time and Rate Coding to Transmit Purkinje Neuron Pauses.

    Science.gov (United States)

    Sudhakar, Shyam Kumar; Torben-Nielsen, Benjamin; De Schutter, Erik

    2015-12-01

    Neurons of the cerebellar nuclei convey the final output of the cerebellum to their targets in various parts of the brain. Within the cerebellum their direct upstream connections originate from inhibitory Purkinje neurons. Purkinje neurons have a complex firing pattern of regular spikes interrupted by intermittent pauses of variable length. How can the cerebellar nucleus process this complex input pattern? In this modeling study, we investigate different forms of Purkinje neuron simple spike pause synchrony and its influence on candidate coding strategies in the cerebellar nuclei. That is, we investigate how different alignments of synchronous pauses in synthetic Purkinje neuron spike trains affect either time-locking or rate-changes in the downstream nuclei. We find that Purkinje neuron synchrony is mainly represented by changes in the firing rate of cerebellar nuclei neurons. Pause beginning synchronization produced a unique effect on nuclei neuron firing, while the effect of pause ending and pause overlapping synchronization could not be distinguished from each other. Pause beginning synchronization produced better time-locking of nuclear neurons for short length pauses. We also characterize the effect of pause length and spike jitter on the nuclear neuron firing. Additionally, we find that the rate of rebound responses in nuclear neurons after a synchronous pause is controlled by the firing rate of Purkinje neurons preceding it.

  5. Cerebellar damage impairs the self-rating of regret feeling in a gambling task.

    Directory of Open Access Journals (Sweden)

    Silvia eClausi

    2015-05-01

    Full Text Available Anatomical, clinical, and neuroimaging evidence implicates the cerebellum in processing emotions and feelings. Moreover recent studies showed a cerebellar involvement in pathologies such as autism, schizophrenia and alexithymia, in which emotional processing have been found altered. However, cerebellar function in the modulation of emotional responses remains debated. In this study, emotions that are involved directly in decision-making were examined in 15 patients (six males; age range 17-60 years affected by cerebellar damage and 15 well matched healthy controls. We used a gambling task, in which subjects’ choices and evaluation of outcomes with regard to their anticipated and actual emotional impact were analyzed. Emotions, such as regret and relief, were elicited, based on the outcome of the unselected gamble. Interestingly, despite their ability to avoid regret in subsequent choices, patients affected by cerebellar lesions were significantly impaired in evaluating the feeling of regret subjectively. These results demonstrate that the cerebellum is involved in conscious recognizing of negative feelings caused by the sense of self-responsibility for an incorrect decision.

  6. [Buspirone in the treatment of cerebellar ataxia].

    Science.gov (United States)

    Svetel, M; Vojvodić, N; Filipović, S R; Dragasević, N; Sternić, N; Kostić, V S

    1999-01-01

    Ataxia is defined as a disturbance which, quite independent of any motor weakness, alters direction and extent of voluntary movement and impairs the sustained voluntary of reflex muscle contraction necessary for maintaining postiue and equilibrium [1]. Since pathophysiological basis of cerebeller ataxia is still not completely clear, the current therapeutic attempts are mainly symptom-oriented [3]. One possible approach could be a modification of potentially involved neurotransmitter systems of the cerebellum, where particularly interesting is the serotonergic system. However, attempts with levorotatory form of tryptophan (5-HT precursors) proved to be ineffective [4, 5]. Since receptors in the cerebellum are mainly of 5-HTIA subtype, the use of specific agonists might be a more reasonable therapy [6]. The study initially involved 11 patients, but only 9 completed the protocol due to unfavorable side effects. Our open label prospective study lasted for 15 weeks. The patients were tested before the beginning of the treatment (initial visit), at 7th (first visit) and 11th week (second visit) of continuous therapy, and eventually at 15th week (final visit). The daily dose was 40 mg at the first and 60 mg at the second visit. We used the evaluation scale gurposed for cerebellar functions testing (speech, gait, coordination and ocular movements). Significant improvement of cerebellar ataxia in patients under buspiron therapy has been noted. We analyzed the results obtained from our 9 patients (4 females and 5 males), of which 6 patients suffered from cerebellar degeneration, one from multiple sclerosis, one from Ramsey-Hunt syndrome, and one from pontine myelinolysis. At the initial visit the patient score was 18.9 (SD = 7.3), subsequently, at the iirst visit the score was 15.4 (SD = 8), while the second visit yielded the score of 12.9 (SD = 8.2), and finally, after a two-weeks lasting wash-out period, it was 17.7 (SD = 7.1) (Table 1). It was found that patients

  7. Dynamic Routing Algorithm Based on the Channel Quality Control for Farmland Sensor Networks

    Directory of Open Access Journals (Sweden)

    Dongfeng Xu

    2014-04-01

    Full Text Available This article reports a Dynamic Routing Algorithm for Farmland Sensor Networks (DRA-FSN based on channel quality control to improve energy efficiency, which combines the distance and communication characteristics of farmland wireless sensor network. The functional architecture of the DRA-FSN algorithm, routing establish the mechanisms, the communication transmission mechanism, the global routing beacon return mechanism, abnormal node handling mechanism and sensor networks timing control mechanisms were designed in detail in this article. This article also evaluates and simulated the performance of DRA-FSN algorithm in different conditions from energy efficiency, packet energy consumption and packet distribution balance by comparing DRA-FSN algorithm with DSDV, EAP algorithm. Simulations showed that the DRA-FSN was more energy efficient than EAP and DSDV, the DRA-FSN algorithm overcame the shortcoming that capacity and bandwidth of the routing table correspondingly increase as more and more nodes joining the network. It has better performance in scalability and network loading balance

  8. The demonstration of the Si nano-tube device with the promising short channel control

    Science.gov (United States)

    Liao, M.-H.; Chen, P.-G.

    2015-10-01

    In addition to the development of the nano-wire device, the vertical gate-all-around (V-GAA) Si nano-tube (NT) device structure is proposed with the promising device performance in this work. The vertical device structure makes the transistor easy to be scaled down continuously to meet the complementary metal-oxide-semiconductor scaling needs of the 10/7 nm technology node and beyond. The NT device with the center hollow structure has the capability to deplete the out-of gate control carriers in the center of the nano-wire device and further results in the better device short channel control. Based on the simulation data, the V-GAA Si NT device can keep the Ion-state current the same and reduce the Ioff-state stand-by power. With the demonstration of the promising device performance, the proposed V-GAA Si NT device can be regarded as one of the most promising candidates for the future application of the sub-10/7 nm logic device.

  9. Meta-gated channel for the discrete control of electromagnetic fields

    Science.gov (United States)

    Yang, Rui; Wang, Hui; Shi, Ayuan; Zhang, Aofang; Wang, Jing; Gao, Dongxing; Lei, Zhenya; Hu, Bowei

    2016-08-01

    We demonstrate the meta-gate controlled wave propagation through multiple metallic plates with properly devised sub-wavelength defect apertures. Different from using gradient refractive-index meta-materials or phase-discontinuity meta-surfaces to produce the discrepancy between the incident angle and the refractive angle, our technique redirects electromagnetic fields by setting-up discrete transmission gateways between adjacent meta-gates and creates the perfect channels for the wave propagation. Electromagnetic fields can be assigned in the response of the driving frequency of meta-gates with extraordinary transmissions and propagate simply relying on their pre-set locations as illustrated by the meta-gate guided electromagnetic fields travelling in the paths of the Silk-Road and the contour line of Xi'an city where the Silk-Road starts. The meta-gate concept, offering the feasibility of the discrete control of electromagnetic fields with gating routes, may pave an alternative way for precisely transmitting of signals and efficiently sharing of resource in the communication.

  10. The mechano-activated K+ channels TRAAK and TREK-1 control both warm and cold perception

    OpenAIRE

    Noël, Jacques; Zimmermann, Katharina; Busserolles, Jérome; Deval, Emanuel; Alloui, Abdelkrim; Diochot, Sylvie; Guy, Nicolas; Borsotto, Marc; Reeh, Peter; Eschalier, Alain; Lazdunski, Michel

    2009-01-01

    The sensation of cold or heat depends on the activation of specific nerve endings in the skin. This involves heat- and cold-sensitive excitatory transient receptor potential (TRP) channels. However, we show here that the mechano-gated and highly temperature-sensitive potassium channels of the TREK/TRAAK family, which normally work as silencers of the excitatory channels, are also implicated. They are important for the definition of temperature thresholds and temperature ranges in which excita...

  11. Transmission Control of Two-User Slotted ALOHA Over Gilbert-Elliott Channel: Stability and Delay Analysis

    CERN Document Server

    Fanous, Anthony

    2011-01-01

    In this paper, we consider the problem of calculating the stability region and average delay of two user slotted ALOHA over a Gilbert-Elliott channel, where users have channel state information and adapt their transmission probabilities according to the channel state. Each channel has two states, namely, the 'good' and 'bad' states. In the 'bad' state, the channel is assumed to be in deep fade and the transmission fails with probability one, while in the 'good' state, there is some positive success probability. We calculate the Stability region with and without Multipacket Reception capability as well as the average delay without MPR. Our results show that the stability region of the controlled S-ALOHA is always a superset of the stability region of uncontrolled S-ALOHA. Moreover, if the channel tends to be in the 'bad' state for long proportion of time, then the stability region is a convex Polyhedron strictly containing the TDMA stability region and the optimal transmission strategy is to transmit with prob...

  12. Sub-Lethal Dose of Shiga Toxin 2 from Enterohemorrhagic Escherichia coli Affects Balance and Cerebellar Cytoarchitecture

    Science.gov (United States)

    Pinto, Alipio; Cangelosi, Adriana; Geoghegan, Patricia A.; Tironi-Farinati, Carla; Brener, Gabriela J.; Goldstein, Jorge

    2016-01-01

    Shiga toxin producing Escherichia coli may damage the central nervous system before or concomitantly to manifested hemolytic–uremic syndrome symptoms. The cerebellum is frequently damaged during this syndrome, however, the deleterious effects of Shiga toxin 2 has never been integrally reported by ultrastructural, physiological and behavioral means. The aim of this study was to determine the cerebellar compromise after intravenous administration of a sub-lethal dose of Shiga toxin 2 by measuring the cerebellar blood–brain barrier permeability, behavioral task of cerebellar functionality (inclined plane test), and ultrastructural analysis (transmission electron microscope). Intravenous administration of vehicle (control group), sub-lethal dose of 0.5 and 1 ηg of Stx2 per mouse were tested for behavioral and ultrastructural studies. A set of three independent experiments were performed for each study (n = 6). Blood–brain barrier resulted damaged and consequently its permeability was significantly increased. Lower scores obtained in the inclined plane task denoted poor cerebellar functionality in comparison to their controls. The most significant lower score was obtained after 5 days of 1 ηg of toxin administration. Transmission electron microscope micrographs from the Stx2-treated groups showed neurons with a progressive neurodegenerative condition in a dose dependent manner. As sub-lethal intravenous Shiga toxin 2 altered the blood brain barrier permeability in the cerebellum the toxin penetrated the cerebellar parenchyma and produced cell damaged with significant functional implications in the test balance. PMID:26904009

  13. Sub-Lethal Dose of Shiga toxin 2 from Enterohemorrhagic Escherichia coli Affects Balance and Cerebellar Cythoarquitecture.

    Directory of Open Access Journals (Sweden)

    Luciana eD’Alessio

    2016-02-01

    Full Text Available Shiga toxin producing Escherichia coli may damage the central nervous system before or concomitantly to manifested hemolytic uremic syndrome symptoms. The cerebellum is frequently damaged during this syndrome, however the deleterious effects of Shiga toxin 2 has never been integrally reported by ultrastructural, physiological and behavioral means. The aim of this study was to determine the cerebellar compromise after intravenous administration of a sub-lethal dose of Shiga toxin 2 by measuring the cerebellar blood brain barrier permeability, behavioral task of cerebellar functionality (inclined plane test, and ultrastructural analysis (transmission electron microscope. Intravenous administration of vehicle (control group, sub-lethal dose of 0.5 ηg and 1 ηg of Stx2 per mouse were tested for behavioral and ultrastructural studies. A set of three independent experiments were performed for each study (n=6. Blood–Brain Barrier resulted damaged and consequently its permeability was significantly increased. Lower scores obtained in the inclined plane task denoted poor cerebellar functionality in comparison to their controls. The most significant lower score was obtained after 5 days of 1ηg of toxin administration. Transmission electron microscope micrographs from the Stx2-treated groups showed neurons with a progressive neurodegenerative condition in a dose dependent manner. As sub-lethal intravenous Shiga toxin 2 altered the blood brain barrier permeability in the cerebellum the toxin penetrated the cerebellar parenchyma and produced cell damaged with significant functional implications in the test balance.

  14. Use of diffusion tensor imaging to identify similarities and differences between cerebellar and Parkinsonism forms of multiple system atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Po-Shan [National Yang-Ming University, Department of Neurology, School of Medicine, Taipei (China); Taipei Veterans General Hospital, Neurological Institute, Taipei (China); Taipei Municipal Gan-Dau Hospital, Neurological Institute, Taipei (China); National Yang-Ming University, Institute of Brain Science, Taipei (China); Wu, Hsiu-Mei [National Yang-Ming University, Department of Neurology, School of Medicine, Taipei (China); Taipei Veterans General Hospital, Department of Radiology, Taipei (China); Lin, Ching-Po [National Yang-Ming University, Institute of Brain Science, Taipei (China); Soong, Bing-Wen [National Yang-Ming University, Department of Neurology, School of Medicine, Taipei (China); Taipei Veterans General Hospital, Neurological Institute, Taipei (China)

    2011-07-15

    We performed diffusion tensor imaging to determine if multiple system atrophy (MSA)-cerebellar (C) and MSA-Parkinsonism (P) show similar changes, as shown in pathological studies. Nineteen patients with MSA-C, 12 patients with MSA-P, 20 patients with Parkinson disease, and 20 healthy controls were evaluated with the use of voxel-based morphometry analysis of diffusion tensor imaging. There was an increase in apparent diffusion coefficient values in the middle cerebellar peduncles and cerebellum and a decrease in fractional anisotropy in the pyramidal tract, middle cerebellar peduncles, and white matter of the cerebellum in patients with MSA-C and MSA-P compared to the controls (P<0.001). In addition, isotropic diffusion-weighted image values were reduced in the cerebellar cortex and deep cerebellar nuclei in patients with MSA-C and increased in the basal ganglia in patients with MSA-P. These results indicate that despite their disparate clinical manifestations, patients with MSA-C and MSA-P share similar diffusion tensor imaging features in the infratentorial region. Further, the combination of FA, ADC and iDWI images can be used to distinguish between MSA (either form) and Parkinson disease, which has potential therapeutic implications. (orig.)

  15. Cerebellar grey-matter deficits, cannabis use and first-episode schizophrenia in adolescents and young adults.

    Science.gov (United States)

    Cohen, Martin; Rasser, Paul E; Peck, Greg; Carr, Vaughan J; Ward, Philip B; Thompson, Paul M; Johnston, Patrick; Baker, Amanda; Schall, Ulrich

    2012-04-01

    Epidemiological data link adolescent cannabis use to psychosis and schizophrenia, but its contribution to schizophrenia neuropathology remains controversial. First-episode schizophrenia (FES) patients show regional cerebral grey- and white-matter changes as well as a distinct pattern of regional grey-matter loss in the vermis of the cerebellum. The cerebellum possesses a high density of cannabinoid type 1 receptors involved in the neuronal diversification of the developing brain. Cannabis abuse may interfere with this process during adolescent brain maturation leading to 'schizophrenia-like' cerebellar pathology. Magnetic resonance imaging and cortical pattern matching techniques were used to investigate cerebellar grey and white matter in FES patients with and without a history of cannabis use and non-psychiatric cannabis users. In the latter group we found lifetime dose-dependent regional reduction of grey matter in the right cerebellar lobules and a tendency for more profound grey-matter reduction in lobule III with younger age at onset of cannabis use. The overall regional grey-matter differences in cannabis users were within the normal variability of grey-matter distribution. By contrast, FES subjects had lower total cerebellar grey-matter:total cerebellar volume ratio and marked grey-matter loss in the vermis, pedunculi, flocculi and lobules compared to pair-wise matched healthy control subjects. This pattern and degree of grey-matter loss did not differ from age-matched FES subjects with comorbid cannabis use. Our findings indicate small dose-dependent effects of juvenile cannabis use on cerebellar neuropathology but no evidence of an additional effect of cannabis use on FES cerebellar grey-matter pathology.

  16. On stochastic geometry modeling of cellular uplink transmission with truncated channel inversion power control

    KAUST Repository

    Elsawy, Hesham

    2014-08-01

    Using stochastic geometry, we develop a tractable uplink modeling paradigm for outage probability and spectral efficiency in both single and multi-tier cellular wireless networks. The analysis accounts for per user equipment (UE) power control as well as the maximum power limitations for UEs. More specifically, for interference mitigation and robust uplink communication, each UE is required to control its transmit power such that the average received signal power at its serving base station (BS) is equal to a certain threshold ρo. Due to the limited transmit power, the UEs employ a truncated channel inversion power control policy with a cutoff threshold of ρo. We show that there exists a transfer point in the uplink system performance that depends on the following tuple: BS intensity λ, maximum transmit power of UEs Pu, and ρo. That is, when Pu is a tight operational constraint with respect to (w.r.t.) λ and ρo, the uplink outage probability and spectral efficiency highly depend on the values of λ and ρo. In this case, there exists an optimal cutoff threshold ρ*o, which depends on the system parameters, that minimizes the outage probability. On the other hand, when Pu is not a binding operational constraint w.r.t. λ and ρo, the uplink outage probability and spectral efficiency become independent of λ and ρo. We obtain approximate yet accurate simple expressions for outage probability and spectral efficiency, which reduce to closed forms in some special cases. © 2002-2012 IEEE.

  17. Charges in the cytoplasmic pore control intrinsic inward rectification and single-channel properties in Kir1.1 and Kir2.1 channels.

    Science.gov (United States)

    Chang, Hsueh-Kai; Yeh, Shih-Hao; Shieh, Ru-Chi

    2007-02-01

    An E224G mutation of the Kir2.1 channel generates intrinsic inward rectification and single-channel fluctuations in the absence of intracellular blockers. In this study, we showed that positively charged residues H226, R228 and R260, near site 224, regulated the intrinsic inward rectification and single-channel properties of the E224G mutant. By carrying out systematic mutations, we found that the charge effect on the intrinsic inward rectification and single-channel conductance is consistent with a long-range electrostatic mechanism. A Kir1.1 channel where the site equivalent to E224 in the Kir2.1 channel is a glycine residue does not show inward rectification or single-channel fluctuations. The G223K and N259R mutations of the Kir1.1 channel induced intrinsic inward rectification and reduced the single-channel conductance but did not generate large open-channel fluctuations. Substituting the cytoplasmic pore of the E224G mutant into the Kir1.1 channel induced open-channel fluctuations and intrinsic inward rectification. The single-channel conductance of the E224G mutant showed inward rectification. Also, a voltage-dependent gating mechanism decreased open probability during depolarization and contributed to the intrinsic inward rectification in the E224G mutant. In addition to an electrostatic effect, a close interaction of K(+) with channel pore may be required for generating open-channel fluctuations in the E224G mutant.

  18. Braiding of submarine channels controlled by aspect ratio similar to rivers

    Science.gov (United States)

    Foreman, Brady Z.; Lai, Steven Y. J.; Komatsu, Yuhei; Paola, Chris

    2015-09-01

    The great majority of submarine channels formed by turbidity and density currents are meandering in planform; they consist of a single, sinuous channel that transports a turbid, dense flow of sediment from submarine canyons to ocean floor environments. Braided turbidite systems consisting of multiple, interconnected channel threads are conspicuously rare. Furthermore, such systems may not represent the spontaneous planform instability of true braiding, but instead result from erosive processes or bathymetric variability. In marked contrast to submarine environments, both meandering and braided planforms are common in fluvial systems. Here we present experiments of subaqueous channel formation conducted at two laboratory facilities. We find that density currents readily produce a braided planform for flow aspect ratios of depth to width that are similar to those that produce river braiding. Moreover, we find that stability model theory for river planform morphology successfully describes submarine channels in both experiments and the field. On the basis of these observations, we propose that the rarity of braided submarine channels is explained by the generally greater flow depths in submarine systems, which necessitate commensurately greater widths to achieve the required aspect ratio, along with feedbacks among flow thickness, suspended sediment concentration and channel relief that induce greater levee deposition rates and limit channel widening.

  19. Extracellular pH dynamically controls cell surface delivery of functional TRPV5 channels.

    NARCIS (Netherlands)

    Lambers, T.T.; Oancea, E.; Groot, T. de; Topala, C.N.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2007-01-01

    Extracellular pH has long been known to affect the rate and magnitude of ion transport processes among others via regulation of ion channel activity. The Ca(2+)-selective transient receptor potential vanilloid 5 (TRPV5) channel constitutes the apical entry gate in Ca(2+)-transporting cells, contribu

  20. Using a terrestrial laser scanner to characterize vegetation-induced flow resistance in a controlled channel

    CERN Document Server

    Vinatier, Fabrice; Belaud, Gilles; Combemale, David

    2016-01-01

    Vegetation characteristics providing spatial heterogeneity at the channel reach scale can produce complex flow patterns and the relationship between plant patterns morphology and flow resistance is still an open question (Nepf 2012). Unlike experiments in laboratory, measuring the vegetation characteristics related to flow resistance on open channel in situ is difficult. Thanks to its high resolution and light weight, scanner lasers allow now to collect in situ 3D vegetation characteristics. In this study we used a 1064 nm usual Terrestrial Laser Scanner (TLS) located 5 meters at nadir above a 8 meters long equipped channel in order to both i) characterize the vegetation structure heterogeneity within the channel form a single scan (blockage factor, canopy height) and ii) to measure the 2D water level all over the channel during steady flow within a few seconds scan. This latter measuring system was possible thanks to an additive dispersive product sprinkled at the water surface. Vegetation characteristics an...

  1. Craniotomy for cerebellar hemangioblastoma excision in a patient with von Hippel–Lindau disease complicated by uncontrolled hypertension due to pheochromocytoma

    Directory of Open Access Journals (Sweden)

    Yoshifumi Mizobuchi

    2015-01-01

    Discu: ssion & conclusion In patients with pheochromocytoma, the effects of catecholamine oversecretion can cause significant perioperative morbidity and mortality, but these can be prevented by appropriate preoperative medical management. When carrying out an excision of cerebellar hemangioblastomas in patients with intracranial hypertension complicated by abnormal hypertension due to pheochromocytoma whose blood pressure is not sufficiently controlled, tumor resection of the pheochromocytoma prior to cerebellar hemangioblastoma excision in the same surgery may prevent increased ICP and reduce perioperative risk.

  2. Fluvial bevelling of topography controlled by lateral channel mobility and uplift rate

    Science.gov (United States)

    Bufe, Aaron; Paola, Chris; Burbank, Douglas W.

    2016-09-01

    Valley morphologies of rivers crossing zones of active uplift range from narrow canyons to broad alluvial surfaces. They provide illuminating examples of the fundamental, but poorly understood, competition between relief creation and landscape flattening. Motivated by a field example of abandoned kilometre-wide, fluvially eroded platforms on active detachment folds in the Tian Shan foreland, we present physical experiments investigating the controls on the area of a growing fold that is reworked by antecedent rivers. These experiments reproduce the range of observed field morphologies, varying from wholesale bevelling of the uplifting fold to the formation of narrow, steep-walled canyons. A log-linear fit to a simple dimensionless parameter shows that the competition between lateral channel mobility and rock-uplift rate explains >95% of the variance in the bevelled fraction of the folds. Our data suggest that lateral bedrock erosion rates of 0.5-40 m yr-1 are required to explain the formation of extensive platforms in the Tian Shan foreland and imply that varying water and sediment fluxes can cause striking changes in the degree of landscape flattening by influencing the lateral erosion rate.

  3. Application of resin system for sand consolidation, mud-loss control, and channel repairing

    Energy Technology Data Exchange (ETDEWEB)

    Wasnik, A.; Mete, S.; Ghosh, B. [Maharashtra Inst. of Technology (India)

    2005-11-01

    Sand production is one of the major challenges facing oil well operators. A technique for sand consolidation and channel repairing with a resin system was described along with a methodology for placing a chemical casing during or after drilling a shale zone that is prone to caving. The methodology is intended to facilitate drilling with reduced mud weight, without reducing the hole size. The resin comprises a mixture of elastomers UF, MF and a suitable plasticizer to impart flexibility and impact resistance. The resin system includes both the resin and a hardener which is a mixture of 2 mild Lewis acids to control curing time. A special additive can be used to enhance surface bonding between the sand and resin. Experiments were then performed to examine the efficiency of resin (Asmid 603) with 7 different chemicals and resin Furmel 301 with Furmel catalyst as a curing modifier. The best combination for sand consolidation and chemical casing was found to be resin Asmid 603 with 0.6 per cent o-phosphoric acid at 80 degrees C and Furmel 301 with 2.5 per cent Furmel catalyst and CFNL with 0.6 per cent o-phosphoric acid. When this combination was used, the permeability was found to be nearly zero after consolidation of resin. The newly developed resin system costs one-third that of epoxy resins. Since it is water soluble, it is also easy to handle and environmentally sound. 15 refs., 2 tabs., 6 figs.

  4. Changes in cerebellar activity and inter-hemispheric coherence accompany improved reading performance following Quadrato Motor Training

    Science.gov (United States)

    Ben-Soussan, Tal Dotan; Avirame, Keren; Glicksohn, Joseph; Goldstein, Abraham; Harpaz, Yuval; Ben-Shachar, Michal

    2014-01-01

    Dyslexia is a multifactorial reading deficit that involves multiple brain systems. Among other theories, it has been suggested that cerebellar dysfunction may be involved in dyslexia. This theory has been supported by findings from anatomical and functional imaging. A possible rationale for cerebellar involvement in dyslexia could lie in the cerebellum’s role as an oscillator, producing synchronized activity within neuronal networks including sensorimotor networks critical for reading. If these findings are causally related to dyslexia, a training regimen that enhances cerebellar oscillatory activity should improve reading performance. We examined the cognitive and neural effects of Quadrato Motor Training (QMT), a structured sensorimotor training program that involves sequencing of motor responses based on verbal commands. Twenty-two adult Hebrew readers (12 dyslexics and 10 controls) were recruited for the study. Using Magnetoencephalography (MEG), we measured changes in alpha power and coherence following QMT in a within-subject design. Reading performance was assessed pre- and post-training using a comprehensive battery of behavioral tests. Our results demonstrate improved performance on a speeded reading task following one month of intensive QMT in both the dyslexic and control groups. Dyslexic participants, but not controls, showed significant increase in cerebellar oscillatory alpha power following training. In addition, across both time points, inter-hemispheric alpha coherence was higher in the dyslexic group compared to the control group. In conclusion, the current findings suggest that the combination of motor and language training embedded in QMT increases cerebellar oscillatory activity in dyslexics and improves reading performance. These results support the hypothesis that the cerebellum plays a role in skilled reading, and begin to unravel the underlying mechanisms that mediate cerebellar contribution in cognitive and neuronal augmentation. PMID

  5. Changes in cerebellar activity and inter-hemispheric coherence accompany improved reading performance following Quadrato Motor Training

    Directory of Open Access Journals (Sweden)

    Tal Dotan Ben-Soussan

    2014-05-01

    Full Text Available Dyslexia is a multifactorial reading deficit that involves multiple brain systems. Among other theories, it has been suggested that cerebellar dysfunction may be involved in dyslexia. This theory has been supported by findings from anatomical and functional imaging. A possible rationale for cerebellar involvement in dyslexia could lie in the cerebellum’s role as an oscillator, producing synchronized activity within neuronal networks including sensorimotor networks critical for reading. If these findings are causally related to dyslexia, a training regimen that enhances cerebellar oscillatory activity should improve reading performance. We examined the cognitive and neural effects of Quadrato Motor Training (QMT, a structured sensorimotor training program that involves sequencing of motor responses based on verbal commands. Twenty-two adult Hebrew readers (12 dyslexics and 10 controls were recruited for the study. Using Magnetoencephalography (MEG, we measured changes in alpha power and coherence following QMT in a within-subject design. Reading performance was assessed pre- and post-training using a comprehensive battery of behavioral tests. Our results demonstrate improved performance on a speeded reading task following one month of intensive QMT in both the dyslexic and control groups. Dyslexic participants, but not controls, showed significant increase in cerebellar oscillatory alpha power following training. In addition, across both time points, inter-hemispheric alpha coherence was higher in the dyslexic group compared to the control group. In conclusion, the current findings suggest that the combination of motor and language training embedded in QMT increases cerebellar oscillatory activity in dyslexics and improves reading performance. These results support the hypothesis that the cerebellum plays a role in skilled reading, and begin to unravel the underlying mechanisms that mediate cerebellar contribution in cognitive and neuronal

  6. Acute cerebellar ataxia with human parvovirus B19 infection

    OpenAIRE

    Shimizu, Y; Ueno, T.; Komatsu, H.; Takada, H.; Nunoue, T.

    1999-01-01

    A 2 year old boy developed acute cerebellar ataxia in association with erythema infectiosum. During the disease, genomic DNA and antibodies against human parvovirus B19 were detected in serum but not in cerebrospinal fluid. Parvovirus B19 associated acute cerebellar ataxia might occur due to transient vascular reaction in the cerebellum during infection.



  7. Cerebellar pleomorphic xanthoastrocytoma in a patient with neurofibromatosis type 1

    Energy Technology Data Exchange (ETDEWEB)

    Naidich, M.J.; Walker, M.T.; Han, G. [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, Illinois (United States); Northwestern Memorial Hospital, Chicago, IL (United States); Gottardi-Littell, N.R. [Northwestern Memorial Hospital, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Pathology, Chicago, Illinois (United States); Chandler, J.P. [Northwestern Memorial Hospital, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Neurological Surgery, Chicago, Illinois (United States)

    2004-10-01

    We describe a case of cerebellar pleomorphic xanthoastrocytoma (PXA) occurring in a patient with neurofibromatosis type 1 (NF1). The histomorphology of this uncommon glial (astrocytic) neoplasm is discussed. The occurrence of this tumor within the posterior fossa is extremely rare. To our knowledge, this is the first reported case of a cerebellar PXA in a patient with NF1. (orig.)

  8. Foxc1 dependent mesenchymal signalling drives embryonic cerebellar growth

    Science.gov (United States)

    Haldipur, Parthiv; Gillies, Gwendolyn S; Janson, Olivia K; Chizhikov, Victor V; Mithal, Divakar S; Miller, Richard J; Millen, Kathleen J

    2014-01-01

    Loss of Foxc1 is associated with Dandy-Walker malformation, the most common human cerebellar malformation characterized by cerebellar hypoplasia and an enlarged posterior fossa and fourth ventricle. Although expressed in the mouse posterior fossa mesenchyme, loss of Foxc1 non-autonomously induces a rapid and devastating decrease in embryonic cerebellar ventricular zone radial glial proliferation and concurrent increase in cerebellar neuronal differentiation. Subsequent migration of cerebellar neurons is disrupted, associated with disordered radial glial morphology. In vitro, SDF1α, a direct Foxc1 target also expressed in the head mesenchyme, acts as a cerebellar radial glial mitogen and a chemoattractant for nascent Purkinje cells. Its receptor, Cxcr4, is expressed in cerebellar radial glial cells and conditional Cxcr4 ablation with Nes-Cre mimics the Foxc1−/− cerebellar phenotype. SDF1α also rescues the Foxc1−/− phenotype. Our data emphasizes that the head mesenchyme exerts a considerable influence on early embryonic brain development and its disruption contributes to neurodevelopmental disorders in humans. DOI: http://dx.doi.org/10.7554/eLife.03962.001 PMID:25513817

  9. Cerebellar glioblastoma multiforme presenting as a cerebellopontine angle mass

    Directory of Open Access Journals (Sweden)

    Anupam Jindal

    2006-01-01

    Full Text Available Cerebellar glioblastoma multiforme (GBM is a highly malignant brain tumour, which is exceedingly rare and such tumour presenting as cerebellopontine angle (CPA mass is even rarer. We here discuss the case of a 15-year-old girl who had cerebellar GBM presenting as CPA mass that resembled meningioma on CT scan and was managed successfully with minimal problems.

  10. Drug-induced cerebellar ataxia: a systematic review

    NARCIS (Netherlands)

    Gaalen, J. van; Kerstens, F.G.; Maas, R.P.P.W.M.; Harmark, L.; Warrenburg, B.P.C. van de

    2014-01-01

    BACKGROUND AND OBJECTIVES: Cerebellar ataxia can be induced by a large number of drugs. We here conducted a systemic review of the drugs that can lead to cerebellar ataxia as an adverse drug reaction (ADR). METHODS: We performed a systematic literature search in Pubmed (1966 to January 2014) and EMB

  11. Molecular markers of neuronal progenitors in the embryonic cerebellar anlage.

    Science.gov (United States)

    Morales, Daniver; Hatten, Mary E

    2006-11-22

    The cerebellum, like the cerebrum, includes a nuclear structure and an overlying cortical structure. Experiments in the past decade have expanded knowledge beyond the traditional function of the cerebellum to include critical roles in motor learning and memory and sensory discrimination. The initial steps in cerebellar development depend on inductive signaling involving FGF and Wnt proteins produced at the mesencephalic/metencephalic boundary. To address the issue of how individual cerebellar cell fates within the cerebellar territory are specified, we examined the expression of transcription factors, including mammalian homologues of LIM homeodomain-containing proteins, basic helix-loop-helix proteins, and three amino acid loop-containing proteins. The results of these studies show that combinatorial codes of transcription factors define precursors of the cerebellar nuclei, and both Purkinje cells and granule neurons of the cerebellar cortex. Examination of gene expression patterns in several hundred lines of Egfp-BAC (bacterial artificial chromosome) transgenic mice in the GENSAT Project revealed numerous genes with restricted expression in cerebellar progenitor populations, including genes specific for cerebellar nuclear precursors and Purkinje cell precursors. In addition, we identified patterns of gene expression that link granule and Purkinje cells to their precerebellar nuclei. These results identify molecular pathways that offer new insights on the development of the nuclear and cortical structures of the cerebellum, as well as components of the cerebellar circuitry.

  12. Time estimation in Parkinson's disease and degenerative cerebellar disease

    NARCIS (Netherlands)

    Beudel, Martijin; Galama, Sjoukje; Leenders, Klaus L.; de Jong, Bauke M.

    2008-01-01

    With functional MRI, we recently identified fronto-cerebellar activations in predicting time to reach a target and basal ganglia activation in velocity estimation, that is, small interval assessment. We now tested these functions in patients with Parkinson's disease (PD) and degenerative cerebellar

  13. Lithologic and hydrologic controls of mixed alluvial-bedrock channels in flood-prone fluvial systems: bankfull and macrochannels in the Llano River watershed, central Texas, USA

    Science.gov (United States)

    Heitmuller, Frank T.; Hudson, Paul F.; Asquith, William H.

    2015-01-01

    The rural and unregulated Llano River watershed located in central Texas, USA, has a highly variable flow regime and a wide range of instantaneous peak flows. Abrupt transitions in surface lithology exist along the main-stem channel course. Both of these characteristics afford an opportunity to examine hydrologic, lithologic, and sedimentary controls on downstream changes in channel morphology. Field surveys of channel topography and boundary composition are coupled with sediment analyses, hydraulic computations, flood-frequency analyses, and geographic information system mapping to discern controls on channel geometry (profile, pattern, and shape) and dimensions along the mixed alluvial-bedrock Llano River and key tributaries. Four categories of channel classification in a downstream direction include: (i) uppermost ephemeral reaches, (ii) straight or sinuous gravel-bed channels in Cretaceous carbonate sedimentary zones, (iii) straight or sinuous gravel-bed or bedrock channels in Paleozoic sedimentary zones, and (iv) straight, braided, or multithread mixed alluvial–bedrock channels with sandy beds in Precambrian igneous and metamorphic zones. Principal findings include: (i) a nearly linear channel profile attributed to resistant bedrock incision checkpoints; (ii) statistically significant correlations of both alluvial sinuosity and valley confinement to relatively high f (mean depth) hydraulic geometry values; (iii) relatively high b (width) hydraulic geometry values in partly confined settings with sinuous channels upstream from a prominent incision checkpoint; (iv) different functional flow categories including frequently occurring events (flood magnitude and noncohesive sandy sediments that collectively minimize development of alluvial bankfull indicators. Collectively, these findings indicate that mixed alluvial–bedrock channels exhibit first-order lithologic controls (lithologic resistance and valley confinement) of channel geometry, second

  14. Cerebellar glioblastoma multiforme in an adult

    OpenAIRE

    Mattos João Paulo; Marenco Horacio Armando; Campos José Maria; Faria Andréa Vasconcellos; Queiroz Luciano de Souza; Borges Guilherme; Oliveira Evandro de

    2006-01-01

    Cerebellar glioblastoma multiforme (GBM) is a rare tumor. This is the third case published in Brazilian literature and, the last one has been described more than 15 years ago. The aggressive behavior of GBM prompts for fast treatment, which can be hampered by the fact that the diagnosis of GBM requires a high degree of suspicion. We describe a case of GBM in a 46 years old man. In conjunction, we present a literature review including particular issues, clinical data, advances in imaging studi...

  15. Cerebellar glioblastoma multiforme in an adult

    Directory of Open Access Journals (Sweden)

    Mattos João Paulo

    2006-01-01

    Full Text Available Cerebellar glioblastoma multiforme (GBM is a rare tumor. This is the third case published in Brazilian literature and, the last one has been described more than 15 years ago. The aggressive behavior of GBM prompts for fast treatment, which can be hampered by the fact that the diagnosis of GBM requires a high degree of suspicion. We describe a case of GBM in a 46 years old man. In conjunction, we present a literature review including particular issues, clinical data, advances in imaging studies, pathological characteristics, treatment options and the behavior of such malignant tumor.

  16. Spicing up the sensation of stretch: TRPV1 controls mechanosensitive Piezo channels.

    Science.gov (United States)

    Altier, Christophe

    2015-02-10

    Piezo proteins--a family of mammalian cation-selective ion channels that respond to mechanical stretch--are molecular mediators of biological processes, including vascular tone, hearing, touch, and pain. In this issue of Science Signaling, Rohacs and colleagues demonstrate that activation of the heat-sensitive transient receptor potential vanilloid 1 (TRPV1), another cation channel, inhibits Piezo channels through a calcium-induced depletion of phosphoinositides. This regulation could contribute to the cellular mechanisms by which the TRPV1 activator capsaicin mitigates mechanical hypersensitivity.

  17. KV 7.4 channels participate in the control of rodent renal vascular resting tone

    DEFF Research Database (Denmark)

    Salomonsson, M.; Brasen, Jens Christian; Braunstein, Thomas Hartig;

    2015-01-01

    .2–5 stimulator flupirtine dose-dependently relaxed isolated rat interlobar arteries and increased (approx. 5%) RBF in vivo. The RBF responses to NE or Ang II administration were not affected by pre-treatment with XE991 or flupirtine. XE991 pre-treatment caused a minor augmentation of the acetylcholine......-induced increase in RBF, while flupirtine pre-treatment did not affect this response. Conclusion: It is concluded that KV7 channels, via nifedipine sensitive channels, have a role in the regulation of basal renal vascular tone. There is no indication that KV7 channels have an effect on agonist-induced renal...

  18. GPUbased, Microsecond Latency, HectoChannel MIMO Feedback Control of Magnetically Confined Plasmas

    Science.gov (United States)

    Rath, Nikolaus

    Feedback control has become a crucial tool in the research on magnetic confinement of plasmas for achieving controlled nuclear fusion. This thesis presents a novel plasma feedback control system that, for the first time, employs a Graphics Processing Unit (GPU) for microsecond-latency, real-time control computations. This novel application area for GPU computing is opened up by a new system architecture that is optimized for low-latency computations on less than kilobyte sized data samples as they occur in typical plasma control algorithms. In contrast to traditional GPU computing approaches that target complex, high-throughput computations with massive amounts of data, the architecture presented in this thesis uses the GPU as the primary processing unit rather than as an auxiliary of the CPU, and data is transferred from A-D/D-A converters directly into GPU memory using peer-to-peer PCI Express transfers. The described design has been implemented in a new, GPU-based control system for the High-Beta Tokamak - Extended Pulse (HBT-EP) device. The system is built from commodity hardware and uses an NVIDIA GeForce GPU and D-TACQ A-D/D-A converters providing a total of 96 input and 64 output channels. The system is able to run with sampling periods down to 4 μs and latencies down to 8 μs. The GPU provides a total processing power of 1.5 x 1012 floating point operations per second. To illustrate the performance and versatility of both the general architecture and concrete implementation, a new control algorithm has been developed. The algorithm is designed for the control of multiple rotating magnetic perturbations in situations where the plasma equilibrium is not known exactly and features an adaptive system model: instead of requiring the rotation frequencies and growth rates embedded in the system model to be set a priori, the adaptive algorithm derives these parameters from the evolution of the perturbation amplitudes themselves. This results in non-linear control

  19. PIP2 controls voltage-sensor movement and pore opening of Kv channels through the S4-S5 linker.

    Science.gov (United States)

    Rodriguez-Menchaca, Aldo A; Adney, Scott K; Tang, Qiong-Yao; Meng, Xuan-Yu; Rosenhouse-Dantsker, Avia; Cui, Meng; Logothetis, Diomedes E

    2012-09-01

    Voltage-gated K(+) (Kv) channels couple the movement of a voltage sensor to the channel gate(s) via a helical intracellular region, the S4-S5 linker. A number of studies link voltage sensitivity to interactions of S4 charges with membrane phospholipids in the outer leaflet of the bilayer. Although the phospholipid phosphatidylinositol-4,5-bisphosphate (PIP(2)) in the inner membrane leaflet has emerged as a universal activator of ion channels, no such role has been established for mammalian Kv channels. Here we show that PIP(2) depletion induced two kinetically distinct effects on Kv channels: an increase in voltage sensitivity and a concomitant decrease in current amplitude. These effects are reversible, exhibiting distinct molecular determinants and sensitivities to PIP(2). Gating current measurements revealed that PIP(2) constrains the movement of the sensor through interactions with the S4-S5 linker. Thus, PIP(2) controls both the movement of the voltage sensor and the stability of the open pore through interactions with the linker that connects them.

  20. Cerebellar stimulation for cerebral palsy--double blind study.

    Science.gov (United States)

    Davis, R; Schulman, J; Delehanty, A

    1987-01-01

    Twenty spastic cerebral palsy (CP) patients undergoing chronic cerebellar stimulation (CCS) for reduction of spasticity and improvement in function have participated in a double-blind study. Seven US centers involving 9 neurosurgeons (1984-6) have replaced the depleted Neurolith 601 fully implantable pulse generator (Pacesetter Systems Incorp.-Neurodyne Corp., Sylmar, CA) with new units in 19 CP patients, 1 patient entered the study following his initial implant. A magnetically controllable switch was placed in line between the Neurolith stimulator and the cerebellar lead, so allowing switching sequences for the study. Physical therapists, living in the vicinity of the patient's home, carried out two quantitative evaluations: 1. Joint angle motion measurements (passive and active). 2. Motor performance testing was done when possible and included: reaction time, hand dynamonetry, grooved peg board placement, hand/foot tapping, and rotary pursuit testing. Testing was done presurgery, at 2 weeks postimplant, then the switch was activated either "on" or "off" to a schedule, with testing and reswitching at 1, 2 and 4 months, then the switch was left turned "on". Of the 20 patients, 16 finished the tests, 2 patients failed to finish and 2 had switch problems and were deleted from the study. Two of the 16 patients were "off" through the entire testing. Of the 14 that had periods of the stimulator being "on", 10 patients (72%) had quantitative improvements of over 20%, (1 pt: 50+% improvements; 4 pts: 30-50%, 5 pts: 20-30%); while 1 patient (7%) had improvements in the 10-20% level, whereas 3 patients (21%) showed no improvement.

  1. Computed tomographic features of cerebellar hemangioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Lan; Ko, Young Tae; Kim, Ho Kyun [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    1980-06-15

    Computed tomographic and angiographic findings of 6 proven cerebellar Hemangiotoma seen in this hospital during last 2 years were analyzed. The results were as follows: 1. Except one 14 years old female, all of them wee 37 to 48 years old males. 2. The operative findings of the tumors were 3 cystic tumors with mural nodules and 3 solid tumors. Computed tomographic findings were: 3. Of three cases of cystic cerebellar hemangiotomas, 2 cases revealed characteristic CT findings such as; a. In precontrast study, a well defined round lower density containing one isodense nodule in its periphery was seen in each case. The absorption coefficiency of each lower density was around 5 EMI unit. b. In post contrast study, the nodules were enhanced densely and homogeneously white the lower densities remain unchanged. 4. Of three cases of solid cerebella hemangiotoma, 2 cases revealed isodense mass suggested by mass effect such as displaced 4th ventricle and peripheral edema in precontrast study, while the remaining case revealed ill defined slightly high density with peripheral edema. In postcontrast study, the 2 isodense masses showed well circumscribed homogenous enhancement with central slight lower density in one of them, while high density mass revealed no enhancement at all. 5. The vertebral angiography performed in 5 cases revealed high vascular tumors with feeding arteries, draining veins and increased circulation time. 6. The tumor blushing seen in vertebral angiography was correlated to the postcontrast enhancement of solid tumors and mural nodules in cystic hemangioblastoma.

  2. Cerebellar ependymal cyst in a dog.

    Science.gov (United States)

    Wyss-Fluehmann, G; Konar, M; Jaggy, A; Vandevelde, M; Oevermann, A

    2008-11-01

    An 11-week-old, male, Staffordshire Bull Terrier had a history of generalized ataxia and falling since birth. The neurologic findings suggested a localization in the cerebellum. Magnetic resonance imaging of the brain was performed. In all sequences the area of the cerebellum was almost replaced by fluid isointense to cerebrospinal fluid. A complete necropsy was performed after euthanasia. Histologically, the lesion was characterized by extensive loss of cerebellar tissue in both hemispheres and vermis. Toward the surface of the cerebellar defect, the cavity was confined by ruptured and folded membranes consisting of a layer of glial fibrillary acidic (GFAP)-positive glial cells covered multifocally by epithelial cells. Some of these cells bore apical cilia and were cytokeratin and GFAP negative, supporting their ependymal origin. The histopathologic features of our case are consistent with the diagnosis of an ependymal cyst. Its glial and ependymal nature as demonstrated by histopathologic and immunohistochemical examination differs from arachnoid cysts, which have also been reported in dogs. The origin of these cysts remains controversial, but it has been suggested that they develop during embryogenesis subsequent to sequestration of developing neuroectoderm. We speculate that the cyst could have been the result of a pre- or perinatal, possibly traumatic, insult because hemorrhage, and tissue destruction had occurred. To our knowledge, this is the first description of an ependymal cyst in the veterinary literature.

  3. Remote cerebellar hemorrhage after lumbar spinal surgery

    Energy Technology Data Exchange (ETDEWEB)

    Cevik, Belma [Baskent University Faculty of Medicine, Department of Radiology, Fevzi Cakmak Cad. 10. sok. No: 45, Bahcelievler, Ankara 06490 (Turkey)], E-mail: belmac@baskent-ank.edu.tr; Kirbas, Ismail; Cakir, Banu; Akin, Kayihan; Teksam, Mehmet [Baskent University Faculty of Medicine, Department of Radiology, Fevzi Cakmak Cad. 10. sok. No: 45, Bahcelievler, Ankara 06490 (Turkey)

    2009-04-15

    Background: Postoperative remote cerebellar hemorrhage (RCH) as a complication of lumbar spinal surgery is an increasingly recognized clinical entity. The aim of this study was to determine the incidence of RCH after lumbar spinal surgery and to describe diagnostic imaging findings of RCH. Methods: Between October 1996 and March 2007, 2444 patients who had undergone lumbar spinal surgery were included in the study. Thirty-seven of 2444 patients were scanned by CT or MRI due to neurologic symptoms within the first 7 days of postoperative period. The data of all the patients were studied with regard to the following variables: incidence of RCH after lumbar spinal surgery, gender and age, coagulation parameters, history of previous arterial hypertension, and position of lumbar spinal surgery. Results: The retrospective study led to the identification of two patients who had RCH after lumbar spinal surgery. Of 37 patients who had neurologic symptoms, 29 patients were women and 8 patients were men. CT and MRI showed subarachnoid hemorrhage in the folia of bilateral cerebellar hemispheres in both patients with RCH. The incidence of RCH was 0.08% among patients who underwent lumbar spinal surgery. Conclusion: RCH is a rare complication of lumbar spinal surgery, self-limiting phenomenon that should not be mistaken for more ominous pathologic findings such as hemorrhagic infarction. This type of bleeding is thought to occur secondary to venous infarction, but the exact pathogenetic mechanism is unknown. CT or MRI allowed immediate diagnosis of this complication and guided conservative management.

  4. Designing responsive pattern generators: stable heteroclinic channel cycles for modeling and control.

    Science.gov (United States)

    Horchler, Andrew D; Daltorio, Kathryn A; Chiel, Hillel J; Quinn, Roger D

    2015-04-01

    A striking feature of biological pattern generators is their ability to respond immediately to multisensory perturbations by modulating the dwell time at a particular phase of oscillation, which can vary force output, range of motion, or other characteristics of a physical system. Stable heteroclinic channels (SHCs) are a dynamical architecture that can provide such responsiveness to artificial devices such as robots. SHCs are composed of sequences of saddle equilibrium points, which yields exquisite sensitivity. The strength of the vector fields in the neighborhood of these equilibria determines the responsiveness to perturbations and how long trajectories dwell in the vicinity of a saddle. For SHC cycles, the addition of stochastic noise results in oscillation with a regular mean period. In this paper, we parameterize noise-driven Lotka-Volterra SHC cycles such that each saddle can be independently designed to have a desired mean sub-period. The first step in the design process is an analytic approximation, which results in mean sub-periods that are within 2% of the specified sub-period for a typical parameter set. Further, after measuring the resultant sub-periods over sufficient numbers of cycles, the magnitude of the noise can be adjusted to control the mean period with accuracy close to that of the integration step size. With these relationships, SHCs can be more easily employed in engineering and modeling applications. For applications that require smooth state transitions, this parameterization permits each state's distribution of periods to be independently specified. Moreover, for modeling context-dependent behaviors, continuously varying inputs in each state dimension can rapidly precipitate transitions to alter frequency and phase. PMID:25712192

  5. Nuclear Factor I and Cerebellar Granule Neuron Development: An Intrinsic–Extrinsic Interplay

    OpenAIRE

    Kilpatrick, Daniel L.; Wang, Wei; Gronostajski, Richard; Litwack, E. David

    2012-01-01

    Granule neurons have a central role in cerebellar function via their synaptic interactions with other neuronal cell types both within and outside this structure. Establishment of these synaptic connections and its control is therefore essential to their function. Both intrinsic as well as environmental mechanisms are required for neuronal development and formation of neuronal circuits, and a key but poorly understood question is how these various events are coordinated and integrated in matur...

  6. The effects of undernutrition on connectivity in the cerebellar cortex of adult rats.

    OpenAIRE

    Yucel, F; Warren, M. A.; Gumusburun, E

    1994-01-01

    The effects of a 30 d period of undernutrition, followed in some animals by nutritional rehabilitation, on neuronal connectivity in adult rat cerebellum were investigated using the disector method. There was no significant difference between well fed (719 +/- 74, mean +/- S.E.) and undernourished (709 +/- 53) synapse-to-neuron ratios in 134-d-old rat cerebellar cortex, nor was there a significant difference in synapse-to-neuron ratios between control animals (941 +/- 71) and previously undern...

  7. Relationship between cerebellar impairments and lexicon retrieval in schizophrenia – preliminary study

    Directory of Open Access Journals (Sweden)

    Chrobak, Adrian Andrzej

    2013-09-01

    Full Text Available Aim of the study. Investigation of relationship between cerebellar motor dysfunctions and language impairments connected with cerebellum during phonological and semantic fluency tasks and verb generationtask in schizophrenic patients and healthy control group. Subject or material and methods. 14 schizophrenic patients on olanzapine, clozapine or quetiapine treatment and 13 healthy volunteers were examined. Motor signs were assessed by using the International Co-operative Ataxia Rating Scale (ICARS. Phonological and semantic fluency tasks were performed. All of the words were recorded and counted.Results. Patients with schizophrenia revealed significantly higher ICARS mean score (12.21 than control group (3.92, and lower number of proper generated words in semantic fluency and verb generation tasks. Strong negative correlation (rs(13 = -0.71, p<0.01 was found between ICARS total score and number of proper answers in verb generation task.Discussion. Higher number of total ICARS score in schizophrenia patients in comparison to control group may suggest cerebellar impairments. There is disproportion between semantic and phonological fluency. Significant correlation between verb generation and cerebellar signs supports a hypothesis of cerebellum dysfunction during this task in schizophrenia patients.Conclusions. Schizophrenic patients reveal impairments which may be connected with the cerebellum.

  8. Static Posturography and Falls According to Pyramidal, Sensory and Cerebellar Functional Systems in People with Multiple Sclerosis

    Science.gov (United States)

    Kalron, Alon; Givon, Uri; Frid, Lior; Dolev, Mark; Achiron, Anat

    2016-01-01

    Balance impairment is common in people with multiple sclerosis (PwMS) and frequently impacts quality of life by decreasing mobility and increasing the risk of falling. However, there are only scarce data examining the contribution of specific neurological functional systems on balance measures in MS. Therefore, the primary aim of our study was to examine the differences in posturography parameters and fall incidence according to the pyramidal, cerebellar and sensory systems functional systems in PwMS. The study included 342 PwMS, 211 women and mean disease duration of 8.2 (S.D = 8.3) years. The study sample was divided into six groups according to the pyramidal, cerebellar and sensory functional system scores, derived from the Expanded Disability Status Scale (EDSS) data. Static postural control parameters were obtained from the Zebris FDM-T Treadmill (zebris® Medical GmbH, Germany). Participants were defined as "fallers" and "non-fallers" based on their fall history. Our findings revealed a trend that PwMS affected solely in the pyramidal system, have reduced stability compared to patients with cerebellar and sensory dysfunctions. Moreover, the addition of sensory impairments to pyramidal dysfunction does not exacerbate postural control. The patients in the pure sensory group demonstrated increased stability compared to each of the three combined groups; pyramidal-cerebellar, pyramidal-sensory and pyramidal-cerebellar-sensory groups. As for fall status, the percentage of fallers in the pure pyramidal, cerebellar and sensory groups were 44.3%, 33.3% and 19.5%, respectively. As for the combined functional system groups, the percentage of fallers in the pyramidal-cerebellar, pyramidal-sensory and pyramidal-cerebellar-sensory groups were 59.7%, 40.7% and 65%, respectively. This study confirms that disorders in neurological functional systems generate different effects on postural control and incidence of falls in the MS population. From a clinical standpoint, the

  9. Brain stem and cerebellar atrophy in chronic progressive neuro-Behçet's disease

    Energy Technology Data Exchange (ETDEWEB)

    Kanoto, Masafumi, E-mail: mkanoto@med.id.yamagata-u.ac.jp [Department of Diagnostic Radiology, Faculty of Medicine, Yamagata University, Iida-Nishi 2-2-2, 990-9585 Yamagata (Japan); Hosoya, Takaaki, E-mail: thosoya@med.id.yamagata-u.ac.jp [Department of Diagnostic Radiology, Faculty of Medicine, Yamagata University, Iida-Nishi 2-2-2, 990-9585 Yamagata (Japan); Toyoguchi, Yuuki, E-mail: c-elegans_0201g@mail.goo.ne.jp [Department of Diagnostic Radiology, Faculty of Medicine, Yamagata University, Iida-Nishi 2-2-2, 990-9585 Yamagata (Japan); Oda, Atsuko, E-mail: a.oda@med.id.yamagata-u.ac.jp [Department of Diagnostic Radiology, Faculty of Medicine, Yamagata University, Iida-Nishi 2-2-2, 990-9585 Yamagata (Japan)

    2013-01-15

    Purpose: Chronic progressive neuro-Behçet's disease (CPNBD) resembles multiple sclerosis (MS) on patient background and image findings, and therefore is difficult to diagnose. The purpose is to identify the characteristic magnetic resonance imaging (MRI) findings of CPNBD and to clarify the differences between the MRI findings of CPNBD and those of MS. Materials and methods: The subjects consist of a CPNBD group (n = 4; 1 male and 3 females; mean age, 51 y.o.), a MS group (n = 19; 3 males and 16 females; mean age, 45 y.o.) and a normal control group (n = 23; 10 males and 13 females; mean age, 45 y.o.). Brain stem atrophy, cerebellar atrophy, and leukoencephalopathy were retrospectively evaluated in each subjects. In middle sagittal brain MR images, the prepontine distance was measured as an indirect index of brain stem and cerebellar atrophy and the pontine and mesencephalic distance was measured as a direct index of brain stem atrophy. These indexes were statistically analyzed. Results: Brain stem atrophy, cerebellar atrophy, and leukoencephalopathy were seen in all CPNBD cases. Prepontine distance was significantly different between the CPNBD group and the MS group (p < 0.05), and between the CPNBD group and the normal control group (p < 0.001). Pontine and mesencephalic distance were significantly different between the CPNBD group and the MS group (p < 0.001, p < 0.01 respectively), and between the CPNBD group and the normal control group (p < 0.001). Conclusions: Chronic progressive neuro-Behçet's disease should be considered in patients with brain stem and cerebellar atrophy in addition to leukoencephalopathy similar to that seen in multiple sclerosis.

  10. Performance Analysis of Spectrum Handoff for Cognitive Radio Ad Hoc Networks without Common Control Channel under Homogeneous Primary Traffic

    CERN Document Server

    Song, Yi

    2011-01-01

    Cognitive radio (CR) technology is regarded as a promising solution to the spectrum scarcity problem. Due to the spectrum varying nature of CR networks, unlicensed users are required to perform spectrum handoffs when licensed users reuse the spectrum. In this paper, we study the performance of the spectrum handoff process in a CR ad hoc network under homogeneous primary traffic. We propose a novel three dimensional discrete-time Markov chain to characterize the process of spectrum handoffs and analyze the performance of unlicensed users. Since in real CR networks, a dedicated common control channel is not practical, in our model, we implement a network coordination scheme where no dedicated common control channel is needed. Moreover, in wireless communications, collisions among simultaneous transmissions cannot be immediately detected and the whole collided packets need to be retransmitted, which greatly affects the network performance. With this observation, we also consider the retransmissions of the collid...

  11. A cerebellar learning model of vestibulo-ocular reflex adaptation in wild-type and mutant mice

    NARCIS (Netherlands)

    Clopath, Claudia; Badura, Aleksandra; De Zeeuw, Chris I; Brunel, Nicolas

    2014-01-01

    Mechanisms of cerebellar motor learning are still poorly understood. The standard Marr-Albus-Ito theory posits that learning involves plasticity at the parallel fiber to Purkinje cell synapses under control of the climbing fiber input, which provides an error signal as in classical supervised learni

  12. Feeders-TDMA: a distributed-control algorithm for satellite channel capacity assignment in a mixed traffic and faded environment

    OpenAIRE

    Celandroni, Nedo; Ferro, Erina; Potort?, Francesco

    1997-01-01

    This paper presents Faded Environments Effective Distributed Engineering Redundant Signalling (FEEDERS), an access scheme for sharing, in time division multiple access (TDMA) mode, the capacity of a satellite channel among a number of stations, on the basis of user demand, This scheme and its companion Distributed Allocation with Request In Fixed Slots (DRIFS), result from a study carried out by the authors on distributed-control protocols for geostationary satellite access. Both protocols de...

  13. Crossed cerebellar and uncrossed basal ganglia and thalamic diaschisis in Alzheimer's disease

    International Nuclear Information System (INIS)

    We detected crossed cerebellar as well as uncrossed basal ganglia and thalamic diaschisis in Alzheimer's disease by positron emission tomography (PET) using 18F-fluorodeoxyglucose. We studied a series of 26 consecutive, clinically diagnosed Alzheimer cases, including 6 proven by later autopsy, and compared them with 9 age-matched controls. We calculated asymmetry indices (AIs) of cerebral metabolic rate for matched left-right regions of interest (ROIs) and determined the extent of diaschisis by correlative analyses. For the Alzheimer group, we found cerebellar AIs correlated negatively, and thalamic AIs positively, with those of the cerebral hemisphere and frontal, temporal, parietal, and angular cortices, while basal ganglia AIs correlated positively with frontal cortical AIs. The only significant correlation of AIs for normal subjects was between the thalamus and cerebral hemisphere. These data indicate that PET is a sensitive technique for detecting diaschisis

  14. System Identification and Control of an Irrigation Channel with a Tunnel

    OpenAIRE

    Bernhoff, Petra

    2008-01-01

    The demand on water is high but the supply of water is low due to the dry and warm climate in Australia. This is especially difficult for farmers that do not get enough water delivered in the irrigation channels which has dramatic consequences. A high percentage of the water lost in the channels can be saved if the systems are managed better. Using system identification techniques to develop a mathematical model which describes the dynamics in the irrigation system is a helpful tool for contr...

  15. [A case of cerebral gigantism with cerebellar atrophy].

    Science.gov (United States)

    Kitazawa, K; Ikeda, M; Tsukagoshi, H

    1990-05-01

    A 37-year-old housewife, who had physical characteristics of cerebral gigantism, such as the tall stature, acromegaly, macrocephalia, high arched palate and antimongoloid slant, developed cerebellar ataxia and dysarthria. Her mother, uncle and grandmother were also reported to have slowly progressive gait disturbance. Her mother was also tall. Endocrinological studies failed to show any definite abnormality. CT and MRI revealed remarkable cerebellar atrophy. Though cerebral gigantism is often associated with clumsiness and incoordination, the etiology of the ataxia is poorly understood. This case indicates that the ataxia in cerebral gigantism may be, at least partly, caused by cerebellar atrophy. PMID:2401112

  16. Variant PTA Terminating in Cerebellar Artery, Associated with Multiple Aneurysms

    Directory of Open Access Journals (Sweden)

    Yeong Uk Hwang

    2016-01-01

    Full Text Available Persistent trigeminal artery (PTA is one of the remnant fetal anastomoses between the carotid artery and basilar artery. PTAs are classified according to angiographic appearance and various connection. Among them, those directly terminating in the cerebellar arteries are rare subtype. In addition, aneurysms of the PTA are unusual in the literature and have not previously accompanied this subtype of PTA connecting cerebellar artery. We present the first case of an aneurysm of the PTA which is directly terminating in the cerebellar arteries and combined with multiple aneurysms.

  17. Variant PTA Terminating in Cerebellar Artery, Associated with Multiple Aneurysms.

    Science.gov (United States)

    Hwang, Yeong Uk; Kim, Jin Woo

    2016-01-01

    Persistent trigeminal artery (PTA) is one of the remnant fetal anastomoses between the carotid artery and basilar artery. PTAs are classified according to angiographic appearance and various connection. Among them, those directly terminating in the cerebellar arteries are rare subtype. In addition, aneurysms of the PTA are unusual in the literature and have not previously accompanied this subtype of PTA connecting cerebellar artery. We present the first case of an aneurysm of the PTA which is directly terminating in the cerebellar arteries and combined with multiple aneurysms. PMID:27446623

  18. Multiple types of cerebellar target neurons and their circuitry in the vestibulo-ocular reflex.

    Science.gov (United States)

    Shin, Minyoung; Moghadam, Setareh H; Sekirnjak, Chris; Bagnall, Martha W; Kolkman, Kristine E; Jacobs, Richard; Faulstich, Michael; du Lac, Sascha

    2011-07-27

    The cerebellum influences behavior and cognition exclusively via Purkinje cell synapses onto neurons in the deep cerebellar and vestibular nuclei. In contrast with the rich information available about the organization of the cerebellar cortex and its synaptic inputs, relatively little is known about microcircuitry postsynaptic to Purkinje cells. Here we examined the cell types and microcircuits through which Purkinje cells influence an oculomotor behavior controlled by the cerebellum, the horizontal vestibulo-ocular reflex, which involves only two eye muscles. Using a combination of anatomical tracing and electrophysiological recordings in transgenic mouse lines, we identified several classes of neurons in the medial vestibular nucleus that receive Purkinje cell synapses from the cerebellar flocculus. Glycinergic and glutamatergic flocculus target neurons (FTNs) with somata densely surrounded by Purkinje cell terminals projected axons to the ipsilateral abducens and oculomotor nuclei, respectively. Of three additional types of FTNs that were sparsely innervated by Purkinje cells, glutamatergic and glycinergic neurons projected to the contralateral and ipsilateral abducens, respectively, and GABAergic neurons projected to contralateral vestibular nuclei. Densely innervated FTNs had high spontaneous firing rates and pronounced postinhibitory rebound firing, and were physiologically homogeneous, whereas the intrinsic excitability of sparsely innervated FTNs varied widely. Heterogeneity in the molecular expression, physiological properties, and postsynaptic targets of FTNs implies that Purkinje cell activity influences the neural control of eye movements in several distinct ways. These results indicate that the cerebellum regulates a simple reflex behavior via at least five different cell types that are postsynaptic to Purkinje cells.

  19. Cerebellar volume deficits in medication-naïve obsessive compulsive disorder.

    Science.gov (United States)

    Narayanaswamy, Janardhanan C; Jose, Dania; Kalmady, Sunil V; Agarwal, Sri Mahavir; Venkatasubramanian, Ganesan; Janardhan Reddy, Y C

    2016-08-30

    Even though conventional neurobiological models of obsessive compulsive disorder (OCD) commonly demonstrate abnormalities involving fronto-striatal circuits, there is emerging evidence regarding the role of posterior brain structures such as cerebellum. In this study, we examined the cerebellar regional volume in a large sample of medication-naïve OCD patients compared to matched healthy controls (HC). In 49 medication naïve right handed OCD patients and 39 age and sex matched HC, sub-region wise volume of cerebellum was extracted from the T1 weighted images using Spatially Unbiased Infra tentorial Template (SUIT) toolbox and compared using hypothesis driven, region of interest approach after clinical assessment with standard scales. After controlling for age, sex and ICV, the subjects with OCD had significantly smaller cerebellum compared to HC, especially in the posterior lobe sub-regions - lobule VI and left crus 1. This study gives preliminary evidence for region specific cerebellar volumetric deficits in the pathophysiological of OCD. Regional cerebellar volume deficits conform to the abnormal connectivity of cerebellum to specific cortical regions and it is indicative of involvement of regions outside the conventional fronto-striatal circuitry. This might be important in the context of cognitive deficits seen in OCD. PMID:27454206

  20. Hereditary Cerebellar Ataxias: A Korean Perspective

    Directory of Open Access Journals (Sweden)

    Ji Sun Kim

    2015-05-01

    Full Text Available Hereditary ataxia is a heterogeneous disorder characterized by progressive ataxia combined with/without peripheral neuropathy, extrapyramidal symptoms, pyramidal symptoms, seizure, and multiple systematic involvements. More than 35 autosomal dominant cerebellar ataxias have been designated as spinocerebellar ataxia, and there are 55 recessive ataxias that have not been named systematically. Conducting genetic sequencing to confirm a diagnosis is difficult due to the large amount of subtypes with phenotypic overlap. The prevalence of hereditary ataxia can vary among countries, and estimations of prevalence and subtype frequencies are necessary for planning a diagnostic strategy in a specific population. This review covers the various hereditary ataxias reported in the Korean population with a focus on the prevalence and subtype frequencies as the clinical characteristics of the various subtypes.

  1. Control of the Selectivity of the Aquaporin Water Channel Family by Global Orientational Tuning

    Science.gov (United States)

    Tajkhorshid, Emad; Nollert, Peter; Jensen, Morten Ø.; Miercke, Larry J. W.; O'Connell, Joseph; Stroud, Robert M.; Schulten, Klaus

    2002-04-01

    Aquaporins are transmembrane channels found in cell membranes of all life forms. We examine their apparently paradoxical property, facilitation of efficient permeation of water while excluding protons, which is of critical importance to preserving the electrochemical potential across the cell membrane. We have determined the structure of the Escherichia coli aquaglyceroporin GlpF with bound water, in native (2.7 angstroms) and in W48F/F200T mutant (2.1 angstroms) forms, and carried out 12-nanosecond molecular dynamics simulations that define the spatial and temporal probability distribution and orientation of a single file of seven to nine water molecules inside the channel. Two conserved asparagines force a central water molecule to serve strictly as a hydrogen bond donor to its neighboring water molecules. Assisted by the electrostatic potential generated by two half-membrane spanning loops, this dictates opposite orientations of water molecules in the two halves of the channel, and thus prevents the formation of a ``proton wire,'' while permitting rapid water diffusion. Both simulations and observations revealed a more regular distribution of channel water and an increased water permeability for the W48F/F200T mutant.

  2. Control of the Aquaporin-4 Channel Water Permeability by Structural Dynamics of Aromatic/Arginine Selectivity Filter Residues.

    Science.gov (United States)

    Kitchen, Philip; Conner, Alex C

    2015-11-17

    The aquaporins (AQPs) make up a family of integral membrane proteins that control cellular water flow. Gating of the water channel by conformational changes induced by phosphorylation or protein-protein interactions is an established regulatory mechanism for AQPs. Recent in silico and crystallographic analyses of the structural biology of AQPs suggest that the rate of water flow can also be controlled by small movements of single-amino acid side chains lining the water pore. Here we use measurements of the membrane water permeability of mammalian cells expressing AQP4 mutants to provide the first in vitro evidence in support of this hypothesis. PMID:26512424

  3. Cerebellar Synaptic Plasticity and the Credit Assignment Problem.

    Science.gov (United States)

    Jörntell, Henrik

    2016-04-01

    The mechanism by which a learnt synaptic weight change can contribute to learning or adaptation of brain function is a type of credit assignment problem, which is a key issue for many parts of the brain. In the cerebellum, detailed knowledge not only of the local circuitry connectivity but also of the topography of different sources of afferent/external information makes this problem particularly tractable. In addition, multiple forms of synaptic plasticity and their general rules of induction have been identified. In this review, we will discuss the possible roles of synaptic and cellular plasticity at specific locations in contributing to behavioral changes. Focus will be on the parts of the cerebellum that are devoted to limb control, which constitute a large proportion of the cortex and where the knowledge of the external connectivity is particularly well known. From this perspective, a number of sites of synaptic plasticity appear to primarily have the function of balancing the overall level of activity in the cerebellar circuitry, whereas the locations at which synaptic plasticity leads to functional changes in terms of limb control are more limited. Specifically, the postsynaptic forms of long-term potentiation (LTP) and long-term depression (LTD) at the parallel fiber synapses made on interneurons and Purkinje cells, respectively, are the types of plasticity that mediate the widest associative capacity and the tightest link between the synaptic change and the external functions that are to be controlled. PMID:25417189

  4. Effectiveness Using Circular Fibre Steel Flap Gate As a Control Structure Towards the Hydraulic Characteristics in Open Channel

    Science.gov (United States)

    Adib, M. R. M.; Amirza, A. R. M.; Wardah, T.; Junaidah, A.

    2016-07-01

    Hydraulic control gate structure plays an important role in regulating the flow of water in river, canal or water reservoir. One of the most appropriate structures in term of resolving the problem of flood occured is the construction of circular fibre steel flap gate. Therefore, an experiment has been conducted by using an open channel model at laboratory. In this case, hydraulic jump and backwater were the method to determined the hydraulic characteristics of circular fibre steel flap gate in an open channel model. From the experiment, the opening angle of flap gate can receive discharges with the highest flow rate of 0.035 m3/s with opening angle was 47°. The type of jump that occurs at the slope of 1/200 for a distance of 5.0 m is a standing jump or undulating wave. The height of the backwater can be identified based on the differences of specific force which is specific force before jump, F1 and specific force after jump, F2 from the formation of backwater. Based on the research conducted, the tendency of incident backwater wave occurred was high in every distance of water control location from water inlet is flap slope and the slope of 1/300 which is 0.84 m/s and 0.75 m/s of celerity in open channel model.

  5. Exploring geomorphic controls on fish bioenergetics in mountain streams: linkages between channel morphology and rearing habitat for cutthroat trout

    Science.gov (United States)

    Cienciala, P.; Hassan, M. A.

    2013-12-01

    Landscape heterogeneity constitutes an important control on spatial distribution of habitat for living organisms, at a range of spatial scales. For example, spatial variation in geomorphic processes can spatially structure populations as well as entire communities, and affect various ecosystem processes. We have coupled a 2D hydrodynamic model with a bioenergetic model to study the effects of various channel morphologies and bed textures on rearing habitat for coastal cutthroat trout (Oncorhynchus clarki clarki) in four reaches of a mountain stream. The bioenergetic model uses energy conservation principle to calculate energy budget for fish at any point of the study domain, given a set of relevant local conditions. Specifically, the energy intake is a function of food availability (invertebrate drift) while the energy expenditure occurs through, for example, basal metabolism and swimming to hold position against the flow. Channel morphology and bed texture, through their influence on channel hydraulics, can exert strong control on the spatial pattern of both food flux and swimming cost for drift-feeding fish. Therefore, the coupled hydrodynamic and bioenergetic models, parameterized using an extensive field data set, enabled us to explore mechanistic linkages between geomorphic properties of the study reaches, food resource availability, and the energetic profitability of rearing habitat for different age-classes at both between- and within-reach spatial scales.

  6. Cerebellar Hemangioblastoma and Von Hippel-Lindau Disease

    Directory of Open Access Journals (Sweden)

    J. Gordon Millichap

    2002-02-01

    Full Text Available Six pediatric patients with cerebellar hemangioblastoma were screened for germline or somatic mutations of the von Hippel-Landau gene, in a study at Stanford University Medical Center, Palo Alto, CA.

  7. Bilateral cerebellar activation in unilaterally challenged essential tremor

    Directory of Open Access Journals (Sweden)

    Marja Broersma

    2016-01-01

    Conclusions: Our results expand on previous findings of bilateral cerebellar involvement in ET. We have identified specific areas in the bilateral somatomotor regions of the cerebellum: lobules V, VI and VIII.

  8. Cerebellar giant cell glioblastoma multiforme in an adult

    Directory of Open Access Journals (Sweden)

    Sudhansu Sekhar Mishra

    2014-01-01

    Full Text Available Cerebellar glioblastoma multiforme (GBM is a rare tumor that accounts for only 1% of all cases of GBM and its giant cell variant is even much rarely encountered in adults. A case of cerebellar giant cell GBM managed at our institution reporting its clinical presentation, radiological and histological findings, and treatment instituted is described. In conjunction, a literature review, including particular issues, clinical data, advances in imaging studies, pathological characteristics, treatment options, and the behavior of such malignant tumor is presented. It is very important for the neurosurgeon to make the differential diagnosis between the cerebellar GBM, and other diseases such as metastasis, anaplastic astrocytomas, and cerebellar infarct because their treatment modalities, prognosis, and outcome are different.

  9. Unilateral absence of cerebellar hemisphere: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Erdogan, N.; Ozturk, O. [Department of Radiology, Erciyes University Faculty of Medicine, Kayseri (Turkey); Kocakoc, E. [Department of Radiology, Women' s Hospital, Sivas (Turkey); Bekar, D. [Department of Neurology, City Hospital, Sivas (Turkey)

    2002-01-01

    We describe a 38-year-old woman with absence of right cerebellar hemisphere incidentally discovered by MR imaging. No cerebellar abnormality was detected on neurological examination. Tissue probably representing dysgenetic cerebellar tissue with no corticomedullary differentiation was present, connected to the right superior cerebellar peduncle. Ipsilateral enlargement of the pons and cerebral peduncle were additional findings. Although the terms ''aplasia'' or ''agenesis'' have been used to describe this entity, intrauterine destruction is the presumed pathogenetic mechanism in our case, and therefore these terms have been avoided. Asymmetry of pons and mesencephalon may be related to compensatory reorganisation or to the impairment of sequential development of nuclei and neural tracts. (orig.)

  10. Cerebellar infarct patterns: The SMART-Medea study

    Directory of Open Access Journals (Sweden)

    Laurens J.L. De Cocker, MD

    2015-01-01

    Conclusions: Small cerebellar infarcts proved to be much more common than larger infarcts, and preferentially involved the cortex. Small cortical infarcts predominantly involved the posterior lobes, showed sparing of subcortical white matter and occurred in characteristic topographic patterns.

  11. Adult-onset cerebellar Ataxia: a clinical and genetic Survey

    NARCIS (Netherlands)

    E. Brusse (Esther)

    2011-01-01

    textabstractCerebellar ataxias represent a heterogeneous group of neurodegenerative disorders. Two main categories are distinguished: hereditary and sporadic ataxias. Sporadic ataxias may be symptomatic or idiopathic. The clinical classification of hereditary ataxias is nowadays being replaced by an

  12. Full equations utilities (FEQUTL) model for the approximation of hydraulic characteristics of open channels and control structures during unsteady flow

    Science.gov (United States)

    Franz, Delbert D.; Melching, Charles S.

    1997-01-01

    The Full EQuations UTiLities (FEQUTL) model is a computer program for computation of tables that list the hydraulic characteristics of open channels and control structures as a function of upstream and downstream depths; these tables facilitate the simulation of unsteady flow in a stream system with the Full Equations (FEQ) model. Simulation of unsteady flow requires many iterations for each time period computed. Thus, computation of hydraulic characteristics during the simulations is impractical, and preparation of function tables and application of table look-up procedures facilitates simulation of unsteady flow. Three general types of function tables are computed: one-dimensional tables that relate hydraulic characteristics to upstream flow depth, two-dimensional tables that relate flow through control structures to upstream and downstream flow depth, and three-dimensional tables that relate flow through gated structures to upstream and downstream flow depth and gate setting. For open-channel reaches, six types of one-dimensional function tables contain different combinations of the top width of flow, area, first moment of area with respect to the water surface, conveyance, flux coefficients, and correction coefficients for channel curvilinearity. For hydraulic control structures, one type of one-dimensional function table contains relations between flow and upstream depth, and two types of two-dimensional function tables contain relations among flow and upstream and downstream flow depths. For hydraulic control structures with gates, a three-dimensional function table lists the system of two-dimensional tables that contain the relations among flow and upstream and downstream flow depths that correspond to different gate openings. Hydraulic control structures for which function tables containing flow relations are prepared in FEQUTL include expansions, contractions, bridges, culverts, embankments, weirs, closed conduits (circular, rectangular, and pipe

  13. Ebola virus. Two-pore channels control Ebola virus host cell entry and are drug targets for disease treatment.

    Science.gov (United States)

    Sakurai, Yasuteru; Kolokoltsov, Andrey A; Chen, Cheng-Chang; Tidwell, Michael W; Bauta, William E; Klugbauer, Norbert; Grimm, Christian; Wahl-Schott, Christian; Biel, Martin; Davey, Robert A

    2015-02-27

    Ebola virus causes sporadic outbreaks of lethal hemorrhagic fever in humans, but there is no currently approved therapy. Cells take up Ebola virus by macropinocytosis, followed by trafficking through endosomal vesicles. However, few factors controlling endosomal virus movement are known. Here we find that Ebola virus entry into host cells requires the endosomal calcium channels called two-pore channels (TPCs). Disrupting TPC function by gene knockout, small interfering RNAs, or small-molecule inhibitors halted virus trafficking and prevented infection. Tetrandrine, the most potent small molecule that we tested, inhibited infection of human macrophages, the primary target of Ebola virus in vivo, and also showed therapeutic efficacy in mice. Therefore, TPC proteins play a key role in Ebola virus infection and may be effective targets for antiviral therapy.

  14. Disposal of waste channels and control rods and radioactive waste; Gestion de canales usados y barras de control como residuos radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Alvarez, L.

    2015-07-01

    Iberdrola and ENRESA are jointly developing a project for the characterization and conditioning of around 200 control rods and 70 used channel from Cofrentes Nuclear Power Plant. This treatment line for high level waste with a radiologic inventory that avoids using the El Cabril low level waste repository is new in Spain and incorporates specific features like the option to carry on with the conditioning stage prior to having a licensed package and available storage facility for this type of waste. (Author)

  15. The Clinical Differentiation of Cerebellar Infarction from Common Vertigo Syndromes

    OpenAIRE

    Nelson, James A.; Viirre, Erik

    2009-01-01

    This article summarizes the emergency department approach to diagnosing cerebellar infarction in the patient presenting with vertigo. Vertigo is defined and identification of a vertigo syndrome is discussed. The differentiation of common vertigo syndromes such as benign paroxysmal positional vertigo, Meniere’s disease, migrainous vertigo, and vestibular neuritis is summarized. Confirmation of a peripheral vertigo syndrome substantially lowers the likelihood of cerebellar infarction, as do ind...

  16. Cerebellar Neuroblastoma in 2.5 Years Old Child

    OpenAIRE

    Pedram, Mohammad; Vafaie, Majid; Fekri, Kiavash; Haghi, Sabahat; Rashidi, Iran; Pirooti, Chia

    2013-01-01

    Neuroblastoma is the third most common malignancy of childhood, after leukemia and brain tumors. Only 2% of all neuroblastoma occur in the brain. Primary cerebellar neuroblastoma is an specific subset of Primitive Neuroectodermal Tumors (PNET). Meduloblastoma is a relatively common and well-established entity, consisting of primitive and multipotential cells that may exhibit some evidence of neuroblastic or gliad differentiation. But cerebellar neuroblastoma with ultrastractural evidence of s...

  17. Cerebellar medulloblastoma in a 65 year old Indian male.

    Directory of Open Access Journals (Sweden)

    Jaiswal A

    2000-04-01

    Full Text Available A case of cerebellar medulloblastoma in a 65 year old male is reported. Cerebellar medulloblastoma is classically seen during childhood, and less than 25% of these tumours are found in adults below 40 years of age. Rarely, cases are reported above the age of 40 years. So far only three cases have been reported in patients aged above 64 years and none of these case reports are from India.

  18. Cerebellar contributions to neurological soft signs in healthy young adults.

    Science.gov (United States)

    Hirjak, Dusan; Thomann, Philipp A; Kubera, Katharina M; Stieltjes, Bram; Wolf, Robert C

    2016-02-01

    Neurological soft signs (NSS) are frequently found in psychiatric disorders of significant neurodevelopmental origin, e.g., in patients with schizophrenia and autism. Yet NSS are also present in healthy individuals suggesting a neurodevelopmental signature of motor function, probably as a continuum between health and disease. So far, little is known about the neural mechanisms underlying these motor phenomena in healthy persons, and it is even less known whether the cerebellum contributes to NSS expression. Thirty-seven healthy young adults (mean age = 23 years) were studied using high-resolution structural magnetic resonance imaging (MRI) and "resting-state" functional MRI at three Tesla. NSS levels were measured using the "Heidelberg Scale." Cerebellar gray matter volume was investigated using cerebellum-optimized voxel-based analysis methods. Cerebellar function was assessed using regional homogeneity (ReHo), a measure of local network strength. The relationship between cerebellar structure and function and NSS was analyzed using regression models. There was no significant relationship between cerebellar volume and NSS (p < 0.005, uncorrected for height, p < 0.05 corrected for spatial extent). Positive associations with cerebellar lobule VI activity were found for the "motor coordination" and "hard signs" NSS domains. A negative relationship was found between lobule VI activity and "complex motor task" domain (p < 0.005, uncorrected for height, p < 0.05 corrected for spatial extent). The data indicate that in healthy young adults, distinct NSS domains are related to cerebellar activity, specifically with activity of cerebellar subregions with known cortical somatomotor projections. In contrast, cerebellar volume is not predictive of NSS in healthy persons. PMID:25708455

  19. Deep Learning for Cerebellar Ataxia Classification and Functional Score Regression

    OpenAIRE

    Yang, Zhen; Zhong, Shenghua; Carass, Aaron; Ying, Sarah H.; Prince, Jerry L.

    2014-01-01

    Cerebellar ataxia is a progressive neuro-degenerative disease that has multiple genetic versions, each with a characteristic pattern of anatomical degeneration that yields distinctive motor and cognitive problems. Studying this pattern of degeneration can help with the diagnosis of disease subtypes, evaluation of disease stage, and treatment planning. In this work, we propose a learning framework using MR image data for discriminating a set of cerebellar ataxia types and predicting a disease ...

  20. Cooperative jamming power control to enhance secrecy communications of AF Relaying systems for Rayleigh fading channel

    KAUST Repository

    Park, Kihong

    2012-09-01

    In this paper, we investigate secrecy communications in two-hop wireless relaying networks which consist of one source, one amplify-and-forward (AF) relay, one legitimate destination, and one eavesdropper. To prevent the eavesdropper from intercepting the source message, we make the destination send the intended noise to the AF relay during the first phase. This is referred to as cooperative jamming. According to the channel information at the destination, we address two types of jamming power allocation; (i) rate-optimal power allocation and (ii) outage-optimal power allocation. More specifically, without the instantaneous channel knowledge for the eavesdropper side, the outage probability of the secrecy rate is minimized with respect to the intended noise power level. We show that the outage-optimal allocation gives almost the same outage probability as the rateoptimal one. In addition, the jamming power consumption can be significantly reduced compared to the fixed and rate-optimal power allocation methods. © 2012 IEEE.

  1. Control of the selectivity of the aquaporin water channel family by global orientational tuning

    DEFF Research Database (Denmark)

    Jensen, Morten Østergaard; Tajkhorshid, E.; Nollert, P.;

    2002-01-01

    and orientation of a single file of seven to nine water molecules inside the channel. Two conserved asparagines force a central water molecule to serve strictly as a hydrogen bond donor to its neighboring water molecules. Assisted by the electrostatic potential generated by two half-membrane spanning loops......Aquaporins are transmembrane channels found in cell membranes of all life forms. We examine their apparently paradoxical property, facilitation of efficient permeation of water while excluding protons, which is of critical importance to preserving the electrochemical potential across the cell...... membrane. We have determined the structure of the Escherichia coli aquaglyceroporin GlpF with bound water, in native (2.7 angstroms) and in W48F/F200T mutant (2.1 angstroms) forms, and carried out 12-nanosecond molecular dynamics simulations that define the spatial and temporal probability distribution...

  2. Causes and typical control model of wind-drift sandy lands in abandoned channel of the Yellow River

    Institute of Scientific and Technical Information of China (English)

    Zhang Guo-zhen; Yang Li; Xu Wei; Sun Bao-ping

    2006-01-01

    The historical formation and development of the abandoned channel of the Yellow River is reviewed and its causes of formation and present condition of prevention and control are analyzed in this paper. Based on this analysis, some ideas about control,critical problems and countermeasures in the next period are proposed with two typical control models as examples. We suggest that in preventing and controlling the wind-drift sandy lands in the region, the emphasis should be to develop, with a greatly expanded effort, a recycling economy. This should realize a combination of two ideas, i.e. integrate combating desertification with a structural adjustment of agricultural and an increase in the income of farmers.

  3. Patterns of spontaneous and head-shaking nystagmus in cerebellar infarction: imaging correlations.

    Science.gov (United States)

    Huh, Young Eun; Kim, Ji Soo

    2011-12-01

    Horizontal head-shaking may induce nystagmus in peripheral as well as central vestibular lesions. While the patterns and mechanism of head-shaking nystagmus are well established in peripheral vestibulopathy, they require further exploration in central vestibular disorders. To define the characteristics and mechanism of head-shaking nystagmus in central vestibulopathies, we investigated spontaneous nystagmus and head-shaking nystagmus in 72 patients with isolated cerebellar infarction. Spontaneous nystagmus was observed in 28 (39%) patients, and was mostly ipsilesional when observed in unilateral infarction (15/18, 83%). Head-shaking nystagmus developed in 37 (51%) patients, and the horizontal component of head-shaking nystagmus was uniformly ipsilesional when induced in patients with unilateral infarction. Perverted head-shaking nystagmus occurred in 23 (23/37, 62%) patients and was mostly downbeat (22/23, 96%). Lesion subtraction analyses revealed that damage to the uvula, nodulus and inferior tonsil was mostly responsible for generation of head-shaking nystagmus in patients with unilateral posterior inferior cerebellar artery infarction. Ipsilesional head-shaking nystagmus in patients with unilateral cerebellar infarction may be explained by unilateral disruption of uvulonodular inhibition over the velocity storage. Perverted (downbeat) head-shaking nystagmus may be ascribed to impaired control over the spatial orientation of the angular vestibulo-ocular reflex due to uvulonodular lesions or a build-up of vertical vestibular asymmetry favouring upward bias due to lesions involving the inferior tonsil.

  4. Thyroid hormone promotes transient nerve growth factor synthesis in rat cerebellar neuroblasts.

    Science.gov (United States)

    Charrasse, S; Jehan, F; Confort, C; Brachet, P; Clos, J

    1992-01-01

    Primary cultures of cerebellum from 5-day-old rats indicated that proliferating neuroblasts synthesize and release nerve growth factor (NGF). Since NGF promotes DNA synthesis in these cells, our findings demonstrate that the early developing cerebellum is a suitable physiological model for studying the autocrine mitogenic action of NGF. Thyroid deficiency led to a greater reduction in the NGF content of the cerebellum than of the olfactory bulbs or hippocampus. Cerebellar NGF mRNA was also very sensitive to hormone deprivation. Physiological amounts of thyroid hormone stimulated both the mitotic activity and NGF production of cultured cerebellar neuroblasts. A lack of thyroid hormone is known to markedly alter cell formation in the cerebellum where postnatal neurogenesis is highly significant, in contrast to the olfactory bulbs and hippocampus. Taken together, these results suggest that the hormonal control of cell formation in the cerebellum is, at least partly, mediated by the autocrine mitogenic action of NGF. The thyroid hormone could temporally regulate the transient NGF synthesis by cerebellar neuroblasts directly and/or through its ontogenetic action, and hence all the NGF-dependent trophic effects. PMID:1295750

  5. Cortico-cerebellar connectivity in Autism Spectrum Disorder: what do we know so far?

    Directory of Open Access Journals (Sweden)

    Alessandro eCrippa

    2016-02-01

    Full Text Available Although the Autism Spectrum Disorder (ASD is renowned to be a connectivity disorder and a condition characterized by cerebellar involvement, the connectivity between the cerebellum and other cortical brain regions is particularly under-examined. Indeed, converging evidence has recently suggested that the cerebellum could play a key role in the etiopathogenesis of ASD, since cerebellar anomalies have been consistently reported in ASD from the molecular to the behavioral level, and damage to the cerebellum early in development has been linked with signs of autistic features. In addition, current data have shown that the cerebellum is a key structure not only for sensory-motor control, but also for higher functions, such as social cognition and emotion, through its extensive connections with cortical areas. The disruption of these circuits could be implicated in the wide range of autistic symptoms that the term spectrum connotes. In this review, we present and discuss the recent findings from imaging studies that investigated cortico-cerebellar connectivity in people with ASD. The literature is still too limited to allow for definitive conclusions; however, this brief review reveals substantial areas for future studies, underlining currently unmet research perspectives.

  6. Thyroid hormone promotes transient nerve growth factor synthesis in rat cerebellar neuroblasts.

    Science.gov (United States)

    Charrasse, S; Jehan, F; Confort, C; Brachet, P; Clos, J

    1992-01-01

    Primary cultures of cerebellum from 5-day-old rats indicated that proliferating neuroblasts synthesize and release nerve growth factor (NGF). Since NGF promotes DNA synthesis in these cells, our findings demonstrate that the early developing cerebellum is a suitable physiological model for studying the autocrine mitogenic action of NGF. Thyroid deficiency led to a greater reduction in the NGF content of the cerebellum than of the olfactory bulbs or hippocampus. Cerebellar NGF mRNA was also very sensitive to hormone deprivation. Physiological amounts of thyroid hormone stimulated both the mitotic activity and NGF production of cultured cerebellar neuroblasts. A lack of thyroid hormone is known to markedly alter cell formation in the cerebellum where postnatal neurogenesis is highly significant, in contrast to the olfactory bulbs and hippocampus. Taken together, these results suggest that the hormonal control of cell formation in the cerebellum is, at least partly, mediated by the autocrine mitogenic action of NGF. The thyroid hormone could temporally regulate the transient NGF synthesis by cerebellar neuroblasts directly and/or through its ontogenetic action, and hence all the NGF-dependent trophic effects.

  7. Channel Morphology and Hydraulics as Controls on Spatial Patterns of Invertebrate Drift in a Mountain Stream.

    Science.gov (United States)

    Cienciala, P.; Hassan, M. A.

    2015-12-01

    In this research we linked spatial variability of invertebrate drift characteristics (e.g. flux, concentration, mean body size) in a mountain stream to channel morphology and hydraulic properties such as at-a-point and depth-averaged velocity and shear velocity. The study was conducted in East Creek, a small stream in British Columbia in which reach-scale morphology transitions from cobble-dominated plane-bed to gravel-bed pool-riffle. To achieve our goal, we collected vertical profiles of invertebrate drift and time-averaged velocity in various morphological units within the study reaches. The data were analyzed using linear mixed model. Our reach-scale results suggested that, generally, the study reaches had statistically similar drift characteristics despite their contrasting morphologies. At the within-reach scale, different drift characteristics displayed different trends in relation to morphological and hydraulic properties of the channel. Longitudinally, highest drift flux occurred in riffle-pool transitions. We attributed this finding primarily to higher flow velocity because there were no statistically significant differences in drift concentration between morphological units. In the vertical dimension, highest drift flux occurred near the surface owing to a combination of higher drift concentration and higher flow velocity. A different pattern was observed for mean body size of drifting invertebrates. On average, body size was smallest in riffle-pool transitions and largest near the bed. The combination of velocity, drift concentration, and drift body size structure resulted in similar biomass flux estimates in all morphological units. In the vertical dimension, biomass flux appeared to be highest near the water surface. Generally, hydraulic variables seemed to be relatively poor predictors of drift concentration and mean body size of drifting invertebrates. Our findings reveal a complex relationship between channel morphology and hydraulics and various

  8. Lithic Resource Control and Economic Change in the Santa Barbara Channel Region

    OpenAIRE

    Arnold, Jeanne E

    1990-01-01

    The territory occupied by the Chumash and their prehistoric predecessors encompassed the northern Channel Islands and a large mainland area extending from modern San Luis Obispo to Malibu and inland to the western margin of the San Joaquin Valley. The region is characterized by significant physiographic, biotic, and geological diversity. Each of these dimensions of variability has implications for the forms of human adaptation that developed during the course of several millennia of prehistor...

  9. Breathtaking TRP Channels: TRPA1 and TRPV1 in Airway Chemosensation and Reflex Control

    OpenAIRE

    Bessac, Bret F.; Jordt, Sven-Eric

    2008-01-01

    New studies have revealed an essential role for TRPA1, a sensory neuronal TRP ion channel, in airway chemosensation and inflammation. TRPA1 is activated by chlorine, reactive oxygen species and noxious constituents of smoke and smog, initiating irritation and airway reflex responses. Together with TRPV1, the capsaicin receptor, TRPA1 may contribute to chemical hypersensitivity, chronic cough and airway inflammation in asthma, COPD and reactive airway dysfunction syndrome.

  10. Breathtaking TRP channels: TRPA1 and TRPV1 in airway chemosensation and reflex control.

    Science.gov (United States)

    Bessac, Bret F; Jordt, Sven-Eric

    2008-12-01

    New studies have revealed an essential role for TRPA1, a sensory neuronal TRP ion channel, in airway chemosensation and inflammation. TRPA1 is activated by chlorine, reactive oxygen species, and noxious constituents of smoke and smog, initiating irritation and airway reflex responses. Together with TRPV1, the capsaicin receptor, TRPA1 may contribute to chemical hypersensitivity, chronic cough, and airway inflammation in asthma, COPD, and reactive airway dysfunction syndrome. PMID:19074743

  11. The control of chick myoblast fusion by ion channels operated by prostaglandins and acetylcholine

    OpenAIRE

    1988-01-01

    Chick myoblast fusion in culture was investigated using prostanoid synthesis inhibitors to delay spontaneous fusion. During this delay myoblast fusion could be induced by prostaglandin E1 (PGE1), by raising extracellular potassium and by addition of carbachol. Carbachol-induced fusion, but not PGE-induced fusion, was prevented by the acetylcholine receptor blocker alpha-bungarotoxin. Fusion induced by any of these agents was prevented by the Ca channel blockers lanthanum and D600. The thresho...

  12. A new Purkinje cell antibody (anti-Ca associated with subacute cerebellar ataxia: immunological characterization

    Directory of Open Access Journals (Sweden)

    Horn Sigrun

    2010-03-01

    Full Text Available Abstract We report on a newly discovered serum and cerebrospinal fluid (CSF reactivity to Purkinje cells (PCs associated with subacute inflammatory cerebellar ataxia. The patient, a previously healthy 33-year-old lady, presented with severe limb and gait ataxia, dysarthria, and diplopia two weeks after she had recovered from a common cold. Immunohistochemical studies on mouse, rat, and monkey brain sections revealed binding of a high-titer (up to 1:10,000 IgG antibody to the cerebellar molecular layer, Purkinje cell (PC layer, and white matter. The antibody is highly specific for PCs and binds to the cytoplasm as well as to the inner side of the membrane of PC somata, dendrites and axons. It is produced by B cell clones within the CNS, belongs to the IgG1 subclass, and activates complement in vitro. Western blotting of primate cerebellum extract revealed binding of CSF and serum IgG to an 80-97 kDa protein. Extensive control studies were performed to rule out a broad panel of previously described paraneoplastic and non-paraneoplastic antibodies known to be associated with cerebellar ataxia. Screening of >9000 human full length proteins by means of a protein array and additional confirmatory experiments revealed Rho GTPase activating protein 26 (ARHGAP26, GRAF, oligophrenin-1-like protein as the target antigen. Preadsorption of the patient's serum with human ARHGAP26 but not preadsorption with other proteins resulted in complete loss of PC staining. Our findings suggest a role of autoimmunity against ARHGAP26 in the pathogenesis of subacute inflammatory cerebellar ataxia, and extend the panel of diagnostic markers for this devastating disease.

  13. The dystrophin complex controls bk channel localization and muscle activity in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Hongkyun Kim

    2009-12-01

    Full Text Available Genetic defects in the dystrophin-associated protein complex (DAPC are responsible for a variety of pathological conditions including muscular dystrophy, cardiomyopathy, and vasospasm. Conserved DAPC components from humans to Caenorhabditis elegans suggest a similar molecular function. C. elegans DAPC mutants exhibit a unique locomotory deficit resulting from prolonged muscle excitation and contraction. Here we show that the C. elegans DAPC is essential for proper localization of SLO-1, the large conductance, voltage-, and calcium-dependent potassium (BK channel, which conducts a major outward rectifying current in muscle under the normal physiological condition. Through analysis of mutants with the same phenotype as the DAPC mutants, we identified the novel islo-1 gene that encodes a protein with two predicted transmembrane domains. We demonstrate that ISLO-1 acts as a novel adapter molecule that links the DAPC to SLO-1 in muscle. We show that a defect in either the DAPC or ISLO-1 disrupts normal SLO-1 localization in muscle. Consistent with observations that SLO-1 requires a high calcium concentration for full activation, we find that SLO-1 is localized near L-type calcium channels in muscle, thereby providing a mechanism coupling calcium influx with the outward rectifying current. Our results indicate that the DAPC modulates muscle excitability by localizing the SLO-1 channel to calcium-rich regions of C. elegans muscle.

  14. Transplantation and Stem Cell Therapy for Cerebellar Degenerations.

    Science.gov (United States)

    Cendelin, Jan

    2016-02-01

    Stem cell-based and regenerative therapy may become a hopeful treatment for neurodegenerative diseases including hereditary cerebellar degenerations. Neurotransplantation therapy mainly aims to substitute lost cells, but potential effects might include various mechanisms including nonspecific trophic effects and stimulation of endogenous regenerative processes and neural plasticity. Nevertheless, currently, there remain serious limitations. There is a wide spectrum of human hereditary cerebellar degenerations as well as numerous cerebellar mutant mouse strains that serve as models for the development of effective therapy. By now, transplantation has been shown to ameliorate cerebellar function, e.g. in Purkinje cell degeneration mice, Lurcher mutant mice and mouse models of spinocerebellar ataxia type 1 and type 2 and Niemann-Pick disease type C. Despite the lack of direct comparative studies, it appears that there might be differences in graft development and functioning between various types of cerebellar degeneration. Investigation of the relation of graft development to specific morphological, microvascular or biochemical features of the diseased host tissue in various cerebellar degenerations may help to identify factors determining the fate of grafted cells and potential of their functional integration. PMID:26155762

  15. Motor dysfunction in the tottering mouse is linked to cerebellar spontaneous low frequency oscillations revealed by flavoprotein autofluorescence optical imaging

    Science.gov (United States)

    Chen, Gang; Popa, Laurentiu S.; Wang, Xinming; Gao, Wangcai; Barnes, Justin; Hendrix, Claudia M.; Hess, Ellen J.; Ebner, Timothy J.

    2009-02-01

    Flavoprotein autofluorescence optical imaging is developing into a powerful research tool to study neural activity, particularly in vivo. In this study we used this imaging technique to investigate the neuronal mechanism underlying the episodic movement disorder that is characteristic of the tottering (tg) mouse, a model of episodic ataxia type 2. Both EA2 and the tg mouse are caused by mutations in the gene encoding Cav2.1 (P/Q-type) voltage-gated Ca2+ channels. These mutations result in a reduction in P/Q Ca2+ channel function. Both EA2 patients and tg mice have a characteristic phenotype consisting of transient motor attacks triggered by stress, caffeine or ethanol. The neural events underlying these episodes of dystonia are unknown. Flavoprotein autofluorescence optical imaging revealed spontaneous, transient, low frequency oscillations in the cerebellar cortex of the tg mouse. Lasting from 30 - 120 minutes, the oscillations originate in one area then spread to surrounding regions over 30 - 60 minutes. The oscillations are reduced by removing extracellular Ca2+ and blocking Cav 1.2/1.3 (L-type) Ca2+ channels. The oscillations are not affected by blocking AMPA receptors or by electrical stimulation of the parallel fiber - Purkinje cell circuit, suggesting the oscillations are generated intrinsically in the cerebellar cortex. Conversely, L-type Ca2+ agonists generate oscillations with similar properties. In the awake tg mouse, transcranial flavoprotein imaging revealed low frequency oscillations that are accentuated during caffeine induced attacks of dystonia. The oscillations increase during the attacks of dystonia and are coupled to oscillations in face and hindlimb EMG activity. These transient oscillations and the associated cerebellar dysfunction provide a novel mechanism by which an ion channel disorder results in episodic motor dysfunction.

  16. Entropy squeezing of a moving atom and control of noise of the quantum mechanical channel via the two-photon process

    Institute of Scientific and Technical Information of China (English)

    Zhou Bing-Ju; Liu Xiao-Juan; Zhou Qing-Ping; Liu Ming-Wei

    2007-01-01

    Based on the quantum information theory, we have investigated the entropy squeezing of a moving two-level atom interacting with the coherent field via the quantum mechanical channel of the two-photon process. The results are compared with those of atomic squeezing based on the Heisenberg uncertainty relation. The influences of the atomic motion and field-mode structure parameter on the atomic entropy squeezing and on the control of noise of the quantum mechanical channel via the two-photon process are examined. Our results show that the squeezed period,duration of optimal entropy squeezing of a two-level atom and the noise of the quantum mechanical channel can be controlled by appropriately choosing the atomic motion and the field-mode structure parameter, respectively. The quantum mechanical channel of two-photon process is an ideal channel for quantum information (atomic quantum state) transmission. Quantum information entropy is a remarkably accurate measure of the atomic squeezing.

  17. Effect of methotrexate on cerebellar development in infant rats.

    Science.gov (United States)

    Sugiyama, Akihiko; Sun, Jing; Ueda, Kota; Furukawa, Satoshi; Takeuchi, Takashi

    2015-07-01

    Six-day-old rats were treated intraperitoneal injections with methotrexate 1 mg/kg, and the cerebellum was examined. Both the length and width of the vermis decreased in the methotrexate-treated group instead of the control from 4 day after treatment (DAT) onward. A significant reduction in the width of the external granular layer was detected on 2 and 3 DAT in the methotrexate group. By 4 DAT, the width of the external granular layer of the methotrexate group was indistinguishable from the control, and by 8 DAT, it was greater than that of the control. The molecular layer of methotrexate group on 8 and 15 DAT was thinner than that of the control. On 1 DAT, in the methotrexate group, there were many TUNEL and cleaved caspase-3-positive granular cells throughout the external granular layer, and they decreased time-dependently. On 1 DAT, in the methotrexate group, phospho-histone H3-positive cells in the external granular layer were fewer than in the control and tended to increase on 2-4 DAT. The p21-positive-rate of the external granule cells in the MTX group was higher than in the control on 1-4 DAT. These results suggested that methotrexate exposure on postnatal day 6 induces a delay, slowing in the migration of external granular cells to the inner granular layer, attributed to decrease or inhibition in the production of external granular cells that had arisen from apoptosis and the decrease in cell proliferative activity, resulting in cerebellar hypoplasia.

  18. Effect of an organic molecular coating on control over the conductance of carbon nanotube channel

    Energy Technology Data Exchange (ETDEWEB)

    Bobrinetskiy, I. I.; Emelianov, A. V.; Nevolin, V. K., E-mail: vkn@miee.ru; Romashkin, A. V. [National Research University “Moscow Institute of Electronic Technology” (MIET) (Russian Federation)

    2014-12-15

    It is shown that the coating of carbon nanotubes with molecules with a constant dipole moment changes the conductance of the tubes due to a variation in the structure of energy levels that participate in charge transport. The I–V characteristics of the investigated structures exhibit significant dependence of the channel conductance on the gate potential. The observed memory effect of conductance level can be explained by the rearrangement of polar groups and molecules as a whole in an electric field. The higher the dipole moment per unit length and the weaker the intermolecular interaction, the faster the rearrangement process is.

  19. Lack of connexin43-mediated Bergmann glial gap junctional coupling does not affect cerebellar long-term depression, motor coordination, or eyeblink conditioning

    Directory of Open Access Journals (Sweden)

    Mika Tanaka

    2008-04-01

    Full Text Available Bergmann glial cells are specialized astrocytes in the cerebellum. In the mature cerebellar molecular layer, Bergmann glial processes are closely associated with Purkinje cells, enclosing Purkinje cell dendritic synapses with a glial sheath. There is intensive gap junctional coupling between Bergmann glial processes, but their significance in cerebellar functions is not known. Connexin43 (Cx43, a major component of astrocytic gap junction channels, is abundantly expressed in Bergmann glial cells. To examine the role of Cx43-mediated gap junctions between Bergmann glial cells in cerebellar functions, we generated Cx43 conditional knockout mice with the S100b-Cre transgenic line (Cx43fl/fl:S100b-Cre, which exhibited a significant loss of Cx43 in the Bergmann glial cells and astrocytes in the cerebellum with a postnatal onset. The Cx43fl/fl:S100b-Cre mice had normal cerebellar architecture. Although gap junctional coupling between the Bergmann glial cells measured by spreading of microinjected Lucifer yellow was virtually abolished in Cx43fl/fl:S100b-Cre mice, electrophysiologic analysis revealed that cerebellar long-term depression could be induced and maintained normally in thier cerebellar slices. In addition, at the behavioral level, Cx43fl/fl:S100b-Cre mice had normal motor coordination in the rotarod task and normal conditioned eyelid response. Our findings suggest that Cx43-mediated gap junctional coupling between Bergmann glial cells is not necessary for the neuron-glia interactions required for cerebellum-dependent motor coordination and motor learning.

  20. Bassoon specifically controls presynaptic P/Q-type Ca(2+) channels via RIM-binding protein.

    Science.gov (United States)

    Davydova, Daria; Marini, Claudia; King, Claire; Klueva, Julia; Bischof, Ferdinand; Romorini, Stefano; Montenegro-Venegas, Carolina; Heine, Martin; Schneider, Romy; Schröder, Markus S; Altrock, Wilko D; Henneberger, Christian; Rusakov, Dmitri A; Gundelfinger, Eckart D; Fejtova, Anna

    2014-04-01

    Voltage-dependent Ca(2+) channels (CaVs) represent the principal source of Ca(2+) ions that trigger evoked neurotransmitter release from presynaptic boutons. Ca(2+) influx is mediated mainly via CaV2.1 (P/Q-type) and CaV2.2 (N-type) channels, which differ in their properties. Their relative contribution to synaptic transmission changes during development and tunes neurotransmission during synaptic plasticity. The mechanism of differential recruitment of CaV2.1 and CaV2.2 to release sites is largely unknown. Here, we show that the presynaptic scaffolding protein Bassoon localizes specifically CaV2.1 to active zones via molecular interaction with the RIM-binding proteins (RBPs). A genetic deletion of Bassoon or an acute interference with Bassoon-RBP interaction reduces synaptic abundance of CaV2.1, weakens P/Q-type Ca(2+) current-driven synaptic transmission, and results in higher relative contribution of neurotransmission dependent on CaV2.2. These data establish Bassoon as a major regulator of the molecular composition of the presynaptic neurotransmitter release sites. PMID:24698275

  1. Calcium influx through CRAC channels controls actin organization and dynamics at the immune synapse.

    Science.gov (United States)

    Hartzell, Catherine A; Jankowska, Katarzyna I; Burkhardt, Janis K; Lewis, Richard S

    2016-01-01

    T cell receptor (TCR) engagement opens Ca(2+) release-activated Ca(2+) (CRAC) channels and triggers formation of an immune synapse between T cells and antigen-presenting cells. At the synapse, actin reorganizes into a concentric lamellipod and lamella with retrograde actin flow that helps regulate the intensity and duration of TCR signaling. We find that Ca(2+) influx is required to drive actin organization and dynamics at the synapse. Calcium acts by promoting actin depolymerization and localizing actin polymerization and the actin nucleation promotion factor WAVE2 to the periphery of the lamellipod while suppressing polymerization elsewhere. Ca(2+)-dependent retrograde actin flow corrals ER tubule extensions and STIM1/Orai1 complexes to the synapse center, creating a self-organizing process for CRAC channel localization. Our results demonstrate a new role for Ca(2+) as a critical regulator of actin organization and dynamics at the synapse, and reveal potential feedback loops through which Ca(2+) influx may modulate TCR signaling. PMID:27440222

  2. Calcium influx through CRAC channels controls actin organization and dynamics at the immune synapse

    Science.gov (United States)

    Hartzell, Catherine A; Jankowska, Katarzyna I; Burkhardt, Janis K; Lewis, Richard S

    2016-01-01

    T cell receptor (TCR) engagement opens Ca2+ release-activated Ca2+ (CRAC) channels and triggers formation of an immune synapse between T cells and antigen-presenting cells. At the synapse, actin reorganizes into a concentric lamellipod and lamella with retrograde actin flow that helps regulate the intensity and duration of TCR signaling. We find that Ca2+ influx is required to drive actin organization and dynamics at the synapse. Calcium acts by promoting actin depolymerization and localizing actin polymerization and the actin nucleation promotion factor WAVE2 to the periphery of the lamellipod while suppressing polymerization elsewhere. Ca2+-dependent retrograde actin flow corrals ER tubule extensions and STIM1/Orai1 complexes to the synapse center, creating a self-organizing process for CRAC channel localization. Our results demonstrate a new role for Ca2+ as a critical regulator of actin organization and dynamics at the synapse, and reveal potential feedback loops through which Ca2+ influx may modulate TCR signaling. DOI: http://dx.doi.org/10.7554/eLife.14850.001 PMID:27440222

  3. Ethanol-Induced Cerebellar Ataxia: Cellular and Molecular Mechanisms.

    Science.gov (United States)

    Dar, M Saeed

    2015-08-01

    The cerebellum is an important target of ethanol toxicity given that cerebellar ataxia is the most consistent physical manifestation of acute ethanol consumption. Despite the significance of the cerebellum in ethanol-induced cerebellar ataxia (EICA), the cellular and molecular mechanisms underlying EICA are incompletely understood. However, two important findings have shed greater light on this phenomenon. First, ethanol-induced blockade of cerebellar adenosine uptake in rodent models points to a role for adenosinergic A1 modulation of EICA. Second, the consistent observation that intracerebellar administration of nicotine in mice leads to antagonism of EICA provides evidence for a critical role of cerebellar nitric oxide (NO) in EICA reversal. Based on these two important findings, this review discusses the potential molecular events at two key synaptic sites (mossy fiber-granule cell-Golgi cell (MGG synaptic site) and granule cell parallel fiber-Purkinje cell (GPP synaptic site) that lead to EICA. Specifically, ethanol-induced neuronal NOS inhibition at the MGG synaptic site acts as a critical trigger for Golgi cell activation which leads to granule cell deafferentation. Concurrently, ethanol-induced inhibition of adenosine uptake at the GPP synaptic site produces adenosine accumulation which decreases glutamate release and leads to the profound activation of Purkinje cells (PCs). These molecular events at the MGG and GPP synaptic sites are mutually reinforcing and lead to cerebellar dysfunction, decreased excitatory output of deep cerebellar nuclei, and EICA. The critical importance of PCs as the sole output of the cerebellar cortex suggests normalization of PC function could have important therapeutic implications.

  4. A cerebellar neuroprosthetic system: computational architecture and in vivo experiments

    Directory of Open Access Journals (Sweden)

    Ivan eHerreros Alonso

    2014-05-01

    Full Text Available Emulating the input-output functions performed by a brain structure opens the possibility for developing neuro-prosthetic systems that replace damaged neuronal circuits. Here, we demonstrate the feasibility of this approach by replacing the cerebellar circuit responsible for the acquisition and extinction of motor memories. Specifically, we show that a rat can undergo acquisition, retention and extinction of the eye-blink reflex even though the biological circuit responsible for this task has been chemically inactivated via anesthesia. This is achieved by first developing a computational model of the cerebellar microcircuit involved in the acquisition of conditioned reflexes and training it with synthetic data generated based on physiological recordings. Secondly, the cerebellar model is interfaced with the brain of an anesthetized rat, connecting the model's inputs and outputs to afferent and efferent cerebellar structures. As a result, we show that the anesthetized rat, equipped with our neuro-prosthetic system, can be classically conditioned to the acquisition of an eye-blink response. However, non-stationarities in the recorded biological signals limit the performance of the cerebellar model. Thus, we introduce an updated cerebellar model and validate it with physiological recordings showing that learning becomes stable and reliable. The resulting system represents an important step towards replacing lost functions of the central nervous system via neuro-prosthetics, obtained by integrating a synthetic circuit with the afferent and efferent pathways of a damaged brain region. These results also embody an early example of science-based medicine, where on the one hand the neuro-prosthetic system directly validates a theory of cerebellar learning that informed the design of the system, and on the other one it takes a step towards the development of neuro-prostheses that could recover lost learning functions in animals and, in the longer term

  5. Cerebellar development in the absence of Gbx function in zebrafish.

    Science.gov (United States)

    Su, Chen-Ying; Kemp, Hilary A; Moens, Cecilia B

    2014-02-01

    The midbrain-hindbrain boundary (MHB) is a well-known organizing center during vertebrate brain development. The MHB forms at the expression boundary of Otx2 and Gbx2, mutually repressive homeodomain transcription factors expressed in the midbrain/forebrain and anterior hindbrain, respectively. The genetic hierarchy of gene expression at the MHB is complex, involving multiple positive and negative feedback loops that result in the establishment of non-overlapping domains of Wnt1 and Fgf8 on either side of the boundary and the consequent specification of the cerebellum. The cerebellum derives from the dorsal part of the anterior-most hindbrain segment, rhombomere 1 (r1), which undergoes a distinctive morphogenesis to give rise to the cerebellar primordium within which the various cerebellar neuron types are specified. Previous studies in the mouse have shown that Gbx2 is essential for cerebellar development. Using zebrafish mutants we show here that in the zebrafish gbx1 and gbx2 are required redundantly for morphogenesis of the cerebellar primordium and subsequent cerebellar differentiation, but that this requirement is alleviated by knocking down Otx. Expression of fgf8, wnt1 and the entire MHB genetic program is progressively lost in gbx1-;gbx2- double mutants but is rescued by Otx knock-down. This rescue of the MHB genetic program depends on rescued Fgf signaling, however the rescue of cerebellar primordium morphogenesis is independent of both Gbx and Fgf. Based on our findings we propose a revised model for the role of Gbx in cerebellar development.

  6. Sudden stopping in patients with cerebellar ataxia.

    Science.gov (United States)

    Serrao, Mariano; Conte, Carmela; Casali, Carlo; Ranavolo, Alberto; Mari, Silvia; Di Fabio, Roberto; Perrotta, Armando; Coppola, Gianluca; Padua, Luca; Monamì, Stefano; Sandrini, Giorgio; Pierelli, Francesco

    2013-10-01

    Stopping during walking, a dynamic motor task frequent in everyday life, is very challenging for ataxic patients, as it reduces their gait stability and increases the incidence of falls. This study was conducted to analyse the biomechanical characteristics of upper and lower body segments during abrupt stopping in ataxic patients in order to identify possible strategies used to counteract the instability in the sagittal and frontal plane. Twelve patients with primary degenerative cerebellar ataxia and 12 age- and sex-matched healthy subjects were studied. Time-distance parameters, dynamic stability of the centre of mass, upper body measures and lower joint kinematic and kinetic parameters were analysed. The results indicate that ataxic patients have a great difficulty in stopping abruptly during walking and adopt a multi-step stopping strategy, occasionally with feet parallel, to compensate for their inability to coordinate the upper body and to generate a well-coordinated lower limb joint flexor-extensor pattern and appropriate braking forces for progressively decelerating the progression of the body in the sagittal plane. A specific rehabilitation treatment designed to improve the ability of ataxic patients to transform unplanned stopping into planned stopping, to coordinate upper body and to execute an effective flexion-extension pattern of the hip and knee joints may be useful in these patients in order to improve their stopping performance and prevent falls.

  7. VANET多信道传输中控制信道冲突缓解算法研究%Research on Collision Mitigation in Control Channel for Multi-channel Transmission in VANET

    Institute of Scientific and Technical Information of China (English)

    张伟; 刘南杰; 赵海涛

    2015-01-01

    针对车载无线网络环境中由于多信道传输需要进行信道切换导致控制信道起始处的同步冲突问题,文中利用车辆节点估算信道占用率并计算发送概率,能够达到动态调整信道拥塞程度并有效缓解冲突的目的。首先对控制信道的传输机制进行规划,为安全消息和业务信道预约消息等设置不同优先级,然后进行自适应信道负载分散。当信道负载较重时发送概率减少,部分节点需要重新竞争信道,从而起到缓解冲突的作用。仿真结果表明,该算法能够提高数据包的成功转发率,降低传输延时,有效缓解由信道切换带来的同步冲突。%Multi-channel transmission will lead to channel switch in VANET,which causes the synchronized collisions at the start of con-trol channel. Propose a method to relieve this collision effectively and adjust the degree of channel congestion dynamically by estimating channel utilization and computing the transmission probability with vehicles. Firstly,the mechanism of control channel transmission has planned. The priority of safety-related messages is higher than reservation message of service channel and so on. Then the channel load will be distributed self-adaptively. When the load is heavy,the transmission probability reduces as well,part of vehicles need re-competi-tion of control channel,for the purpose of collision mitigation. Simulation results show that this method can improve the rate of package forwards,reducing the transmission delay and relieving the synchronized collisions caused by channel switch effectively.

  8. Familial periodic cerebellar ataxia without myokymia maps to a 19-cM region on 19p13

    Energy Technology Data Exchange (ETDEWEB)

    Teh, B.T.; Lindblad, K.; Betz, R. [Karolinska Hospital, Stockholm (Switzerland)] [and others

    1995-06-01

    Familial periodic cerebellar ataxia (FPCA) is a heterogenous group of rare autosomal dominant disorders characterized by episodic cerebellar disturbance. A potassium-channel gene (KCNA1) has been found to be responsible for one of its subgroups, familial periodic cerebellar ataxia with myokymia (FPCA/+M; MIM 160120). A different subgroup that is not associated with myokymia (FPCA/-M; MIM 108500) was recently mapped to chromosome 19p. Here we have performed linkage analysis in two large families with FPCA/-M that also demonstrated neurodegenerative pathology of the cerebellum. Three markers in 19p13 gave significant lod scores (>3.0), while linkage to KCNA1 and three known loci for spinocerebellar ataxia (SCA1, SCA2, and SCA3) was excluded. The highest lod score was obtained with the marker D19S413 (4.4 at recombination fraction 0), and identification of meiotic recombinants in affected individuals placed the locus between the flanking markers D19S406 and D19S226, narrowing the interval to 19 cM. A CAG trinucleotide-repeat expansion was detected in one family but did not consegregate with the disease. 30 refs., 3 figs., 1 tab.

  9. Methionine stimulates motor impairment and cerebellar mercury deposition in methylmercury-exposed mice.

    Science.gov (United States)

    Zimmermann, Luciana T; dos Santos, Danúbia B; Colle, Dirleise; dos Santos, Alessandra A; Hort, Mariana A; Garcia, Solange C; Bressan, Lucas Paines; Bohrer, Denise; Farina, Marcelo

    2014-01-01

    Methylmercury (MeHg) is a highly toxic environmental contaminant that produces neurological and developmental impairments in animals and humans. Although its neurotoxic properties have been widely reported, the molecular mechanisms by which MeHg enters the cells and exerts toxicity are not yet completely understood. Taking into account that MeHg is found mostly bound to sulfhydryl-containing molecules such as cysteine in the environment and based on the fact that the MeHg-cysteine complex (MeHg-S-Cys) can be transported via the L-type neutral amino acid carrier transport (LAT) system, the potential beneficial effects of L-methionine (L-Met, a well known LAT substrate) against MeHg (administrated as MeHg-S-Cys)-induced neurotoxicity in mice were investigated. Mice were exposed to MeHg (daily subcutaneous injections of MeHg-S-Cys, 10 mg Hg/kg) and/or L-Met (daily intraperitoneal injections, 250 mg/kg) for 10 consecutive days. After treatments, the measured hallmarks of toxicity were mostly based on behavioral parameters related to motor performance, as well as biochemical parameters related to the cerebellar antioxidant glutathione (GSH) system. MeHg significantly decreased motor activity (open-field test) and impaired motor performance (rota-rod task) compared with controls, as well as producing disturbances in the cerebellar antioxidant GSH system. Interestingly, L-Met administration did not protect against MeHg-induced behavioral and cerebellar changes, but rather increased motor impairments in animals exposed to MeHg. In agreement with this observation, cerebellar levels of mercury (Hg) were higher in animals exposed to MeHg plus L-Met compared to those only exposed to MeHg. However, this event was not observed in kidney and liver. These results are the first to demonstrate that L-Met enhances cerebellar deposition of Hg in mice exposed to MeHg and that this higher deposition may be responsible for the greater motor impairment observed in mice simultaneously

  10. mGluR1-mediated excitation of cerebellar GABAergic interneurons requires both G protein-dependent and Src-ERK1/2-dependent signaling pathways.

    Directory of Open Access Journals (Sweden)

    Hideo Kubota

    Full Text Available Stimulation of type I metabotropic glutamate receptors (mGluR1/5 in several neuronal types induces slow excitatory responses through activation of transient receptor potential canonical (TRPC channels. GABAergic cerebellar molecular layer interneurons (MLIs modulate firing patterns of Purkinje cells (PCs, which play a key role in cerebellar information processing. MLIs express mGluR1, and activation of mGluR1 induces an inward current, but its precise intracellular signaling pathways are unknown. We found that mGluR1 activation facilitated spontaneous firing of mouse cerebellar MLIs through an inward current mediated by TRPC1 channels. This mGluR1-mediated inward current depends on both G protein-dependent and -independent pathways. The nonselective protein tyrosine kinase inhibitors genistein and AG490 as well as the selective extracellular signal-regulated kinase 1/2 (ERK1/2 inhibitors PD98059 and SL327 suppressed the mGluR1-mediated current responses. Following G protein blockade, the residual mGluR1-mediated inward current was significantly reduced by the selective Src tyrosine kinase inhibitor PP2. In contrast to cerebellar PCs, GABAB receptor activation in MLIs did not alter the mGluR1-mediated inward current, suggesting that there is no cross-talk between mGluR1 and GABAB receptors in MLIs. Thus, activation of mGluR1 facilitates firing of MLIs through the TRPC1-mediated inward current, which depends on not only G protein-dependent but also Src-ERK1/2-dependent signaling pathways, and consequently depresses the excitability of cerebellar PCs.

  11. Design of a 32-Channel EEG System for Brain Control Interface Applications

    Directory of Open Access Journals (Sweden)

    Ching-Sung Wang

    2012-01-01

    Full Text Available This study integrates the hardware circuit design and the development support of the software interface to achieve a 32-channel EEG system for BCI applications. Since the EEG signals of human bodies are generally very weak, in addition to preventing noise interference, it also requires avoiding the waveform distortion as well as waveform offset and so on; therefore, the design of a preamplifier with high common-mode rejection ratio and high signal-to-noise ratio is very important. Moreover, the friction between the electrode pads and the skin as well as the design of dual power supply will generate DC bias which affects the measurement signals. For this reason, this study specially designs an improved single-power AC-coupled circuit, which effectively reduces the DC bias and improves the error caused by the effects of part errors. At the same time, the digital way is applied to design the adjustable amplification and filter function, which can design for different EEG frequency bands. For the analog circuit, a frequency band will be taken out through the filtering circuit and then the digital filtering design will be used to adjust the extracted frequency band for the target frequency band, combining with MATLAB to design man-machine interface for displaying brain wave. Finally the measured signals are compared to the traditional 32-channel EEG signals. In addition to meeting the IFCN standards, the system design also conducted measurement verification in the standard EEG isolation room in order to demonstrate the accuracy and reliability of this system design.

  12. The cerebellar nodulus/uvula integrates otolith signals for the translational vestibulo-ocular reflex.

    Directory of Open Access Journals (Sweden)

    Mark F Walker

    Full Text Available BACKGROUND: The otolith-driven translational vestibulo-ocular reflex (tVOR generates compensatory eye movements to linear head accelerations. Studies in humans indicate that the cerebellum plays a critical role in the neural control of the tVOR, but little is known about mechanisms of this control or the functions of specific cerebellar structures. Here, we chose to investigate the contribution of the nodulus and uvula, which have been shown by prior studies to be involved in the processing of otolith signals in other contexts. METHODOLOGY/PRINCIPAL FINDINGS: We recorded eye movements in two rhesus monkeys during steps of linear motion along the interaural axis before and after surgical lesions of the cerebellar uvula and nodulus. The lesions strikingly reduced eye velocity during constant-velocity motion but had only a small effect on the response to initial head acceleration. We fit eye velocity to a linear combination of head acceleration and velocity and to a dynamic mathematical model of the tVOR that incorporated a specific integrator of head acceleration. Based on parameter optimization, the lesion decreased the gain of the pathway containing this new integrator by 62%. The component of eye velocity that depended directly on head acceleration changed little (gain decrease of 13%. In a final set of simulations, we compared our data to the predictions of previous models of the tVOR, none of which could account for our experimental findings. CONCLUSIONS/ SIGNIFICANCE: Our results provide new and important information regarding the neural control of the tVOR. Specifically, they point to a key role for the cerebellar nodulus and uvula in the mathematical integration of afferent linear head acceleration signals. This function is likely to be critical not only for the tVOR but also for the otolith-mediated reflexes that control posture and balance.

  13. Oral Administration of PF-01247324, a Subtype-Selective Nav1.8 Blocker, Reverses Cerebellar Deficits in a Mouse Model of Multiple Sclerosis

    OpenAIRE

    Shields, Shannon D.; Butt, Richard P.; Dib-Hajj, Sulayman D; WAXMAN, STEPHEN G.

    2015-01-01

    Cerebellar symptoms significantly diminish quality of life in patients with multiple sclerosis (MS). We previously showed that sodium channel Nav1.8, although normally restricted to peripheral somatosensory neurons, is upregulated in the cerebellum in MS, and that Nav1.8 expression is linked to ataxia and MS-like symptoms in mice. Furthermore, intracerebroventricular administration of the Nav1.8 blocker A-803467 temporarily reversed electrophysiological and behavioral manifestations of diseas...

  14. MR imaging of solid cerebellar tumors in adult

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Kee Hyun; Han, Moon Hee; Yu, In Kyu [Seoul National University College of Medicine, Seoul (Korea, Republic of); Choo, Sung Wook; Byun, Hong Sik [Samsung Medical Center, Seoul (Korea, Republic of); Choi, Kyu Ho; Kim, Ki Jun [Catholic University Medical College, Seoul (Korea, Republic of)

    1995-07-15

    The solid variety of cerebellar tumors in adult is relatively uncommon. This study is to describe the characteristic MR findings of various solid cerebellar tumors in adult. Twenty three cerebellar solid tumors from 22 consecutive patients over age of 15 with surgical confirmations were retrospectively evaluated with MR findings. Histologic diagnosis included hemangioblastoma (n = 6), metastasis (n = 6), high-grade astrocytoma (n = 3), and medulloblastoma (n = 8). The MR findings were reviewed with attention of the size, the signal intensity of the tumors, pattern of enhancement, tumoral margin, degree of peritumoral edema, signal void vascular structures within and/or around the tumor, and location in relation to attachment to the pial surface of the tumor. Solid hemangioblastomas consistently showed slightly low or iso signal intensity on T1-weighted images and high intensity on T2-weighted images, dense homogeneous enhancement, and signal void vessels within and/or around the mass. Metastatic tumors showed various findings with predominantly low or iso signal intensity on T2-weighted images. Medulloblastomas was midline and/or paramidline in location, and had larger mass formation. High-grade astrocytomas revealed nonspecific MR findings with no signal void vessels. Hemangioblastoma, metastasis, malignant astrocytoma, and medulloblastoma should be included in differential diagnosis of solid cerebellar tumors in adult. Dense homogeneous enhancement and signal void vessels are characteristic of hemangioblastoma. The signal intensity of the tumor, and presence of signal void vessels, location and enhancement pattern can be some value in differential diagnosis of solid cerebellar tumors in adult.

  15. Development of the cerebellar cortex in the mouse

    Institute of Scientific and Technical Information of China (English)

    Xiangshu Cheng; Jin Du; Dongming Yu; Qiying Jiang; Yanqiu Hu; Lei Wang; Mingshan Li; Jinbo Deng

    2011-01-01

    The cerebellum is a highly conserved structure in the central nervous system of vertebrates, and is involved in the coordination of voluntary motor behavior. Supporting this function, the cerebellar cortex presents a layered structure which requires precise spatial and temporal coordination of proliferation, migration, differentiation, and apoptosis events. The formation of the layered structure in the developing cerebellum remains unclear. The present study investigated the development of the cerebellar cortex. The results demonstrate that the primordium of the cerebellum comprises the ependymal, mantle, and marginal layers at embryonic day 12 (E12). Subsequently, the laminated cerebellar cortex undergoes cell proliferation, differentiation, and migration, and at about postnatal day 0 (P0), the cerebellar cortex presents an external granular layer, a molecular layer, a Purkinje layer, and an internal granular layer. The external granular layer is thickest at P6/7 and disappears at P20. From P0 to P30, the internal granular cells and the Purkinje cells gradually differentiate and develop until maturity. Apoptotic neurons are evident in the layered structure in the developing cerebellar cortex. The external granular layer disappears gradually because of cell migration and apoptosis. The cells of the other layers primarily undergo differentiation, development, and apoptosis.

  16. Decreased cortical inhibition and yet cerebellar pathology in 'familial cortical myoclonic tremor with epilepsy'

    NARCIS (Netherlands)

    van Rootselaar, Anne-Fleur; van der Salm, Sandra M. A.; Bour, Lo J.; Edwards, Mark J.; Brown, Peter; Aronica, Eleonora; Rozemuller-Kwakkel, Johanna M.; Koehler, Peter J.; Koelman, Johannes H. T. M.; Rothwell, John C.; Tijssen, Marina A. J.

    2007-01-01

    Cortical hyperexcitability is a feature of "familial cortical myoclonic tremor with epilepsy" (FCMTE). However, neuropathological investigations in a single FCMTE patient showed isolated cerebellar pathology. Pathological investigations in a second FCMTE patient, reported here, confirmed cerebellar

  17. Biallelic CACNA1A mutations cause early onset epileptic encephalopathy with progressive cerebral, cerebellar, and optic nerve atrophy.

    Science.gov (United States)

    Reinson, Karit; Õiglane-Shlik, Eve; Talvik, Inga; Vaher, Ulvi; Õunapuu, Anne; Ennok, Margus; Teek, Rita; Pajusalu, Sander; Murumets, Ülle; Tomberg, Tiiu; Puusepp, Sanna; Piirsoo, Andres; Reimand, Tiia; Õunap, Katrin

    2016-08-01

    The CACNA1A gene encodes the transmembrane pore-forming alpha-1A subunit of the Cav 2.1 P/Q-type voltage-gated calcium channel. Several heterozygous mutations within this gene, including nonsense mutations, missense mutations, and expansion of cytosine-adenine-guanine repeats, are known to cause three allelic autosomal dominant conditions-episodic ataxia type 2, familial hemiplegic migraine type 1, and spinocerebellar ataxia type 6. An association with epilepsy and CACNA1A mutations has also been described. However, the link with epileptic encephalopathies has emerged only recently. Here we describe two patients, sister and brother, with compound heterozygous mutations in CACNA1A. Exome sequencing detected biallelic mutations in CACNA1A: A missense mutation c.4315T>A (p.Trp1439Arg) in exon 27, and a seven base pair deletion c.472_478delGCCTTCC (p.Ala158Thrfs*6) in exon 3. Both patients were normal at birth, but developed daily recurrent seizures in early infancy with concomitant extreme muscular hypotonia, hypokinesia, and global developmental delay. The brain MRI images showed progressive cerebral, cerebellar, and optic nerve atrophy. At the age of 5, both patients were blind and bedridden with a profound developmental delay. The elder sister died at that age. Their parents and two siblings were heterozygotes for one of those pathogenic mutations and expressed a milder phenotype. Both of them have intellectual disability and in addition the mother has adult onset cerebellar ataxia with a slowly progressive cerebellar atrophy. Compound heterozygous mutations in the CACNA1A gene presumably cause early onset epileptic encephalopathy, and progressive cerebral, cerebellar and optic nerve atrophy with reduced lifespan. © 2016 Wiley Periodicals, Inc. PMID:27250579

  18. Mitotic Events in Cerebellar Granule Progenitor Cells that Expand Cerebellar Surface Area Are Critical for Normal Cerebellar Cortical Lamination in Mice

    Science.gov (United States)

    Chang, Joshua C.; Leung, Mark; Gokozan, Hamza Numan; Gygli, Patrick Edwin; Catacutan, Fay Patsy; Czeisler, Catherine; Otero, José Javier

    2015-01-01

    Late embryonic and postnatal cerebellar folial surface area expansion promotes cerebellar cortical cytoarchitectural lamination. We developed a streamlined sampling scheme to generate unbiased estimates of murine cerebellar surface area and volume using stereological principles. We demonstrate that during the proliferative phase of the external granule layer (EGL) and folial surface area expansion, EGL thickness does not change and thus is a topological proxy for progenitor self-renewal. The topological constraints indicate that during proliferative phases, migration out of the EGL is balanced by self-renewal. Progenitor self-renewal must, therefore, include mitotic events yielding either 2 cells in the same layer to increase surface area (β-events) and mitotic events yielding 2 cells, with 1 cell in a superficial layer and 1 cell in a deeper layer (α-events). As the cerebellum grows, therefore, β-events lie upstream of α-events. Using a mathematical model constrained by the measurements of volume and surface area, we could quantify inter-mitotic times for β-events on a per-cell basis in post-natal mouse cerebellum. Furthermore, we found that loss of CCNA2, which decreases EGL proliferation and secondarily induces cerebellar cortical dyslamination, shows preserved α-type events. Thus, CCNA2-null cerebellar granule progenitor cells are capable of self-renewal of the EGL stem cell niche; this is concordant with prior findings of extensive apoptosis in CCNA2-null mice. Similar methodologies may provide another layer of depth to the interpretation of results from stereological studies. PMID:25668568

  19. Transmembrane proteoglycans control stretch-activated channels to set cytosolic calcium levels

    DEFF Research Database (Denmark)

    Gopal, Sandeep; Søgaard, Pernille; Multhaupt, Hinke A B;

    2015-01-01

    with subsequent control of the cytoskeleton and the myofibroblast phenotype. In epidermal keratinocytes a syndecan-TRPC4 complex controls adhesion, adherens junction composition, and early differentiation in vivo and in vitro. In Caenorhabditis elegans, the TRPC orthologues TRP-1 and -2 genetically complement...

  20. Exposure to extremely low-frequency electromagnetic fields modulates Na+ currents in rat cerebellar granule cells through increase of AA/PGE2 and EP receptor-mediated cAMP/PKA pathway.

    Directory of Open Access Journals (Sweden)

    Yan-Lin He

    Full Text Available Although the modulation of Ca(2+ channel activity by extremely low-frequency electromagnetic fields (ELF-EMF has been studied previously, few reports have addressed the effects of such fields on the activity of voltage-activated Na(+ channels (Na(v. Here, we investigated the effects of ELF-EMF on Na(v activity in rat cerebellar granule cells (GCs. Our results reveal that exposing cerebellar GCs to ELF-EMF for 10-60 min significantly increased Na(v currents (I(Na by 30-125% in a time- and intensity-dependent manner. The Na(v channel steady-state activation curve, but not the steady-state inactivation curve, was significantly shifted (by 5.2 mV towards hyperpolarization by ELF-EMF stimulation. This phenomenon is similar to the effect of intracellular application of arachidonic acid (AA and prostaglandin E(2 (PGE(2 on I(Na in cerebellar GCs. Increases in intracellular AA, PGE(2 and phosphorylated PKA levels in cerebellar GCs were observed following ELF-EMF exposure. Western blottings indicated that the Na(V 1.2 protein on the cerebellar GCs membrane was increased, the total expression levels of Na(V 1.2 protein were not affected after exposure to ELF-EMF. Cyclooxygenase inhibitors and PGE(2 receptor (EP antagonists were able to eliminate this ELF-EMF-induced increase in phosphorylated PKA and I(Na. In addition, ELF-EMF exposure significantly enhanced the activity of PLA(2 in cerebellar GCs but did not affect COX-1 or COX-2 activity. Together, these data demonstrate for the first time that neuronal I(Na is significantly increased by ELF-EMF exposure via a cPLA2 AA PGE(2 EP receptors PKA signaling pathway.

  1. Internal carotid-cerebellar artery anastomosis. So-called persistent trigeminal artery variant

    Energy Technology Data Exchange (ETDEWEB)

    Tanohata, Kazunori; Maehara, Tadayuki; Noda, Masanobu; Katoh, Hiromi

    1987-09-01

    Five cases of internal carotid-cerebellar artery anastomosis are presented. These anomalous vessels are identical to the so-called persistent trigeminal artery variant (PTAV). In our cases, two superior cerebellar arteries (SCAs), two anterior inferior cerebellar arteries (AICAs) and one posterior inferior cerebellar artery (PICA) arose from the precavernous segment of the internal carotid artery. We discuss the embryolgical and neuroradiological aspects of this anomaly.

  2. Orai1 pore residues control CRAC channel inactivation independently of calmodulin.

    Science.gov (United States)

    Mullins, Franklin M; Yen, Michelle; Lewis, Richard S

    2016-02-01

    Ca(2+) entry through CRAC channels causes fast Ca(2+)-dependent inactivation (CDI). Previous mutagenesis studies have implicated Orai1 residues W76 and Y80 in CDI through their role in binding calmodulin (CaM), in agreement with the crystal structure of Ca(2+)-CaM bound to an Orai1 N-terminal peptide. However, a subsequent Drosophila melanogaster Orai crystal structure raises concerns about this model, as the side chains of W76 and Y80 are predicted to face the pore lumen and create a steric clash between bound CaM and other Orai1 pore helices. We further tested the functional role of CaM using several dominant-negative CaM mutants, none of which affected CDI. Given this evidence against a role for pretethered CaM, we altered side-chain volume and charge at the Y80 and W76 positions to better understand their roles in CDI. Small side chain volume had different effects at the two positions: it accelerated CDI at position Y80 but reduced the extent of CDI at position W76. Positive charges at Y80 and W76 permitted partial CDI with accelerated kinetics, whereas introducing negative charge at any of five consecutive pore-lining residues (W76, Y80, R83, K87, or R91) completely eliminated CDI. Noise analysis of Orai1 Y80E and Y80K currents indicated that reductions in CDI for these mutations could not be accounted for by changes in unitary current or open probability. The sensitivity of CDI to negative charge introduced into the pore suggested a possible role for anion binding in the pore. However, although Cl(-) modulated the kinetics and extent of CDI, we found no evidence that CDI requires any single diffusible cytosolic anion. Together, our results argue against a CDI mechanism involving CaM binding to W76 and Y80, and instead support a model in which Orai1 residues Y80 and W76 enable conformational changes within the pore, leading to CRAC channel inactivation. PMID:26809793

  3. Offset-Free Model Predictive Control of Open Water Channel Based on Moving Horizon Estimation

    Science.gov (United States)

    Ekin Aydin, Boran; Rutten, Martine

    2016-04-01

    Model predictive control (MPC) is a powerful control option which is increasingly used by operational water managers for managing water systems. The explicit consideration of constraints and multi-objective management are important features of MPC. However, due to the water loss in open water systems by seepage, leakage and evaporation a mismatch between the model and the real system will be created. These mismatch affects the performance of MPC and creates an offset from the reference set point of the water level. We present model predictive control based on moving horizon estimation (MHE-MPC) to achieve offset free control of water level for open water canals. MHE-MPC uses the past predictions of the model and the past measurements of the system to estimate unknown disturbances and the offset in the controlled water level is systematically removed. We numerically tested MHE-MPC on an accurate hydro-dynamic model of the laboratory canal UPC-PAC located in Barcelona. In addition, we also used well known disturbance modeling offset free control scheme for the same test case. Simulation experiments on a single canal reach show that MHE-MPC outperforms disturbance modeling offset free control scheme.

  4. Bearer channel control protocol for the dynamic VB5.2 interface in ATM access networks

    Science.gov (United States)

    Fragoulopoulos, Stratos K.; Mavrommatis, K. I.; Venieris, Iakovos S.

    1996-12-01

    In the multi-vendor systems, a customer connected to an Access network (AN) must be capable of selecting a specific Service Node (SN) according to the services the SN provides. The multiplicity of technologically varying AN calls for the definition of a standard reference point between the AN and the SN widely known as the VB interface. Two versions are currently offered. The VB5.1 is simpler to implement but is not as flexible as the VB5.2, which supports switched connections. The VB5.2 functionality is closely coupled to the Broadband Bearer Channel Connection Protocol (B-BCCP). The B-BCCP is used for conveying the necessary information for dynamic resource allocation, traffic policing and routing in the AN as well as for information exchange concerning the status of the AN before a new call is established by the SN. By relying on such a protocol for the exchange of information instead of intercepting and interpreting signalling messages in the AN, the architecture of the AN is simplified because the functionality related to processing is not duplicated. In this paper a prominent B- BCCP candidate is defined, called the Service node Access network Interaction Protocol.

  5. UBE3A Regulates Synaptic Plasticity and Learning and Memory by Controlling SK2 Channel Endocytosis

    Directory of Open Access Journals (Sweden)

    Jiandong Sun

    2015-07-01

    Full Text Available Gated solely by activity-induced changes in intracellular calcium, small-conductance potassium channels (SKs are critical for a variety of functions in the CNS, from learning and memory to rhythmic activity and sleep. While there is a wealth of information on SK2 gating, kinetics, and Ca2+ sensitivity, little is known regarding the regulation of SK2 subcellular localization. We report here that synaptic SK2 levels are regulated by the E3 ubiquitin ligase UBE3A, whose deficiency results in Angelman syndrome and overexpression in increased risk of autistic spectrum disorder. UBE3A directly ubiquitinates SK2 in the C-terminal domain, which facilitates endocytosis. In UBE3A-deficient mice, increased postsynaptic SK2 levels result in decreased NMDA receptor activation, thereby impairing hippocampal long-term synaptic plasticity. Impairments in both synaptic plasticity and fear conditioning memory in UBE3A-deficient mice are significantly ameliorated by blocking SK2. These results elucidate a mechanism by which UBE3A directly influences cognitive function.

  6. An unusual cause of adult onset cerebellar ataxia with hypogonadism

    Directory of Open Access Journals (Sweden)

    Menon Ramshekhar

    2009-01-01

    Full Text Available We report an unusual case of sporadic adult onset cerebellar ataxia with hypogonadism. A 40-year-old unmarried man presented with progressive ataxia and dysarthria along with complaints of non-development of secondary sexual characteristics and erectile dysfunction. There were complaints of intermittent diarrhea. Clinical examination revealed a pan-cerebellar syndrome with features of hypoandrogenism. No eye movement abnormalities were evident. There were signs of malabsorption. Investigations confirmed the presence of auto-antibodies found in celiac disease, and a duodenal biopsy confirmed the same. Hypoandrogenism was postulated to be due to hypergonadotropic hypogonadism which has been mentioned in a few patients of celiac disease. However, the pattern seen in our patient was of a hypogonadotropic hypogonadism. This is probably secondary to an autoimmune hypophysitis seen in some patients in the absence of other clinical manifestations. Autoantibody testing should be a diagnostic necessity in any adult with a sporadic cerebellar ataxia.

  7. The long-term control of vegetation and woody debris on channel and flood-plain evolution: insights from a paired catchment study in southeastern Australia

    Science.gov (United States)

    Brooks, Andrew P.; Brierley, Gary J.; Millar, Robert G.

    2003-03-01

    Numerous case studies have demonstrated that alluvial and semi-alluvial rivers in SE Australia have undergone dramatic metamorphosis in historical times. However, very few studies place these changes within a long-term evolutionary context. As a consequence, the magnitude of, and ultimate controls on, the changes to river form and processes are not fully appreciated. In this study, a paired catchment analysis is undertaken between two moderate-sized sand-bed rivers in East Gippsland, Australia. From the Thurra River, direct insight is gained into the predisturbance control exerted by riparian vegetation and wood in a lowland alluvial river. This river is effectively in the same condition today as it was at the time of the arrival of Europeans in Australia. In contrast, the adjacent Cann River, which has been settled by Europeans for 150 years, but was previously very similar to the Thurra River, exhibits stark differences today. Channel morphodynamics observed within the Thurra River, when coupled with historical and geomorphic evidence for the former condition of the Cann River, provide a detailed reference by which the recent changes to the Cann River are measured. Chronostratigraphic evidence from both flood plains places recent channel behavior within an evolutionary context extending well into the Pleistocene. Since European settlement, the study reach of the Cann River has experienced a 360% increase in channel depth, a 240% increase in channel slope, a 700% increase in channel capacity, and up to a 150-fold increase in the rate of lateral channel migration. The contemporary condition of the Cann River channel differs profoundly to that which has prevailed over at least the previous 27 ka. The first-order control on the historical channel metamorphosis is the removal of riparian vegetation and woody debris (WD). Numerous thresholds have been crossed as a result of historical channel changes, particularly the relationship between average length of woody debris

  8. File list: Unc.Neu.20.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  9. File list: Pol.Neu.10.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.10.AllAg.Cerebellar_Cortex mm9 RNA polymerase Neural Cerebellar Cortex SRX0...62942,SRX143820,SRX685286,SRX685285 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.10.AllAg.Cerebellar_Cortex.bed ...

  10. File list: ALL.Neu.05.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.05.AllAg.Cerebellar_Cortex mm9 All antigens Neural Cerebellar Cortex SRX112...18103 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.05.AllAg.Cerebellar_Cortex.bed ...

  11. File list: Unc.Neu.50.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  12. File list: Oth.Neu.50.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.50.AllAg.Cerebellar_Cortex mm9 TFs and others Neural Cerebellar Cortex SRX0...62939,SRX143819,SRX209672,SRX1028899,SRX968953 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.50.AllAg.Cerebellar_Cortex.bed ...

  13. File list: ALL.Neu.50.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  14. File list: Pol.Neu.50.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.50.AllAg.Cerebellar_Cortex mm9 RNA polymerase Neural Cerebellar Cortex SRX0...62942,SRX143820,SRX685286,SRX685285 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.50.AllAg.Cerebellar_Cortex.bed ...

  15. File list: Unc.Neu.10.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  16. File list: NoD.Neu.50.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  17. File list: His.Neu.20.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  18. File list: Oth.Neu.20.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.20.AllAg.Cerebellar_Cortex mm9 TFs and others Neural Cerebellar Cortex SRX0...62939,SRX143819,SRX209672,SRX1028899,SRX968953 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.20.AllAg.Cerebellar_Cortex.bed ...

  19. File list: NoD.Neu.05.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Neu.05.AllAg.Cerebellar_Cortex mm9 No description Neural Cerebellar Cortex http...://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Neu.05.AllAg.Cerebellar_Cortex.bed ...

  20. File list: Pol.Neu.05.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.05.AllAg.Cerebellar_Cortex mm9 RNA polymerase Neural Cerebellar Cortex SRX0...62942,SRX143820,SRX685285,SRX685286 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.05.AllAg.Cerebellar_Cortex.bed ...

  1. File list: Oth.Neu.10.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.10.AllAg.Cerebellar_Cortex mm9 TFs and others Neural Cerebellar Cortex SRX0...62939,SRX143819,SRX209672,SRX1028899,SRX968953 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.10.AllAg.Cerebellar_Cortex.bed ...

  2. File list: ALL.Neu.20.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.20.AllAg.Cerebellar_Cortex mm9 All antigens Neural Cerebellar Cortex SRX323...85926 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.20.AllAg.Cerebellar_Cortex.bed ...

  3. File list: ALL.Neu.10.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.10.AllAg.Cerebellar_Cortex mm9 All antigens Neural Cerebellar Cortex SRX112...18094 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.10.AllAg.Cerebellar_Cortex.bed ...

  4. File list: His.Neu.05.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.05.AllAg.Cerebellar_Cortex mm9 Histone Neural Cerebellar Cortex SRX062940,S...92,SRX1318090,SRX1318091,SRX1318089,SRX1318093,SRX1318094 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.05.AllAg.Cerebellar_Cortex.bed ...

  5. File list: Oth.Neu.05.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.05.AllAg.Cerebellar_Cortex mm9 TFs and others Neural Cerebellar Cortex SRX0...62939,SRX143819,SRX209672,SRX1028899,SRX968953 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.05.AllAg.Cerebellar_Cortex.bed ...

  6. File list: His.Neu.10.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.10.AllAg.Cerebellar_Cortex mm9 Histone Neural Cerebellar Cortex SRX323779,S...45,SRX1318089,SRX1318093,SRX1318090,SRX1318091,SRX1318094 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.10.AllAg.Cerebellar_Cortex.bed ...

  7. File list: Unc.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Neu.50.AllAg.Cerebellar_granule_neurons mm9 Unclassified Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  8. File list: Unc.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Neu.10.AllAg.Cerebellar_granule_neurons mm9 Unclassified Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  9. File list: Unc.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Neu.05.AllAg.Cerebellar_granule_neurons mm9 Unclassified Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  10. File list: DNS.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Neu.20.AllAg.Cerebellar_granule_neurons mm9 DNase-seq Neural Cerebellar granule... neurons SRX685885,SRX685882,SRX685880 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  11. File list: His.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.50.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule n...eurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  12. File list: DNS.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Neu.50.AllAg.Cerebellar_granule_neurons mm9 DNase-seq Neural Cerebellar granule... neurons SRX685885,SRX685882,SRX685880 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  13. File list: Oth.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.05.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  14. File list: ALL.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.20.AllAg.Cerebellar_granule_neurons mm9 All antigens Neural Cerebellar gran...ule neurons SRX685885,SRX685882,SRX685880 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  15. File list: DNS.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Neu.10.AllAg.Cerebellar_granule_neurons mm9 DNase-seq Neural Cerebellar granule... neurons SRX685882,SRX685880,SRX685883,SRX685885,SRX685877,SRX685878 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  16. File list: Oth.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.50.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  17. File list: His.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.10.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule n...eurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  18. File list: Pol.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.50.AllAg.Cerebellar_granule_neurons mm9 RNA polymerase Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  19. File list: Pol.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.20.AllAg.Cerebellar_granule_neurons mm9 RNA polymerase Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  20. File list: Unc.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  1. File list: ALL.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.50.AllAg.Cerebellar_granule_neurons mm9 All antigens Neural Cerebellar gran...ule neurons SRX685885,SRX685882,SRX685880 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  2. File list: ALL.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.05.AllAg.Cerebellar_granule_neurons mm9 All antigens Neural Cerebellar gran...ule neurons SRX685885,SRX685878,SRX685882,SRX685877,SRX685880,SRX685883 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  3. File list: Oth.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.10.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  4. File list: ALL.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.10.AllAg.Cerebellar_granule_neurons mm9 All antigens Neural Cerebellar gran...ule neurons SRX685882,SRX685880,SRX685883,SRX685885,SRX685877,SRX685878 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  5. File list: Oth.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.20.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  6. File list: His.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.05.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule n...eurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  7. File list: Pol.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.10.AllAg.Cerebellar_granule_neurons mm9 RNA polymerase Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  8. File list: DNS.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Neu.05.AllAg.Cerebellar_granule_neurons mm9 DNase-seq Neural Cerebellar granule... neurons SRX685885,SRX685878,SRX685882,SRX685877,SRX685880,SRX685883 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  9. File list: His.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.20.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule n...eurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  10. File list: Pol.Neu.20.AllAg.Cerebellar_Cortex [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.20.AllAg.Cerebellar_Cortex mm9 RNA polymerase Neural Cerebellar Cortex SRX0...62942,SRX143820,SRX685286,SRX685285 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.20.AllAg.Cerebellar_Cortex.bed ...

  11. Coolability of a control rod which has melted and foamed in its septifoil channel

    Energy Technology Data Exchange (ETDEWEB)

    Walkowiak, D.A.

    1991-10-01

    During a Loss of Control Rod Cooling (LCRC) event, the control rods which are in the affected septifoil can be postulated to melt. Melting of a control rod which has been irradiated creates a special concern since the entrapped gases expand rapidly and cause the melt to manifest itself initially in a foamed state. The foamed material then contacts the septifoil outer housing and the inner septifoil web material, where heat is conducted out of the foamed material. A second concern relating to the foamed melt is that its thermal conductivity is greatly reduced from that of the solid material, and also that of the non-foamed liquid. The purpose of this report is to address how, even in the presence of decreased thermal conductivity, the foamed melt may aid in cooling the control rod material.

  12. LMI & BMI technics for the design of a PI control for irrigation channels

    OpenAIRE

    Rodrigues, Mickael; Wu, Yongxin; Aberkane, Samir; Dos Santos, Valérie

    2013-01-01

    This paper considers the problem of control design for a nonlinear distributed parameter system in infinite dimension which is described by hyperbolic Partial Differential Equations (PDEs) of de Saint-Venant. For describing the dynamic of this nonlinear system over a wide operating range, the Multi-Models approach, which takes into account Linear Time Invariant (LTI) models defined around a set of operating points, has been used. By means of an Internal Model Boundary Control (IMBC), a new de...

  13. Cerebellar substrates for error correction in motor conditioning.

    Science.gov (United States)

    Gluck, M A; Allen, M T; Myers, C E; Thompson, R F

    2001-11-01

    The authors evaluate a mapping of Rescorla and Wagner's (1972) behavioral model of classical conditioning onto the cerebellar substrates for motor reflex learning and illustrate how the limitations of the Rescorla-Wagner model are just as useful as its successes for guiding the development of new psychobiological theories of learning. They postulate that the inhibitory pathway that returns conditioned response information from the cerebellar interpositus nucleus back to the inferior olive is the neural basis for the error correction learning proposed by Rescorla and Wagner (Gluck, Myers, & Thompson, 1994; Thompson, 1986). The authors' cerebellar model expects that behavioral processes described by the Rescorla-Wagner model will be localized within the cerebellum and related brain stem structures, whereas behavioral processes beyond the scope of the Rescorla-Wagner model will depend on extracerebellar structures such as the hippocampus and related cortical regions. Simulations presented here support both implications. Several novel implications of the authors' cerebellar error-correcting model are described including a recent empirical study by Kim, Krupa, and Thompson (1998), who verified that suppressing the putative error correction pathway should interfere with the Kamin (1969) blocking effect, a behavioral manifestation of error correction learning. The authors also discuss the model's implications for understanding the limits of cerebellar contributions to associative learning and how this informs our understanding of hippocampal function in conditioning. This leads to a more integrative view of the neural substrates of conditioning in which the authors' real-time circuit-level model of the cerebellum can be viewed as a generalization of the long-term memory module of Gluck and Myers' (1993) trial-level theory of cerebellar-hippocampal interaction in motor conditioning.

  14. Controlled generation of comb-like electron beams in plasma channels for polychromatic inverse Thomson γ-ray sources

    Science.gov (United States)

    Kalmykov, S. Y.; Davoine, X.; Ghebregziabher, I.; Lehe, R.; Lifschitz, A. F.; Shadwick, B. A.

    2016-03-01

    Propagating a relativistically intense, negatively chirped laser pulse (the bandwidth  >150 nm) in a plasma channel makes it possible to generate background-free, comb-like electron beams—sequences of synchronized bunches with a low phase-space volume and controlled energy spacing. The tail of the pulse, confined in the accelerator cavity (an electron density ‘bubble’), experiences periodic focusing, while the head, which is the most intense portion of the pulse, steadily self-guides. Oscillations of the cavity size cause periodic injection of electrons from the ambient plasma, creating an electron energy comb with the number of components, their mean energy, and energy spacing dependent on the channel radius and pulse length. These customizable electron beams enable the design of a tunable, all-optical source of pulsed, polychromatic γ-rays using the mechanism of inverse Thomson scattering, with up to  ˜10-5 conversion efficiency from the drive pulse in the electron accelerator to the γ-ray beam. Such a source may radiate  ˜107 quasi-monochromatic photons per shot into a microsteradian-scale cone. The photon energy is distributed among several distinct bands, each having sub-30% energy spread, with a highest energy of 12.5 MeV.

  15. Medical-Grade Channel Access and Admission Control in 802.11e EDCA for Healthcare Applications.

    Science.gov (United States)

    Son, Sunghwa; Park, Kyung-Joon; Park, Eun-Chan

    2016-01-01

    In this paper, we deal with the problem of assuring medical-grade quality of service (QoS) for real-time medical applications in wireless healthcare systems based on IEEE 802.11e. Firstly, we show that the differentiated channel access of IEEE 802.11e cannot effectively assure medical-grade QoS because of priority inversion. To resolve this problem, we propose an efficient channel access algorithm. The proposed algorithm adjusts arbitrary inter-frame space (AIFS) in the IEEE 802.11e protocol depending on the QoS measurement of medical traffic, to provide differentiated near-absolute priority for medical traffic. In addition, based on rigorous capacity analysis, we propose an admission control scheme that can avoid performance degradation due to network overload. Via extensive simulations, we show that the proposed mechanism strictly assures the medical-grade QoS and improves the throughput of low-priority traffic by more than several times compared to the conventional IEEE 802.11e. PMID:27490666

  16. Mathematical Analysis of EDCA's Performance on the Control Channel of an IEEE 802.11p WAVE Vehicular Network

    Directory of Open Access Journals (Sweden)

    Hussein T. Mouftah

    2010-01-01

    Full Text Available Wireless networks for vehicular environments are gaining increasing importance due to their ability to provide a means for stations on the roadside and radio units on board of vehicles to communicate and share safety-related information, thus reducing the probability of accidents and increasing the efficiency of the transportation system. With this goal in mind, the IEEE is currently developing the Wireless Access in Vehicular Environments (WAVE IEEE 802.11p standard. WAVE devices use the IEEE 802.11's Enhanced Distributed Channel Access (EDCA MAC protocol to compete for the transmission medium. This work proposes an analytical tool to evaluate the performance of EDCA under the specific conditions of the so-called control channel (CCH of a WAVE environment, including the particular EDCA parameter values and the fact that all safety-critical data frames are broadcasted. The protocol is modeled using Markov chains and results related to throughput, frame-error rate, buffer occupancy and delay are obtained under different traffic-load conditions. The main analysis is performed assuming that the CCH works continuously, and then an explanation is given as to the considerations that are needed to account for the fact that activity on the CCH is intermittent.

  17. Optopharmacological control of TRPC channels by coumarin-caged lipids is associated with a phototoxic membrane effect.

    Science.gov (United States)

    Tiapko, Oleksandra; Bacsa, Bernadett; de la Cruz, Gema Guedes; Glasnov, Toma; Groschner, Klaus

    2016-08-01

    Photouncaging of second messengers has been successfully employed to gain mechanistic insight of cellular signaling pathways. One of the most enigmatic processes of ion channel regulation is lipid recognition and lipid-gating of TRPC channels, which represents pivotal mechanisms of cellular Ca(2+) homeostasis. Recently, optopharmacological tools including caged lipid mediators became available, enabling an unprecedented level of temporal and spatial control of the activating lipid species within a cellular environment. Here we tested a commonly used caged ligand approach for suitability to investigate TRPC signaling at the level of membrane conductance and cellular Ca(2+) handling. We report a specific photouncaging artifact that is triggered by the cage structure coumarin at UV illumination. Electrophysiological characterization identified a light-dependent membrane effect of coumarin. UV light (340 nm) as used for photouncaging, initiated a membrane conductance specifically in the presence of coumarin as low as 30 μmol L(-1) concentrations. This conductance masked the TRPC3 conductance evoked by photouncaging, while TRPC-mediated cellular Ca(2+) responses were largely preserved. The observed light-induced membrane effects of the released caging moiety may well interfere with certain cellular functions, and prompt caution in using coumarin-caged second messengers in cellular studies.

  18. Paraneoplastic cerebellar degeneration as a marker of endometrial cancer recurrence.

    Science.gov (United States)

    Lie, Geoffrey; Morley, Thomas; Chowdhury, Muhammad

    2016-01-01

    An 84-year-old woman developed a cerebellar syndrome having undergone a total abdominal hysterectomy and bilateral salpingo-oophorectomy for endometrial cancer 1 year previously. She was found to be anti-Yo antibody positive and was diagnosed with paraneoplastic cerebellar degeneration (PCD). A subsequent positron emission tomography scan and lymph node biopsy identified recurrence of her endometrial cancer. This case illustrates how PCD can be an indicator of cancer recurrence, underlines the significance of PCD as a prompt to search for underlying malignancy, and highlights the difficulties PCD poses to the clinician in terms of diagnosis and management.

  19. cAMP control of HCN2 channel Mg2+ block reveals loose coupling between the cyclic nucleotide-gating ring and the pore.

    Directory of Open Access Journals (Sweden)

    Alex K Lyashchenko

    Full Text Available Hyperpolarization-activated cyclic nucleotide-regulated HCN channels underlie the Na+-K+ permeable IH pacemaker current. As with other voltage-gated members of the 6-transmembrane KV channel superfamily, opening of HCN channels involves dilation of a helical bundle formed by the intracellular ends of S6 albeit this is promoted by inward, not outward, displacement of S4. Direct agonist binding to a ring of cyclic nucleotide-binding sites, one of which lies immediately distal to each S6 helix, imparts cAMP sensitivity to HCN channel opening. At depolarized potentials, HCN channels are further modulated by intracellular Mg2+ which blocks the open channel pore and blunts the inhibitory effect of outward K+ flux. Here, we show that cAMP binding to the gating ring enhances not only channel opening but also the kinetics of Mg2+ block. A combination of experimental and simulation studies demonstrates that agonist acceleration of block is mediated via acceleration of the blocking reaction itself rather than as a secondary consequence of the cAMP enhancement of channel opening. These results suggest that the activation status of the gating ring and the open state of the pore are not coupled in an obligate manner (as required by the often invoked Monod-Wyman-Changeux allosteric model but couple more loosely (as envisioned in a modular model of protein activation. Importantly, the emergence of second messenger sensitivity of open channel rectification suggests that loose coupling may have an unexpected consequence: it may endow these erstwhile "slow" channels with an ability to exert voltage and ligand-modulated control over cellular excitability on the fastest of physiologically relevant time scales.

  20. Cerebellar stimulation for spastic cerebral palsy: preliminary report; on-going double blind study.

    Science.gov (United States)

    Schulman, J H; Davis, R; Nanes, M

    1987-01-01

    To date, June 1, 1986, 33 spastic cerebral palsy (CP) patients have taken part in a double blind study testing the safety and efficacy of chronic cerebellar stimulation (CCS) for reduction of spasticity and improvement in function. Seven U.S. surgical centers involving ten neurosurgeons have implanted the Neurolith 601 cerebellar stimulator supplied by Pacesetter Systems Inc. (Sylmar, CA). A pilot study was run with three patients at Stanford University (Stanford, CA) using taped-on real (strong) and dummy (weak) magnets to control the ON-OFF status. Following the pilot study, a magnetically controllable switch was placed in line between the Neurolith stimulator and the cerebellar lead to allow more reliable switching sequences for the study. The test battery included joint angle measurements (passive and active), motor performance testing, reaction time, hand dynamometry, grooved peg board placement, hand/foot tapping, and rotary pursuit testing. Testing only was done at presurgery. Testing and ON-OFF switching was performed following recovery from surgery and at one, two, and four months. After four months, the switch was left turned ON. Of the 30 patients using the implanted switch, 11 were dropped from the study and seven are still in progress. Of the 11 dropped from the study, four were due to switch problems and three were due to double blind protocol violations, i.e., the participants discovered the stimulus status. The remaining four were removed because of a broken lead, infection, or unrelated medical problems, or refusal to participate after implant. A preliminary analysis indicated that three-quarters of the patients have a demonstrable quantitative improvement during the time the stimulation was "ON." Three patients showed no significant change.