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Sample records for early cerebellar granule

  1. AMPK is activated early in cerebellar granule cells undergoing apoptosis and influences VADC1 phosphorylation status and activity.

    PubMed

    Bobba, A; Casalino, E; Amadoro, G; Petragallo, V A; Atlante, A

    2017-09-01

    The neurodegeneration of cerebellar granule cells, after low potassium induced apoptosis, is known to be temporally divided into an early and a late phase. Voltage-dependent anion channel-1 (VDAC1) protein, changing from the closed inactive state to the active open state, is central to the switch between the early and late phase. It is also known that: (i) VDAC1 can undergo phosphorylation events and (ii) AMP-activated protein kinase (AMPK), the sensor of cellular stress, may have a role in neuronal homeostasis. In the view of this, the involvement of AMPK activation and its correlation with VDAC1 status and activity has been investigated in the course of cerebellar granule cells apoptosis. The results reported in this study show that an increased level of the phosphorylated, active, isoform of AMPK occurs in the early phase, peaks at 3 h and guarantees an increase in the phosphorylation status of VDCA1, resulting in a reduced activity of this latter. However this situation is transient in nature, since, in the late phase, AMPK activation decreases as well as the level of phosphorylated VDAC1. In a less phosphorylated status, VDAC1 fully recovers its gating activity and drives cells along the death route.

  2. Exposure to 50 Hz electromagnetic radiation promote early maturation and differentiation in newborn rat cerebellar granule neurons.

    PubMed

    Lisi, A; Ciotti, M T; Ledda, M; Pieri, M; Zona, C; Mercanti, D; Rieti, S; Giuliani, L; Grimaldi, S

    2005-08-01

    The wish of this work is the study of the effect of electromagnetic (EMF) radiations at a frequency of 50 Hz on the development of cerebellar granule neurons (CGN). Granule neurons, prepared from newborn rat cerebellum (8 days after birth), were cultured after plate-seeding in the presence of EMF radiations, with the plan of characterizing their cellular and molecular biochemistry, after exposure to the electromagnetic stimulus. Five days challenge to EMF radiations showed, by the cytotoxic glutamate (Glu) pulse test, a 30% decrease of cells survival, while only 5% of mortality was reported for unexposed sample. Moreover, blocking the glutamate receptor (GluR) with the Glu competitor MK-801, no toxicity effect after CGN challenge to EMF radiations and Glu was detected. By patch-clamp recording technique, the Kainate-induced currents from 6 days old exposed CGN exhibited a significant increase with respect to control cells. Western blot and reverse transcription-polymerase chain reaction (RT-PCR) analyses show that EMF exposure of rats CGN, induces a change in both GluRs proteins and mRNAs expression with respect to control. In addition, the use of monoclonal antibody raised against neurofilament protein (NF-200) reveals an increase in NF-200 synthesis in the exposed CGN. All these results indicate that exposure to non-ionizing radiations contribute to a premature expression of GluRs reducing the life span of CGN, leading to a more rapid cell maturation. (c) 2005 Wiley-Liss, Inc.

  3. Cerebellar granule cells encode the expectation of reward

    PubMed Central

    Wagner, Mark J; Kim, Tony Hyun; Savall, Joan; Schnitzer, Mark J; Luo, Liqun

    2017-01-01

    The human brain contains ~60 billion cerebellar granule cells1, which outnumber all other neurons combined. Classical theories posit that a large, diverse population of granule cells allows for highly detailed representations of sensorimotor context, enabling downstream Purkinje cells to sense fine contextual changes2–6. Although evidence suggests a role for cerebellum in cognition7–10, granule cells are known to encode only sensory11–13 and motor14 context. Using two-photon calcium imaging in behaving mice, here we show that granule cells convey information about the expectation of reward. Mice initiated voluntary forelimb movements for delayed water reward. Some granule cells responded preferentially to reward or reward omission, whereas others selectively encoded reward anticipation. Reward responses were not restricted to forelimb movement, as a Pavlovian task evoked similar responses. Compared to predictable rewards, unexpected rewards elicited markedly different granule cell activity despite identical stimuli and licking responses. In both tasks, reward signals were widespread throughout multiple cerebellar lobules. Tracking the same granule cells over several days of learning revealed that cells with reward-anticipating responses emerged from those that responded at the start of learning to reward delivery, whereas reward omission responses grew stronger as learning progressed. The discovery of predictive, non-sensorimotor encoding in granule cells is a major departure from current understanding of these neurons and dramatically enriches contextual information available to postsynaptic Purkinje cells, with important implications for cognitive processing in the cerebellum. PMID:28321129

  4. Morphological Constraints on Cerebellar Granule Cell Combinatorial Diversity.

    PubMed

    Gilmer, Jesse I; Person, Abigail L

    2017-12-13

    Combinatorial expansion by the cerebellar granule cell layer (GCL) is fundamental to theories of cerebellar contributions to motor control and learning. Granule cells (GrCs) sample approximately four mossy fiber inputs and are thought to form a combinatorial code useful for pattern separation and learning. We constructed a spatially realistic model of the cerebellar GCL and examined how GCL architecture contributes to GrC combinatorial diversity. We found that GrC combinatorial diversity saturates quickly as mossy fiber input diversity increases, and that this saturation is in part a consequence of short dendrites, which limit access to diverse inputs and favor dense sampling of local inputs. This local sampling also produced GrCs that were combinatorially redundant, even when input diversity was extremely high. In addition, we found that mossy fiber clustering, which is a common anatomical pattern, also led to increased redundancy of GrC input combinations. We related this redundancy to hypothesized roles of temporal expansion of GrC information encoding in service of learned timing, and we show that GCL architecture produces GrC populations that support both temporal and combinatorial expansion. Finally, we used novel anatomical measurements from mice of either sex to inform modeling of sparse and filopodia-bearing mossy fibers, finding that these circuit features uniquely contribute to enhancing GrC diversification and redundancy. Our results complement information theoretic studies of granule layer structure and provide insight into the contributions of granule layer anatomical features to afferent mixing. SIGNIFICANCE STATEMENT Cerebellar granule cells are among the simplest neurons, with tiny somata and, on average, just four dendrites. These characteristics, along with their dense organization, inspired influential theoretical work on the granule cell layer as a combinatorial expander, where each granule cell represents a unique combination of inputs

  5. LXR agonist rescued the deficit in the proliferation of the cerebellar granule cells induced by dexamethasone

    SciTech Connect

    Bian, Xuting; Zhong, Hongyu; Li, Fen

    Dexamethasone (DEX) exposure during early postnatal life produces permanent neuromotor and intellectual deficits and stunts cerebellar growth. The liver X receptor (LXR) plays important roles in CNS development. However, the effects of LXR on the DEX-mediated impairment of cerebellar development remain undetermined. Thus, mice were pretreated with LXR agonist TO901317 (TO) and were later exposed to DEX to evaluate its protective effects on DEX-mediated deficit during cerebellar development. The results showed that an acute exposure of DEX on postnatal day 7 resulted in a significant impairment in cerebellar development and decreased the proliferation of granule neuron precursors in the externalmore » granule layer of cerebellum. This effect was attenuated by pretreatment with TO. We further found that the decrease in the proliferation caused by DEX occurred via up-regulation of glucocorticoid receptor and p27kip1, which could be partially prevented by LXR agonist pretreatment. Overall, our results suggest that LXR agonist pretreatment could protect against DEX-induced deficits in cerebellar development in postnatal mice and may thus be perspective recruited to counteract such GC side effects.« less

  6. Conditional induction of Math1 specifies embryonic stem cells to cerebellar granule neuron lineage and promotes differentiation into mature granule neurons.

    PubMed

    Srivastava, Rupali; Kumar, Manoj; Peineau, Stéphane; Csaba, Zsolt; Mani, Shyamala; Gressens, Pierre; El Ghouzzi, Vincent

    2013-04-01

    Directing differentiation of embryonic stem cells (ESCs) to specific neuronal subtype is critical for modeling disease pathology in vitro. An attractive means of action would be to combine regulatory differentiation factors and extrinsic inductive signals added to the culture medium. In this study, we have generated mature cerebellar granule neurons by combining a temporally controlled transient expression of Math1, a master gene in granule neuron differentiation, with inductive extrinsic factors involved in cerebellar development. Using a Tetracyclin-On transactivation system, we overexpressed Math1 at various stages of ESCs differentiation and found that the yield of progenitors was considerably increased when Math1 was induced during embryonic body stage. Math1 triggered expression of Mbh1 and Mbh2, two target genes directly involved in granule neuron precursor formation and strong expression of early cerebellar territory markers En1 and NeuroD1. Three weeks after induction, we observed a decrease in the number of glial cells and an increase in that of neurons albeit still immature. Combining Math1 induction with extrinsic factors specifically increased the number of neurons that expressed Pde1c, Zic1, and GABAα6R characteristic of mature granule neurons, formed "T-shaped" axons typical of granule neurons, and generated synaptic contacts and action potentials in vitro. Finally, in vivo implantation of Math1-induced progenitors into young adult mice resulted in cell migration and settling of newly generated neurons in the cerebellum. These results show that conditional induction of Math1 drives ESCs toward the cerebellar fate and indicate that acting on both intrinsic and extrinsic factors is a powerful means to modulate ESCs differentiation and maturation into a specific neuronal lineage. Copyright © 2012 AlphaMed Press.

  7. Proton sensitivity of rat cerebellar granule cell GABAA receptors: dependence on neuronal development

    PubMed Central

    Krishek, Belinda J; Smart, Trevor G

    2001-01-01

    The effect of GABAA receptor development in culture on the modulation of GABA-induced currents by external H+ was examined in cerebellar granule cells using whole-cell and single-channel recording. Equilibrium concentration-response curves revealed a lower potency for GABA between 11 and 12 days in vitro (DIV) resulting in a shift of the EC50 from 10.7 to 2.4 μM. For granule cells before 11 DIV, the peak GABA-activated current was inhibited at low external pH and enhanced at high pH with a pKa of 6.65. For the steady-state response, low pH was inhibitory with a pKa of 5.56. After 11 DIV, the peak GABA-activated current was largely pH insensitive; however, the steady-state current was potentiated at low pH with a pKa of 6.84. Single GABA-activated ion channels were recorded from outside-out patches of granule cell bodies. At pH 5.4-9.4, single GABA channels exhibited multiple conductance states occurring at 22-26, 16-17 and 12-14 pS. The conductance levels were not significantly altered over the time period of study, nor by changing the external H+ concentration. Two exponential functions were required to fit the open-time frequency histograms at both early (< 11 DIV) and late (> 11 DIV) development times at each H+ concentration. The short and long open time constants were unaffected either by the extracellular H+ concentration or by neuronal development. The distribution of all shut times was fitted by the sum of three exponentials designated as short, intermediate and long. At acidic pH, the long shut time constant decreased with development as did the relative contribution of these components to the overall distribution. This was concurrent with an increase in the mean probability of channel opening. In conclusion, this study demonstrates in cerebellar granule cells that external pH can either reduce, have no effect on, or enhance GABA-activated responses depending on the stage of development, possibly related to the subunit composition of the GABAA receptors

  8. LKB1 Regulates Cerebellar Development by Controlling Sonic Hedgehog-mediated Granule Cell Precursor Proliferation and Granule Cell Migration.

    PubMed

    Men, Yuqin; Zhang, Aizhen; Li, Haixiang; Jin, Yecheng; Sun, Xiaoyang; Li, Huashun; Gao, Jiangang

    2015-11-09

    The Liver Kinase B1 (LKB1) gene plays crucial roles in cell differentiation, proliferation and the establishment of cell polarity. We created LKB1 conditional knockout mice (LKB1(Atoh1) CKO) to investigate the function of LKB1 in cerebellar development. The LKB1(Atoh1) CKO mice displayed motor dysfunction. In the LKB1(Atoh1) CKO cerebellum, the overall structure had a larger volume and more lobules. LKB1 inactivation led to an increased proliferation of granule cell precursors (GCPs), aberrant granule cell migration and overproduction of unipolar brush cells. To investigate the mechanism underlying the abnormal foliation, we examined sonic hedgehog signalling (Shh) by testing its transcriptional mediators, the Gli proteins, which regulate the GCPs proliferation and cerebellar foliation during cerebellar development. The expression levels of Gli genes were significantly increased in the mutant cerebellum. In vitro assays showed that the proliferation of cultured GCPs from mutant cerebellum significantly increased, whereas the proliferation of mutant GCPs significantly decreased in the presence of a Shh inhibitor GDC-0049. Thus, LKB1 deficiency in the LKB1(Atoh1) CKO mice enhanced Shh signalling, leading to the excessive GCP proliferation and the formation of extra lobules. We proposed that LKB1 regulates cerebellar development by controlling GCPs proliferation through Shh signalling during cerebellar development.

  9. LKB1 Regulates Cerebellar Development by Controlling Sonic Hedgehog-mediated Granule Cell Precursor Proliferation and Granule Cell Migration

    PubMed Central

    Men, Yuqin; Zhang, Aizhen; Li, Haixiang; Jin, Yecheng; Sun, Xiaoyang; Li, Huashun; Gao, Jiangang

    2015-01-01

    The Liver Kinase B1 (LKB1) gene plays crucial roles in cell differentiation, proliferation and the establishment of cell polarity. We created LKB1 conditional knockout mice (LKB1Atoh1 CKO) to investigate the function of LKB1 in cerebellar development. The LKB1Atoh1 CKO mice displayed motor dysfunction. In the LKB1Atoh1 CKO cerebellum, the overall structure had a larger volume and morelobules. LKB1 inactivationled to an increased proliferation of granule cell precursors (GCPs), aberrant granule cell migration and overproduction of unipolar brush cells. To investigate the mechanism underlying the abnormal foliation, we examined sonic hedgehog signalling (Shh) by testing its transcriptional mediators, the Gli proteins, which regulate the GCPs proliferation and cerebellar foliation during cerebellar development. The expression levels of Gli genes were significantly increased in the mutant cerebellum. In vitro assays showed that the proliferation of cultured GCPs from mutant cerebellum significantly increased, whereas the proliferation of mutant GCPs significantly decreased in the presence of a Shh inhibitor GDC-0049. Thus, LKB1 deficiency in the LKB1Atoh1 CKO mice enhanced Shh signalling, leading to the excessive GCP proliferation and the formation of extra lobules. We proposed that LKB1 regulates cerebellar development by controlling GCPs proliferation through Shh signalling during cerebellar development. PMID:26549569

  10. Preterm birth disrupts cerebellar development by affecting granule cell proliferation program and Bergmann glia.

    PubMed

    Iskusnykh, Igor Y; Buddington, Randal K; Chizhikov, Victor V

    2018-08-01

    Preterm birth is a leading cause of long-term motor and cognitive deficits. Clinical studies suggest that some of these deficits result from disruption of cerebellar development, but the mechanisms that mediate cerebellar abnormalities in preterm infants are largely unknown. Furthermore, it remains unclear whether preterm birth and precocious exposure to the ex-utero environment directly disrupt cerebellar development or indirectly by increasing the probability of cerebellar injury, including that resulting from clinical interventions and protocols associated with the care of preterm infants. In this study, we analyzed the cerebellum of preterm pigs delivered via c-section at 91% term and raised for 10 days, until term-equivalent age. The pigs did not receive any treatments known or suspected to affect cerebellar development and had no evidence of brain damage. Term pigs sacrificed at birth were used as controls. Immunohistochemical analysis revealed that preterm birth did not affect either size or numbers of Purkinje cells or molecular layer interneurons at term-equivalent age. The number of granule cell precursors and Bergmann glial fibers, however, were reduced in preterm pigs. Preterm pigs had reduced proliferation but not differentiation of granule cells. qRT-PCR analysis of laser capture microdissected external granule cell layer showed that preterm pigs had a reduced expression of Ccnd1 (Cyclin D1), Ccnb1 (Cyclin B1), granule cell master regulatory transcription factor Atoh1, and signaling molecule Jag1. In vitro rescue experiments identified Jag1 as a central granule cell gene affected by preterm birth. Thus, preterm birth and precocious exposure to the ex-utero environment disrupt cerebellum by modulating expression of key cerebellar developmental genes, predominantly affecting development of granule precursors and Bergmann glia. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Discovery of Transcription Factors Novel to Mouse Cerebellar Granule Cell Development Through Laser-Capture Microdissection.

    PubMed

    Zhang, Peter G Y; Yeung, Joanna; Gupta, Ishita; Ramirez, Miguel; Ha, Thomas; Swanson, Douglas J; Nagao-Sato, Sayaka; Itoh, Masayoshi; Kawaji, Hideya; Lassmann, Timo; Daub, Carsten O; Arner, Erik; de Hoon, Michiel; Carninci, Piero; Forrest, Alistair R R; Hayashizaki, Yoshihide; Goldowitz, Dan

    2018-06-01

    Laser-capture microdissection was used to isolate external germinal layer tissue from three developmental periods of mouse cerebellar development: embryonic days 13, 15, and 18. The cerebellar granule cell-enriched mRNA library was generated with next-generation sequencing using the Helicos technology. Our objective was to discover transcriptional regulators that could be important for the development of cerebellar granule cells-the most numerous neuron in the central nervous system. Through differential expression analysis, we have identified 82 differentially expressed transcription factors (TFs) from a total of 1311 differentially expressed genes. In addition, with TF-binding sequence analysis, we have identified 46 TF candidates that could be key regulators responsible for the variation in the granule cell transcriptome between developmental stages. Altogether, we identified 125 potential TFs (82 from differential expression analysis, 46 from motif analysis with 3 overlaps in the two sets). From this gene set, 37 TFs are considered novel due to the lack of previous knowledge about their roles in cerebellar development. The results from transcriptome-wide analyses were validated with existing online databases, qRT-PCR, and in situ hybridization. This study provides an initial insight into the TFs of cerebellar granule cells that might be important for development and provide valuable information for further functional studies on these transcriptional regulators.

  12. Convergence of pontine and proprioceptive streams onto multimodal cerebellar granule cells

    PubMed Central

    Huang, Cheng-Chiu; Sugino, Ken; Shima, Yasuyuki; Guo, Caiying; Bai, Suxia; Mensh, Brett D; Nelson, Sacha B; Hantman, Adam W

    2013-01-01

    Cerebellar granule cells constitute the majority of neurons in the brain and are the primary conveyors of sensory and motor-related mossy fiber information to Purkinje cells. The functional capability of the cerebellum hinges on whether individual granule cells receive mossy fiber inputs from multiple precerebellar nuclei or are instead unimodal; this distinction is unresolved. Using cell-type-specific projection mapping with synaptic resolution, we observed the convergence of separate sensory (upper body proprioceptive) and basilar pontine pathways onto individual granule cells and mapped this convergence across cerebellar cortex. These findings inform the long-standing debate about the multimodality of mammalian granule cells and substantiate their associative capacity predicted in the Marr-Albus theory of cerebellar function. We also provide evidence that the convergent basilar pontine pathways carry corollary discharges from upper body motor cortical areas. Such merging of related corollary and sensory streams is a critical component of circuit models of predictive motor control. DOI: http://dx.doi.org/10.7554/eLife.00400.001 PMID:23467508

  13. Mitotic events in cerebellar granule progenitor cells that expand cerebellar surface area are critical for normal cerebellar cortical lamination in mice.

    PubMed

    Chang, Joshua C; Leung, Mark; Gokozan, Hamza Numan; Gygli, Patrick Edwin; Catacutan, Fay Patsy; Czeisler, Catherine; Otero, José Javier

    2015-03-01

    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 stereologic principles. We demonstrate that, during the proliferative phase of the external granular 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 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 intermitotic times for β events on a per-cell basis in postnatal 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 stereologic studies.

  14. Electrophysiological evidence for glial-subtype glutamate transporter functional expression in rat cerebellar granule neurons.

    PubMed

    Mafra, R A; Leão, R M; Beirão, P S L; Cruz, J S

    2003-07-01

    A glutamate-sensitive inward current (Iglu) is described in rat cerebellar granule neurons and related to a glutamate transport mechanism. We examined the features of Iglu using the patch-clamp technique. In steady-state conditions the Iglu measured 8.14 1.9 pA. Iglu was identified as a voltage-dependent inward current showing a strong rectification at positive potentials. L-Glutamate activated the inward current in a dose-dependent manner, with a half-maximal effect at about 18 M and a maximum increase of 51.2 4.4%. The inward current was blocked by the presence of dihydrokainate (0.5 mM), shown by others to readily block the GLT1 isoform. We thus speculate that Iglu could be attributed to the presence of a native glutamate transporter in cerebellar granule neurons.

  15. 4-aminopyridine, a Kv channel antagonist, prevents apoptosis of rat cerebellar granule neurons.

    PubMed

    Hu, Chang-Long; Liu, Zheng; Zeng, Xi-Min; Liu, Zi-Qiang; Chen, Xian-Hua; Zhang, Zhi-Hong; Mei, Yan-Ai

    2006-09-01

    Compelling evidence indicates that excessive potassium (K+) efflux and intracellular K+ depletion are the key early steps in apoptosis. Previously, we reported that apoptosis of cerebellar granule neurons induced by incubation in low-K+ (5 mM) and serum-free medium was associated with an increase in A-type transient inactivation of K+ channel current (IA) amplitude and modulation of channels' gating properties. Here, we showed that a classic K+ channel blocker, 4-aminopyradine (4-AP), significantly inhibited IA amplitude in a concentration-dependent manner (reduction of current by 10 microM and 10 mM 4-AP was 11.4+/-1.3% and 72.2+/-3.3%, respectively). Moreover, 4-AP modified the steady-state activation and inactivation kinetics of IA channels, such that the activation and inactivation curves were shifted to the right about 20 mV and 17 mV, respectively. Fluorescence staining showed that 4-AP dramatically increased the viability of cells undergoing apoptosis in a dose-dependent manner. That is, while 5 mM 4-AP was present, cell viability was 84.9+/-5.2%. Consistent with the cell viability analysis, internucleosomal DNA fragmentation by gel electrophoresis analysis showed that 5 mM 4-AP also protected against neuronal apoptosis. Furthermore, 4-AP significantly inhibited cytochrome c release and caspase-3 activity induced by low-K+/serum-free incubation. Finally, current-clamp analysis indicated that 5 mM 4-AP did not significantly depolarize the membrane potential. These results suggest that 4-AP has robust neuroprotective effects on apoptotic granule cells. The neuroprotective effect of 4-AP is likely not due to membrane depolarization, but rather that 4-AP may modulate the gating properties of IA channels in an anti-apoptotic manner.

  16. Changes in biochemical processes in cerebellar granule cells of mice exposed to methylmercury.

    PubMed

    Bellum, Sairam; Bawa, Bhupinder; Thuett, Kerry A; Stoica, Gheorghe; Abbott, Louise C

    2007-01-01

    At postnatal day 34, male and female C57BL/6J mice were exposed orally once a day to a total of five doses totaling 1.0 or 5.0 mg/kg of methylmercuric chloride or sterile deionized water in moistened rodent chow. Eleven days after the last dose cerebellar granule cells were acutely isolated to measure reactive oxygen species (ROS) levels and mitochondrial membrane potential using CM-H(2)DCFDA and TMRM dyes, respectively. For visualizing intracellular calcium ion distribution using transmission electron microscopy, mice were perfused 11 days after the last dose of methylmercury (MeHg) using the oxalate-pyroantimonate method. Cytosolic and mitochondrial protein fractions from acutely isolated granule cells were analyzed for cytochrome c content using Western blot analysis. Histochemistry (Fluoro-Jade dye) and immunohistochemistry (activated caspase 3) was performed on frozen serial cerebellar sections to label granule cell death and activation of caspase 3, respectively. Granule cells isolated from MeHg-treated mice showed elevated ROS levels and decreased mitochondrial membrane potential when compared to granule cells from control mice. Electron photomicrographs of MeHg-treated granule cells showed altered intracellular calcium ion homeostasis ([Ca(2+)](i)) when compared to control granule cells. However, in spite of these subcellular changes and moderate relocalization of cytochrome c into the cytosol, the concentrations of MeHg used in this study did not produce significant neuronal cell death/apoptosis at the time point examined, as evidenced by Fluoro-Jade and activated caspase 3 immunostaining, respectively. These results demonstrate that short-term in vivo exposure to total doses of 1.0 and 5.0 mg/kg MeHg through the most common exposure route (oral) can result in significant subcellular changes that are not accompanied by overt neuronal cell death.

  17. Gap Junction Modulation of Low-Frequency Oscillations in the Cerebellar Granule Cell Layer.

    PubMed

    Robinson, Jennifer Claire; Chapman, C Andrew; Courtemanche, Richard

    2017-08-01

    Local field potential (LFP) oscillations in the granule cell layer (GCL) of the cerebellar cortex have been identified previously in the awake rat and monkey during immobility. These low-frequency oscillations are thought to be generated through local circuit interactions between Golgi cells and granule cells within the GCL. Golgi cells display rhythmic firing and pacemaking properties, and also are electrically coupled through gap junctions within the GCL. Here, we tested if gap junctions in the rat cerebellar cortex contribute to the generation of LFP oscillations in the GCL. We recorded LFP oscillations under urethane anesthesia, and examined the effects of local infusion of gap junction blockers on 5-15 Hz oscillations. Local infusion of the gap junction blockers carbenoxolone and mefloquine resulted in significant decreases in the power of oscillations over a 30-min period, but the power of oscillations was unchanged in control experiments following vehicle injections. In addition, infusion of gap junction blockers had no significant effect on multi-unit activity, suggesting that the attenuation of low-frequency oscillations was likely due to reductions in electrical coupling rather than a decreased excitability within the granule cell layer. Our results indicate that electrical coupling among the Golgi cell networks in the cerebellar cortex contributes to the local circuit mechanisms that promote the occurrence of GCL LFP slow oscillations in the anesthetized rat.

  18. Aryl Hydrocarbon Receptor (AhR) Deletion in Cerebellar Granule Neuron Precursors Impairs Neurogenesis

    PubMed Central

    Dever, Daniel P.; Adham, Zachariah O.; Thompson, Bryan; Genestine, Matthieu; Cherry, Jonathan; Olschowka, John A.; DiCicco-Bloom, Emanuel; Opanashuk, Lisa A.

    2015-01-01

    The aryl hydrocarbon receptor (AhR) is a ligand-activated member of the basic-helix-loop-helix (bHLH)/PER-ARNT-SIM(PAS) transcription factor superfamily that also mediates the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Increasing evidence suggests that AhR influences the development of many tissues, including the central nervous system. Our previous studies suggest that sustained AhR activation by TCDD and/or AhR deletion disrupts cerebellar granule neuron precursor (GNP) development. In the current study, to determine whether endogenous AhR controls GNP development in a cell autonomous manner, we created a GNP-specific AhR deletion mouse, AhRfx/fx/Math1CRE/+ (AhR CKO). Selective AhR deletion in GNPs produced abnormalities in proliferation and differentiation. Specifically, fewer GNPs were engaged in S-phase, as demonstrated by ~25% reductions in thymidine (in vitro) and BrdU (in vivo) incorporation. Furthermore, total granule neuron numbers in the IGL at PND21 and PND60 were diminished in AhR CKO mice compared to controls. On the other hand, differentiation was enhanced, including ~40% increase in neurite outgrowth and 50% increase in GABARα6 receptor expression in deletion mutants. Our results suggest that AhR activity plays a role in regulating granule neuron number and differentiation, possibly by coordinating this GNP developmental transition. These studies provide novel insights for understanding the normal roles of AhR signaling during cerebellar granule cell neurogenesis, and may have important implications for the effects of environmental factors in cerebellar dysgenesis. PMID:26243376

  19. A low-density culture method of cerebellar granule neurons with paracrine support applicable for the study of neuronal morphogenesis.

    PubMed

    Kubota, Kenta; Seno, Takeshi; Konishi, Yoshiyuki

    2013-11-20

    Cerebellar granule neuronal cultures have been used to study the molecular mechanisms underlying neuronal functions, including neuronal morphogenesis. However, a limitation of this system is the difficulty to analyze isolated neurons because these are required to be maintained at a high density. Therefore, in the present study, we aimed to develop a simple and cost-effective method for culturing low-density cerebellar granule neurons. Cerebellar granule cells at two different densities (low- and high-density) were co-cultivated in order for the low-density culture to be supported by the paracrine signals from the high-density culture. This method enabled morphology analysis of isolated cerebellar granule neurons without astrocytic feeder cultures or supplements such as B27. Using this method, we investigated the function of a polarity factor. Studies using hippocampal neurons suggested that glycogen synthase kinase-3 (GSK-3) is an essential regulator of neuronal polarity, and inhibition of GSK-3 results in the formation of multiple axons. Pharmacological inhibitors for GSK-3 (6-bromoindirubin-3'-oxime and lithium chloride) did not cause the formation of multiple axons of cerebellar granule neurons but significantly reduced their length. Consistent results were obtained by introducing kinase-dead form of GSK-3 beta (K85A). These results indicated that GSK-3 is not directly involved in the control of neuronal polarity in cerebellar granule neurons. Overall, this study provides a simple method for culturing low-density cerebellar granule neurons and insights in to the neuronal-type dependent function of GSK-3 in neuronal morphogenesis. © 2013 Elsevier B.V. All rights reserved.

  20. Intrauterine Growth Restriction Affects Cerebellar Granule Cells in the Developing Guinea Pig Brain.

    PubMed

    Tolcos, Mary; McDougall, Annie; Shields, Amy; Chung, Yoonyoung; O'Dowd, Rachael; Turnley, Ann; Wallace, Megan; Rees, Sandra

    2018-01-01

    Intrauterine growth restriction (IUGR) can lead to adverse neurodevelopmental sequelae in postnatal life. However, the effects of IUGR on the cerebellum are still to be fully elucidated. A major determinant of growth and development of the cerebellum is proliferation and subsequent migration of cerebellar granule cells. Our objective was to determine whether IUGR, induced by chronic placental insufficiency (CPI) in guinea pigs, results in abnormal cerebellar development due to deficits suggestive of impaired granule cell proliferation and/or migration. CPI was induced by unilateral ligation of the uterine artery at mid-gestation, producing growth-restricted (GR) foetuses at 52 and 60 days of gestation (dg), and neonates at 1 week postnatal age (term approx. 67 dg). Controls were from sham-operated animals. In GR foetuses compared with controls at 52 dg, the external granular layer (EGL) width and internal granular layer (IGL) area were similar. In GR foetuses compared with controls at 60 dg: (a) the EGL width was greater (p < 0.005); (b) the IGL area was smaller (p < 0.005); (c) the density of Ki67-negative (postmitotic) granule cells in the EGL was greater (p < 0.01); (d) the somal area of Purkinje cells was reduced (p < 0.005), and (e) the linear density of Bergmann glia was similar. The EGL width in GR foetuses at 60 dg was comparable to that of 52 dg control and GR foetuses. The pattern of p27-immunoreactivity in the EGL was the inverse of Ki67-immunoreactivity at both foetal ages; there was no difference between control and GR foetuses at either age in the width of p27-immunoreactivity, or in the percentage of the EGL width that it occupied. In the molecular layer of GR neonates compared with controls there was an increase in the areal density of granule cells (p < 0.05) and in the percentage of migrating to total number of granule cells (p < 0.01) at 1 week but not at 60 dg (p > 0.05). Thus, we found no specific evidence that IUGR affects granule cell

  1. Shp2 Acts Downstream of SDF-1α/CXCR4 in Guiding Granule Cell Migration During Cerebellar Development

    PubMed Central

    Hagihara, Kazuki; Zhang, Eric E.; Ke, Yue-Hai; Liu, Guofa; Liu, Jan-Jan; Rao, Yi; Feng, Gen-Sheng

    2009-01-01

    Shp2 is a non-receptor protein tyrosine phosphatase containing two Src homology 2 (SH2) domains that is implicated in intracellular signaling events controlling cell proliferation, differentiation and migration. To examine the role of Shp2 in brain development, we created mice with Shp2 selectively deleted in neural stem/progenitor cells. Homozygous mutant mice exhibited early postnatal lethality with defects in neural stem cell self-renewal and neuronal/glial cell fate specification. Here we report a critical role of Shp2 in guiding neuronal cell migration in the cerebellum. In homozygous mutants, we observed reduced and less foliated cerebellum, ectopic presence of external granule cells and mispositioned Purkinje cells, a phenotype very similar to that of mutant mice lacking either SDF-1α or CXCR4. Consistently, Shp2-deficient granule cells failed to migrate toward SDF-1α in an in vitro cell migration assay, and SDF-1α treatment triggered a robust induction of tyrosyl phosphorylation on Shp2. Together, these results suggest that although Shp2 is involved in multiple signaling events during brain development, a prominent role of the phosphatase is to mediate SDF-1α/CXCR4 signal in guiding cerebellar granule cell migration. PMID:19635473

  2. ROS Produced by NOX2 Controls In Vitro Development of Cerebellar Granule Neurons Development

    PubMed Central

    Olguín-Albuerne, Mauricio

    2015-01-01

    Reactive oxygen species (ROS) act as signaling molecules that regulate nervous system physiology. ROS have been related to neural differentiation, neuritogenesis, and programmed cell death. Nevertheless, little is known about the mechanisms involved in the regulation of ROS during neuronal development. In this study, we evaluated the mechanisms by which ROS are regulated during neuronal development and the implications of these molecules in this process. Primary cultures of cerebellar granule neurons (CGN) were used to address these issues. Our results show that during the first 3 days of CGN development in vitro (days in vitro; DIV), the levels of ROS increased, reaching a peak at 2 and 3 DIV under depolarizing (25 mM KCl) and nondepolarizing (5 mM KCl) conditions. Subsequently, under depolarizing conditions, the ROS levels markedly decreased, but in nondepolarizing conditions, the ROS levels increased gradually. This correlated with the extent of CGN maturation. Also, antioxidants and NADPH-oxidases (NOX) inhibitors reduced the expression of Tau and MAP2. On the other hand, the levels of glutathione markedly increased at 1 DIV. We inferred that the ROS increase at this time is critical for cell survival because glutathione depletion leads to axonal degeneration and CGN death only at 2 DIV. During the first 3 DIV, NOX2 was upregulated and expressed in filopodia and growth cones, which correlated with the hydrogen peroxide (H2O2) distribution in the cell. Finally, NOX2 KO CGN showed shorter neurites than wild-type CGN. Taken together, these results suggest that the regulation of ROS is critical during the early stages of CGN development. PMID:25873309

  3. Persistent Nav1.6 current at axon initial segments tunes spike timing of cerebellar granule cells

    PubMed Central

    Osorio, Nancy; Cathala, Laurence; Meisler, Miriam H; Crest, Marcel; Magistretti, Jacopo; Delmas, Patrick

    2010-01-01

    Cerebellar granule (CG) cells generate high-frequency action potentials that have been proposed to depend on the unique properties of their voltage-gated ion channels. To address the in vivo function of Nav1.6 channels in developing and mature CG cells, we combined the study of the developmental expression of Nav subunits with recording of acute cerebellar slices from young and adult granule-specific Scn8a KO mice. Nav1.2 accumulated rapidly at early-formed axon initial segments (AISs). In contrast, Nav1.6 was absent at early postnatal stages but accumulated at AISs of CG cells from P21 to P40. By P40–P65, both Nav1.6 and Nav1.2 co-localized at CG cell AISs. By comparing Na+ currents in mature CG cells (P66–P74) from wild-type and CG-specific Scn8a KO mice, we found that transient and resurgent Na+ currents were not modified in the absence of Nav1.6 whereas persistent Na+ current was strongly reduced. Action potentials in conditional Scn8a KO CG cells showed no alteration in threshold and overshoot, but had a faster repolarization phase and larger post-spike hyperpolarization. In addition, although Scn8a KO CG cells kept their ability to fire action potentials at very high frequency, they displayed increased interspike-interval variability and firing irregularity in response to sustained depolarization. We conclude that Nav1.6 channels at axon initial segments contribute to persistent Na+ current and ensure a high degree of temporal precision in repetitive firing of CG cells. PMID:20173079

  4. Procaspase-activating compound 1 induces a caspase-3-dependent cell death in cerebellar granule neurons

    SciTech Connect

    Aziz, Gulzeb; Akselsen, Oyvind W.; Hansen, Trond V.

    2010-09-15

    Procaspase-activating compound 1, PAC-1, has been introduced as a direct activator of procaspase-3 and has been suggested as a therapeutic agent against cancer. Its activation of procaspase-3 is dependent on the chelation of zinc. We have tested PAC-1 and an analogue of PAC-1 as zinc chelators in vitro as well as their ability to activate caspase-3 and induce cell death in chicken cerebellar granule neuron cultures. These neurons are non-dividing, primary cells with normal caspase-3. The results reported herein show that PAC-1 chelates zinc, activates procaspase-3, and leads to caspase-3-dependent cell death in neurons, as the specific caspase-3-inhibitor Ac-DEVD-cmk inhibitedmore » both the caspase-3 activity and cell death. Thus, chicken cerebellar granule neurons is a suitable model to study mechanisms of interference with apoptosis of PAC-1 and similar compounds. Furthermore, the present study also raises concern about potential neurotoxicity of PAC-1 if used in cancer therapy.« less

  5. Model cerebellar granule cells can faithfully transmit modulated firing rate signals

    PubMed Central

    Rössert, Christian; Solinas, Sergio; D'Angelo, Egidio; Dean, Paul; Porrill, John

    2014-01-01

    A crucial assumption of many high-level system models of the cerebellum is that information in the granular layer is encoded in a linear manner. However, granule cells are known for their non-linear and resonant synaptic and intrinsic properties that could potentially impede linear signal transmission. In this modeling study we analyse how electrophysiological granule cell properties and spike sampling influence information coded by firing rate modulation, assuming no signal-related, i.e., uncorrelated inhibitory feedback (open-loop mode). A detailed one-compartment granule cell model was excited in simulation by either direct current or mossy-fiber synaptic inputs. Vestibular signals were represented as tonic inputs to the flocculus modulated at frequencies up to 20 Hz (approximate upper frequency limit of vestibular-ocular reflex, VOR). Model outputs were assessed using estimates of both the transfer function, and the fidelity of input-signal reconstruction measured as variance-accounted-for. The detailed granule cell model with realistic mossy-fiber synaptic inputs could transmit information faithfully and linearly in the frequency range of the vestibular-ocular reflex. This was achieved most simply if the model neurons had a firing rate at least twice the highest required frequency of modulation, but lower rates were also adequate provided a population of neurons was utilized, especially in combination with push-pull coding. The exact number of neurons required for faithful transmission depended on the precise values of firing rate and noise. The model neurons were also able to combine excitatory and inhibitory signals linearly, and could be replaced by a simpler (modified) integrate-and-fire neuron in the case of high tonic firing rates. These findings suggest that granule cells can in principle code modulated firing-rate inputs in a linear manner, and are thus consistent with the high-level adaptive-filter model of the cerebellar microcircuit. PMID:25352777

  6. Utilization of alpha-ketoglutarate as a precursor for transmitter glutamate in cultured cerebellar granule cells.

    PubMed

    Peng, L A; Schousboe, A; Hertz, L

    1991-01-01

    Alpha-ketoglutarate together with an amino group donor (alanine) was shown to be able to serve as a precursor for the glutamate pool which is released by potassium-induced depolarization (i.e., transmitter glutamate) in cerebellar granule cells. However, these compounds could not be utilized as precursors for intracellular glutamate or for release of transmitter aspartate. The formation of transmitter glutamate was inhibited by the transamination inhibitor aminooxyacetic acid but not by phenylsuccinate, an inhibitor of the dicarboxylate carrier in the mitochondrial membrane. Both of these inhibitors have previously been found to inhibit synthesis of transmitter glutamate from glutamine. The results support the hypothesis that alpha-ketoglutarate and alanine undergo transmination in the cytosol to form pyruvate and glutamate, and that this glutamate pool is available for transmitter release of glutamate but does not constitute the major intracellular pool of glutamate.

  7. Neurotoxic effects of indocyanine green -cerebellar granule cell culture viability study

    PubMed Central

    Toczylowska, Beata; Zieminska, Elzbieta; Goch, Grazyna; Milej, Daniel; Gerega, Anna; Liebert, Adam

    2014-01-01

    The aim of this study was to examine neurotoxicity indocyanine green (ICG). We assessed viability of primary cerebellar granule cell culture (CGC) exposed to ICG to test two mechanisms that could be the first triggers causing neuronal toxicity: imbalance in calcium homeostasis and the degree of oligomerization of ICG molecules. We have observed this imbalance in CGC after exposure to 75-125μΜ ICG and dose and application sequence dependent protective effect of Gadovist on surviving neurons in vitro when used with ICG. Spectroscopic studies suggest the major cause of toxicity of the ICG is connected with oligomers formation. ICG at concentration of 25 μM (which is about 4 times higher than the highest concentration of ICG in the brain applied in in-vivo human studies) is not neurotoxic in the cell culture. PMID:24688815

  8. Profilin1 activity in cerebellar granule neurons is required for radial migration in vivo

    PubMed Central

    Kullmann, Jan A; Wickertsheim, Ines; Minnerup, Lara; Costell, Mercedes; Friauf, Eckhard; Rust, Marco B

    2015-01-01

    Neuron migration defects are an important aspect of human neuropathies. The underlying molecular mechanisms of such migration defects are largely unknown. Actin dynamics has been recognized as an important determinant of neuronal migration, and we recently found that the actin-binding protein profilin1 is relevant for radial migration of cerebellar granule neurons (CGN). As the exploited brain-specific mutants lacked profilin1 in both neurons and glial cells, it remained unknown whether profilin1 activity in CGN is relevant for CGN migration in vivo. To test this, we capitalized on a transgenic mouse line that expresses a tamoxifen-inducible Cre variant in CGN, but no other cerebellar cell type. In these profilin1 mutants, the cell density was elevated in the molecular layer, and ectopic CGN occurred. Moreover, 5-bromo-2′-deoxyuridine tracing experiments revealed impaired CGN radial migration. Hence, our data demonstrate the cell autonomous role of profilin1 activity in CGN for radial migration. PMID:25495756

  9. The effect of cyclic phosphatidic acid on the proliferation and differentiation of mouse cerebellar granule precursor cells during cerebellar development.

    PubMed

    Konakazawa, Misa; Gotoh, Mari; Murakami-Murofushi, Kimiko; Hamano, Ayana; Miyamoto, Yasunori

    2015-07-21

    The proliferation and differentiation of cerebellar granule cell precursors (GCPs) are highly regulated spatiotemporally during development. We focused on cyclic phosphatidic acid (cPA) as a lipid mediator with a cyclic phosphate group as a regulatory factor of GCPs. While its structure is similar to that of lysophosphatidic acid (LPA), its function is very unique. cPA is known to be present in the cerebellum at high levels, but its function has not been fully elucidated. In this study, we examined the role of cPA on the proliferation and differentiation of GCPs. A cell cycle analysis of GCPs revealed that cPA reduced the number of phospho-histone H3 (Phh3)-positive cells and bromodeoxy uridine (BrdU)-incorporated cells and increased an index of the cell cycle exit. We next analyzed the effect of cPA on GCP differentiation using Tuj1 as a neuronal marker of final differentiation. The results show that cPA increased the number of Tuj1-positive cells. Further analysis of the proliferation of GCPs showed that cPA suppressed Sonic hedgehog (Shh)-dependent proliferation, but did not suppress insulin-like growth factor-1 (IGF-1)-dependent proliferation. P2Y5 (LPA6), an LPA receptor, is highly expressed in GCPs. The knockdown of P2Y5 suppressed the inhibitory effect of cPA on the proliferation of GCPs, suggesting that P2Y5 is a candidate receptor for cPA. Thus, cPA suppresses the Shh-dependent proliferation of GCPs and promotes the differentiation of GCPs through P2Y5. These results demonstrate that cPA plays a critical role in the development of GCPs. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Early Disruption of Extracellular Pleiotrophin Distribution Alters Cerebellar Neuronal Circuit Development and Function.

    PubMed

    Hamza, M M; Rey, S A; Hilber, P; Arabo, A; Collin, T; Vaudry, D; Burel, D

    2016-10-01

    The cerebellum is a structure of the central nervous system involved in balance, motor coordination, and voluntary movements. The elementary circuit implicated in the control of locomotion involves Purkinje cells, which receive excitatory inputs from parallel and climbing fibers, and are regulated by cerebellar interneurons. In mice as in human, the cerebellar cortex completes its development mainly after birth with the migration, differentiation, and synaptogenesis of granule cells. These cellular events are under the control of numerous extracellular matrix molecules including pleiotrophin (PTN). This cytokine has been shown to regulate the morphogenesis of Purkinje cells ex vivo and in vivo via its receptor PTPζ. Since Purkinje cells are the unique output of the cerebellar cortex, we explored the consequences of their PTN-induced atrophy on the function of the cerebellar neuronal circuit in mice. Behavioral experiments revealed that, despite a normal overall development, PTN-treated mice present a delay in the maturation of their flexion reflex. Moreover, patch clamp recording of Purkinje cells revealed a significant increase in the frequency of spontaneous excitatory postsynaptic currents in PTN-treated mice, associated with a decrease of climbing fiber innervations and an abnormal perisomatic localization of the parallel fiber contacts. At adulthood, PTN-treated mice exhibit coordination impairment on the rotarod test associated with an alteration of the synchronization gait. Altogether these histological, electrophysiological, and behavior data reveal that an early ECM disruption of PTN composition induces short- and long-term defaults in the establishment of proper functional cerebellar circuit.

  11. Characterization of Ca2+ channel currents in cultured rat cerebellar granule neurones.

    PubMed

    Pearson, H A; Sutton, K G; Scott, R H; Dolphin, A C

    1995-02-01

    1. High-threshold voltage-gated calcium channel currents (IBa) were studied in cultured rat cerebellar granule neurones using the whole-cell patch clamp technique with 10 mM Ba2+ as the charge carrier. The putative P-type component of whole-cell current was characterized by utilizing the toxin omega-agatoxin IVA (omega-Aga IVA) in combination with other blockers. 2. omega-Aga IVA (100 nM) inhibited the high voltage-activated (HVA) IBa by 40.9 +/- 3.4% (n = 27), and the dissociation constant Kd was 2.7 nM. Maximal inhibition occurred within a 2-3 min time course, and was irreversible. The isolated omega-Aga IVA-sensitive current was non-inactivating. 3. omega-Aga IVA exhibited overlapping selectivity with both N- and L-channel blockers; omega-conotoxin GVIA (omega-CTX GVIA) (1 microM) and the dihydropyridine (-)-202-709 (1 microM), respectively. Together these toxins reduced the omega-Aga IVA-sensitive component to just 4.5 +/- 1.4% (n = 3). Thus only a small proportion of the current can be unequivocally attributed to P-type current. Inhibition of the HVA IBa by omega-Aga IA also reduced the proportion of omega-Aga IVA-sensitive current to 28.0 +/- 3.2% (n = 3). 4. Application of omega-Aga IVA and a synthetic form of funnel-web toxin, N-(7-amino-4-azaheptyl)-L-argininamide (sFTX-3.3; 10 microM), produced an additive block of the HVA IBa. Consequently these two toxins do not act on the same channel in cerebellar granule neurones. 5. omega-Aga IVA inhibition of low voltage-activated (LVA) IBa was studied in the ND7-23 neuronal cell line. omega-Aga IVA (100 nM) reduced the LVA current by 41.3 +/- 3.2% (n = 17) in a fully reversible manner with no shift in the steady-state inactivation of the channel. 6. A component of current insensitive to N-, L- and P-channel blockers remained unclassified in all our studies. This component, and also that remaining following block by omega-Aga IVA and omega-Aga IA, exhibited relatively rapid, although incomplete, inactivation

  12. Ethanol impairs activation of retinoic acid receptors in cerebellar granule cells in a rodent model of fetal alcohol spectrum disorders.

    PubMed

    Kumar, Ambrish; Singh, Chandra K; DiPette, Donald D; Singh, Ugra S

    2010-05-01

    Ethanol is the main addictive and neurotoxic constituent of alcohol. Ethanol exposure during embryonic development causes dysfunction of the central nervous system (CNS) and leads to fetal alcohol spectrum disorders. The cerebellum is one of the CNS regions that are particularly vulnerable to ethanol toxic effects. Retinoic acid (RA) is a physiologically active metabolite of vitamin A that is locally synthesized in the cerebellum. Studies have shown that RA is required for neuronal development, but it remains unknown if ethanol impairs RA signaling and thus induces neuronal malformations. In this study, we tested the hypothesis that ethanol impairs the expression and activation of RA receptors in cerebellum and in cerebellar granule cells. The cerebellum of ethanol unexposed and exposed pups was used to study the expression of retinoic acid receptors (RARs or RXRs) by immunohistochemistry and by Western blot analysis. We also studied the effect of ethanol on expression of RA receptors in the cerebellar granule cells. Activation of RA receptors (DNA-binding activities) in response to high-dose ethanol was determined by electrophoretic mobility shift and supershift assays. Findings from these studies demonstrated that ethanol exposure reduced the expression of RARalpha/gamma while it increased the expression of RXRalpha/gamma in the cerebellum and in cerebellar granule neurons. Immuno-histological studies further strengthened the expression pattern of RA receptors in response to ethanol. The DNA-binding activity of RARs was reduced, while DNA-binding activity of RXRs was increased in response to ethanol exposure. For the first time, our studies have demonstrated that high-dose ethanol affects the expression and activation of RA receptors, which could impair the signaling events and induce harmful effects on the survival and differentiation of cerebellar granule cells. Taken together, these findings could provide insight into the treatment options for brain defects

  13. Simulating spinal border cells and cerebellar granule cells under locomotion--a case study of spinocerebellar information processing.

    PubMed

    Spanne, Anton; Geborek, Pontus; Bengtsson, Fredrik; Jörntell, Henrik

    2014-01-01

    The spinocerebellar systems are essential for the brain in the performance of coordinated movements, but our knowledge about the spinocerebellar interactions is very limited. Recently, several crucial pieces of information have been acquired for the spinal border cell (SBC) component of the ventral spinocerebellar tract (VSCT), as well as the effects of SBC mossy fiber activation in granule cells of the cerebellar cortex. SBCs receive monosynaptic input from the reticulospinal tract (RST), which is an important driving system under locomotion, and disynaptic inhibition from Ib muscle afferents. The patterns of activity of RST neurons and Ib afferents under locomotion are known. The activity of VSCT neurons under fictive locomotion, i.e. without sensory feedback, is also known, but there is little information on how these neurons behave under actual locomotion and for cerebellar granule cells receiving SBC input this is completely unknown. But the available information makes it possible to simulate the interactions between the spinal and cerebellar neuronal circuitries with a relatively large set of biological constraints. Using a model of the various neuronal elements and the network they compose, we simulated the modulation of the SBCs and their target granule cells under locomotion and hence generated testable predictions of their general pattern of modulation under this condition. This particular system offers a unique opportunity to simulate these interactions with a limited number of assumptions, which helps making the model biologically plausible. Similar principles of information processing may be expected to apply to all spinocerebellar systems.

  14. Endogenous bax translocation in SH-SY5Y human neuroblastoma cells and cerebellar granule neurons undergoing apoptosis.

    PubMed

    McGinnis, K M; Gnegy, M E; Wang, K K

    1999-05-01

    Changes at the mitochondria are an early, required step in apoptosis in various cell types. We used western blot analysis to demonstrate that the proapoptotic protein Bax translocated from the cytosolic to the mitochondrial fraction in SH-SY5Y human neuroblastoma cells undergoing staurosporine- or EGTA-mediated apoptosis. Levels of mitochondrial Bax increased 15 min after staurosporine treatment. In EGTA-treated cells, increased levels of mitochondrial Bax were seen at 4 h, consistent with a slower onset of apoptosis in EGTA versus staurosporine treatments. We also demonstrate the concomitant translocation of cytochrome c from the mitochondrial to the cytosolic fractions. We correlated these translocations with changes in caspase-3-like activity. An increase in caspase-3-like activity was evident 2 h after staurosporine treatment. Inhibition of the mitochondrial permeability transition had no effect on Bax translocation or caspase-3-like activity in staurosporine-treated SH-SY5Y cells. In primary cultures of cerebellar granule neurons undergoing low K(+)-mediated apoptosis, Bax translocation to the mitochondrial fraction was evident at 3 h. Cytochrome c release into the cytosol was not significant until 8 h after treatment. These data support a model of apoptosis in which Bax acts directly at the mitochondria to allow the release of cytochrome c.

  15. Drebrin-mediated microtubule–actomyosin coupling steers cerebellar granule neuron nucleokinesis and migration pathway selection

    PubMed Central

    Trivedi, Niraj; Stabley, Daniel R.; Cain, Blake; Howell, Danielle; Laumonnerie, Christophe; Ramahi, Joseph S.; Temirov, Jamshid; Kerekes, Ryan A.; Gordon-Weeks, Phillip R.; Solecki, David J.

    2017-01-01

    Neuronal migration from a germinal zone to a final laminar position is essential for the morphogenesis of neuronal circuits. While it is hypothesized that microtubule–actomyosin crosstalk is required for a neuron's ‘two-stroke' nucleokinesis cycle, the molecular mechanisms controlling such crosstalk are not defined. By using the drebrin microtubule–actin crosslinking protein as an entry point into the cerebellar granule neuron system in combination with super-resolution microscopy, we investigate how these cytoskeletal systems interface during migration. Lattice light-sheet and structured illumination microscopy reveal a proximal leading process nanoscale architecture wherein f-actin and drebrin intervene between microtubules and the plasma membrane. Functional perturbations of drebrin demonstrate that proximal leading process microtubule–actomyosin coupling steers the direction of centrosome and somal migration, as well as the switch from tangential to radial migration. Finally, the Siah2 E3 ubiquitin ligase antagonizes drebrin function, suggesting a model for control of the microtubule–actomyosin interfaces during neuronal differentiation. PMID:28230156

  16. Neurotoxicity of amphetamine derivatives is mediated by caspase pathway activation in rat cerebellar granule cells.

    PubMed

    Jiménez, Andrés; Jordà, Elvira G; Verdaguer, Ester; Pubill, David; Sureda, Francesc X; Canudas, Anna M; Escubedo, Elena; Camarasa, Jordi; Camins, Antoni; Pallàs, Mercè

    2004-04-15

    The neurotoxic action of the abuse drugs methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA) on cerebellar granule neurones (CGNs) culture was examined. Treatment for 48 h with METH or MDMA (1-5 mM) induced a higher decrease in viability than 24 h treatment. z.VAD.fmk (100 microM) but not MK-801 nor NBQX recovered control viability values. In both cases, cell death was characterised as apoptotic rather than necrotic by morphology cell observation. Apoptosis measured by flow cytometry indicated an increase in the hypodiploid population after 48 h treatment with METH and MDMA. Apoptosis was reverted by the presence of z.VAD.fmk (100 microM) but not by 10 microM MK-801 or NBQX. Similar results were obtained by analysing nuclear chromatine condensation. These results ruled out excitotoxic participation in amphetamine derivative-induced neurotoxicity in CGNs. Participation of radical oxygen species (ROS) was evaluated using alpha-tocopherol (1-15 microM) and cytometric studies. The co-treatment with 4 mM METH or MDMA for 48 h partially reverted neurotoxic action and apoptotic features, indicating ROS implication in CGNs death by amphetamine derivatives. Alteration of mitochondrial function induced cytochrome C (Cyt C) release after 48-h treatment with METH and MDMA (4 mM). There was also indication of caspase-3-like activation, measured by immunoanalysis and biochemically. Finally, neurodegenerative action caused by amphetamine derivatives may be prevented by using caspase inhibitors.

  17. Single Neuron Optimization as a Basis for Accurate Biophysical Modeling: The Case of Cerebellar Granule Cells.

    PubMed

    Masoli, Stefano; Rizza, Martina F; Sgritta, Martina; Van Geit, Werner; Schürmann, Felix; D'Angelo, Egidio

    2017-01-01

    In realistic neuronal modeling, once the ionic channel complement has been defined, the maximum ionic conductance (G i-max ) values need to be tuned in order to match the firing pattern revealed by electrophysiological recordings. Recently, selection/mutation genetic algorithms have been proposed to efficiently and automatically tune these parameters. Nonetheless, since similar firing patterns can be achieved through different combinations of G i-max values, it is not clear how well these algorithms approximate the corresponding properties of real cells. Here we have evaluated the issue by exploiting a unique opportunity offered by the cerebellar granule cell (GrC), which is electrotonically compact and has therefore allowed the direct experimental measurement of ionic currents. Previous models were constructed using empirical tuning of G i-max values to match the original data set. Here, by using repetitive discharge patterns as a template, the optimization procedure yielded models that closely approximated the experimental G i-max values. These models, in addition to repetitive firing, captured additional features, including inward rectification, near-threshold oscillations, and resonance, which were not used as features. Thus, parameter optimization using genetic algorithms provided an efficient modeling strategy for reconstructing the biophysical properties of neurons and for the subsequent reconstruction of large-scale neuronal network models.

  18. Sigma-1 Receptor Enhances Neurite Elongation of Cerebellar Granule Neurons via TrkB Signaling

    PubMed Central

    Kimura, Yuriko; Fujita, Yuki; Shibata, Kumi; Mori, Megumi; Yamashita, Toshihide

    2013-01-01

    Sigma-1 receptor (Sig-1R) is an integral membrane protein predominantly expressed in the endoplasmic reticulum. Sig-1R demonstrates a high affinity to various synthetic compounds including well-known psychotherapeutic drugs in the central nervous system (CNS). For that, it is considered as an alternative target for psychotherapeutic drugs. On the cellular level, when Sig-1R is activated, it is known to play a role in neuroprotection and neurite elongation. These effects are suggested to be mediated by its ligand-operated molecular chaperone activity, and/or upregulation of various Ca2+ signaling. In addition, recent studies show that Sig-1R activation induces neurite outgrowth via neurotrophin signaling. Here, we tested the hypothesis that Sig-1R activation promotes neurite elongation through activation of tropomyosin receptor kinase (Trk), a family of neurotrophin receptors. We found that 2-(4-morpholinethyl)1-phenylcyclohexanecarboxylate (PRE-084), a selective Sig-1R agonist, significantly promoted neurite outgrowth, and K252a, a Trk inhibitor, attenuated Sig-1R-mediated neurite elongation in cerebellar granule neurons (CGNs). Moreover, we revealed that Sig-1R interacts with TrkB, and PRE-084 treatment enhances phosphorylation of Y515, but not Y706. Thus, our results indicate that Sig-1R activation promotes neurite outgrowth in CGNs through Y515 phosphorylation of TrkB. PMID:24116072

  19. Sigma-1 receptor enhances neurite elongation of cerebellar granule neurons via TrkB signaling.

    PubMed

    Kimura, Yuriko; Fujita, Yuki; Shibata, Kumi; Mori, Megumi; Yamashita, Toshihide

    2013-01-01

    Sigma-1 receptor (Sig-1R) is an integral membrane protein predominantly expressed in the endoplasmic reticulum. Sig-1R demonstrates a high affinity to various synthetic compounds including well-known psychotherapeutic drugs in the central nervous system (CNS). For that, it is considered as an alternative target for psychotherapeutic drugs. On the cellular level, when Sig-1R is activated, it is known to play a role in neuroprotection and neurite elongation. These effects are suggested to be mediated by its ligand-operated molecular chaperone activity, and/or upregulation of various Ca(2+) signaling. In addition, recent studies show that Sig-1R activation induces neurite outgrowth via neurotrophin signaling. Here, we tested the hypothesis that Sig-1R activation promotes neurite elongation through activation of tropomyosin receptor kinase (Trk), a family of neurotrophin receptors. We found that 2-(4-morpholinethyl)1-phenylcyclohexanecarboxylate (PRE-084), a selective Sig-1R agonist, significantly promoted neurite outgrowth, and K252a, a Trk inhibitor, attenuated Sig-1R-mediated neurite elongation in cerebellar granule neurons (CGNs). Moreover, we revealed that Sig-1R interacts with TrkB, and PRE-084 treatment enhances phosphorylation of Y515, but not Y706. Thus, our results indicate that Sig-1R activation promotes neurite outgrowth in CGNs through Y515 phosphorylation of TrkB.

  20. Tactile responses in the granule cell layer of cerebellar folium crus IIa of freely behaving rats

    NASA Technical Reports Server (NTRS)

    Hartmann, M. J.; Bower, J. M.

    2001-01-01

    We recorded activity from the granule cell layer (GCL) of cerebellar folium Crus IIa as freely moving rats engaged in a variety of natural behaviors, including grooming, eating, and free tactile exploration. Multiunit responses in the 1000-4500 Hz range were found to be strongly correlated with tactile stimulation of lip and whisker (perioral) regions. These responses occurred regardless of whether the stimulus was externally or self-generated and during both active and passive touch. In contrast, perioral movements that did not tactually stimulate this region of the face (e.g., chewing) produced no detectable increases in GCL activity. In addition, GCL responses were not correlated with movement extremes. When rats used their lips actively for palpation and exploration, the tactile responses in the GCL were not detectably modulated by ongoing jaw movements. However, active palpation and exploratory behaviors did result in the largest and most continuous bursts of GCL activity: responses were on average 10% larger and 50% longer during palpation and exploration than during grooming or passive stimulation. Although activity levels differed between behaviors, the position and spatial extent of the peripheral receptive field was similar over all behaviors that resulted in tactile input. Overall, our data suggest that the 1000-4500 Hz multiunit responses in the Crus IIa GCL of awake rats are correlated with tactile input rather than with movement or any movement parameter and that these responses are likely to be of particular importance during the acquisition of sensory information by perioral structures.

  1. Bax-inhibiting peptide protects glutamate-induced cerebellar granule cell death by blocking Bax translocation.

    PubMed

    Iriyama, Takayuki; Kamei, Yoshimasa; Kozuma, Shiro; Taketani, Yuji

    2009-02-13

    Glutamate-induced excitotoxicity has been implicated in the pathogenesis of various neurological damages and disorders. In the brain damage of immature animals such as neonatal hypoxic-ischemic brain injury, the excitotoxicity appears to be more intimately involved through apoptosis. Bax, a member of the Bcl-2 family proteins, plays a key role in the promotion of apoptosis by translocation from the cytosol to the mitochondria and the release of apoptogenic factors such as cytochrome c. Recently, Bax-inhibiting peptide (BIP), a novel membrane-permeable peptide which can bind Bax in the cytosol and inhibit its translocation to the mitochondria, was developed. To investigate the possibility of a new neuroprotection strategy targeting Bax translocation in glutamate-induced neuronal cell death, cerebellar granule neurons (CGNs) were exposed to glutamate with or without BIP. Pretreatment of CGNs with BIP elicited a dose-dependent reduction of glutamate-induced neuronal cell death as measured by MTT assay. BIP significantly suppressed both the number of TUNEL-positive cells and the increase in caspases 3 and 9 activities induced by glutamate. In addition, immunoblotting after subcellular fractionation revealed that BIP prevented the glutamate-induced Bax translocation to the mitochondria and the release of cytochrome c from the mitochondria. These results suggest that agents capable of inhibiting Bax activity such as BIP might lead to new drugs for glutamate-related diseases in the future.

  2. Drebrin-mediated microtubule–actomyosin coupling steers cerebellar granule neuron nucleokinesis and migration pathway selection

    DOE PAGES

    Trivedi, Niraj; Stabley, Daniel R.; Cain, Blake; ...

    2017-02-23

    Neuronal migration from a germinal zone to a final laminar position is essential for the morphogenesis of neuronal circuits. While it is hypothesized that microtubule–actomyosin crosstalk is required for a neuron’s ‘two-stroke’ nucleokinesis cycle, the molecular mechanisms controlling such crosstalk are not defined. By using the drebrin microtubule–actin crosslinking protein as an entry point into the cerebellar granule neuron system in combination with super-resolution microscopy, we investigate how these cytoskeletal systems interface during migration. Lattice light-sheet and structured illumination microscopy reveal a proximal leading process nanoscale architecture wherein f-actin and drebrin intervene between microtubules and the plasma membrane. Functional perturbationsmore » of drebrin demonstrate that proximal leading process microtubule–actomyosin coupling steers the direction of centrosome and somal migration, as well as the switch from tangential to radial migration. Finally, the Siah2 E3 ubiquitin ligase antagonizes drebrin function, suggesting a model for control of the microtubule–actomyosin interfaces during neuronal differentiation.« less

  3. Sensorimotor Representations in Cerebellar Granule Cells in Larval Zebrafish Are Dense, Spatially Organized, and Non-temporally Patterned.

    PubMed

    Knogler, Laura D; Markov, Daniil A; Dragomir, Elena I; Štih, Vilim; Portugues, Ruben

    2017-05-08

    A fundamental question in neurobiology is how animals integrate external sensory information from their environment with self-generated motor and sensory signals in order to guide motor behavior and adaptation. The cerebellum is a vertebrate hindbrain region where all of these signals converge and that has been implicated in the acquisition, coordination, and calibration of motor activity. Theories of cerebellar function postulate that granule cells encode a variety of sensorimotor signals in the cerebellar input layer. These models suggest that representations should be high-dimensional, sparse, and temporally patterned. However, in vivo physiological recordings addressing these points have been limited and in particular have been unable to measure the spatiotemporal dynamics of population-wide activity. In this study, we use both calcium imaging and electrophysiology in the awake larval zebrafish to investigate how cerebellar granule cells encode three types of sensory stimuli as well as stimulus-evoked motor behaviors. We find that a large fraction of all granule cells are active in response to these stimuli, such that representations are not sparse at the population level. We find instead that most responses belong to only one of a small number of distinct activity profiles, which are temporally homogeneous and anatomically clustered. We furthermore identify granule cells that are active during swimming behaviors and others that are multimodal for sensory and motor variables. When we pharmacologically change the threshold of a stimulus-evoked behavior, we observe correlated changes in these representations. Finally, electrophysiological data show no evidence for temporal patterning in the coding of different stimulus durations. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  4. Neurite outgrowth of murine cerebellar granule cells can be enhanced by aniracetam with or without alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA).

    PubMed

    Fushiki, S; Matsumoto, K; Nagata, A

    1995-10-27

    To assess the neurotrophic effects of a nootropic drug, aniracetam, we studied neurite extension of mouse cerebellar granule cells in culture with low or with high K+ under different combinations of drugs and then immunohistochemically stained the cells with an antibody against L1, a neural cell adhesion molecule on cerebellar granule cells. Quantitative analyses using parameters of the total neurite length, maximal neurite length and number of branches disclosed that aniracetam, in the presence of high K+ and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA), significantly enhanced neurite extension of cultured granule neurons. Aniracetam alone also stimulated neurite extension of cerebellar granule cells at a longer period of culture with low K+ showing a bell-shaped dose response curve with maximal effects at 10 microM. Aniracetam may influence remodeling of the neural network after injury.

  5. Early childhood obesity is associated with compromised cerebellar development.

    PubMed

    Miller, Jennifer L; Couch, Jessica; Schwenk, Krista; Long, Michelle; Towler, Stephen; Theriaque, Douglas W; He, Guojun; Liu, Yijun; Driscoll, Daniel J; Leonard, Christiana M

    2009-01-01

    As part of a study investigating commonalities between Prader-Willi syndrome (PWS-a genetic imprinting disorder) and early-onset obesity of unknown etiology (EMO) we measured total cerebral and cerebellar volume on volumetric magnetic resonance imaging (MRI) images. Individuals with PWS (N = 16) and EMO (N = 12) had smaller cerebellar volumes than a control group of 15 siblings (p = .02 control vs. EMO; p = .0005 control vs. PWS), although there was no difference among the groups in cerebral volume. Individuals with PWS and EMO also had impaired cognitive function: general intellectual ability (GIA): PWS 65 +/- 25; EMO 81 +/- 19; and Controls 112 +/- 13 (p < .0001 controls vs. PWS and controls vs. EMO). As both conditions are characterized by early-onset obesity and slowed cognitive development, these results raise the possibility that early childhood obesity retards both cerebellar and cognitive development.

  6. Cannabinoid Type 1 Receptors Transiently Silence Glutamatergic Nerve Terminals of Cultured Cerebellar Granule Cells

    PubMed Central

    Ramírez-Franco, Jorge; Bartolomé-Martín, David; Alonso, Beatris; Torres, Magdalena; Sánchez-Prieto, José

    2014-01-01

    Cannabinoid receptors are the most abundant G protein-coupled receptors in the brain and they mediate retrograde short-term inhibition of neurotransmitter release, as well as long-term depression of synaptic transmission at many excitatory synapses. The induction of presynaptically silent synapses is a means of modulating synaptic strength, which is important for synaptic plasticity. Persistent activation of cannabinoid type 1 receptors (CB1Rs) mutes GABAergic terminals, although it is unclear if CB1Rs can also induce silencing at glutamatergic synapses. Cerebellar granule cells were transfected with VGLUT1-pHluorin to visualise the exo-endocytotic cycle. We found that prolonged stimulation (10 min) of cannabinoid receptors with the agonist HU-210 induces the silencing of previously active synapses. However, the presynaptic silencing induced by HU-210 is transient as it reverses after 20 min. cAMP with forskolin prevented CB1R-induced synaptic silencing, via activation of the Exchange Protein directly Activated by cAMP (Epac). Furthermore, Epac activation accelerated awakening of already silent boutons. Electron microscopy revealed that silencing was associated with synaptic vesicle (SV) redistribution within the nerve terminal, which diminished the number of vesicles close to the active zone of the plasma membrane. Finally, by combining functional and immunocytochemical approaches, we observed a strong correlation between the release capacity of the nerve terminals and RIM1α protein content, but not that of Munc13-1 protein. These results suggest that prolonged stimulation of cannabinoid receptors can transiently silence glutamatergic nerve terminals. PMID:24533119

  7. Synthetic regulators of the 2-oxoglutarate oxidative decarboxylation alleviate the glutamate excitotoxicity in cerebellar granule neurons.

    PubMed

    Kabysheva, Maria S; Storozhevykh, Tatiana P; Pinelis, Vsevolod G; Bunik, Victoria I

    2009-05-01

    Impairment of the 2-oxoglutarate oxidative decarboxylation by the 2-oxoglutarate dehydrogenase complex (OGDHC) is associated with the glutamate accumulation, ROS production and neuropathologies. We hypothesized that correct function of OGDHC under metabolic stress is essential to overcome the glutamate excitotoxic action on neurons. We show that synthetic phosphono analogs of 2-oxoglutarate, succinyl phosphonate and its phosphono ethyl ester, improve the catalysis by brain OGDHC through inhibiting the side reaction of irreversible inactivation of its first component, 2-oxoglutarate dehydrogenase. Under the substrate and cofactor saturation, the component and complex undergo the inactivation during catalysis with the apparent rate constant 0.2 min(-1). The inactivation rate is reduced by 90% and 60% in the presence of 50 microM succinyl phosphonate and its phosphono ethyl ester, correspondingly. In cultured cerebellar granule neurons exposed to excitotoxic glutamate, the phosphonates (100 microM) protect from the irreversible impairment of mitochondrial function and delayed calcium deregulation. The deregulation amplitude is decreased by succinyl phosphonate and its phosphono ethyl ester by 50% and 30%, correspondingly. Thus, succinyl phosphonate is more potent than its phosphono ethyl ester in protecting both the isolated brain OGDHC from inactivation and cultured neurons from the glutamate-induced calcium deregulation. The correlation of the relative efficiency of the phosphonates in vitro and in situ indicates that their cellular effects are due to targeting OGDHC, which is in accord with independent studies. We conclude that the compounds preserving the 2-oxoglutarate dehydrogenase activity are of neuroprotective value upon metabolic disbalance induced by glutamate excess.

  8. The effect of methylmercury exposure on behavior and cerebellar granule cell physiology in aged mice.

    PubMed

    Bellum, Sairam; Thuett, Kerry A; Bawa, Bhupinder; Abbott, Louise C

    2013-09-01

    Epidemiology studies have clearly documented that the central nervous system is highly susceptible to methylmercury toxicity, and exposure to this neurotoxicant in humans primarily results from consumption of contaminated fish. While the effects of methylmercury exposure have been studied in great detail, comparatively little is known about the effects of moderate to low dose methylmercury toxicity in the aging central nervous system. We examined the toxic effects of a moderate dose of methylmercury on the aging mouse cerebellum. Male and female C57BL/6 mice at 16-20 months of age were exposed to methylmercury by feeding a total dose of 5.0 mg kg(-1) body weight and assessed using four behavioral tests. Methylmercury-treated aged mice performed significantly worse in open field, footprint analysis and the vertical pole test compared with age-matched control mice. Isolated cerebellar granule cells from methylmercury-treated aged mice exhibited higher levels of reactive oxygen species and reduced mitochondrial membrane potentials, but no differences in basal intracellular calcium ion levels compared with age-matched control mice. When aged mice were exposed to a moderate dose of methylmercury, they exhibited a similar degree of impairment when compared with young adult mice exposed to the same moderate dose of methylmercury, as reported in earlier studies from this laboratory. Thus, at least in mice, exposure of the aged brain to moderate concentrations methylmercury does not pose greater risk compared with the young adult brain exposed to similar concentrations of methylmercury. Copyright © 2012 John Wiley & Sons, Ltd.

  9. Select putative neurodevelopmental toxins modify SNAP-25 expression in primary cultures of rat cerebellar granule cells.

    PubMed

    Zieminska, Elzbieta; Lenart, Jacek; Lazarewicz, Jerzy W

    2016-08-31

    A presynaptic protein SNAP-25 belonging to SNARE complex which is instrumental in intracellular vesicular trafficking and exocytosis, has been implicated in hyperactivity and cognitive abilities in some neuropsychiatric disorders. The unclear etiology of the behavior disrupting neurodevelopmental disabilities in addition to genetic causes most likely involves environmental factors. The aim of this in vitro study was to test if various suspected developmental neurotoxins can alter SNAP-25 mRNA and protein expression in neurons. Real-time PCR and Western blotting analyses were used to assess SNAP-25 mRNA and protein levels in primary cultures of rat cerebellar granule cells (CGCs). The test substances: tetrabromobisphenol-A (TBBPA), thimerosal (TH), silver nanoparticles (NAg), valproic acid (VPA) and thalidomide (THAL), were administered to CGC cultures at subtoxic concentrations for 24h. The results demonstrated that SNAP-25 mRNA levels were increased by 49 and 66% by TBBPA and THAL, respectively, whereas VPA and NAg reduced these levels to 48 and 64% of the control, respectively. The SNAP-25 protein content in CGCs was increased by 79% by TBBPA, 25% by THAL and 21% by NAg; VPA and TH reduced these levels to 73 and 69% of the control, respectively. The variety of changes in SNAP-25 expression on mRNA and protein level suggests the diversity of the mechanism of action of the test substances. This initial study provided no data on concentration-effect relations and on functional changes in CGCs. However it is the first to demonstrate the effect of different compounds that are suspected of causing neurodevelopmental disabilities on SNAP-25 expression. These results suggest that this protein may be a common target for not only inherited but also environmental modifications linked to behavioral deficits in neurodevelopmental disabilities. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Proneurotrophin-3 promotes cell cycle withdrawal of developing cerebellar granule cell progenitors via the p75 neurotrophin receptor.

    PubMed

    Zanin, Juan Pablo; Abercrombie, Elizabeth; Friedman, Wilma J

    2016-07-19

    Cerebellar granule cell progenitors (GCP) proliferate extensively in the external granule layer (EGL) of the developing cerebellum prior to differentiating and migrating. Mechanisms that regulate the appropriate timing of cell cycle withdrawal of these neuronal progenitors during brain development are not well defined. The p75 neurotrophin receptor (p75(NTR)) is highly expressed in the proliferating GCPs, but is downregulated once the cells leave the cell cycle. This receptor has primarily been characterized as a death receptor for its ability to induce neuronal apoptosis following injury. Here we demonstrate a novel function for p75(NTR) in regulating proper cell cycle exit of neuronal progenitors in the developing rat and mouse EGL, which is stimulated by proNT3. In the absence of p75(NTR), GCPs continue to proliferate beyond their normal period, resulting in a larger cerebellum that persists into adulthood, with consequent motor deficits.

  11. Frequency-dependent actions of benzodiazepines on GABAA receptors in cultured murine cerebellar granule cells.

    PubMed Central

    Mellor, J R; Randall, A D

    1997-01-01

    1. Miniature IPSCs recorded from cultured murine cerebellar granule cells increased in half-width and amplitude following application of the benzodiazepine (BDZ) Flunitrazepam (Flu, 1 microM). The increase in the half-width was much greater than that in the amplitude. 2. Five-millisecond applications of 1 mM GABA to nucleated outside-out patches elicited rapidly rising biexponentially decaying responses that resembled IPSCs. Flu had no effect on the amplitude of such responses, but consistently slowed their deactivation by approximately 50%. This effect was reversed by Flu washout or application of the BDZ antagonist Ro15-1788. The partial inverse agonist. Ro15-4513 speeded deactivation and depressed peak current amplitude by 23 +/- 12%. 3. The EC50 for GABA was between 45 and 50 microM. At submaximally effective agonist concentrations, Flu increased response amplitude and slowed response deactivation. Both effects were present in all cells taken from young cultures (4-7 days in vitro) but the latter was absent in 55% of the neurones obtained from older cultures (14-27 days in vitro). 4. With 120 ms applications of 20 microM GABA, responses activated monoexponentially (time constant, 39.8 +/- 2.8 ms) and deactivated biexponentially (time constants, 40.4 +/- 2.1 and 251 +/- 15 ms). Application of Flu slowed both activation and deactivation. The latter effect arose from an increased contribution of the slower component of decay. 5. Desensitization of responses to 1 mM GABA was biexponential, with time constants of 47 +/- 11 and 479 +/- 49 ms. Flu speeded desensitization by decreasing both fast and slow time constants. GABAA receptor desensitization consistently slowed subsequent deactivation. No significant relationship between the level of desensitization and the amount of slowing of deactivation produced by Flu was found. 6. Responses to paired 5 ms applications of 1 mM GABA indicated that the slowing of deactivation and the speeding of desensitization produced by

  12. Bmi1 overexpression in the cerebellar granule cell lineage of mice affects cell proliferation and survival without initiating medulloblastoma formation

    PubMed Central

    Behesti, Hourinaz; Bhagat, Heeta; Dubuc, Adrian M.; Taylor, Michael D.; Marino, Silvia

    2013-01-01

    SUMMARY BMI1 is a potent inducer of neural stem cell self-renewal and neural progenitor cell proliferation during development and in adult tissue homeostasis. It is overexpressed in numerous human cancers – including medulloblastomas, in which its functional role is unclear. We generated transgenic mouse lines with targeted overexpression of Bmi1 in the cerebellar granule cell lineage, a cell type that has been shown to act as a cell of origin for medulloblastomas. Overexpression of Bmi1 in granule cell progenitors (GCPs) led to a decrease in cerebellar size due to decreased GCP proliferation and repression of the expression of cyclin genes, whereas Bmi1 overexpression in postmitotic granule cells improved cell survival in response to stress by altering the expression of genes in the mitochondrial cell death pathway and of Myc and Lef-1. Although no medulloblastomas developed in ageing cohorts of transgenic mice, crosses with Trp53−/− mice resulted in a low incidence of medulloblastoma formation. Furthermore, analysis of a large collection of primary human medulloblastomas revealed that tumours with a BMI1high TP53low molecular profile are significantly enriched in Group 4 human medulloblastomas. Our data suggest that different levels and timing of Bmi1 overexpression yield distinct cellular outcomes within the same cellular lineage. Importantly, Bmi1 overexpression at the GCP stage does not induce tumour formation, suggesting that BMI1 overexpression in GCP-derived human medulloblastomas probably occurs during later stages of oncogenesis and might serve to enhance tumour cell survival. PMID:23065639

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

    PubMed Central

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

    2015-01-01

    Classical feed-forward inhibition involves an excitation–inhibition sequence that enhances the temporal precision of neuronal responses by narrowing the window for synaptic integration. In the input layer of the cerebellum, feed-forward inhibition is thought to preserve the temporal fidelity of granule cell spikes during mossy fiber stimulation. Although this classical feed-forward inhibitory circuit has been demonstrated in vitro, the extent to which inhibition shapes granule cell sensory responses in vivo remains unresolved. Here we combined whole-cell patch-clamp recordings in vivo and dynamic clamp recordings in vitro to directly assess the impact of Golgi cell inhibition on sensory information transmission in the granule cell layer of the cerebellum. We show that the majority of granule cells in Crus II of the cerebrocerebellum receive sensory-evoked phasic and spillover inhibition prior to mossy fiber excitation. This preceding inhibition reduces granule cell excitability and sensory-evoked spike precision, but enhances sensory response reproducibility across the granule cell population. Our findings suggest that neighboring granule cells and Golgi cells can receive segregated and functionally distinct mossy fiber inputs, enabling Golgi cells to regulate the size and reproducibility of sensory responses. PMID:26432880

  14. Gaze holding deficits discriminate early from late onset cerebellar degeneration.

    PubMed

    Tarnutzer, Alexander A; Weber, K P; Schuknecht, B; Straumann, D; Marti, S; Bertolini, G

    2015-08-01

    The vestibulo-cerebellum calibrates the output of the inherently leaky brainstem neural velocity-to-position integrator to provide stable gaze holding. In healthy humans small-amplitude centrifugal nystagmus is present at extreme gaze-angles, with a non-linear relationship between eye-drift velocity and eye eccentricity. In cerebellar degeneration this calibration is impaired, resulting in pathological gaze-evoked nystagmus (GEN). For cerebellar dysfunction, increased eye drift may be present at any gaze angle (reflecting pure scaling of eye drift found in controls) or restricted to far-lateral gaze (reflecting changes in shape of the non-linear relationship) and resulting eyed-drift patterns could be related to specific disorders. We recorded horizontal eye positions in 21 patients with cerebellar neurodegeneration (gaze-angle = ±40°) and clinically confirmed GEN. Eye-drift velocity, linearity and symmetry of drift were determined. MR-images were assessed for cerebellar atrophy. In our patients, the relation between eye-drift velocity and gaze eccentricity was non-linear, yielding (compared to controls) significant GEN at gaze-eccentricities ≥20°. Pure scaling was most frequently observed (n = 10/18), followed by pure shape-changing (n = 4/18) and a mixed pattern (n = 4/18). Pure shape-changing patients were significantly (p = 0.001) younger at disease-onset compared to pure scaling patients. Atrophy centered around the superior/dorsal vermis, flocculus/paraflocculus and dentate nucleus and did not correlate with the specific drift behaviors observed. Eye drift in cerebellar degeneration varies in magnitude; however, it retains its non-linear properties. With different drift patterns being linked to age at disease-onset, we propose that the gaze-holding pattern (scaling vs. shape-changing) may discriminate early- from late-onset cerebellar degeneration. Whether this allows a distinction among specific cerebellar disorders remains to be determined.

  15. Cerebellar Granule Cell Replenishment Post-Injury by Adaptive Reprogramming of Nestin+ Progenitors

    PubMed Central

    Wojcinski, Alexandre; Lawton, Andrew K.; Bayin, N Sumru.; Lao, Zhimin; Stephen, Daniel N.; Joyner, Alexandra L.

    2017-01-01

    Regeneration of several organs involves adaptive reprogramming of progenitors, however, the intrinsic capacity of the developing brain to replenish lost cells remains largely unknown. In this study, we discovered that the developing cerebellum has unappreciated progenitor plasticity, since it undergoes near full growth and functional recovery following acute depletion of granule cells, the most plentiful neuron population in the brain. We demonstrate that following postnatal ablation of granule cell progenitors, Nestin-expressing progenitors (NEPs) specified during mid-embryogenesis to produce astroglia and interneurons, switch their fate and generate granule neurons in mice. Moreover, Hedgehog-signaling in two NEP populations is crucial not only for the compensatory replenishment of granule neurons but also to scale interneuron and astrocyte numbers. Thus we provide insights into the mechanisms underlying robustness of circuit formation in the cerebellum, and speculate that adaptive reprogramming of progenitors in other brain regions plays a greater role than appreciated in developmental regeneration. PMID:28805814

  16. Pseudomonas fluorescens lipopolysaccharide inhibits both delayed rectifier and transient A-type K+ channels of cultured rat cerebellar granule neurons.

    PubMed

    Mezghani-Abdelmoula, Sana; Chevalier, Sylvie; Lesouhaitier, Olivier; Orange, Nicole; Feuilloley, Marc G J; Cazin, Lionel

    2003-09-05

    Pseudomonas fluorescens is a Gram-negative bacillus closely related to the pathogen P. aeruginosa known to provoke infectious disorders in the central nervous system (CNS). The endotoxin lipopolysaccharide (LPS) expressed by the bacteria is the first infectious factor that can interact with the plasma membrane of host cells. In the present study, LPS extracted from P. fluorescens MF37 was examined for its actions on delayed rectifier and A-type K(+) channels, two of the main types of voltage-activated K(+) channels involved in the action potential firing. Current recordings were performed in cultured rat cerebellar granule neurons at days 7 or 8, using the whole-cell patch-clamp technique. A 3-h incubation with LPS (200 ng/ml) markedly depressed both the delayed rectifier (I(KV)) and transient A-type (I(A)) K(+) currents evoked by depolarizations above 0 and -40 mV, respectively. The percent decrease of I(KV) and I(A) ( approximately 30%) did not vary with membrane potential, suggesting that inhibition of both types of K(+) channels by LPS was voltage-insensitive. The endotoxin did neither modify the steady-state voltage-dependent activation properties of I(KV) and I(A) nor the steady-state inactivation of I(A). The present results suggest that, by inhibiting I(KV) and I(A), LPS applied extracellulary increases the action potential firing in cerebellar granule neurons. It is concluded that P. fluorescens MF37 may provoke in the CNS disorders associated with sever alterations of membrane ionic channel functions.

  17. Effects of pentylenetetrazole and glutamate on metabolism of [U-(13)C]glucose in cultured cerebellar granule neurons.

    PubMed

    Eloqayli, Haytham; Qu, Hong; Unsgård, Geirmund; Sletvold, Olav; Hadidi, Hakam; Sonnewald, Ursula

    2002-02-01

    This study was performed to analyze the effects of glutamate and the epileptogenic agent pentylenetetrazole (PTZ) on neuronal glucose metabolism. Cerebellar granule neurons were incubated for 2 h in medium containing 3 mM [U-(13)C]glucose, with and without 0.25 mM glutamate and/or 10 mM PTZ. In the presence of PTZ, decreased glucose consumption with unchanged lactate release was observed, indicating decreased glucose oxidation. PTZ also slowed down tricarboxylic acid (TCA) cycle activity as evidenced by the decreased amounts of labeled aspartate and [1,2-(13)C]glutamate. When glutamate was present, glucose consumption was also decreased. However, the amount of glutamate, derived from [U-(13)C]glucose via the first turn of the TCA cycle, was increased. The decreased amount of [1,2-(13)C]glutamate, derived from the second turn in the TCA cycle, and increased amount of aspartate indicated the dilution of label due to the entrance of unlabeled glutamate into TCA cycle. In the presence of glutamate plus PTZ, the effect of PTZ was enhanced by glutamate. Labeled alanine was detected only in the presence of glutamate plus PTZ, which indicated that oxaloacetate was a better amino acid acceptor than pyruvate. Furthermore, there was also evidence for intracellular compartmentation of oxaloacetate metabolism. Glutamate and PTZ caused similar metabolic changes, however, via different mechanisms. Glutamate substituted for glucose as energy substrate in the TCA cycle, whereas, PTZ appeared to decrease mitochondrial activity.

  18. Leading-process actomyosin coordinates organelle positioning and adhesion receptor dynamics in radially migrating cerebellar granule neurons

    SciTech Connect

    Trivedi, Niraj; Ramahi, Joseph S.; Karakaya, Mahmut

    During brain development, neurons migrate from germinal zones to their final positions to assemble neural circuits. A unique saltatory cadence involving cyclical organelle movement (e.g., centrosome motility) and leading-process actomyosin enrichment prior to nucleokinesis organizes neuronal migration. While functional evidence suggests that leading-process actomyosin is essential for centrosome motility, the role of the actin-enriched leading process in globally organizing organelle transport or traction forces remains unexplored. Our results show that myosin ii motors and F-actin dynamics are required for Golgi apparatus positioning before nucleokinesis in cerebellar granule neurons (CGNs) migrating along glial fibers. Moreover, we show that primary cilia aremore » motile organelles, localized to the leading-process F-actin-rich domain and immobilized by pharmacological inhibition of myosin ii and F-actin dynamics. Finally, leading process adhesion dynamics are dependent on myosin ii and F-actin. In conclusion, we propose that actomyosin coordinates the overall polarity of migrating CGNs by controlling asymmetric organelle positioning and cell-cell contacts as these cells move along their glial guides.« less

  19. Attenuation of excitatory amino acid toxicity by metabotropic glutamate receptor agonists and aniracetam in primary cultures of cerebellar granule cells.

    PubMed

    Pizzi, M; Fallacara, C; Arrighi, V; Memo, M; Spano, P F

    1993-08-01

    Activation of glutamate ionotropic receptors represents the primary event in the neurotoxicity process triggered by excitatory amino acids. We demonstrate here that the concentration-dependent stimulation of metabotropic glutamate receptor (mGluR) by the selective agonist trans-1-aminocyclopentane-1,3-dicarboxylate or by quisqualate counteracts both glutamate- and kainate-induced neurotoxicity in primary cultures of rat cerebellar granule cells. The mGluR-evoked responses are potentiated by aniracetam, which per se also elicits neuroprotection. Aniracetam concentration-dependently counteracted glutamate-, kainate-, or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-induced cell death and greatly facilitated neuroprotective response achieved by different concentrations of both quisqualate and trans-1-aminocyclopentane-1,3-dicarboxylate. In addition, aniracetam potentiated the mGluR-coupled stimulation of phospholipase C, as revealed by the measurement of 3H-inositol phosphate formation. Thus, mGluRs could be a suitable target for novel pharmacological strategies pointing to the treatment of neurodegenerative diseases.

  20. Leading-process actomyosin coordinates organelle positioning and adhesion receptor dynamics in radially migrating cerebellar granule neurons

    DOE PAGES

    Trivedi, Niraj; Ramahi, Joseph S.; Karakaya, Mahmut; ...

    2014-12-02

    During brain development, neurons migrate from germinal zones to their final positions to assemble neural circuits. A unique saltatory cadence involving cyclical organelle movement (e.g., centrosome motility) and leading-process actomyosin enrichment prior to nucleokinesis organizes neuronal migration. While functional evidence suggests that leading-process actomyosin is essential for centrosome motility, the role of the actin-enriched leading process in globally organizing organelle transport or traction forces remains unexplored. Our results show that myosin ii motors and F-actin dynamics are required for Golgi apparatus positioning before nucleokinesis in cerebellar granule neurons (CGNs) migrating along glial fibers. Moreover, we show that primary cilia aremore » motile organelles, localized to the leading-process F-actin-rich domain and immobilized by pharmacological inhibition of myosin ii and F-actin dynamics. Finally, leading process adhesion dynamics are dependent on myosin ii and F-actin. In conclusion, we propose that actomyosin coordinates the overall polarity of migrating CGNs by controlling asymmetric organelle positioning and cell-cell contacts as these cells move along their glial guides.« less

  1. Glucose deprivation stimulates Cu(2+) toxicity in cultured cerebellar granule neurons and Cu(2+)-dependent zinc release.

    PubMed

    Isaev, Nickolay K; Genrikhs, Elisaveta E; Aleksandrova, Olga P; Zelenova, Elena A; Stelmashook, Elena V

    2016-05-27

    Copper chloride (0.01mM, 2h) did not have significant influence on the survival of cerebellar granule neurons (CGNs) incubated in balanced salt solution. However, CuCl2 caused severe neuronal damage by glucose deprivation (GD). The glutamate NMDA-receptors blocker MK-801 partially and antioxidant N-acetyl-l-cysteine (NAC) or Zn(2+) chelator, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) almost entirely protected CGNs from this toxic effect. Measurements of intracellular calcium ions using Fluo-4 AM, or zinc ions with FluoZin-3 AM demonstrated that 1 h-exposure to GD induced intensive increase of Fluo-4 but not FluoZin-3 fluorescence in neurons. The supplementation of solution with CuCl2 caused an increase of FluoZin-3, Fluo-4 and CellROX Green (reactive oxygen species probe) fluorescence by GD. The stimulation of Fluo-4 but not FluoZin-3 fluorescence by copper could be prevented partially by MK-801 and as well as CellROX Green fluorescence by NAC at GD. This data imply that during GD copper ions induce intense displacement zinc ions from intracellular stores, in addition free radical production, glutamate release and Ca(2+) overload of CGNs, that causes death of neurons as a result. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. CYP2E1 induction leads to oxidative stress and cytotoxicity in glutathione-depleted cerebellar granule neurons.

    PubMed

    Valencia-Olvera, Ana Carolina; Morán, Julio; Camacho-Carranza, Rafael; Prospéro-García, Oscar; Espinosa-Aguirre, Jesús Javier

    2014-10-01

    Increasing evidence suggests that brain cytochrome P450 (CYP) can contribute to the in situ metabolism of xenobiotics. In the liver, some xenobiotics can be metabolized by CYPs into more reactive products that can damage hepatocytes and induce cell death. In addition, normal CYP activity may produce reactive oxygen species (ROS) that contribute to cell damage through oxidative mechanisms. CYP2E1 is a CYP isoform that can generate ROS leading to cytotoxicity in multiple tissue types. The aim of this study was to determine whether CYP2E1 induction may lead to significant brain cell impairment. Immunological analysis revealed that exposure of primary cerebellar granule neuronal cultures to the CYP inducer isoniazid, increased CYP2E1 expression. In the presence of buthionine sulfoximine, an agent that reduces glutathione levels, isoniazid treatment also resulted in reactive oxygen species (ROS) production, DNA oxidation and cell death. These effects were attenuated by simultaneous exposure to diallyl sulfide, a CYP2E1 inhibitor, or to a mimetic of superoxide dismutase/catalase, (Euka). These results suggest that in cases of reduced antioxidant levels, the induction of brain CYP2E1 could represent a risk of in situ neuronal damage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Dendrites of cerebellar granule cells correctly recognize their target axons for synaptogenesis in vitro.

    PubMed

    Ito, Shoko; Takeichi, Masatoshi

    2009-08-04

    Neural circuits are generated by precisely ordered synaptic connections among neurons, and this process is thought to rely on the ability of neurons to recognize specific partners. However, it is also known that neurons promiscuously form synapses with nonspecific partners, in particular when cultured in vitro, causing controversies about neural recognition mechanisms. Here we reexamined whether neurons can or cannot select particular partners in vitro. In the cerebellum, granule cell (GC) dendrites form synaptic connections specifically with mossy fibers, but not with climbing fibers. We cocultured GC neurons with pontine or inferior olivary axons, the major sources for mossy and climbing fibers, respectively, as well as with hippocampal axons as a control. The GC neurons formed synapses with pontine axons predominantly at the distal ends of their dendrites, reproducing the characteristic morphology of their synapses observed in vivo, whereas they failed to do so when combined with other axons. In the latter case, synaptic proteins could accumulate between axons and dendrites, but these synapses were randomly distributed throughout the contact sites, and also their synaptic vesicle recycling was anomalous. These observations suggest that GC dendrites can select their authentic partners for synaptogenesis even in vitro, forming the synapses with a GC-specific nature only with them.

  4. Different Molecular Mechanisms Mediate Direct or Glia-Dependent Prion Protein Fragment 90-231 Neurotoxic Effects in Cerebellar Granule Neurons.

    PubMed

    Thellung, Stefano; Gatta, Elena; Pellistri, Francesca; Villa, Valentina; Corsaro, Alessandro; Nizzari, Mario; Robello, Mauro; Florio, Tullio

    2017-10-01

    Glia over-stimulation associates with amyloid deposition contributing to the progression of central nervous system neurodegenerative disorders. Here we analyze the molecular mechanisms mediating microglia-dependent neurotoxicity induced by prion protein (PrP)90-231, an amyloidogenic polypeptide corresponding to the protease-resistant portion of the pathological prion protein scrapie (PrP Sc ). PrP90-231 neurotoxicity is enhanced by the presence of microglia within neuronal culture, and associated to a rapid neuronal [Ca ++ ] i increase. Indeed, while in "pure" cerebellar granule neuron cultures, PrP90-231 causes a delayed intracellular Ca ++ entry mediated by the activation of NMDA receptors; when neuron and glia are co-cultured, a transient increase of [Ca ++ ] i occurs within seconds after treatment in both granule neurons and glial cells, then followed by a delayed and sustained [Ca ++ ] i raise, associated with the induction of the expression of inducible nitric oxide synthase and phagocytic NADPH oxidase. [Ca ++ ] i fast increase in neurons is dependent on the activation of multiple pathways since it is not only inhibited by the blockade of voltage-gated channel activity and NMDA receptors but also prevented by the inhibition of nitric oxide and PGE 2 release from glial cells. Thus, Ca ++ homeostasis alteration, directly induced by PrP90-231 in cerebellar granule cells, requires the activation of NMDA receptors, but is greatly enhanced by soluble molecules released by activated glia. In glia-enriched cerebellar granule cultures, the activation of inducible nitric oxide (iNOS) and NADPH oxidase represents the main mechanism of toxicity since their pharmacological inhibition prevented PrP90-231 neurotoxicity, whereas NMDA blockade by D(-)-2-amino-5-phosphonopentanoic acid is ineffective; conversely, in pure cerebellar granule cultures, NMDA blockade but not iNOS inhibition strongly reduced PrP90-231 neurotoxicity. These data indicate that amyloidogenic peptides

  5. Excitotoxicity through NMDA receptors mediates cerebellar granule neuron apoptosis induced by prion protein 90-231 fragment.

    PubMed

    Thellung, Stefano; Gatta, Elena; Pellistri, Francesca; Corsaro, Alessandro; Villa, Valentina; Vassalli, Massimo; Robello, Mauro; Florio, Tullio

    2013-05-01

    Prion diseases recognize, as a unique molecular trait, the misfolding of CNS-enriched prion protein (PrP(C)) into an aberrant isoform (PrP(Sc)). In this work, we characterize the in vitro toxicity of amino-terminally truncated recombinant PrP fragment (amino acids 90-231, PrP90-231), on rat cerebellar granule neurons (CGN), focusing on glutamatergic receptor activation and Ca(2+) homeostasis impairment. This recombinant fragment assumes a toxic conformation (PrP90-231(TOX)) after controlled thermal denaturation (1 h at 53 °C) acquiring structural characteristics identified in PrP(Sc) (enrichment in β-structures, increased hydrophobicity, partial resistance to proteinase K, and aggregation in amyloid fibrils). By annexin-V binding assay, and evaluation of the percentage of fragmented and condensed nuclei, we show that treatment with PrP90-231(TOX), used in pre-fibrillar aggregation state, induces CGN apoptosis. This effect was associated with a delayed, but sustained elevation of [Ca(2+)]i. Both CGN apoptosis and [Ca(2+)]i increase were not observed using PrP90-231 in PrP(C)-like conformation. PrP90-231(TOX) effects were significantly reduced in the presence of ionotropic glutamate receptor antagonists. In particular, CGN apoptosis and [Ca(2+)]i increase were largely reduced, although not fully abolished, by pre-treatment with the NMDA antagonists APV and memantine, while the AMPA antagonist CNQX produced a lower, although still significant, effect. In conclusion, we report that CGN apoptosis induced by PrP90-231(TOX) correlates with a sustained elevation of [Ca(2+)]i mediated by the activation of NMDA and AMPA receptors.

  6. Mefenamic acid bi-directionally modulates the transient outward K{sup +} current in rat cerebellar granule cells

    SciTech Connect

    Zhang Man; Shi Wenjie; Fei Xiaowei

    2008-02-01

    The effect of non-steroidal anti-inflammatory drugs (NSAIDs) on ion channels has been widely studied in several cell models, but less is known about their modulatory mechanisms. In this report, the effect of mefenamic acid on voltage-activated transient outward K{sup +} current (I{sub A}) in cultured rat cerebellar granule cells was investigated. At a concentration of 5 {mu}M to 100 {mu}M, mefenamic acid reversibly inhibited I{sub A} in a dose-dependent manner. However, mefenamic acid at a concentration of 1 {mu}M significantly increased the amplitude of I{sub A} to 113 {+-} 1.5% of the control. At more than 10 {mu}M, mefenamic acidmore » inhibited the amplitude of I{sub A} without any effect on activation or inactivation. In addition, a higher concentration of mefenamic acid induced a significant acceleration of recovery from inactivation with an increase of the peak amplitude elicited by the second test pulse. Intracellular application of mefenamic acid could significantly increase the amplitude of I{sub A}, but had no effect on the inhibition induced by extracellular mefenamic acid, implying that mefenamic acid may exert its effect from both inside and outside the ion channel. Furthermore, the activation of current induced by intracellular application of mefenamic acid was mimicked by other cyclooxygenase inhibitors and arachidonic acid. Our data demonstrate that mefenamic acid is able to bi-directionally modulate I{sub A} channels in neurons at different concentrations and by different methods of application, and two different mechanisms may be involved.« less

  7. Hydroxylated polychlorinated biphenyls increase reactive oxygen species formation and induce cell death in cultured cerebellar granule cells

    SciTech Connect

    Dreiem, Anne; Norwegian Defence Research Establishment, Department for Protection, Kjeller; Rykken, Sidsel

    2009-10-15

    Polychlorinated biphenyls (PCBs) are persistent organic pollutants that bioaccumulate in the body, however, they can be metabolized to more water-soluble products. Although they are more readily excreted than the parent compounds, some of the metabolites are still hydrophobic and may be more available to target tissues, such as the brain. They can also cross the placenta and reach a developing foetus. Much less is known about the toxicity of PCB metabolites than about the parent compounds. In the present study, we have investigated the effects of eight hydroxylated (OH) PCB congeners (2'-OH PCB 3, 4-OH PCB 14, 4-OH PCB 34,more » 4'-OH PCB 35, 4-OH PCB 36, 4'-OH PCB 36, 4-OH PCB 39, and 4'-OH PCB 68) on reactive oxygen species (ROS) formation and cell viability in rat cerebellar granule cells. We found that, similar to their parent compounds, OH-PCBs are potent ROS inducers with potency 4-OH PCB 14 < 4-OH PCB 36 < 4-OH PCB 34 < 4'-OH PCB 36 < 4'-OH PCB 68 < 4-OH PCB 39 < 4'-OH PCB 35. 4-OH PCB 36 was the most potent cell death inducer, and caused apoptotic or necrotic morphology depending on concentration. Inhibition of ERK1/2 kinase with U0126 reduced both cell death and ROS formation, suggesting that ERK1/2 activation is involved in OH-PCB toxicity. The results indicate that the hydroxylation of PCBs may not constitute a detoxification reaction. Since OH-PCBs like their parent compounds are retained in the body and may be more widely distributed to sensitive tissues, it is important that not only the levels of the parent compounds but also the levels of their metabolites are taken into account during risk assessment of PCBs and related compounds.« less

  8. Identification of polypeptides with selective affinity to intact mouse cerebellar granule neurons from a random peptide-presenting phage library.

    PubMed

    Hou, Sheng T; Dove, Mike; Anderson, Erica; Zhang, Jiangbing; MacKenzie, C Roger

    2004-09-30

    Targeting of postmitotic neurons selectively for gene delivery poses a challenge. One way to achieve such a selective targeting is to link the gene delivery vector with small ligand-binding polypeptides which have selective affinity to intact neurons. In order to identify such novel neuron selective polypeptides, we screened a phage-display library displaying random 12-mer polypeptides and subtractively bio-panned for clones having selectivity towards cultured mouse cerebellar granule neurons. The selected phage clones were amplified and sequenced. Affinities of these clones to neurons were determined by the visible presence or absence of fluorescence of phage particles as detected by immunocytochemistry using an antibody to M-13 phage. This affinity was further qualified by how much phage was bound, and where in or on the cell it tended to accumulate. The selectivity of binding to neurons was determined by the negative binding of these clones to several cultured non-neuronal cells, including, primary glial cells, NT2 cells, human embryonic kidney 293 cells, neuroblastoma cells, and mouse 3T3 cells. Among the 46 clones that we have sequenced and characterized, four clones appeared to have excellent selectivity in binding to neurons. Homology comparison of these polypeptides revealed that three of them contained a consensus D(E)-W(F)-I(N)-D-W motif. This motif was also present in the Bdm1 gene product which was predominantly expressed in postnatal brains. Further characterizations of these polypeptides are required to reveal the utilities of these peptides to function as an effective linker to facilitate gene transfer selectively to neurons.

  9. Survival of Swiss-Webster mouse cerebellar granule neurons is promoted by a combination of potassium channel blockers.

    PubMed

    Collins, Anthony; Larson, Maureen K; Pfaff, Jilleen E; Ishmael, Jane E

    2007-06-15

    Cultured cerebellar granule neurons (CGN) are commonly used to assess neurotoxicity, but are routinely maintained in supraphysiological (25 mM) extracellular K(+) concentrations [K(+)](o). We investigated the effect of potassium channel blockade on survival of CGN derived from Swiss-Webster mice in supraphysiological (25 mM) and physiological (5.6 mM) [K(+)](o). CGN were cultured for 5 days in 25 mM K(+), then in 5.6 mM K(+) or 25 mM K(+) (control). Viability, assayed 24 h later by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) reduction and by lactate dehydrogenase (LDH) release, was approximately 50% in 5.6 mM K(+) versus 25 mM K(+) (p<.001). Potassium channel blockers, 2 mM 4-aminopyridine (4-AP), 2 mM tetraethylammonium (TEA) or 1 mM Ba(2+), individually afforded limited protection in 5.6 mM K(+). However, survival in 5.6 mM K(+) with a combination of 4-AP, TEA and Ba(2+) was similar to survival in 25 mM K(+) without blockers (p<.001 versus 5.6 mM K(+) alone). CGN survival in 25 mM K(+) was attenuated 25% by 2 microM nifedipine (p>.001), but nifedipine did not attenuate neuroprotection by K(+) channel blockers. Together, these results suggest that the survival of CGN depends on the K(+) permeability of the membrane rather than the activity of a particular type of K(+) channel, and that the mechanism of neuroprotection by K(+) channel blockers is different from that of elevated [K(+)](o).

  10. The natural scorpion peptide, BmK NT1 activates voltage-gated sodium channels and produces neurotoxicity in primary cultured cerebellar granule cells.

    PubMed

    Zou, Xiaohan; He, Yuwei; Qiao, Jinping; Zhang, Chunlei; Cao, Zhengyu

    2016-01-01

    The scorpion Buthus martensii Karsch has been used in Traditional Chinese Medicine to treat neuronal diseases such as neuropathic pain, paralysis and epilepsy for thousands of years. Studies have demonstrated that scorpion venom is the primary active component. Although scorpion venom can effectively attenuate pain in the clinic, it also produces neurotoxic response. In this study, toxicity guided purification led to identify a mammalian toxin termed BmK NT1 comprising of 65 amino acid residues and an amidated C-terminus, a mature peptide encoded by the nucleotide sequence (GenBank No. AF464898). In contract to the recombinant product of the same nucleotide sequence, BmK AGAP, which displayed analgesic and anti-tumor effect, intravenous injection (i.v.) of BmK NT1 produced acute toxicity in mice with an LD50 value of 1.36 mg/kg. In primary cultured cerebellar granule cells, BmK NT1 produced a concentration-dependent cell death with an IC50 value of 0.65 μM (0.41-1.03 μM, 95% Confidence Intervals, 95% CI) which was abolished by TTX, a voltage-gated sodium channel (VGSC) blocker. We also demonstrated that BmK NT1 produced modest sodium influx in cerebellar granule cell cultures with an EC50 value of 2.19 μM (0.76-6.40 μM, 95% CI), an effect similar to VGSC agonist, veratridine. The sodium influx response was abolished by TTX suggesting that BmK NT1-induced sodium influx is solely through activation of VGSC. Considered these data together, we demonstrated that BmK NT1 activated VGSC and produced neurotoxicity in cerebellar granule cell cultures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Changes in mitogen-activated protein kinase in cerebellar granule neurons by polybrominated diphenyl ethers and polychlorinated biphenyls

    SciTech Connect

    Fan Chunyang; Curriculum in Toxicology, University of North Carolina, Chapel Hill, NC 27599; Besas, Jonathan

    2010-05-15

    Polybrominated diphenyl ethers (PBDEs) are used as additive flame retardants and have been detected in human blood, adipose tissue, and breast milk. Both in vitro and in vivo studies have shown that the effects of PBDEs are similar to the known human developmental neurotoxicants such as polychlorinated biphenyls (PCBs) on a molar basis. Previously, we reported that PBDE mixtures and congeners, perturbed calcium homeostasis which is critical for the development and function of the nervous system. In the present study, we tested whether environmentally relevant PBDE/PCB mixtures and congeners affected mitogen-activated protein kinase (MAPK) pathways, which are down-stream events ofmore » calcium signaling in cerebellar granule neuronal cultures. In this study, phosphorylated extracellular signal-regulated kinase (pERK)1/2, a widely studied MAPK cascade and known to be involved in learning and memory, levels were quantitated using western blot technique with phospho-specific antibodies. Glutamate (a positive control) increased pERK1/2 in a time- and concentration-dependent manner reaching maximum activation at 5-30 min of exposure and at doses >= 10 muM. Both Aroclor 1254 (a commercial penta PCB mixture) and DE-71 (a commercial penta PBDE mixture) elevated phospho-ERK1/2, producing maximum stimulation at 30 min and at concentrations >= 3 mug/ml; Aroclor 1254 was more efficacious than DE-71. DE-79 (an octabrominated diphenyl ether mixture) also elevated phospho-ERK1/2, but to a lesser extent than that of DE-71. PBDE congeners 47, 77, 99, and 153 also increased phospo-ERK1/2 in a concentration-dependent manner. The data indicated that PBDE congeners are more potent than the commercial mixtures. PCB 47 also increased phospho-ERK1/2 like its structural analog PBDE 47, but to a lesser extent, suggesting that these chemicals affect similar pathways. Cytotoxicity, measured as %LDH release, data showed that higher concentrations (> 30 muM) and longer exposures (> 30 min

  12. Arachidonic acid enhances intracellular [Ca2+]i increase and mitochondrial depolarization induced by glutamate in cerebellar granule cells.

    PubMed

    Surin, A M; Bolshakov, A P; Mikhailova, M M; Sorokina, E G; Senilova, Ya E; Pinelis, V G; Khodorov, B I

    2006-08-01

    Maturation of primary neuronal cultures is accompanied by an increase in the proportion of cells that exhibit biphasic increase in free cytoplasmic Ca2+ ([Ca2+]i) followed by synchronic decrease in electrical potential difference across the inner mitochondrial membrane (DeltaPsim) in response to stimulation of glutamate receptors. In the present study we have examined whether the appearance of the second phase of [Ca2+]i change can be attributed to arachidonic acid (AA) release in response to the effect of glutamate (Glu) on neurons. Using primary culture of rat cerebellar granule cells we have investigated the effect of AA (1-20 microM) on [Ca2+]i, DeltaPsim, and [ATP] and changes in these parameters induced by neurotoxic concentrations of Glu (100 microM, 10-40 min). At =10 microM, AA caused insignificant decrease in DeltaPsim without any influence on [Ca2+]i. The mitochondrial ATPase inhibitor oligomycin enhanced AA-induced decrease in DeltaPsim; this suggests that AA may inhibit mitochondrial respiration. Addition of AA during the treatment with Glu resulted in more pronounced augmentation of [Ca2+]i and the decrease in DeltaPsim than the changes in these parameters observed during independent action of AA; removal of Glu did not abolish these changes. An inhibitor of the cyclooxygenase and lipoxygenase pathways of AA metabolism, 5,8,11,14-eicosatetraynoic acid, increased the proportion of neurons characterized by Glu-induced biphasic increase in [Ca2+]i and the decrease in DeltaPsim. Palmitic acid (30 microM) did not increase the percentage of neurons exhibiting biphasic response to Glu. Co-administration of AA and Glu caused 2-3 times more pronounced decrease in ATP concentrations than that observed during the independent effect of AA and Glu. The data suggest that AA may influence the functional state of mitochondria, and these changes may promote biphasic [Ca2+]i and DeltaPsim responses of neurons to the neurotoxic effect of Glu.

  13. Cerebellar GABAergic progenitors adopt an external granule cell-like phenotype in the absence of Ptf1a transcription factor expression.

    PubMed

    Pascual, Marta; Abasolo, Ibane; Mingorance-Le Meur, Ana; Martínez, Albert; Del Rio, José A; Wright, Christopher V E; Real, Francisco X; Soriano, Eduardo

    2007-03-20

    We report in this study that, in the cerebellum, the pancreatic transcription factor Ptf1a is required for the specific generation of Purkinje cells (PCs) and interneurons. Moreover, granule cell progenitors in the external GCL (EGL) appear to be unaffected by deletion of Ptf1a. Cell lineage analysis in Ptf1a(Cre/Cre) mice was used to establish that, in the absence of Ptf1a expression, ventricular zone progenitors, normally fated to produce PCs and interneurons, aberrantly migrate to the EGL and express typical markers of these cells, such as Math1, Reelin, and Zic1/2. Furthermore, these cells have a fine structure typical of EGL progenitors, indicating that they adopt an EGL-like cell phenotype. These findings indicate that Ptf1a is necessary for the specification and normal production of PCs and cerebellar interneurons. Moreover, our results suggest that Ptf1a is also required for the suppression of the granule cell specification program in cerebellar ventricular zone precursors.

  14. Developmental Injury to the Cerebellar Cortex Following Hydroxyurea Treatment in Early Postnatal Life: An Immunohistochemical and Electron Microscopic Study.

    PubMed

    Martí, Joaquín; Molina, Vanesa; Santa-Cruz, M C; Hervás, José P

    2017-02-01

    Postnatal development of the cerebellar cortex was studied in rats administered with a single dose (2 mg/g) of the cytotoxic agent hydroxyurea (HU) on postnatal day (P) 9 and collected at appropriate times ranging from 6 h to 45 days. Quantification of several parameters such as the density of pyknotic, mitotic, BrdU-positive, and vimentin-stained cells revealed that HU compromises the survival of the external granular layer (EGL) cells. Moreover, vimentin immunocytochemistry revealed overexpression and thicker immunoreactive glial processes in HU-treated rats. On the other hand, we also show that HU leads to the activation of apoptotic cellular events, resulting in a substantial number of dying EGL cells, as revealed by TUNEL staining and at the electron microscope level. Additionally, we quantified several features of the cerebellar cortex of rats exposed to HU in early postnatal life and collected in adulthood. Data analysis indicated that the analyzed parameters were less pronounced in rats administered with this agent. Moreover, we observed several alterations in the cerebellar cortex cytoarchitecture of rats injected with HU. Anomalies included ectopic placement of Purkinje cells and abnormities in the dendritic arbor of these macroneurons. Ectopic granule cells were also found in the molecular layer. These findings provide a clue for investigating the mechanisms of HU-induced toxicity during the development of the central nervous system. Our results also suggest that it is essential to avoid underestimating the adverse effects of this hydroxylated analog of urea when administered during early postnatal life.

  15. Mice deficient in carbonic anhydrase type 8 exhibit motor dysfunctions and abnormal calcium dynamics in the somatic region of cerebellar granule cells.

    PubMed

    Lamont, Matthew G; Weber, John T

    2015-06-01

    The waddles (wdl) mouse is characterized by a namesake "side-to-side" waddling gait due to a homozygous mutation of the Car8 gene. This mutation results in non-functional copies of the protein carbonic anhydrase type 8. Rota-rod testing was conducted to characterize the wdl mutations' effect on motor output. Results indicated that younger homozygotes outperformed their older cohorts, an effect not seen in previous studies. Heterozygotes, which were thought to be free of motor impairment, displayed motor learning deficiencies when compared with wild type performance. Acute cerebellar slices were then utilized for fluorescent calcium imaging experiments, which revealed significant alterations in cerebellar granule cell somatic calcium signaling when exposed to glutamate. The contribution of GABAergic signaling to these alterations was also verified using bath application of bicuculline. Changes in somatic calcium signals were found to be applicable to an in vivo scenario by comparing group responses to electrical stimulation of afferent mossy fiber projections. Finally, intracellular calcium store function was also found to be altered by the wdl mutation when slices were treated with thapsigargin. These findings, taken together with previous work on the wdl mouse, indicate a widespread disruption in cerebellar circuitry hampering proper neuronal communication. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    EPA Science Inventory

    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, ...

  17. Early Cerebellar Network Shifting in Spinocerebellar Ataxia Type 6

    PubMed Central

    Falcon, M.I.; Gomez, C.M.; Chen, E.E.; Shereen, A.; Solodkin, A.

    2016-01-01

    Spinocerebellar ataxia 6 (SCA6), an autosomal dominant degenerative disease, is characterized by diplopia, gait ataxia, and incoordination due to severe progressive degeneration of Purkinje cells in the vestibulo- and spinocerebellum. Ocular motor deficits are common, including difficulty fixating on moving objects, nystagmus and disruption of smooth pursuit movements. In presymptomatic SCA6, there are alterations in saccades and smooth-pursuit movements. We sought to assess functional and structural changes in cerebellar connectivity associated with a visual task, hypothesizing that gradual changes would parallel disease progression. We acquired functional magnetic resonance imaging and diffusion tensor imaging data during a passive smooth-pursuit task in 14 SCA6 patients, representing a range of disease duration and severity, and performed a cross-sectional comparison of cerebellar networks compared with healthy controls. We identified a shift in activation from vermis in presymptomatic individuals to lateral cerebellum in moderate-to-severe cases. Concomitantly, effective connectivity between regions of cerebral cortex and cerebellum was at its highest in moderate cases, and disappeared in severe cases. Finally, we noted structural differences in the cerebral and cerebellar peduncles. These unique results, spanning both functional and structural domains, highlight widespread changes in SCA6 and compensatory mechanisms associated with cerebellar physiology that could be utilized in developing new therapies. PMID:26209844

  18. Somato-synaptic variation of GABA(A) receptors in cultured murine cerebellar granule cells: investigation of the role of the alpha6 subunit.

    PubMed

    Mellor, J R; Wisden, W; Randall, A D

    2000-07-10

    Electrophysiological investigation of cultured cerebellar murine granule cells revealed differences between the GABA(A) receptors at inhibitory synapses and those on the cell body. Specifically, mIPSCs decayed more rapidly than cell body receptors deactivated, the mean single channel conductance at the synapse (32 pS) was greater than that at cell body (21 pS) and only cell body receptors were sensitive to Zn(2+) (150 microM), which depressed response amplitude by 82+/-5% and almost doubled the rate of channel deactivation. The GABA(A) receptor alpha6 subunit is selectively expressed in cerebellar granule cells. Although concentrated at synapses, it is also found on extrasynaptic membranes. Using a mouse line (Deltaalpha6lacZ) lacking this subunit, we investigated its role in the somato-synaptic differences in GABA(A) receptor function. All differences between cell body and synaptic GABA(A) receptors observed in wild-type (WT) granule cells persisted in Deltaalpha6lacZ cells, thus demonstrating that they are not specifically due to the cellular distribution of the alpha6 subunit. However, mIPSCs from WT and Deltaalpha6lacZ cells differed in both their kinetics (faster decay in WT cells) and underlying single channel conductance (32 pS WT, 25 pS Deltaalpha6lacZ). This provides good evidence for a functional contribution of the alpha6 subunit to postsynaptic GABA(A) receptors in these cells. Despite this, deactivation kinetics of mIPSCs in WT and Deltaalpha6lacZ granule cells exhibited similar benzodiazepene (BDZ) sensitivity. This suggests that the enhanced BDZ-induced ataxia seen in Deltaalpha6lacZ mice may reflect physiological activity at extrasynaptic receptors which, unlike those at synapses, display differential BDZ-sensitivity in WT and Deltaalpha6lacZ granule cells (Jones, A.M., Korpi, E.R., McKernan, R.M., Nusser, Z., Pelz, R., Makela, R., Mellor, J.R., Pollard, S., Bahn, S., Stephenson, F.A., Randall, A.D., Sieghart, W., Somogyi, P., Smith, A.J.H., Wisden

  19. YB-1 is elevated in medulloblastoma and drives proliferation in Sonic hedgehog-dependent cerebellar granule neuron progenitor cells and medulloblastoma cells.

    PubMed

    Dey, A; Robitaille, M; Remke, M; Maier, C; Malhotra, A; Gregorieff, A; Wrana, J L; Taylor, M D; Angers, S; Kenney, A M

    2016-08-11

    Postnatal proliferation of cerebellar granule neuron precursors (CGNPs), proposed cells of origin for the SHH-associated subgroup of medulloblastoma, is driven by Sonic hedgehog (Shh) and insulin-like growth factor (IGF) in the developing cerebellum. Shh induces the oncogene Yes-associated protein (YAP), which drives IGF2 expression in CGNPs and mouse Shh-associated medulloblastomas. To determine how IGF2 expression is regulated downstream of YAP, we carried out an unbiased screen for transcriptional regulators bound to IGF2 promoters. We report that Y-box binding protein-1 (YB-1), an onco-protein regulating transcription and translation, binds to IGF2 promoter P3. We observed that YB-1 is upregulated across human medulloblastoma subclasses as well as in other varieties of pediatric brain tumors. Utilizing the cerebellar progenitor model for the Shh subgroup of medulloblastoma in mice, we show for the first time that YB-1 is induced by Shh in CGNPs. Its expression is YAP-dependent and it is required for IGF2 expression in CGNPs. Finally, both gain-of function and loss-of-function experiments reveal that YB-1 activity is required for sustaining CGNP and medulloblastoma cell (MBC) proliferation. Collectively, our findings describe a novel role for YB-1 in driving proliferation in the developing cerebellum and MBCs and they identify the SHH:YAP:YB1:IGF2 axis as a powerful target for therapeutic intervention in medulloblastomas.

  20. Kinetic and functional analysis of transient, persistent and resurgent sodium currents in rat cerebellar granule cells in situ: an electrophysiological and modelling study

    PubMed Central

    Magistretti, Jacopo; Castelli, Loretta; Forti, Lia; D'Angelo, Egidio

    2006-01-01

    Cerebellar neurones show complex and differentiated mechanisms of action potential generation that have been proposed to depend on peculiar properties of their voltage-dependent Na+ currents. In this study we analysed voltage-dependent Na+ currents of rat cerebellar granule cells (GCs) by performing whole-cell, patch-clamp experiments in acute rat cerebellar slices. A transient Na+ current (INaT) was always present and had the properties of a typical fast-activating/inactivating Na+ current. In addition to INaT, robust persistent (INaP) and resurgent (INaR) Na+ currents were observed. INaP peaked at ∼−40 mV, showed half-maximal activation at ∼−55 mV, and its maximal amplitude was about 1.5% of that of INaT. INaR was elicited by repolarizing pulses applied following step depolarizations able to activate/inactivate INaT, and showed voltage- and time-dependent activation and voltage-dependent decay kinetics. The conductance underlying INaR showed a bell-shaped voltage dependence, with peak at −35 mV. A significant correlation was found between GC INaR and INaT peak amplitudes; however, GCs expressing INaT of similar size showed marked variability in terms of INaR amplitude, and in a fraction of cells INaR was undetectable. INaT, INaP and INaR could be accounted for by a 13-state kinetic scheme comprising closed, open, inactivated and blocked states. Current-clamp experiments carried out to identify possible functional correlates of INaP and/or INaR revealed that in GCs single action potentials were followed by depolarizing afterpotentials (DAPs). In a majority of cells, DAPs showed properties consistent with INaR playing a role in their generation. Computer modelling showed that INaR promotes DAP generation and enhances high-frequency firing, whereas INaP boosts near-threshold firing activity. Our findings suggest that special properties of voltage-dependent Na+ currents provides GCs with mechanisms suitable for shaping activity patterns, with potentially

  1. EVIDENCE FOR GRANULATION IN EARLY A-TYPE STARS

    SciTech Connect

    Kallinger, Thomas; Matthews, Jaymie M.

    2010-03-01

    Stars with spectral types earlier than about F0 on (or close) to the main sequence have long been believed to lack observable surface convection, although evolutionary models of A-type stars do predict very thin surface convective zones. We present evidence for granulation in two {delta} Scuti stars of spectral type A2: HD 174936 and HD 50844. Recent analyses of space-based CoRoT data revealed up to some 1000 frequencies in the photometry of these stars. The frequencies were interpreted as individual pulsation modes. If true, there must be large numbers of nonradial modes of very high degree l which should suffermore » cancellation effects in disk-integrated photometry (even of high space-based precision). The p-mode interpretation of all the frequencies in HD 174936 and HD 50844 depends on the assumption of white (frequency-independent) noise. Our independent analyses of the data provide an alternative explanation: most of the peaks in the Fourier spectra are the signature of non-white granulation background noise, and less than about 100 of the frequencies are actual stellar p-modes in each star. We find granulation timescales which are consistent with scaling relations that describe cooler stars with known surface convection. If the granulation interpretation is correct, the hundreds of low-amplitude Fourier peaks reported in recent studies are falsely interpreted as independent pulsation modes and a significantly lower number of frequencies are associated with pulsation, consistent with only modes of low degree.« less

  2. Inhibitors of the alpha-ketoglutarate dehydrogenase complex alter [1-13C]glucose and [U-13C]glutamate metabolism in cerebellar granule neurons.

    PubMed

    Santos, Sónia Sá; Gibson, Gary E; Cooper, Arthur J L; Denton, Travis T; Thompson, Charles M; Bunik, Victoria I; Alves, Paula M; Sonnewald, Ursula

    2006-02-15

    Diminished activity of the alpha-ketoglutarate dehydrogenase complex (KGDHC), an important component of the tricarboxylic acid (TCA) cycle, occurs in several neurological diseases. The effect of specific KGDHC inhibitors [phosphonoethyl ester of succinyl phosphonate (PESP) and the carboxy ethyl ester of succinyl phosphonate (CESP)] on [1-13C]glucose and [U-13C]glutamate metabolism in intact cerebellar granule neurons was investigated. Both inhibitors decreased formation of [4-13C]glutamate from [1-13C]glucose, a reduction in label in glutamate derived from [1-13C]glucose/[U-13C]glutamate through a second turn of the TCA cycle and a decline in the amounts of gamma-aminobutyric acid (GABA), aspartate, and alanine. PESP decreased formation of [U-13C]aspartate and total glutathione, whereas CESP decreased concentrations of valine and leucine. The findings are consistent with decreased KGDHC activity; increased alpha-ketoglutarate formation; increased transamination of alpha-ketoglutarate with valine, leucine, and GABA; and new equilibrium position of the aspartate aminotransferase reaction. Overall, the findings also suggest that some carbon derived from alpha-ketoglutarate may bypass the block in the TCA cycle at KGDHC by means of the GABA shunt and/or conversion of valine to succinate. The results suggest the potential of succinyl phosphonate esters for modeling the biochemical and pathophysiological consequences of reduced KGDHC activity in brain diseases.

  3. N-acetyl-l-cysteine and Mn2+ attenuate Cd2+-induced disturbance of the intracellular free calcium homeostasis in cultured cerebellar granule neurons.

    PubMed

    Isaev, Nickolay K; Avilkina, Svetlana; Golyshev, Sergey A; Genrikhs, Elisaveta E; Alexandrova, Olga P; Kapkaeva, Marina R; Stelmashook, Elena V

    2018-01-15

    Cadmium is a highly toxic heavy metal that is capable of accumulating in the body via direct exposure or through the alimentary and respiratory tract, leading to neurodegeneration. In this article, we show that the application of CdCl 2 (0.001-0.005mM) for 48h induced high dose-dependent death rate of cultured cerebellar granule neurons (CGNs). Unlike Trolox or vitamin E, antioxidant N-acetyl-l-cysteine (NAC, 1mM) and Mn 2+ (0.0025-0.005mM) significantly protected CGNs from this toxic effect. Using Fluo-4 AM, measurements of intracellular calcium ions demonstrated that 24h-exposure to Cd 2+ induced intensive increase of Fluo-4 fluorescence in neurons accompanied by mitochondria swelling. These data imply that the cadmium-induced Ca 2+ increase is an important element in the death of neurons due to toxic effect of cadmium and the mechanism of protective action of manganese and NAC is mediated by the prevention of increase in calcium levels. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Evidence of two populations of GABA(A) receptors in cerebellar granule cells in culture: different desensitization kinetics, pharmacology, serine/threonine kinase sensitivity, and localization.

    PubMed

    Robello, M; Amico, C; Cupello, A

    1999-12-20

    GABA(A) receptors of rat cerebellar granule cells in culture have been studied by the whole cell patch clamp technique. The biphasic desensitization kinetic observed could be due either to different desensitization mechanisms of a single receptor population or to different receptor populations. The overall data indicate that the latter hypothesis is most probably the correct one. In fact, the fast desensitizing component was selectively potentiated by a benzodiazepine agonist and preferentially down-regulated by activation of the protein serine/threonine kinases A and G, as a consequence of the latter characteristic that receptor population was preferentially down-regulated by previous activation of N-methyl-d-aspartate glutamate receptors, via production of nitric oxide and PKG activation, most probably in dendrites. The other population is benzodiazepine insensitive and not influenced by activation of PKA or PKG. This slowly desensitizing population may correspond to the extrasynaptic delta subunit containing GABA(A) receptors described by other authors. Instead, the rapidly desensitizing population appears to represent dendritic synaptic GABA(A) receptors. Copyright 1999 Academic Press.

  5. Inhibition of glutamate-induced intensification of free radical reactions by gangliosides: possible role in their protective effect in rat cerebellar granule cells and brain synaptosomes.

    PubMed

    Avrova, N F; Victorov, I V; Tyurin, V A; Zakharova, I O; Sokolova, T V; Andreeva, N A; Stelmaschuk, E V; Tyurina, Y Y; Gonchar, V S

    1998-07-01

    The neurotoxic effect of exposure of rat cerebellar granule cells to glutamate (100 microM) is to a large extent prevented by incubation of neurons not only with micromolar, but even with nanomolar concentrations of gangliosides GM1, GD1b, and GT1b. GM1 was also shown to decrease significantly the per cent of dead neurons in culture after induction of lipid peroxidation. Exposure to glutamate was found to cause a significant decrease of the activity of Na+, K+-ATP-ase in rat brain cortex synaptosomes, but superoxide dismutase, alpha-tocopherol, or 10-100 nM GM1 practically prevented its action. Other data showing the ability of gangliosides to inhibit the intensification of free radical reactions by glutamate (based on the estimation of methemoglobin formation, SH group content, etc.) have been obtained. The results suggest that gangliosides are able to decrease the glutamate-induced activation of free radical reactions in nerve cells. This effect appears to contribute to their protective action against glutamate neurotoxicity.

  6. Substance P provides neuroprotection in cerebellar granule cells through Akt and MAPK/Erk activation: evidence for the involvement of the delayed rectifier potassium current.

    PubMed

    Amadoro, G; Pieri, M; Ciotti, M T; Carunchio, I; Canu, N; Calissano, P; Zona, C; Severini, C

    2007-05-01

    In the current study, we have evaluated the ability of substance P (SP) and other neurokinin 1 receptor (NK1) agonists to protect, in a dose- and time-dependent manner, primary cultures of rat cerebellar granule cells (CGCs) from serum and potassium deprivation-induced cell death (S-K5). We also established the presence of SP high affinity NK1 transcripts and the NK1 protein localization in the membrane of a sub-population of CGCs. Moreover, SP significantly and dose-dependently reduced the Akt 1/2 and Erk1/2 dephosphorylation induced by S-K5 conditions, as demonstrated by Western blot analysis. Surprisingly, in SP-treated CGCs caspase-3 activity was not inhibited, while the calpain-1 activity was moderately reduced. Corroborating this result, SP blocked calpain-mediated cleavage of tau protein, as demonstrated by the reduced appearance of a diagnostic fragment of 17 kDa by Western blot analysis. In addition, SP induced a significant reduction of the delayed rectifier K+ currents (Ik) in about 42% of the patched neurons, when these were evoked with depolarizing potential steps. Taken together, the present results demonstrate that the activation of NK1 receptors expressed in CGCs promote the neuronal survival via pathways involving Akt and Erk activation and by inhibition of Ik which can contribute to the neuroprotective effect of the peptide.

  7. Depolarization- and transmitter-induced changes in intracellular Ca2+ of rat cerebellar granule cells in explant cultures.

    PubMed

    Connor, J A; Tseng, H Y; Hockberger, P E

    1987-05-01

    Digital imaging of the Ca indicator fura-2 has been used to study the responses of developing granule cells in culture to depolarization and transmitter action. Unstimulated cells bathed in Krebs saline exhibited cytoplasmic Ca ion concentrations, [Ca2+], that were generally in the 30-60 nM range. Exposure of cells to high-potassium (25 mM) saline depolarized the membrane potential and produced an immediate rise in [Ca2+] that recovered within 2-3 min in normal saline. The response grew progressively larger over the first 20 d in culture. Transient increases in [Ca2+] to levels greater than 1 microM were observed after 12-14 d in vitro, at which time the cells displayed intense electrical activity when exposed to high K. At this stage, the increases were attenuated by blocking action potential activity with TTX. In TTX-treated or immature cells, in which the transient phase of the Ca change was relatively small, a second exposure to high K typically produced a much larger Ca response that the initial exposure. The duration of this facilitation of the response persisted for periods longer than 5 min. Application of the neurotransmitter GABA induced a transient increase in membrane conductance, with a reversal potential near resting potential (approx. -60 mV), and caused an intracellular Ca2+ increase that outlasted the exposure to GABA by several minutes. Glutamate, or kainate, induced an increase in membrane conductance but with a reversal potential more positive than spike threshold. These agents also elevated intracellular Ca2+, but unlike the case with GABA, this Ca response reversed rapidly upon removal of the transmitter. The facilitatory effect of repeated exposures to high-K saline, as well as the persistent Ca elevation following a brief GABA application, suggests that granule cells possess the capability of displaying activity-dependent changes in Ca levels in culture.

  8. Early VGLUT1-specific parallel fiber synaptic deficits and dysregulated cerebellar circuit in the KIKO mouse model of Friedreich ataxia.

    PubMed

    Lin, Hong; Magrane, Jordi; Clark, Elisia M; Halawani, Sarah M; Warren, Nathan; Rattelle, Amy; Lynch, David R

    2017-12-19

    Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder with progressive ataxia that affects both the peripheral and central nervous system (CNS). While later CNS neuropathology involves loss of large principal neurons and glutamatergic and GABAergic synaptic terminals in the cerebellar dentate nucleus, early pathological changes in FRDA cerebellum remain largely uncharacterized. Here, we report early cerebellar VGLUT1 (SLC17A7)-specific parallel fiber (PF) synaptic deficits and dysregulated cerebellar circuit in the frataxin knock-in/knockout (KIKO) FRDA mouse model. At asymptomatic ages, VGLUT1 levels in cerebellar homogenates are significantly decreased, whereas VGLUT2 (SLC17A6) levels are significantly increased, in KIKO mice compared with age-matched controls. Additionally, GAD65 (GAD2) levels are significantly increased, while GAD67 (GAD1) levels remain unaltered. This suggests early VGLUT1-specific synaptic input deficits, and dysregulation of VGLUT2 and GAD65 synaptic inputs, in the cerebellum of asymptomatic KIKO mice. Immunohistochemistry and electron microscopy further show specific reductions of VGLUT1-containing PF presynaptic terminals in the cerebellar molecular layer, demonstrating PF synaptic input deficiency in asymptomatic and symptomatic KIKO mice. Moreover, the parvalbumin levels in cerebellar homogenates and Purkinje neurons are significantly reduced, but preserved in other interneurons of the cerebellar molecular layer, suggesting specific parvalbumin dysregulation in Purkinje neurons of these mice. Furthermore, a moderate loss of large principal neurons is observed in the dentate nucleus of asymptomatic KIKO mice, mimicking that of FRDA patients. Our findings thus identify early VGLUT1-specific PF synaptic input deficits and dysregulated cerebellar circuit as potential mediators of cerebellar dysfunction in KIKO mice, reflecting developmental features of FRDA in this mouse model. © 2017. Published by The Company of

  9. Curcumin Pretreatment Induces Nrf2 and an Antioxidant Response and Prevents Hemin-Induced Toxicity in Primary Cultures of Cerebellar Granule Neurons of Rats

    PubMed Central

    González-Reyes, Susana; Guzmán-Beltrán, Silvia; Medina-Campos, Omar Noel; Pedraza-Chaverri, José

    2013-01-01

    Curcumin is a bifunctional antioxidant derived from Curcuma longa. This study identifies curcumin as a neuroprotectant against hemin-induced damage in primary cultures of cerebellar granule neurons (CGNs) of rats. Hemin, the oxidized form of heme, is a highly reactive compound that induces cellular injury. Pretreatment of CGNs with 5–30 μM curcumin effectively increased by 2.3–4.9 fold heme oxygenase-1 (HO-1) expression and by 5.6–14.3-fold glutathione (GSH) levels. Moreover, 15 μM curcumin attenuated by 55% the increase in reactive oxygen species (ROS) production, by 94% the reduction of GSH/glutathione disulfide (GSSG) ratio, and by 49% the cell death induced by hemin. The inhibition of heme oxygenase system or GSH synthesis with tin mesoporphyrin and buthionine sulfoximine, respectively, suppressed the protective effect of curcumin against hemin-induced toxicity. These data strongly suggest that HO-1 and GSH play a major role in the protective effect of curcumin. Furthermore, it was found that 24 h of incubation with curcumin increases by 1.4-, 2.3-, and 5.2-fold the activity of glutathione reductase, glutathione S-transferase and superoxide dismutase, respectively. Additionally, it was found that curcumin was capable of inducing nuclear factor (erythroid-derived 2)-like 2 (Nrf2) translocation into the nucleus. These data suggest that the pretreatment with curcumin induces Nrf2 and an antioxidant response that may play an important role in the protective effect of this antioxidant against hemin-induced neuronal death. PMID:24454990

  10. Sex-specific activation of cell death signalling pathways in cerebellar granule neurons exposed to oxygen glucose deprivation followed by reoxygenation

    PubMed Central

    Sharma, Jaswinder; Nelluru, Geetha; Ann Wilson, Mary; Johnston, Michael V; Ahamed Hossain, Mir

    2011-01-01

    Neuronal death pathways following hypoxia–ischaemia are sexually dimorphic, but the underlying mechanisms are unclear. We examined cell death mechanisms during OGD (oxygen-glucose deprivation) followed by Reox (reoxygenation) in segregated male (XY) and female (XX) mouse primary CGNs (cerebellar granule neurons) that are WT (wild-type) or Parp-1 [poly(ADP-ribose) polymerase 1] KO (knockout). Exposure of CGNs to OGD (1.5 h)/Reox (7 h) caused cell death in XY and XX neurons, but cell death during Reox was greater in XX neurons. ATP levels were significantly lower after OGD/Reox in WT-XX neurons than in XY neurons; this difference was eliminated in Parp-1 KO-XX neurons. AIF (apoptosis-inducing factor) was released from mitochondria and translocated to the nucleus by 1 h exclusively in WT-XY neurons. In contrast, there was a release of Cyt C (cytochrome C) from mitochondria in WT-XX and Parp-1 KO neurons of both sexes; delayed activation of caspase 3 was observed in the same three groups. Thus deletion of Parp-1 shunted cell death towards caspase 3-dependent apoptosis. Delayed activation of caspase 8 was also observed in all groups after OGD/Reox, but was much greater in XX neurons, and caspase 8 translocated to the nucleus in XX neurons only. Caspase 8 activation may contribute to increased XX neuronal death during Reox, via caspase 3 activation. Thus, OGD/Reox induces death of XY neurons via a PARP-1-AIF-dependent mechanism, but blockade of PARP-1-AIF pathway shifts neuronal death towards a caspase-dependent mechanism. In XX neurons, OGD/Reox caused prolonged depletion of ATP and delayed activation of caspase 8 and caspase 3, culminating in greater cell death during Reox. PMID:21382016

  11. Activation of sodium channels by α-scorpion toxin, BmK NT1, produced neurotoxicity in cerebellar granule cells: an association with intracellular Ca2+ overloading.

    PubMed

    He, Yuwei; Zou, Xiaohan; Li, Xichun; Chen, Juan; Jin, Liang; Zhang, Fan; Yu, Boyang; Cao, Zhengyu

    2017-02-01

    Voltage-gated sodium channels (VGSCs) are responsible for the action potential generation in excitable cells including neurons and involved in many physiological and pathological processes. Scorpion toxins are invaluable tools to explore the structure and function of ion channels. BmK NT1, a scorpion toxin from Buthus martensii Karsch, stimulates sodium influx in cerebellar granule cells (CGCs). In this study, we characterized the mode of action of BmK NT1 on the VGSCs and explored the cellular response in CGC cultures. BmK NT1 delayed the fast inactivation of VGSCs, increased the Na + currents, and shifted the steady-state activation and inactivation to more hyperpolarized membrane potential, which was similar to the mode of action of α-scorpion toxins. BmK NT1 stimulated neuron death (EC 50  = 0.68 µM) and produced massive intracellular Ca 2+ overloading (EC 50  = 0.98 µM). TTX abrogated these responses, suggesting that both responses were subsequent to the activation of VGSCs. The Ca 2+ response of BmK NT1 was primary through extracellular Ca 2+ influx since reducing the extracellular Ca 2+ concentration suppressed the Ca 2+ response. Further pharmacological evaluation demonstrated that BmK NT1-induced Ca 2+ influx and neurotoxicity were partially blocked either by MK-801, an NMDA receptor blocker, or by KB-R7943, an inhibitor of Na + /Ca 2+ exchangers. Nifedipine, an L-type Ca 2+ channel inhibitor, slightly suppressed both Ca 2+ response and neurotoxicity. A combination of these three inhibitors abrogated both responses. Considered together, these data ambiguously demonstrated that activation of VGSCs by an α-scorpion toxin was sufficient to produce neurotoxicity which was associated with intracellular Ca 2+ overloading through both NMDA receptor- and Na + /Ca 2+ exchanger-mediated Ca 2+ influx.

  12. GDF15 regulates Kv2.1-mediated outward K+ current through the Akt/mTOR signalling pathway in rat cerebellar granule cells.

    PubMed

    Wang, Chang-Ying; Huang, An-Qi; Zhou, Meng-Hua; Mei, Yan-Ai

    2014-05-15

    GDF15 (growth/differentiation factor 15), a novel member of the TGFβ (transforming growth factor β) superfamily, plays critical roles in the central and peripheral nervous systems, but the signal transduction pathways and receptor subtypes involved are not well understood. In the present paper, we report that GDF15 specifically increases the IK (delayed-rectifier outward K+ current) in rat CGNs (cerebellar granule neurons) in time- and concentration-dependent manners. The GDF15-induced amplification of the IK is mediated by the increased expression and reduced lysosome-dependent degradation of the Kv2.1 protein, the main α-subunit of the IK channel. Exposure of CGNs to GDF15 markedly induced the phosphorylation of ERK (extracellular-signal-regulated kinase), Akt and mTOR (mammalian target of rapamycin), but the GDF15-induced IK densities and increased expression of Kv2.1 were attenuated only by Akt and mTOR, and not ERK, inhibitors. Pharmacological inhibition of the Src-mediated phosphorylation of TGFβR2 (TGFβ receptor 2), not TGFβR1, abrogated the effect of GDF15 on IK amplification and Kv2.1 induction. Immunoprecipitation assays showed that GDF15 increased the tyrosine phosphorylation of TGFβRII in the CGN lysate. The results of the present study reveal a novel regulation of Kv2.1 by GDF15 mediated through the TGFβRII-activated Akt/mTOR pathway, which is a previously uncharacterized Smad-independent mechanism of GDF15 signalling.

  13. The Role of Ca2+ Imbalance in the Induction of Acute Oxidative Stress and Cytotoxicity in Cultured Rat Cerebellar Granule Cells Challenged with Tetrabromobisphenol A.

    PubMed

    Zieminska, Elzbieta; Lenart, Jacek; Diamandakis, Dominik; Lazarewicz, Jerzy W

    2017-03-01

    Using primary cultures of rat cerebellar granule cells (CGC) we examined the role of calcium transients induced by tetrabromobisphenol A (TBBPA) in triggering oxidative stress and cytotoxicity. CGC were exposed for 30 min to 10 or 25 µM TBBPA. Changes in intracellular calcium concentration ([Ca 2+ ] i ), in the production of reactive oxygen species (ROS), and in the potential of mitochondria (∆Ψm) were measured fluorometrically during the exposure. The intracellular glutathione (GSH) and catalase activity were determined after the incubation; cell viability was evaluated 24 h later. TBBPA concentration-dependently increased [Ca 2+ ] i and ROS production, and reduced GSH content, catalase activity, ∆Ψm and neuronal viability. The combination of NMDA and ryanodine receptor antagonists, MK-801 and bastadin 12 with ryanodine, respectively, prevented Ca 2+ transients and partially reduced cytotoxicity induced by TBBPA at both concentrations. The antagonists also completely inhibited oxidative stress and depolarization of mitochondria evoked by 10 µM TBBPA, whereas these effects were only partially reduced in the 25 µM TBBPA treatment. Free radical scavengers prevented TBBPA-induced development of oxidative stress and improved CGC viability without having any effect on the rises in Ca 2+ and drop in ∆Ψm. The co-administration of scavengers with NMDA and ryanodine receptor antagonists provided almost complete neuroprotection. These results indicate that Ca 2+ imbalance and oxidative stress both mediate acute toxicity of TBBPA in CGC. At 10 µM TBBPA Ca 2+ imbalance is a primary event, inducing oxidative stress, depolarization of mitochondria and cytotoxicity, whilst at a concentration of 25 µM TBBPA an additional Ca 2+ -independent portion of oxidative stress and cytotoxicity emerges.

  14. Weaker control of the electrical properties of cerebellar granule cells by tonically active GABAA receptors in the Ts65Dn mouse model of Down’s syndrome

    PubMed Central

    2013-01-01

    Background Down’s syndrome (DS) is caused by triplication of all or part of human chromosome 21 and is characterized by a decrease in the overall size of the brain. One of the brain regions most affected is the cerebellum, in which the number of granule cells (GCs) is markedly decreased. GCs process sensory information entering the cerebellum via mossy fibres and pass it on to Purkinje cells and inhibitory interneurons. How GCs transform incoming signals depends on their input–output relationship, which is adjusted by tonically active GABAA receptor channels. Results We report that in the Ts65Dn mouse model of DS, in which cerebellar volume and GC number are decreased as in DS, the tonic GABAA receptor current in GCs is smaller than in wild-type mice and is less effective in moderating input resistance and raising the minimum current required for action potential firing. We also find that tonically active GABAA receptors curb the height and broaden the width of action potentials in wild-type GCs but not in Ts65Dn GCs. Single-cell real-time quantitative PCR reveals that these electrical differences are accompanied by decreased expression of the gene encoding the GABAA receptor β3 subunit but not genes coding for some of the other GABAA receptor subunits expressed in GCs (α1, α6, β2 and δ). Conclusions Weaker moderation of excitability and action potential waveform in GCs of the Ts65Dn mouse by tonically active GABAA receptors is likely to contribute to atypical transfer of information through the cerebellum. Similar changes may occur in DS. PMID:23870245

  15. BNN27, a 17-Spiroepoxy Steroid Derivative, Interacts With and Activates p75 Neurotrophin Receptor, Rescuing Cerebellar Granule Neurons from Apoptosis.

    PubMed

    Pediaditakis, Iosif; Kourgiantaki, Alexandra; Prousis, Kyriakos C; Potamitis, Constantinos; Xanthopoulos, Kleanthis P; Zervou, Maria; Calogeropoulou, Theodora; Charalampopoulos, Ioannis; Gravanis, Achille

    2016-01-01

    Neurotrophin receptors mediate a plethora of signals affecting neuronal survival. The p75 pan-neurotrophin receptor controls neuronal cell fate after its selective activation by immature and mature isoforms of all neurotrophins. It also exerts pleiotropic effects interacting with a variety of ligands in different neuronal or non-neuronal cells. In the present study, we explored the biophysical and functional interactions of a blood-brain-barrier (BBB) permeable, C17-spiroepoxy steroid derivative, BNN27, with p75 NTR receptor. BNN27 was recently shown to bind to NGF high-affinity receptor, TrkA. We now tested the p75 NTR -mediated effects of BNN27 in mouse Cerebellar Granule Neurons (CGNs), expressing p75 NTR , but not TrkA receptors. Our findings show that BNN27 physically interacts with p75 NTR receptors in specific amino-residues of its extracellular domain, inducing the recruitment of p75 NTR receptor to its effector protein RIP2 and the simultaneous release of RhoGDI in primary neuronal cells. Activation of the p75 NTR receptor by BNN27 reverses serum deprivation-induced apoptosis of CGNs resulting in the decrease of the phosphorylation of pro-apoptotic JNK kinase and of the cleavage of Caspase-3, effects completely abolished in CGNs, isolated from p75 NTR null mice. In conclusion, BNN27 represents a lead molecule for the development of novel p75 NTR ligands, controlling specific p75 NTR -mediated signaling of neuronal cell fate, with potential applications in therapeutics of neurodegenerative diseases and brain trauma.

  16. BNN27, a 17-Spiroepoxy Steroid Derivative, Interacts With and Activates p75 Neurotrophin Receptor, Rescuing Cerebellar Granule Neurons from Apoptosis

    PubMed Central

    Pediaditakis, Iosif; Kourgiantaki, Alexandra; Prousis, Kyriakos C.; Potamitis, Constantinos; Xanthopoulos, Kleanthis P.; Zervou, Maria; Calogeropoulou, Theodora; Charalampopoulos, Ioannis; Gravanis, Achille

    2016-01-01

    Neurotrophin receptors mediate a plethora of signals affecting neuronal survival. The p75 pan-neurotrophin receptor controls neuronal cell fate after its selective activation by immature and mature isoforms of all neurotrophins. It also exerts pleiotropic effects interacting with a variety of ligands in different neuronal or non-neuronal cells. In the present study, we explored the biophysical and functional interactions of a blood-brain-barrier (BBB) permeable, C17-spiroepoxy steroid derivative, BNN27, with p75NTR receptor. BNN27 was recently shown to bind to NGF high-affinity receptor, TrkA. We now tested the p75NTR-mediated effects of BNN27 in mouse Cerebellar Granule Neurons (CGNs), expressing p75NTR, but not TrkA receptors. Our findings show that BNN27 physically interacts with p75NTR receptors in specific amino-residues of its extracellular domain, inducing the recruitment of p75NTR receptor to its effector protein RIP2 and the simultaneous release of RhoGDI in primary neuronal cells. Activation of the p75NTR receptor by BNN27 reverses serum deprivation-induced apoptosis of CGNs resulting in the decrease of the phosphorylation of pro-apoptotic JNK kinase and of the cleavage of Caspase-3, effects completely abolished in CGNs, isolated from p75NTR null mice. In conclusion, BNN27 represents a lead molecule for the development of novel p75NTR ligands, controlling specific p75NTR-mediated signaling of neuronal cell fate, with potential applications in therapeutics of neurodegenerative diseases and brain trauma. PMID:28082899

  17. In vitro study of uptake and synthesis of creatine and its precursors by cerebellar granule cells and astrocytes suggests some hypotheses on the physiopathology of the inherited disorders of creatine metabolism

    PubMed Central

    2012-01-01

    Background The discovery of the inherited disorders of creatine (Cr) synthesis and transport in the last few years disclosed the importance of blood Cr supply for the normal functioning of the brain. These putatively rare diseases share a common pathogenetic mechanism (the depletion of brain Cr) and similar phenotypes characterized by mental retardation, language disturbances, seizures and movement disorders. In the effort to improve our knowledge on the mechanisms regulating Cr pool inside the nervous tissue, Cr transport and synthesis and related gene transcripts were explored in primary cultures of rat cerebellar granule cells and astrocytes. Methods Cr uptake and synthesis were explored in vitro by incubating monotypic primary cultures of rat type I astrocytes and cerebellar granule cells with: a) D3-Creatine (D3Cr) and D3Cr plus β-guanidinopropionate (GPA, an inhibitor of Cr transporter), and b) labelled precursors of Guanidinoacetate (GAA) and Cr (Arginine, Arg; Glycine, Gly). Intracellular D3Cr and labelled GAA and Cr were assessed by ESI-MS/MS. Creatine transporter (CT1), L-arginine:glycine amidinotransferase (AGAT), and S-adenosylmethionine:guanidinoacetate N-methyltransferase (GAMT) gene expression was assessed in the same cells by real time PCR. Results D3Cr signal was extremely high in cells incubated with this isotope (labelled/unlabelled Cr ratio reached about 10 and 122, respectively in cerebellar granule cells and astrocytes) and was reduced by GPA. Labelled Arg and Gly were taken up by the cells and incorporated in GAA, whose concentration paralleled that of these precursors both in the extracellular medium and inside the cells (astrocytes). In contrast, the increase of labelled Cr was relatively much more limited since labelled Cr after precursors' supplementation did not exceed 2,7% (cerebellar granule cells) and 21% (astrocytes) of unlabelled Cr. Finally, AGAT, GAMT and SLC6A8 were expressed in both kind of cells. Conclusions Our results

  18. In vitro study of uptake and synthesis of creatine and its precursors by cerebellar granule cells and astrocytes suggests some hypotheses on the physiopathology of the inherited disorders of creatine metabolism.

    PubMed

    Carducci, Claudia; Carducci, Carla; Santagata, Silvia; Adriano, Enrico; Artiola, Cristiana; Thellung, Stefano; Gatta, Elena; Robello, Mauro; Florio, Tullio; Antonozzi, Italo; Leuzzi, Vincenzo; Balestrino, Maurizio

    2012-04-26

    The discovery of the inherited disorders of creatine (Cr) synthesis and transport in the last few years disclosed the importance of blood Cr supply for the normal functioning of the brain. These putatively rare diseases share a common pathogenetic mechanism (the depletion of brain Cr) and similar phenotypes characterized by mental retardation, language disturbances, seizures and movement disorders. In the effort to improve our knowledge on the mechanisms regulating Cr pool inside the nervous tissue, Cr transport and synthesis and related gene transcripts were explored in primary cultures of rat cerebellar granule cells and astrocytes. Cr uptake and synthesis were explored in vitro by incubating monotypic primary cultures of rat type I astrocytes and cerebellar granule cells with: a) D3-Creatine (D3Cr) and D3Cr plus β-guanidinopropionate (GPA, an inhibitor of Cr transporter), and b) labelled precursors of Guanidinoacetate (GAA) and Cr (Arginine, Arg; Glycine, Gly). Intracellular D3Cr and labelled GAA and Cr were assessed by ESI-MS/MS. Creatine transporter (CT1), L-arginine:glycine amidinotransferase (AGAT), and S-adenosylmethionine:guanidinoacetate N-methyltransferase (GAMT) gene expression was assessed in the same cells by real time PCR. D3Cr signal was extremely high in cells incubated with this isotope (labelled/unlabelled Cr ratio reached about 10 and 122, respectively in cerebellar granule cells and astrocytes) and was reduced by GPA. Labelled Arg and Gly were taken up by the cells and incorporated in GAA, whose concentration paralleled that of these precursors both in the extracellular medium and inside the cells (astrocytes). In contrast, the increase of labelled Cr was relatively much more limited since labelled Cr after precursors' supplementation did not exceed 2,7% (cerebellar granule cells) and 21% (astrocytes) of unlabelled Cr. Finally, AGAT, GAMT and SLC6A8 were expressed in both kind of cells. Our results confirm that both neurons and astrocytes have

  19. Early healing in alveolar sockets grafted with titanium granules. An experimental study in a dog model.

    PubMed

    Arruda, Thiago; Sukekava, Flávia; de Souza, André B; Rasmusson, Lars; Araújo, Maurício G

    2013-07-01

    The aim of the present study was to evaluate the effect of the placement of titanium granules in fresh extraction sockets on early bone formation. The mesial roots of the third maxillary premolars of five adult beagle dogs were removed. On one side of the maxilla (Test group) the fresh extraction socket was grafted with titanium granules, while the contra-lateral socket was left non-grafted (Control group). After 1 month of healing, the dogs were euthanized and biopsies were obtained. The healing tissues were described, and histometric measurements were performed to obtain the percentage area occupied by connective tissue, new mineralized bone, bone marrow, and biomaterial particles. After 1 month of healing the findings from the histological examination revealed the titanium graft to be well incorporated into the provisional connective tissue or newly formed woven bone. The histometric measurements showed, however, that less mineralized bone was formed in the Test group than in the Control group. The present study suggests that the use of titanium granules in fresh extraction sockets was conducive to new bone formation. The graft of titanium granules seems, however, to delay the early phase of the healing process. Copyright © 2012 Wiley Periodicals, Inc.

  20. Updates to a 13C metabolic flux analysis model for evaluating energy metabolism in cultured cerebellar granule neurons from neonatal rats.

    PubMed

    Jekabsons, Mika B; Gebril, Hoda M; Wang, Yan-Hong; Avula, Bharathi; Khan, Ikhlas A

    2017-10-01

    A hexose phosphate recycling model previously developed to infer fluxes through the major glucose consuming pathways in cultured cerebellar granule neurons (CGNs) from neonatal rats metabolizing [1,2- 13 C 2 ]glucose was revised by considering reverse flux through the non-oxidative pentose phosphate pathway (PPP) and symmetrical succinate oxidation within the tricarboxylic acid (TCA) cycle. The model adjusts three flux ratios to effect 13 C distribution in the hexose, pentose, and triose phosphate pools, and in TCA cycle malate to minimize the error between predicted and measured 13 C labeling in exported lactate (i.e., unlabeled, single-, double-, and triple-labeled; M, M1, M2, and M3, respectively). Inclusion of reverse non-oxidative PPP flux substantially increased the number of calculations but ultimately had relatively minor effects on the labeling of glycolytic metabolites. From the error-minimized solution in which the predicted M-M3 lactate differed by 0.49% from that measured by liquid chromatography-triple quadrupole mass spectrometry, the neurons exhibited negligible forward non-oxidative PPP flux. Thus, no glucose was used by the pentose cycle despite explicit consideration of hexose phosphate recycling. Mitochondria consumed only 16% of glucose while 45% was exported as lactate by aerobic glycolysis. The remaining 39% of glucose was shunted to pentose phosphates presumably for de novo nucleotide synthesis, but the proportion metabolized through the oxidative PPP vs. the reverse non-oxidative PPP could not be determined. The lactate exported as M1 (2.5%) and M3 (1.2%) was attributed to malic enzyme, which was responsible for 7.8% of pyruvate production (vs. 92.2% by glycolysis). The updated model is more broadly applicable to different cell types by considering bi-directional flux through the non-oxidative PPP. Its application to cultured neurons utilizing glucose as the sole exogenous substrate has demonstrated substantial oxygen-independent glucose

  1. Protection by imidazol(ine) drugs and agmatine of glutamate-induced neurotoxicity in cultured cerebellar granule cells through blockade of NMDA receptor

    PubMed Central

    Olmos, Gabriel; DeGregorio-Rocasolano, Nuria; Regalado, M Paz; Gasull, Teresa; Boronat, M Assumpció; Trullas, Ramón; Villarroel, Alvaro; Lerma, Juan; García-Sevilla, Jesús A

    1999-01-01

    This study was designed to assess the potential neuroprotective effect of several imidazol(ine) drugs and agmatine on glutamate-induced necrosis and on apoptosis induced by low extracellular K+ in cultured cerebellar granule cells.Exposure (30 min) of energy deprived cells to L-glutamate (1–100 μM) caused a concentration-dependent neurotoxicity, as determined 24 h later by a decrease in the ability of the cells to metabolize 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) into a reduced formazan product. L-glutamate-induced neurotoxicity (EC50=5 μM) was blocked by the specific NMDA receptor antagonist MK-801 (dizocilpine).Imidazol(ine) drugs and agmatine fully prevented neurotoxicity induced by 20 μM (EC100) L-glutamate with the rank order (EC50 in μM): antazoline (13)>cirazoline (44)>LSL 61122 [2-styryl-2-imidazoline] (54)>LSL 60101 [2-(2-benzofuranyl) imidazole] (75)>idazoxan (90)>LSL 60129 [2-(1,4-benzodioxan-6-yl)-4,5-dihydroimidazole] (101)>RX821002 (2-methoxy idazoxan) (106)>agmatine (196). No neuroprotective effect of these drugs was observed in a model of apoptotic neuronal cell death (reduction of extracellular K+) which does not involve stimulation of NMDA receptors.Imidazol(ine) drugs and agmatine fully inhibited [3H]-(+)-MK-801 binding to the phencyclidine site of NMDA receptors in rat brain. The profile of drug potency protecting against L-glutamate neurotoxicity correlated well (r=0.90) with the potency of the same compounds competing against [3H]-(+)-MK-801 binding.In HEK-293 cells transfected to express the NR1-1a and NR2C subunits of the NMDA receptor, antazoline and agmatine produced a voltage- and concentration-dependent block of glutamate-induced currents. Analysis of the voltage dependence of the block was consistent with the presence of a binding site for antazoline located within the NMDA channel pore with an IC50 of 10–12 μM at 0 mV.It is concluded that imidazol(ine) drugs and agmatine are

  2. Acute Ethanol Exposure Prevents PMA-mediated Augmentation of N-methyl-d-aspartate Receptor Function in Primary Cultured Cerebellar Granule Cells

    PubMed Central

    Reneau, Jason; Reyland, Mary E.; Popp, R. Lisa

    2011-01-01

    Many intracellular proteins and signaling cascades contribute to the ethanol sensitivity of native N-methyl-d-aspartate receptors (NMDARs). One putative protein is the serine / threonine kinase, Protein kinase C (PKC). The purpose of this study was to assess if PKC modulates the ethanol sensitivity of native NMDARs expressed in primary cultured cerebellar granule cells (CGCs). With the whole-cell patch-clamp technique, we assessed if ethanol inhibition of NMDA-induced currents (INMDA) (100 μM NMDA plus 10 μM glycine) were altered in CGCs in which the novel and classical PKC isoforms were activated by phorbol-12-myristate-13-acetate (PMA). Percent inhibition by 10, 50 or 100 mM ethanol of NMDA-induced steady-state (ISS) or peak current amplitudes (IPk) of NMDARs expressed in CGCs in which PKC was activated by a 12.5 min, 100 nM PMA exposure at 37° C did not differ from currents obtained from receptors contained in control cells. However, PMA-mediated augmentation of IPk in the absence of ethanol was abolished after brief applications of 10 or 1 mM ethanol co-applied with agonists, and this suppression of enhanced receptor function was observed for up to eight minutes post-ethanol exposure. Because we had previously shown that PMA-mediated augmentation of INMDA of NMDARs expressed in these cells is by activation of PKCα, we assessed the effect of ethanol (1, 10, 50 and 100 mM) on PKCα activity. Ethanol decreased PKCα activity by 18% for 1 mM ethanol and activity decreased with increasing ethanol concentrations with a 50% inhibition observed with 100 mM ethanol. The data suggest that ethanol disruption of PMA-mediated augmentation of INMDA may be due to a decrease in PKCα activity by ethanol. However, given the incomplete blockade of PKCα activity and the low concentration of ethanol at which this phenomenon is observed, other ethanol-sensitive signaling cascades must also be involved. PMID:21624785

  3. Time-dependent effects of perfluorinated compounds on viability in cerebellar granule neurons: Dependence on carbon chain length and functional group attached.

    PubMed

    Berntsen, Hanne Friis; Bjørklund, Cesilie Granum; Audinot, Jean-Nicolas; Hofer, Tim; Verhaegen, Steven; Lentzen, Esther; Gutleb, Arno Christian; Ropstad, Erik

    2017-12-01

    The toxicity of long chained perfluoroalkyl acids (PFAAs) has previously been reported to be related to the length of the perfluorinated carbon chain and functional group attached. In the present study, we compared the cytotoxicity of six PFAAs, using primary cultures of rat cerebellar granule neurons (CGNs). Two perfluoroalkyl sulfonic acids (PFSAs, chain length C 6 and C 8 ) and four perfluoroalkyl carboxylic acids (PFCAs, chain length C 8 -C 11 ) were studied. These PFAAs have been detected in human blood and the brain tissue of mammals. The cell viability trypan blue and MTT assays were used to determine toxicity potencies (based on LC 50 values) after 24h exposure (in descending order): perfluoroundecanoic acid (PFUnDA)≥perfluorodecanoic acid (PFDA)>perfluorooctanesulfonic acid potassium salt (PFOS)>perfluorononanoic acid (PFNA)>perfluorooctanoic acid (PFOA)>perfluorohexanesulfonic acid potassium salt (PFHxS). Concentrations of the six PFAAs that produced equipotent effects after 24h exposure were used to further explore the dynamics of viability changes during this period. Therefore viability was assessed at 10, 30, 60, 90, 120 and 180min as well as 6, 12, 18 and 24h. A difference in the onset of reduction in viability was observed, occurring relatively quickly (30-60min) for PFOS, PFDA and PFUnDA, and much slower (12-24h) for PFHxS, PFOA and PFNA. A slight protective effect of vitamin E against PFOA, PFNA and PFOS-induced reduction in viability indicated a possible involvement of oxidative stress. PFOA and PFOS did not induce lipid peroxidation on their own, but significantly accelerated cumene hydroperoxide-induced lipid peroxidation. When distribution of the six PFAAs in the CGN-membrane was investigated using NanoSIMS50 imaging, two distinct patterns appeared. Whereas PFHxS, PFOS and PFUnDA aggregated in large hotspots, PFOA, PFNA and PFDA showed a more dispersed distribution pattern. In conclusion, the toxicity of the investigated PFAAs increased with

  4. Ternary Kv4.2 channels recapitulate voltage-dependent inactivation kinetics of A-type K+ channels in cerebellar granule neurons.

    PubMed

    Amarillo, Yimy; De Santiago-Castillo, Jose A; Dougherty, Kevin; Maffie, Jonathon; Kwon, Elaine; Covarrubias, Manuel; Rudy, Bernardo

    2008-04-15

    Kv4 channels mediate most of the somatodendritic subthreshold operating A-type current (I(SA)) in neurons. This current plays essential roles in the regulation of spike timing, repetitive firing, dendritic integration and plasticity. Neuronal Kv4 channels are thought to be ternary complexes of Kv4 pore-forming subunits and two types of accessory proteins, Kv channel interacting proteins (KChIPs) and the dipeptidyl-peptidase-like proteins (DPPLs) DPPX (DPP6) and DPP10. In heterologous cells, ternary Kv4 channels exhibit inactivation that slows down with increasing depolarization. Here, we compared the voltage dependence of the inactivation rate of channels expressed in heterologous mammalian cells by Kv4.2 proteins with that of channels containing Kv4.2 and KChIP1, Kv4.2 and DPPX-S, or Kv4.2, KChIP1 and DPPX-S, and found that the relation between inactivation rate and membrane potential is distinct for these four conditions. Moreover, recordings from native neurons showed that the inactivation kinetics of the I(SA) in cerebellar granule neurons has voltage dependence that is remarkably similar to that of ternary Kv4 channels containing KChIP1 and DPPX-S proteins in heterologous cells. The fact that this complex and unique behaviour (among A-type K(+) currents) is observed in both the native current and the current expressed in heterologous cells by the ternary complex containing Kv4, DPPX and KChIP proteins supports the hypothesis that somatically recorded native Kv4 channels in neurons include both types of accessory protein. Furthermore, quantitative global kinetic modelling showed that preferential closed-state inactivation and a weakly voltage-dependent opening step can explain the slowing of the inactivation rate with increasing depolarization. Therefore, it is likely that preferential closed-state inactivation is the physiological mechanism that regulates the activity of both ternary Kv4 channel complexes and native I(SA)-mediating channels.

  5. Delayed rotation of the cerebellar vermis: a pitfall in early second-trimester fetal magnetic resonance imaging.

    PubMed

    Pinto, J; Paladini, D; Severino, M; Morana, G; Pais, R; Martinetti, C; Rossi, A

    2016-07-01

    We describe two cases in which delayed rotation of the cerebellar vermis simulated a Dandy-Walker malformation (DWM) on early second-trimester magnetic resonance imaging (MRI). Two pregnant women with suspected fetal posterior fossa anomaly on ultrasound examination underwent fetal MRI at 21 (Case 1) and 19 (Case 2) weeks' gestation. In both cases, upward rotation of the cerebellar vermis was noted; on midsagittal imaging, the brainstem-vermis angle was 28° and 43°, respectively, while cerebellar morphometry showed a reduced vermian anteroposterior diameter compared to reference data. The posterior fossa appeared to be mildly enlarged, while all other findings were normal. Follow-up MRI at 28 + 3 weeks' gestation (Case 1) and at 1 postnatal year (Case 2) showed completely normal findings. Both children had normal psychomotor development and neurological examinations at 1 year of age. Incomplete rotation of the cerebellar vermis can be a physiological finding on early second-trimester fetal MRI examination and can simulate DWM or other forms of cerebellar hypoplasia. Embryologically, delayed permeabilization of Blake's pouch could account for the delayed vermian rotation. Follow-up imaging at a later gestational age is crucial to ensure that this condition is not over-reported and to avoid the potential risk of unnecessary pregnancy interruption. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

  6. FGF-2 signal promotes proliferation of cerebellar progenitor cells and their oligodendrocytic differentiation at early postnatal stage

    SciTech Connect

    Naruse, Masae; Shibasaki, Koji; Ishizaki, Yasuki, E-mail: yasukiishizaki@gunma-u.ac.jp

    The origins and developmental regulation of cerebellar oligodendrocytes are largely unknown, although some hypotheses of embryonic origins have been suggested. Neural stem cells exist in the white matter of postnatal cerebellum, but it is unclear whether these neural stem cells generate oligodendrocytes at postnatal stages. We previously showed that cerebellar progenitor cells, including neural stem cells, widely express CD44 at around postnatal day 3. In the present study, we showed that CD44-positive cells prepared from the postnatal day 3 cerebellum gave rise to neurospheres, while CD44-negative cells prepared from the same cerebellum did not. These neurospheres differentiated mainly into oligodendrocytesmore » and astrocytes, suggesting that CD44-positive neural stem/progenitor cells might generate oligodendrocytes in postnatal cerebellum. We cultured CD44-positive cells from the postnatal day 3 cerebellum in the presence of signaling molecules known as mitogens or inductive differentiation factors for oligodendrocyte progenitor cells. Of these, only FGF-2 promoted survival and proliferation of CD44-positive cells, and these cells differentiated into O4+ oligodendrocytes. Furthermore, we examined the effect of FGF-2 on cerebellar oligodendrocyte development ex vivo. FGF-2 enhanced proliferation of oligodendrocyte progenitor cells and increased the number of O4+ and CC1+ oligodendrocytes in slice cultures. These results suggest that CD44-positive cells might be a source of cerebellar oligodendrocytes and that FGF-2 plays important roles in their development at an early postnatal stage. - Highlights: • CD44 is expressed in cerebellar neural stem/progenitor cells at postnatal day 3 (P3). • FGF-2 promoted proliferation of CD44-positive progenitor cells from P3 cerebellum. • FGF-2 promoted oligodendrocytic differentiation of CD44-positive progenitor cells. • FGF-2 increased the number of oligodendrocytes in P3 cerebellar slice culture.« less

  7. Repeated intermittent alcohol exposure during the third trimester-equivalent increases expression of the GABA(A) receptor δ subunit in cerebellar granule neurons and delays motor development in rats.

    PubMed

    Diaz, Marvin R; Vollmer, Cyndel C; Zamudio-Bulcock, Paula A; Vollmer, William; Blomquist, Samantha L; Morton, Russell A; Everett, Julie C; Zurek, Agnieszka A; Yu, Jieying; Orser, Beverley A; Valenzuela, C Fernando

    2014-04-01

    Exposure to ethanol (EtOH) during fetal development can lead to long-lasting alterations, including deficits in fine motor skills and motor learning. Studies suggest that these are, in part, a consequence of cerebellar damage. Cerebellar granule neurons (CGNs) are the gateway of information into the cerebellar cortex. Functionally, CGNs are heavily regulated by phasic and tonic GABAergic inhibition from Golgi cell interneurons; however, the effect of EtOH exposure on the development of GABAergic transmission in immature CGNs has not been investigated. To model EtOH exposure during the 3rd trimester-equivalent of human pregnancy, neonatal pups were exposed intermittently to high levels of vaporized EtOH from postnatal day (P) 2 to P12. This exposure gradually increased pup serum EtOH concentrations (SECs) to ∼60 mM (∼0.28 g/dl) during the 4 h of exposure. EtOH levels gradually decreased to baseline 8 h after the end of exposure. Surprisingly, basal tonic and phasic GABAergic currents in CGNs were not significantly affected by postnatal alcohol exposure (PAE). However, PAE increased δ subunit expression at P28 as detected by immunohistochemical and western blot analyses. Also, electrophysiological studies with an agonist that is highly selective for δ-containing GABA(A) receptors, 4,5,6,7-tetrahydroisoxazolo[4,5-c]pyridine-3-ol (THIP), showed an increase in THIP-induced tonic current. Behavioral studies of PAE rats did not reveal any deficits in motor coordination, except for a delay in the acquisition of the mid-air righting reflex that was apparent at P15 to P18. These findings demonstrate that repeated intermittent exposure to high levels of EtOH during the equivalent of the last trimester of human pregnancy has significant but relatively subtle effects on motor coordination and GABAergic transmission in CGNs in rats. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Modified Da Chengqi granules improvement in immune function in early severe acute pancreatitis patients.

    PubMed

    Jiang, D-L; Yang, J; Jiang, S-Y; Yuan, F-L; Gu, Y-L; Li, J-P; Pei, Z-J

    2016-06-24

    We investigated the role of modified Da Chengqi granules in improving immune function in early severe acute pancreatitis patients. Early severe acute pancreatitis patients who agreed to receive combined treatment of traditional Chinese and Western medicine were randomly assigned to the experimental or control group. All subjects received conventional therapy to support organ function. The experimental group also received modified Da Chengqi granules. Cytokine (interleukin-6, interleukin-10, and tumor necrosis factor-α) levels, immunological markers (HLA-DR, Treg, and Th1/Th2), urinary lactulose/mannitol ratio, and endotoxin levels were measured at 1, 3, 7, and 14 days after hospital admission. The total mortality rate was 11.69% (9/77), which was significantly lower in the experimental group [4.88% (2/41)] than in the control group [19.44% (7/36); χ(2) = 3.940, P < 0.05]. Serum interleukin-6, interleukin-10, tumor necrosis factor-α and endotoxin levels and the lactulose/mannitol ratio were significantly lower on day 7 and day 14 than on day 1 in experimental and control groups (P < 0.01). Immunological indices were significantly lower in the experimental group than in the control group on day 14 (all P < 0.01 or 0.05). HLA-DR-positive cell ratio gradually increased over 14 days in experimental and control groups (P < 0.01 vs day 1), but was higher in the experimental group than in the control group by day 14 (P < 0.05). Notably, Treg cell prevalence and Th1/Th2 cell ratio deteriorated within 7 days in both groups (P < 0.01 vs day 1), but then returned to day 1 levels (P < 0.01 or 0.05 vs day 1). Significant differences in Treg levels and Th1/Th2 cell ratio between experimental and control groups were observed on day 14 (P < 0.01). These results show that modified Da Chengqi granules can improve immune function in early severe acute pancreatitis patients.

  9. Improvement of Early Strength of Cement Mortar Containing Granulated Blast Furnace Slag Using Industrial Byproducts.

    PubMed

    Kim, Jin-Hyoung; Lee, Han-Seung

    2017-09-07

    In the field of construction, securing the early strength of concrete (on the first and third days of aging) has been an important problem in deciding the mold release time (i.e., shortening the construction time period). Therefore, the problem of reduced compressive strength in the early aging stage caused by mixing granulated blast furnace slag (GBFS) with concrete must certainly be resolved. In this study, we conduct experiments to explore methods for generating a concrete that develops an early strength equivalent to that of 100% OPC. The objective of this study is the development of an early-strength accelerator (ESA) made from an industrial by-product, for a GBFS-mixed cement mortar. This study also analyzes the mechanism of the early-strength generation in the concrete to evaluate the influence of the burning temperature of ESA on the optimal compressive strength of the concrete. According to the results of the experiment, GBFS, whose ESA is burnt at 800 °C, shows an activation factor of 102.6-104.7% in comparison with 100% OPC on the first and third days during early aging, thereby meeting the target compressive strength. The results of the micro-analytic experiment are as follows: ESA showed a pH of strongly alkaline. In addition, it was found that the content of SO₃ was high in the chemical components, thus activating the hydration reaction of GBFS in the early age. This initial hydration reaction was thought to be due to the increase in the filling effect of the hydrate and the generation of C-S-H of the early age by the mass production of Ettringite.

  10. Improvement of Early Strength of Cement Mortar Containing Granulated Blast Furnace Slag Using Industrial Byproducts

    PubMed Central

    Kim, Jin-Hyoung; Lee, Han-Seung

    2017-01-01

    In the field of construction, securing the early strength of concrete (on the first and third days of aging) has been an important problem in deciding the mold release time (i.e., shortening the construction time period). Therefore, the problem of reduced compressive strength in the early aging stage caused by mixing granulated blast furnace slag (GBFS) with concrete must certainly be resolved. In this study, we conduct experiments to explore methods for generating a concrete that develops an early strength equivalent to that of 100% OPC. The objective of this study is the development of an early-strength accelerator (ESA) made from an industrial by-product, for a GBFS-mixed cement mortar. This study also analyzes the mechanism of the early-strength generation in the concrete to evaluate the influence of the burning temperature of ESA on the optimal compressive strength of the concrete. According to the results of the experiment, GBFS, whose ESA is burnt at 800 °C, shows an activation factor of 102.6–104.7% in comparison with 100% OPC on the first and third days during early aging, thereby meeting the target compressive strength. The results of the micro-analytic experiment are as follows: ESA showed a pH of strongly alkaline. In addition, it was found that the content of SO3 was high in the chemical components, thus activating the hydration reaction of GBFS in the early age. This initial hydration reaction was thought to be due to the increase in the filling effect of the hydrate and the generation of C-S-H of the early age by the mass production of Ettringite. PMID:28880256

  11. P2X7, NMDA and BDNF receptors converge on GSK3 phosphorylation and cooperate to promote survival in cerebellar granule neurons.

    PubMed

    Ortega, Felipe; Pérez-Sen, Raquel; Morente, Verónica; Delicado, Esmerilda G; Miras-Portugal, Maria Teresa

    2010-05-01

    Glycogen synthase kinase-3 (GSK3) is a key player in the regulation of neuronal survival. Herein, we report evidence of an interaction between P2X7 receptors with NMDA and BDNF receptors at the level of GSK3 signalling and neuroprotection. The activation of these receptors in granule neurons led to a sustained pattern of GSK3 phosphorylation that was mainly PKC-dependent. BDNF was the most potent at inducing GSK3 phosphorylation, which was also dependent on PI3K. The P2X7 agonist, BzATP, exhibited additive effects with both NMDA and BDNF to rescue granule neurons from cell death induced by PI3K inhibition. This survival effect was mediated by the PKC-dependent GSK3 pathway. In addition, ERK1/2 proteins were also involved in BDNF protective effect. These results show the function of ATP in amplifying neuroprotective actions of glutamate and neurotrophins, and support the role of GSK3 as an important convergence point for these survival promoting factors in granule neurons.

  12. The type II cGMP dependent protein kinase regulates GluA1 levels at the plasma membrane of developing cerebellar granule cells

    PubMed Central

    Incontro, Salvatore; Ciruela, Francisco; Ziff, Edward; Hofmann, Franz; Sánchez-Prieto, José; Torres, Magdalena

    2014-01-01

    Trafficking of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) is regulated by specific interactions with other proteins and by post-translational mechanisms, such as phosphorylation. We have found that the type II cGMP-dependent protein kinase (cGKII) phosphorylates GluA1 (formerly GluR1) at S845, augmenting the surface expression of AMPARs at both synaptic and extrasynaptic sites. Activation of cGKII by 8-Br-cGMP enhances the surface expression of GluA1, whereas its inhibition or suppression effectively diminished the expression of this protein at the cell surface. In granule cells, NMDA receptor activation (NMDAR) stimulates nitric oxide and cGMP production, which in turn activates cGKII and induces the phosphorylation of GluA1, promoting its accumulation in the plasma membrane. GluA1 is mainly incorporated into calcium permeable AMPARs as exposure to 8-Br-cGMP or NMDA activation enhanced AMPA-elicited calcium responses that are sensitive to NASPM inhibition. We summarize evidence for an increase of calcium permeable AMPA receptors downstream of NMDA receptor activation that might be relevant for granule cell development and plasticity. PMID:23545413

  13. Cadherins in cerebellar development: translation of embryonic patterning into mature functional compartmentalization.

    PubMed

    Redies, Christoph; Neudert, Franziska; Lin, Juntang

    2011-09-01

    Cadherins are cell adhesion molecules with multiple morphogenic functions in brain development, for example, in neuroblast migration and aggregation, axon navigation, neural circuit formation, and synaptogenesis. More than 100 members of the cadherin superfamily are expressed in the developing and mature brain. Most of the cadherins investigated, in particular classic cadherins and δ-protocadherins, are expressed in the cerebellum. For several cadherin subtypes, expression begins at early embryonic stages and persists until mature stages of cerebellar development. At intermediate stages, distinct Purkinje cell clusters exhibit unique rostrocaudal and mediolateral expression profiles for each cadherin. In the chicken, mouse, and other species, the Purkinje cell clusters are separated by intervening raphes of migrating granule cells. This pattern of Purkinje cell clusters/raphes is, at least in part, continuous with the parasagittal striping pattern that is apparent in the mature cerebellar cortex, for example, for zebrin II/aldolase C. Moreover, subregions of the deep cerebellar nuclei, vestibular nuclei and the olivary complex also express cadherins differentially. Neuroanatomical evidence suggests that the nuclear subregions and cortical domains that express the same cadherin subtype are connected to each other, to form neural subcircuits of the cerebellar system. Cadherins thus provide a molecular code that specifies not only embryonic structures but also functional cerebellar compartmentalization. By following the implementation of this code, it can be revealed how mature functional architecture emerges from embryonic patterning during cerebellar development. Dysfunction of some cadherins is associated with psychiatric diseases and developmental impairments and may also affect cerebellar function.

  14. Semaphorin 5A inhibits synaptogenesis in early postnatal- and adult-born hippocampal dentate granule cells.

    PubMed

    Duan, Yuntao; Wang, Shih-Hsiu; Song, Juan; Mironova, Yevgeniya; Ming, Guo-li; Kolodkin, Alex L; Giger, Roman J

    2014-10-14

    Human SEMAPHORIN 5A (SEMA5A) is an autism susceptibility gene; however, its function in brain development is unknown. In this study, we show that mouse Sema5A negatively regulates synaptogenesis in early, developmentally born, hippocampal dentate granule cells (GCs). Sema5A is strongly expressed by GCs and regulates dendritic spine density in a cell-autonomous manner. In the adult mouse brain, newly born Sema5A-/- GCs show an increase in dendritic spine density and increased AMPA-type synaptic responses. Sema5A signals through PlexinA2 co-expressed by GCs, and the PlexinA2-RasGAP activity is necessary to suppress spinogenesis. Like Sema5A-/- mutants, PlexinA2-/- mice show an increase in GC glutamatergic synapses, and we show that Sema5A and PlexinA2 genetically interact with respect to GC spine phenotypes. Sema5A-/- mice display deficits in social interaction, a hallmark of autism-spectrum-disorders. These experiments identify novel intra-dendritic Sema5A/PlexinA2 interactions that inhibit excitatory synapse formation in developmentally born and adult-born GCs, and they provide support for SEMA5A contributions to autism-spectrum-disorders.

  15. An Ultra-High Field Study of Cerebellar Pathology in Early Relapsing-Remitting Multiple Sclerosis Using MP2RAGE.

    PubMed

    Fartaria, Mário João; OʼBrien, Kieran; Şorega, Alexandra; Bonnier, Guillaume; Roche, Alexis; Falkovskiy, Pavel; Krueger, Gunnar; Kober, Tobias; Bach Cuadra, Meritxell; Granziera, Cristina

    2017-05-01

    The aim of this study was to study focal cerebellar pathology in early stages of multiple sclerosis (MS) using ultra-high-field magnetization-prepared 2 inversion-contrast rapid gradient-echo (7T MP2RAGE). Twenty early-stage relapsing-remitting MS patients underwent an MP2RAGE acquisition at 7 T magnetic resonance imaging (MRI) (images acquired at 2 different resolutions: 0.58 × 0.58 × 0.58 mm, 7T_0.58, and 0.75 × 0.75 × 0.90 mm, 7T_0.75) and 3 T MRI (1.0 × 1.0 × 1.2 mm, 3T_1.0). Total cerebellar lesion load and volume and mean cerebellar lesion volume were compared across images using a Wilcoxon signed-rank test. Mean T1 relaxation times in lesions and normal-appearing tissue as well as contrast-to-noise ratio (CNR) measurements were also compared using a Wilcoxon signed-rank test. A multivariate analysis was applied to assess the contribution of MRI metrics to clinical performance in MS patients. Both 7T_0.58 and 7T_0.75 MP2RAGE showed significantly higher lesion load compared with 3T_1.0 MP2RAGE (P < 0.001). Plaques that were judged as leukocortical in 7T_0.75 and 3T_1.0 MP2RAGEs were instead identified as WM lesions in 7T_0.58 MP2RAGE. Cortical lesion CNR was significantly higher in MP2RAGEs at 7 T than at 3 T. Total lesion load as well as total and mean lesion volume obtained at both 7 T and 3 T MP2RAGE significantly predicted attention (P < 0.05, adjusted R = 0.5), verbal fluency (P < 0.01, adjusted R = 0.6), and motor performance (P = 0.01, adjusted R = 0.7). This study demonstrates the value of 7 T MP2RAGE to study the cerebellum in early MS patients. 7T_0.58 MP2RAGE provides a more accurate anatomical description of white and gray matter pathology compared with 7T_0.75 and 3T_1.0 MP2RAGE, likely due to the improved spatial resolution, lower partial volume effects, and higher CNR.

  16. Gene expression as a sensitive endpoint to evaluate cell differentiation and maturation of the developing central nervous system in primary cultures of rat cerebellar granule cells (CGCs) exposed to pesticides

    SciTech Connect

    Hogberg, Helena T.; Department of Physiology, Wenner-Gren Institute, Stockholm University; Kinsner-Ovaskainen, Agnieszka

    The major advantage of primary neuronal cultures for developmental neurotoxicity (DNT) testing is their ability to replicate the crucial stages of neurodevelopment. In our studies using primary culture of cerebellar granule cells (CGCs) we have evaluated whether the gene expression relevant to the most critical developmental processes such as neuronal differentiation (NF-68 and NF-200) and functional maturation (NMDA and GABA{sub A} receptors), proliferation and differentiation of astrocytes (GFAP and S100{beta}) as well as the presence of neural precursor cells (nestin and Sox10) could be used as an endpoint for in vitro DNT. The expression of these genes was assessed aftermore » exposure to various pesticides (paraquat parathion, dichlorvos, pentachlorophenol and cycloheximide) that could induce developmental neurotoxicity through different mechanisms. All studied pesticides significantly modified the expression of selected genes, related to the different stages of neuronal and/or glial cell development and maturation. The most significant changes were observed after exposure to paraquat and parathion (i.e. down-regulation of mRNA expression of NF-68 and NF-200, NMDA and GABA{sub A} receptors). Similarly, dichlorvos affected mainly neurons (decreased mRNA expression of NF-68 and GABA{sub A} receptors) whereas cycloheximide had an effect on neurons and astrocytes, as significant decreases in the mRNA expression of both neurofilaments (NF-68 and NF-200) and the astrocyte marker (S100{beta}) were observed. Our results suggest that toxicity induced by pesticides that target multiple pathways of neurodevelopment can be identified by studying expression of genes that are involved in different stages of cell development and maturation, and that gene expression could be used as a sensitive endpoint for initial screening to identify the compounds with the potential to cause developmental neurotoxicity.« less

  17. Bacterial Selection during the Formation of Early-Stage Aerobic Granules in Wastewater Treatment Systems Operated Under Wash-Out Dynamics

    PubMed Central

    Weissbrodt, David G.; Lochmatter, Samuel; Ebrahimi, Sirous; Rossi, Pierre; Maillard, Julien; Holliger, Christof

    2012-01-01

    Aerobic granular sludge is attractive for high-rate biological wastewater treatment. Biomass wash-out conditions stimulate the formation of aerobic granules. Deteriorated performances in biomass settling and nutrient removal during start-up have however often been reported. The effect of wash-out dynamics was investigated on bacterial selection, biomass settling behavior, and metabolic activities during the formation of early-stage granules from activated sludge of two wastewater treatment plants (WWTP) over start-up periods of maximum 60 days. Five bubble-column sequencing batch reactors were operated with feast-famine regimes consisting of rapid pulse or slow anaerobic feeding followed by aerobic starvation. Slow-settling fluffy granules were formed when an insufficient superficial air velocity (SAV; 1.8 cm s−1) was applied, when the inoculation sludge was taken from a WWTP removing organic matter only, or when reactors were operated at 30°C. Fast-settling dense granules were obtained with 4.0 cm s−1 SAV, or when the inoculation sludge was taken from a WWTP removing all nutrients biologically. However, only carbon was aerobically removed during start-up. Fluffy granules and dense granules were displaying distinct predominant phylotypes, namely filamentous Burkholderiales affiliates and Zoogloea relatives, respectively. The latter were predominant in dense granules independently from the feeding regime. A combination of insufficient solid retention time and of leakage of acetate into the aeration phase during intensive biomass wash-out was the cause for the proliferation of Zoogloea spp. in dense granules, and for the deterioration of BNR performances. It is however not certain that Zoogloea-like organisms are essential in granule formation. Optimal operation conditions should be elucidated for maintaining a balance between organisms with granulation propensity and nutrient removing organisms in order to form granules with BNR activities in short

  18. Bacterial Selection during the Formation of Early-Stage Aerobic Granules in Wastewater Treatment Systems Operated Under Wash-Out Dynamics.

    PubMed

    Weissbrodt, David G; Lochmatter, Samuel; Ebrahimi, Sirous; Rossi, Pierre; Maillard, Julien; Holliger, Christof

    2012-01-01

    Aerobic granular sludge is attractive for high-rate biological wastewater treatment. Biomass wash-out conditions stimulate the formation of aerobic granules. Deteriorated performances in biomass settling and nutrient removal during start-up have however often been reported. The effect of wash-out dynamics was investigated on bacterial selection, biomass settling behavior, and metabolic activities during the formation of early-stage granules from activated sludge of two wastewater treatment plants (WWTP) over start-up periods of maximum 60 days. Five bubble-column sequencing batch reactors were operated with feast-famine regimes consisting of rapid pulse or slow anaerobic feeding followed by aerobic starvation. Slow-settling fluffy granules were formed when an insufficient superficial air velocity (SAV; 1.8 cm s(-1)) was applied, when the inoculation sludge was taken from a WWTP removing organic matter only, or when reactors were operated at 30°C. Fast-settling dense granules were obtained with 4.0 cm s(-1) SAV, or when the inoculation sludge was taken from a WWTP removing all nutrients biologically. However, only carbon was aerobically removed during start-up. Fluffy granules and dense granules were displaying distinct predominant phylotypes, namely filamentous Burkholderiales affiliates and Zoogloea relatives, respectively. The latter were predominant in dense granules independently from the feeding regime. A combination of insufficient solid retention time and of leakage of acetate into the aeration phase during intensive biomass wash-out was the cause for the proliferation of Zoogloea spp. in dense granules, and for the deterioration of BNR performances. It is however not certain that Zoogloea-like organisms are essential in granule formation. Optimal operation conditions should be elucidated for maintaining a balance between organisms with granulation propensity and nutrient removing organisms in order to form granules with BNR activities in short

  19. Staufen recruitment into stress granules does not affect early mRNA transport in oligodendrocytes.

    PubMed

    Thomas, María G; Martinez Tosar, Leandro J; Loschi, Mariela; Pasquini, Juana M; Correale, Jorge; Kindler, Stefan; Boccaccio, Graciela L

    2005-01-01

    Staufen is a conserved double-stranded RNA-binding protein required for mRNA localization in Drosophila oocytes and embryos. The mammalian homologues Staufen 1 and Staufen 2 have been implicated in dendritic RNA targeting in neurons. Here we show that in rodent oligodendrocytes, these two proteins are present in two independent sets of RNA granules located at the distal myelinating processes. A third kind of RNA granules lacks Staufen and contains major myelin mRNAs. Myelin Staufen granules associate with microfilaments and microtubules, and their subcellular distribution is affected by polysome-disrupting drugs. Under oxidative stress, both Staufen 1 and Staufen 2 are recruited into stress granules (SGs), which are stress-induced organelles containing transiently silenced messengers. Staufen SGs contain the poly(A)-binding protein (PABP), the RNA-binding proteins HuR and TIAR, and small but not large ribosomal subunits. Staufen recruitment into perinuclear SGs is paralleled by a similar change in the overall localization of polyadenylated RNA. Under the same conditions, the distribution of recently transcribed and exported mRNAs is not affected. Our results indicate that Staufen 1 and Staufen 2 are novel and ubiquitous SG components and suggest that Staufen RNPs are involved in repositioning of most polysomal mRNAs, but not of recently synthesized transcripts, during the stress response.

  20. Epigenetic remodelling and dysregulation of DLGAP4 is linked with early-onset cerebellar ataxia

    PubMed Central

    Minocherhomji, Sheroy; Hansen, Claus; Kim, Hyung-Goo; Mang, Yuan; Bak, Mads; Guldberg, Per; Papadopoulos, Nickolas; Eiberg, Hans; Doh, Gerald Dayebga; Møllgård, Kjeld; Hertz, Jens Michael; Nielsen, Jørgen E.; Ropers, Hans-Hilger; Tümer, Zeynep; Tommerup, Niels; Kalscheuer, Vera M.; Silahtaroglu, Asli

    2014-01-01

    Genome instability, epigenetic remodelling and structural chromosomal rearrangements are hallmarks of cancer. However, the coordinated epigenetic effects of constitutional chromosomal rearrangements that disrupt genes associated with congenital neurodevelopmental diseases are poorly understood. To understand the genetic–epigenetic interplay at breakpoints of chromosomal translocations disrupting CG-rich loci, we quantified epigenetic modifications at DLGAP4 (SAPAP4), a key post-synaptic density 95 (PSD95) associated gene, truncated by the chromosome translocation t(8;20)(p12;q11.23), co-segregating with cerebellar ataxia in a five-generation family. We report significant epigenetic remodelling of the DLGAP4 locus triggered by the t(8;20)(p12;q11.23) translocation and leading to dysregulation of DLGAP4 expression in affected carriers. Disruption of DLGAP4 results in monoallelic hypermethylation of the truncated DLGAP4 promoter CpG island. This induced hypermethylation is maintained in somatic cells of carriers across several generations in a t(8;20) dependent-manner however, is erased in the germ cells of the translocation carriers. Subsequently, chromatin remodelling of the locus-perturbed monoallelic expression of DLGAP4 mRNAs and non-coding RNAs in haploid cells having the translocation. Our results provide new mechanistic insight into the way a balanced chromosomal rearrangement associated with a neurodevelopmental disorder perturbs allele-specific epigenetic mechanisms at breakpoints leading to the deregulation of the truncated locus. PMID:24986922

  1. [A case of early onset cerebellar ataxia with hearing loss, mental disturbance and primary hypogonadism].

    PubMed

    Ikezoe, K; Yamada, A; Takeuchi, H; Miki, H; Katanaka, J

    1992-09-01

    A 14-year-old girl, whose birth and developmental history were normal till the age of 7, was admitted to our hospital because of slowly progressive difficulties in walking, speaking and hearing. She also complained of absence of menstruation. She showed poor school records since the age of 7. On neurological examination, she showed limb and truncal ataxia. There was no nystagmus but slurred speech was found. Muscular power was good and her sensory system was normal. Tendon reflexes were equally present, and plantar reflexes were flexor. Bilateral moderate nerve deafness was also present. Mental deficiency was diagnosed on an intelligence test. Brain CT and MRI showed cerebellar atrophy. Gynecological examination revealed scanty pubic hair and small uterus. Karyotype was 46XX. Endocrinological studies demonstrated high level of FSH, low level of E2, and the normal response to pituitary stimulation with LHRH, indicating the existence of primary hypogonadism. Although the etiology of this multisystem disorder is unknown, it is possible that both nervous and endocrine disorders were genetically determined.

  2. Evolution of vacuolar proton pyrophosphatase domains and volutin granules: clues into the early evolutionary origin of the acidocalcisome

    PubMed Central

    2011-01-01

    domains support the early origin of the acidocalcisome organelle. In particular, the universality of volutin granules and presence of a functional V-H+PPase domain in the three superkingdoms of life reveals that the acidocalcisomes may have appeared earlier than the divergence of the superkingdoms. This result is remarkable and highlights the possibility that a high degree of cellular compartmentalization could already have been present in the LUCA. Reviewers This article was reviewed by Anthony Poole, Lakshminarayan Iyer and Daniel Kahn PMID:21974828

  3. Incorporation of DPP6a and DPP6K variants in ternary Kv4 channel complex reconstitutes properties of A-type K current in rat cerebellar granule cells.

    PubMed

    Jerng, Henry H; Pfaffinger, Paul J

    2012-01-01

    Dipeptidyl peptidase-like protein 6 (DPP6) proteins co-assemble with Kv4 channel α-subunits and Kv channel-interacting proteins (KChIPs) to form channel protein complexes underlying neuronal somatodendritic A-type potassium current (I(SA)). DPP6 proteins are expressed as N-terminal variants (DPP6a, DPP6K, DPP6S, DPP6L) that result from alternative mRNA initiation and exhibit overlapping expression patterns. Here, we study the role DPP6 variants play in shaping the functional properties of I(SA) found in cerebellar granule (CG) cells using quantitative RT-PCR and voltage-clamp recordings of whole-cell currents from reconstituted channel complexes and native I(SA) channels. Differential expression of DPP6 variants was detected in rat CG cells, with DPP6K (41 ± 3%)>DPP6a (33 ± 3%)>DPP6S (18 ± 2%)>DPP6L (8 ± 3%). To better understand how DPP6 variants shape native neuronal I(SA), we focused on studying interactions between the two dominant variants, DPP6K and DPP6a. Although previous studies did not identify unique functional effects of DPP6K, we find that the unique N-terminus of DPP6K modulates the effects of KChIP proteins, slowing recovery and producing a negative shift in the steady-state inactivation curve. By contrast, DPP6a uses its distinct N-terminus to directly confer rapid N-type inactivation independently of KChIP3a. When DPP6a and DPP6K are co-expressed in ratios similar to those found in CG cells, their distinct effects compete in modulating channel function. The more rapid inactivation from DPP6a dominates during strong depolarization; however, DPP6K produces a negative shift in the steady-state inactivation curve and introduces a slow phase of recovery from inactivation. A direct comparison to the native CG cell I(SA) shows that these mixed effects are present in the native channels. Our results support the hypothesis that the precise expression and co-assembly of different auxiliary subunit variants are important factors in shaping the I

  4. Implied functional crossed cerebello-cerebral diaschisis and interhemispheric compensation during hand grasping more than 20 years after unilateral cerebellar injury in early childhood.

    PubMed

    Nakahachi, Takayuki; Ishii, Ryouhei; Canuet, Leonides; Iwase, Masao

    2015-01-01

    Crossed cerebello-cerebral diaschisis (CCCD) conventionally refers to decreased resting cerebral activity caused by injury to the contralateral cerebellum. We investigated whether functional activation of a contralesional cerebral cortical region controlling a specific task is reduced during task performance in a patient with a unilateral cerebellar lesion. We also examined functional compensation by the corresponding ipsilesional cerebral cortex. It was hypothesized that dysfunction of the primary sensorimotor cortex (SM1) contralateral to the cerebellar lesion would be detected together with a compensatory increase in neural activity of the ipsilesional SM1. To test these possibilities, we conducted non-invasive functional neuroimaging techniques for bilateral SM1 during hand grasping, a task known to activate predominantly the SM1 contralateral to the grasping hand. Activity in SM1 during hand grasping was measured electrophysiologically by magnetoencephalography and hemodynamically by near-infrared spectroscopy in an adult with mild right hemiataxia associated with a large injury of the right cerebellum due to resection of a tumor in early childhood. During left hand grasping, increased neural activity was detected predominantly in the right SM1, the typical developmental pattern. In contrast, neural activity increased in the bilateral SM1 with slight right-side dominance during right (ataxic) hand grasping. This study reported a case that implied functional CCCD and compensatory neural activity in the SM1 during performance of a simple hand motor task in an adult with unilateral cerebellar injury and mild hemiataxia 24 years prior to the study without rehabilitative interventions. This suggests that unilateral cerebellar injuries in early childhood may result in persistent functional abnormalities in the cerebrum into adulthood. Therapeutic treatments that target functional CCCD and interhemispheric compensation might be effective for treating ataxia due to

  5. 3D perfusion bioreactor-activated porous granules on implant fixation and early bone formation in sheep.

    PubMed

    Ding, Ming; Henriksen, Susan S; Martinetti, Roberta; Overgaard, Søren

    2017-11-01

    Early fixation of total joint arthroplasties is crucial for ensuring implant survival. An alternative bone graft material in revision surgery is needed to replace the current gold standard, allograft, seeing that the latter is associated with several disadvantages. The incubation of such a construct in a perfusion bioreactor has been shown to produce viable bone graft materials. This study aimed at producing larger amounts of viable bone graft material (hydroxyapatite 70% and β-tricalcium-phosphate 30%) in a novel perfusion bioreactor. The abilities of the bioreactor-activated graft material to induce early implant fixation were tested in a bilateral implant defect model in sheep, with allograft as the control group. Defects were bilaterally created in the distal femurs of the animals, and titanium implants were inserted. The concentric gaps around the implants were randomly filled with either allograft, granules, granules with bone marrow aspirate or bioreactor-activated graft material. Following an observation time of 6 weeks, early implant fixation and bone formation were assessed by micro-CT scanning, mechanical testing, and histomorphometry. Bone formations were seen in all groups, while no significant differences between groups were found regarding early implant fixation. The microarchitecture of the bone formed by the synthetic graft materials resembled that of allograft. Histomorphometry revealed that allograft induced significantly more bone and less fibrous tissue (p < 0.05). In conclusion, bone formation was observed in all groups, while the bioreactor-activated graft material did not reveal additional effects on early implant fixation comparable to allograft in this model. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2465-2476, 2017. © 2016 Wiley Periodicals, Inc.

  6. Structure–function relationships in the developing cerebellum: evidence from early-life cerebellar injury and neurodevelopmental disorders

    PubMed Central

    Stoodley, Catherine J.; Limperopoulos, Catherine

    2016-01-01

    SUMMARY The increasing appreciation of the role of the cerebellum in motor and non-motor functions is crucial to understanding the outcomes of acquired cerebellar injury and developmental lesions in high-risk fetal and neonatal populations, children with cerebellar damage (e.g. posterior fossa tumors), and neurodevelopmental disorders (e.g. autism). We review available data regarding the relationship between the topography of cerebellar injury or abnormality and functional outcomes. We report emerging structure–function relationships with specific symptoms: cerebellar regions that interconnect with sensorimotor cortices are associated with motor impairments when damaged; disruption to posterolateral cerebellar regions that form circuits with association cortices impact long-term cognitive outcomes; and midline posterior vermal damage is associated with behavioral dysregulation and an autism-like phenotype. We also explore the impact of age and the potential role for critical periods on cerebellar structure and child function. These findings suggest that the cerebellum plays a critical role in motor, cognitive, and social–behavioral development, possibly via modulatory effects on the developing cerebral cortex. PMID:27184461

  7. West nile virus infections suppress early viral RNA synthesis and avoid inducing the cell stress granule response.

    PubMed

    Courtney, S C; Scherbik, S V; Stockman, B M; Brinton, M A

    2012-04-01

    West Nile virus (WNV) recently became endemic in the United States and is a significant cause of human morbidity and mortality. Natural WNV strain infections do not induce stress granules (SGs), while W956IC (a lineage 2/1 chimeric WNV infectious clone) virus infections produce high levels of early viral RNA and efficiently induce SGs through protein kinase R (PKR) activation. Additional WNV chimeric viruses made by replacing one or more W956IC genes with the lineage 1 Eg101 equivalent in the W956IC backbone were analyzed. The Eg-NS4b+5, Eg-NS1+3+4a, and Eg-NS1+4b+5 chimeras produced low levels of viral RNA at early times of infection and inefficiently induced SGs, suggesting the possibility that interactions between viral nonstructural proteins and/or between viral nonstructural proteins and cell proteins are involved in suppressing early viral RNA synthesis and membrane remodeling during natural WNV strain infections. Detection of exposed viral double-stranded RNA (dsRNA) in W956IC-infected cells suggested that the enhanced early viral RNA synthesis surpassed the available virus-induced membrane protection and allowed viral dsRNA to activate PKR.

  8. Potential mechanisms of cerebellar hypoplasia in prematurity.

    PubMed

    Tam, Emily W Y

    2013-09-01

    The cerebellum undergoes dramatic growth and maturation over the neonatal period after preterm birth and is thus particularly sensitive to impaired development due to various clinical factors. Impairments in growth can occur independent of cerebellar parenchymal damage, such as from local hemorrhage, resulting from reduced expression of sonic hedgehog signaling to trigger the appropriate expansion of the granule precursor cells. The primary risk factors for impaired cerebellar development include postnatal glucocorticoid exposure, which has direct effects on the sonic hedgehog pathway, and supratentorial brain injury, including intraventricular hemorrhage and white matter injury, which may result in crossed cerebellar diaschisis and local toxic effects of blood products on the external granular layer. Other cardiorespiratory and nutritional factors may also exist. Impaired cerebellar development is associated with adverse outcomes in motor and cognitive development. New approaches to care to counteract these risk factors may help improve long-term outcome after preterm birth.

  9. Cell proliferation and apoptosis during histogenesis of the guinea pig and rabbit cerebellar cortex.

    PubMed

    Lossi, Laura; Coli, Alessandra; Giannessi, Elisabetta; Stornelli, Maria Rita; Marroni, Paolo

    2002-01-01

    Cell proliferation and apoptosis are essential for development of the nervous system. In this study we have investigated the histogenesis of the cerebellar cortex in guinea pig (a precocial species) and rabbit (an altricial species) at different stages of pregnancy and postnatal life. Proliferating cells were identified after labeling with antibodies against the proliferating cell nuclear antigen (PCNA) and/or the Ki-67 antigen. Apoptotic cells were visualized in situ by the TUNEL method and by immunodetection of cleaved caspase 3 and 9. In guinea pigs, both proliferating and apoptotic cells were detected during pre-natal life (E0-E40). Conversely, cell proliferation and apoptosis in rabbits were temporally restricted to early postnatal weeks (P0-P20). In both species cell proliferation was mainly linked to differentiation and migration of the granule cells. In both species, the majority of cells undergoing programmed cell death likely corresponded to granule cells. They were mainly detected in the external granular layer, and were by far more common than previously reported in other locations of the postnatal brain. This study shows that apoptosis is a shared process of cell death during cerebellar development in both altricial and precocial animals, and that there is a direct spatial and temporal correlation between cell proliferation and death in two mammals with different time tables in cerebellar maturation.

  10. Local and long-range circuit elements for cerebellar function.

    PubMed

    Xiao, Le; Scheiffele, Peter

    2018-02-01

    The view of cerebellar functions has been extended from controlling sensorimotor processes to processing 'contextual' information and generating predictions for a diverse range of behaviors. These functions rely on the computation of the local cerebellar microcircuits and long-range connectivity that relays cerebellar output to various brain areas. In this review, we discuss recent work on two of the circuit elements, which are thought to be fundamental for a wide range of non-sensorimotor behaviors: The role for cerebellar granule cells in multimodal integration in the cerebellar cortex and the long-range connectivity between the deep cerebellar nuclei and the basal ganglia. Lastly, we discuss how studies on synapses and circuits of the cerebellum in rodent models of autism-spectrum disorders might contribute to our understanding of the pathophysiology of this class of neurodevelopmental disorders. Copyright © 2017. Published by Elsevier Ltd.

  11. The life cycle of platelet granules.

    PubMed

    Sharda, Anish; Flaumenhaft, Robert

    2018-01-01

    Platelet granules are unique among secretory vesicles in both their content and their life cycle. Platelets contain three major granule types-dense granules, α-granules, and lysosomes-although other granule types have been reported. Dense granules and α-granules are the most well-studied and the most physiologically important. Platelet granules are formed in large, multilobulated cells, termed megakaryocytes, prior to transport into platelets. The biogenesis of dense granules and α-granules involves common but also distinct pathways. Both are formed from the trans -Golgi network and early endosomes and mature in multivesicular bodies, but the formation of dense granules requires trafficking machinery different from that of α-granules. Following formation in the megakaryocyte body, both granule types are transported through and mature in long proplatelet extensions prior to the release of nascent platelets into the bloodstream. Granules remain stored in circulating platelets until platelet activation triggers the exocytosis of their contents. Soluble N -ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, located on both the granules and target membranes, provide the mechanical energy that enables membrane fusion during both granulogenesis and exocytosis. The function of these core fusion engines is controlled by SNARE regulators, which direct the site, timing, and extent to which these SNAREs interact and consequently the resulting membrane fusion. In this review, we assess new developments in the study of platelet granules, from their generation to their exocytosis.

  12. Impaired eye-blink conditioning in waggler, a mutant mouse with cerebellar BDNF deficiency.

    PubMed

    Bao, S; Chen, L; Qiao, X; Knusel, B; Thompson, R F

    1998-01-01

    In addition to their trophic functions, neurotrophins are also implicated in synaptic modulation and learning and memory. Although gene knockout techniques have been used widely in studying the roles of neurotrophins at molecular and cellular levels, behavioral studies using neurotrophin knockouts are limited by the early-onset lethality and various sensory deficits associated with the gene knockout mice. In the present study, we found that in a spontaneous mutant mouse, waggler, the expression of brain-derived neurotrophic factor (BDNF) was selectively absent in the cerebellar granule cells. The cytoarchitecture of the waggler cerebellum appeared to be normal at the light microscope level. The mutant mice exhibited no sensory deficits to auditory stimuli or heat-induced pain. However, they were massively impaired in classic eye-blink conditioning. These results suggest that BDNF may have a role in normal cerebellar neuronal function, which, in turn, is essential for classic eye-blink conditioning.

  13. Early postnatal exposure to methylphenidate alters stress reactivity and increases hippocampal ectopic granule cells in adult rats

    PubMed Central

    Torres-Reveron, Annelyn; Gray, Jason D.; Melton, Jay T.; Punsoni, Michael; Tabori, Nora E.; Ward, Mary J.; Frys, Kelly; Iadecola, Costantino; Milner, Teresa A.

    2009-01-01

    To mimic clinical treatment with methylphenidate (MPH; Ritalin) for attention deficit/hyperactivity disorder (ADHD), rat pups were injected with MPH (5 mg/kg, I.P.) or placebo twice daily during their nocturnal active phase from postnatal day (PND) 7 to 35. Thirty-nine days after the last MPH administration (PND76), four litters of rats experienced stressful conditions during the 2003 New York City blackout. MPH-treated rats that endured the blackout lost more weight and regained it at a slower pace than controls (p<0.05; N=7–11/group). Furthermore, MPH-treated rats had elevated systolic arterial blood pressure (from 115.6 ± 1.2 to 126 ± 1.8 mmHg; p<0.05), assessed on PND130 by tail cuff plethysmography. Immunocytochemical studies of transmitter systems in the brain demonstrated rearrangements of catecholamine and neuropeptide Y fibers in select brain regions at PND135, which did not differ between blackout and control groups. However, MPH-treated rats that endured the blackout had more ectopic granule cells in the hilus of the dorsal hippocampal dentate gyrus compared to controls at PND 135 (p<0.05; N=6/group). These findings indicate that early postnatal exposure to high therapeutic doses of MPH can have long lasting effects on the plasticity of select brain regions and can induce changes in the reactivity to stress that persist into adulthood. PMID:19100815

  14. Acquisition of granule neuron precursor identity is a critical determinant of progenitor cell competence to form Hedgehog-induced medulloblastoma

    PubMed Central

    Schüller, Ulrich; Heine, Vivi M.; Mao, Junhao; Kho, Alvin T.; Dillon, Allison K.; Han, Young-Goo; Huillard, Emmanuelle; Sun, Tao; Ligon, Azra H.; Qian, Ying; Ma, Qiufu; Alvarez-Buylla, Arturo; McMahon, Andrew P.; Rowitch, David H.; Ligon, Keith L.

    2008-01-01

    Origins of the brain tumor, medulloblastoma, from stem cells or restricted progenitor cells are unclear. To investigate this, we activated oncogenic Hedgehog (Hh) signaling in multipotent and lineage-restricted CNS progenitors. We observed that normal unipotent cerebellar granule neuron precursors (CGNP) derive from hGFAP+ and Olig2+ RL progenitors. Hh activation in a spectrum of early and late stage CNS progenitors generated similar medulloblastomas, but not other brain cancers, indicating that acquisition of CGNP identity is essential for tumorigenesis. We show in human and mouse medulloblastoma that cells expressing the glia-associated markers Gfap and Olig2 are neoplastic and that they retain features of embryonic-type granule lineage progenitors. Thus, oncogenic Hh signaling promotes medulloblastoma from lineage-restricted granule cell progenitors. PMID:18691547

  15. Postnatal Migration of Cerebellar Interneurons

    PubMed Central

    Galas, Ludovic; Bénard, Magalie; Lebon, Alexis; Komuro, Yutaro; Schapman, Damien; Vaudry, Hubert; Vaudry, David; Komuro, Hitoshi

    2017-01-01

    Due to its continuing development after birth, the cerebellum represents a unique model for studying the postnatal orchestration of interneuron migration. The combination of fluorescent labeling and ex/in vivo imaging revealed a cellular highway network within cerebellar cortical layers (the external granular layer, the molecular layer, the Purkinje cell layer, and the internal granular layer). During the first two postnatal weeks, saltatory movements, transient stop phases, cell-cell interaction/contact, and degradation of the extracellular matrix mark out the route of cerebellar interneurons, notably granule cells and basket/stellate cells, to their final location. In addition, cortical-layer specific regulatory factors such as neuropeptides (pituitary adenylate cyclase-activating polypeptide (PACAP), somatostatin) or proteins (tissue-type plasminogen activator (tPA), insulin growth factor-1 (IGF-1)) have been shown to inhibit or stimulate the migratory process of interneurons. These factors show further complexity because somatostatin, PACAP, or tPA have opposite or no effect on interneuron migration depending on which layer or cell type they act upon. External factors originating from environmental conditions (light stimuli, pollutants), nutrients or drug of abuse (alcohol) also alter normal cell migration, leading to cerebellar disorders. PMID:28587295

  16. Abnormal cerebellar development and Purkinje cell defects in Lgl1-Pax2 conditional knockout mice.

    PubMed

    Hou, Congzhe; Ding, Lingcui; Zhang, Jian; Jin, Yecheng; Sun, Chen; Li, Zhenzu; Sun, Xiaoyang; Zhang, Tingting; Zhang, Aizhen; Li, Huashun; Gao, Jiangang

    2014-11-01

    Lgl1 was initially identified as a tumour suppressor in flies and is characterised as a key regulator of epithelial polarity and asymmetric cell division. A previous study indicated that More-Cre-mediated Lgl1 knockout mice exhibited significant brain dysplasia and died within 24h after birth. To overcome early neonatal lethality, we generated Lgl1 conditional knockout mice mediated by Pax2-Cre, which is expressed in almost all cells in the cerebellum, and we examined the functions of Lgl1 in the cerebellum. Impaired motor coordination was detected in the mutant mice. Consistent with this abnormal behaviour, homozygous mice possessed a smaller cerebellum with fewer lobes, reduced granule precursor cell (GPC) proliferation, decreased Purkinje cell (PC) quantity and dendritic dysplasia. Loss of Lgl1 in the cerebellum led to hyperproliferation and impaired differentiation of neural progenitors in ventricular zone. Based on the TUNEL assay, we observed increased apoptosis in the cerebellum of mutant mice. We proposed that impaired differentiation and increased apoptosis may contribute to decreased PC quantity. To clarify the effect of Lgl1 on cerebellar granule cells, we used Math1-Cre to specifically delete Lgl1 in granule cells. Interestingly, the Lgl1-Math1 conditional knockout mice exhibited normal proliferation of GPCs and cerebellar development. Thus, we speculated that the reduction in the proliferation of GPCs in Lgl1-Pax2 conditional knockout mice may be secondary to the decreased number of PCs, which secrete the mitogenic factor Sonic hedgehog to regulate GPC proliferation. Taken together, these findings suggest that Lgl1 plays a key role in cerebellar development and folia formation by regulating the development of PCs. Copyright © 2014. Published by Elsevier Inc.

  17. Laminin α1 is essential for mouse cerebellar development

    PubMed Central

    Ichikawa-Tomikawa, Naoki; Ogawa, Junko; Douet, Vanessa; Xu, Zhuo; Kamikubo, Yuji; Sakurai, Takashi; Kohsaka, Shinichi; Chiba, Hideki; Hattori, Nobutaka; Yamada, Yoshihiko; Arikawa-Hirasawa, Eri

    2011-01-01

    Laminin α1 (Lama1), which is a subunit of laminin-1 (laminin-111), a heterotrimeric ECM protein, is essential for embryonic development and promotes neurite outgrowth in culture. Because the deletion of Lama1 causes lethality at early embryonic stages in mice, the in vivo role of Lama1 in neural development and functions has not yet been possible to determine. In this study, we generated conditional Lama1 knockout (Lama1CKO) mice in the epiblast lineage using Sox2-Cre mice. These Lama1CKO mice survived, but displayed behavioral disorders and impaired formation of the cerebellum. Deficiency of Lama1 in the pial basement membrane of the meninges resulted in defects in the conformation of the meninges. During cerebellar development, Lama1 deficiency also caused a decrease in the proliferation and migration of granule cell precursors, disorganization of Bergmann glial fibers and endfeet, and a transient reduction in the activity of Akt. A marked reduction in numbers of dendritic processes in Purkinje cells was observed in Lama1CKO mice. Together, these results indicate that Lama1 is required for cerebellar development and functions. PMID:21983115

  18. The autism susceptibility gene met regulates zebrafish cerebellar development and facial motor neuron migration

    PubMed Central

    Elsen, Gina E.; Choi, Louis Y.; Prince, Victoria E.; Ho, Robert K.

    2009-01-01

    During development, Met signaling regulates a range of cellular processes including growth, differentiation, survival and migration. The Met gene encodes a tyrosine kinase receptor, which is activated by Hgf (hepatocyte growth factor) ligand. Altered regulation of human MET expression has been implicated in autism. In mouse, Met signaling has been shown to regulate cerebellum development. Since abnormalities in cerebellar structure have been reported in some autistic patients, we have used the zebrafish to address the role of Met signaling during cerebellar development and thus further our understanding of the molecular basis of autism. We find that zebrafish met is expressed in the cerebellar primordium, later localizing to the ventricular zone (VZ), with the hgf1 and hgf2 ligand genes expressed in surrounding tissues. Morpholino knockdown of either Met or its Hgf ligands leads to a significant reduction in the size of the cerebellum, primarily as a consequence of reduced proliferation. Met signaling knockdown disrupts specification of VZ-derived cell types, and also reduces granule cell numbers, due to an early effect on cerebellar proliferation and/or as an indirect consequence of loss of signals from VZ-derived cells later in development. These patterning defects preclude analysis of cerebellar neuronal migration, but we have found that Met signaling is necessary for migration of hindbrain facial motor neurons. In summary, we have described roles for Met signaling in coordinating growth and cell type specification within the developing cerebellum, and in migration of hindbrain neurons. These functions may underlie the correlation between altered MET regulation and Autism Spectrum Disorders. PMID:19732764

  19. Paraneoplastic cerebellar ataxia and the paraneoplastic syndromes

    PubMed Central

    Afzal, Sadaf; Recio, Maria

    2015-01-01

    Paraneoplastic cerebellar ataxia, also known as paraneoplastic cerebellar degeneration, is one of the wide array of paraneoplastic neurological syndromes in which neurological symptoms are indirectly caused by an underlying malignancy, most commonly gynecological, breast, or lung cancer or Hodgkin's lymphoma. We describe a patient with severe cerebellar dysfunction attributed to a paraneoplastic neurological syndrome. The case highlights the need to look for paraneoplastic syndromes—both to discover malignancies early, at a treatable stage, and, as in our case, to address very distressing symptoms for the patient's relief even if the malignancy is not curable. PMID:25829659

  20. Early increase and late decrease of purkinje cell dendritic spine density in prion-infected organotypic mouse cerebellar cultures.

    PubMed

    Campeau, Jody L; Wu, Gengshu; Bell, John R; Rasmussen, Jay; Sim, Valerie L

    2013-01-01

    Prion diseases are infectious neurodegenerative diseases associated with the accumulation of protease-resistant prion protein, neuronal loss, spongiform change and astrogliosis. In the mouse model, the loss of dendritic spines is one of the earliest pathological changes observed in vivo, occurring 4-5 weeks after the first detection of protease-resistant prion protein in the brain. While there are cell culture models of prion infection, most do not recapitulate the neuropathology seen in vivo. Only the recently developed prion organotypic slice culture assay has been reported to undergo neuronal loss and the development of some aspects of prion pathology, namely small vacuolar degeneration and tubulovesicular bodies. Given the rapid replication of prions in this system, with protease-resistant prion protein detectable by 21 days, we investigated whether the dendritic spine loss and altered dendritic morphology seen in prion disease might also develop within the lifetime of this culture system. Indeed, six weeks after first detection of protease-resistant prion protein in tga20 mouse cerebellar slice cultures infected with RML prion strain, we found a statistically significant loss of Purkinje cell dendritic spines and altered dendritic morphology in infected cultures, analogous to that seen in vivo. In addition, we found a transient but statistically significant increase in Purkinje cell dendritic spine density during infection, at the time when protease-resistant prion protein was first detectable in culture. Our findings support the use of this slice culture system as one which recapitulates prion disease pathology and one which may facilitate study of the earliest stages of prion disease pathogenesis.

  1. Cerebellar defects in a mouse model of juvenile neuronal ceroid lipofuscinosis.

    PubMed

    Weimer, Jill M; Benedict, Jared W; Getty, Amanda L; Pontikis, Charlie C; Lim, Ming J; Cooper, Jonathan D; Pearce, David A

    2009-04-17

    Juvenile neuronal ceroid lipofuscinosis (JNCL), or Batten disease, is a neurodegenerative disease resulting from a mutation in CLN3, which presents clinically with visual deterioration, seizures, motor impairments, cognitive decline, hallucinations, loss of circadian rhythm, and premature death in the late-twenties to early-thirties. Using a Cln3 null (Cln3(-/-)) mouse, we report here several deficits in the cerebellum in the absence of Cln3, including cell loss and early onset motor deficits. Surprisingly, early onset glial activation and selective neuronal loss within the mature fastigial pathway of the deep cerebellar nuclei (DCN), a region critical for balance and coordination, are seen in many regions of the Cln3(-/-) cerebellum. Additionally, there is a loss of Purkinje cells (PC) in regions of robust Bergmann glia activation in Cln3(-/-) mice and human JNCL post-mortem cerebellum. Moreover, the Cln3(-/-) cerebellum had a mis-regulation in granule cell proliferation and maintenance of PC dendritic arborization and spine density. Overall, this study defines a novel multi-faceted, early-onset cerebellar disruption in the Cln3 null brain, including glial activation, cell loss, and aberrant cell proliferation and differentiation. These early alterations in the maturation of the cerebellum could underlie some of the motor deficits and pathological changes seen in JNCL patients.

  2. Cerebellar defects in a mouse model of juvenile neuronal ceroid lipofuscinosis

    PubMed Central

    Weimer, Jill M.; Benedict, Jared W.; Getty, Amanda L.; Pontikis, Charlie C.; Lim, Ming J.; Cooper, Jonathan D.; Pearce, David A.

    2013-01-01

    Juvenile neuronal ceroid lipofuscinosis (JNCL), or Batten disease, is a neurodegenerative disease resulting from a mutation in CLN3, which presents clinically with visual deterioration, seizures, motor impairments, cognitive decline, hallucinations, loss of circadian rhythm, and premature death in the late-twenties to early-thirties. Using a Cln3 null (Cln3−/−) mouse, we report here several deficits in the cerebellum in the absence of Cln3, including cell loss and early onset motor deficits. Surprisingly, early onset glial activation and selective neuronal loss within the mature fastigial pathway of the deep cerebellar nuclei (DCN), a region critical for balance and coordination, are seen in many regions of the Cln3−/− cerebellum. Additionally, there is a loss of Purkinje cells (PC) in regions of robust Bergmann glia activation in Cln3−/− mice and human JNCL post-mortem cerebellum. Moreover, the Cln3−/− cerebellum had a mis-regulation in granule cell proliferation and maintenance of PC dendritic arborization and spine density. Overall, this study defines a novel multi-faceted, early-onset cerebellar disruption in the Cln3 null brain, including glial activation, cell loss, and aberrant cell proliferation and differentiation. These early alterations in the maturation of the cerebellum could underlie some of the motor deficits and pathological changes seen in JNCL patients. PMID:19230832

  3. Autosomal recessive cerebellar ataxias

    PubMed Central

    Palau, Francesc; Espinós, Carmen

    2006-01-01

    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. PMID:17112370

  4. A novel DNMT1 mutation associated with early onset hereditary sensory and autonomic neuropathy, cataplexy, cerebellar atrophy, scleroderma, endocrinopathy, and common variable immune deficiency.

    PubMed

    Fox, Robin; Ealing, John; Murphy, Helen; Gow, David P; Gosal, David

    2016-09-01

    DNA methyltransferase 1 (DNMT1) is an enzyme which has a role in methylation of DNA, gene regulation, and chromatin stability. Missense mutations in the DNMT1 gene have been previously associated with two neurological syndromes: hereditary sensory and autonomic neuropathy type 1 with dementia and deafness (HSAN1E) and autosomal dominant cerebellar ataxia, deafness, and narcolepsy (ADCA-DN). We report a case showing overlap of both of these syndromes plus associated clinical features of common variable immune deficiency, scleroderma, and endocrinopathy that could also be mutation associated. Our patient was found to be heterozygous for a previously unreported frameshift mutation, c.1635_1637delCAA p.(Asn545del) in the DNMT1 gene exon 20. This case displays both the first frameshift mutation described in the literature which is associated with a phenotype with a high degree of overlap between HSAN1E and ADCA-DN and early age of onset (c. 8 years). Our case is also of interest as the patient displays a number of new non-neurological features, which could also be DNMT1 mutation related. © 2016 Peripheral Nerve Society.

  5. The Starch Granule-Associated Protein EARLY STARVATION1 Is Required for the Control of Starch Degradation in Arabidopsis thaliana Leaves[OPEN

    PubMed Central

    Feike, Doreen; Seung, David; Graf, Alexander; Bischof, Sylvain; Ellick, Tamaryn; Coiro, Mario; Soyk, Sebastian; Eicke, Simona; Mettler-Altmann, Tabea; Lu, Kuan Jen; Trick, Martin; Zeeman, Samuel C.

    2016-01-01

    To uncover components of the mechanism that adjusts the rate of leaf starch degradation to the length of the night, we devised a screen for mutant Arabidopsis thaliana plants in which starch reserves are prematurely exhausted. The mutation in one such mutant, named early starvation1 (esv1), eliminates a previously uncharacterized protein. Starch in mutant leaves is degraded rapidly and in a nonlinear fashion, so that reserves are exhausted 2 h prior to dawn. The ESV1 protein and a similar uncharacterized Arabidopsis protein (named Like ESV1 [LESV]) are located in the chloroplast stroma and are also bound into starch granules. The region of highest similarity between the two proteins contains a series of near-repeated motifs rich in tryptophan. Both proteins are conserved throughout starch-synthesizing organisms, from angiosperms and monocots to green algae. Analysis of transgenic plants lacking or overexpressing ESV1 or LESV, and of double mutants lacking ESV1 and another protein necessary for starch degradation, leads us to propose that these proteins function in the organization of the starch granule matrix. We argue that their misexpression affects starch degradation indirectly, by altering matrix organization and, thus, accessibility of starch polymers to starch-degrading enzymes. PMID:27207856

  6. Effects of Transforming Growth Factor Beta 1 in Cerebellar Development: Role in Synapse Formation

    PubMed Central

    Araujo, Ana P. B.; Diniz, Luan P.; Eller, Cristiane M.; de Matos, Beatriz G.; Martinez, Rodrigo; Gomes, Flávia C. A.

    2016-01-01

    Granule cells (GC) are the most numerous glutamatergic neurons in the cerebellar cortex and represent almost half of the neurons of the central nervous system. Despite recent advances, the mechanisms of how the glutamatergic synapses are formed in the cerebellum remain unclear. Among the TGF-β family, TGF-beta 1 (TGF-β1) has been described as a synaptogenic molecule in invertebrates and in the vertebrate peripheral nervous system. A recent paper from our group demonstrated that TGF-β1 increases the excitatory synapse formation in cortical neurons. Here, we investigated the role of TGF-β1 in glutamatergic cerebellar neurons. We showed that the expression profile of TGF-β1 and its receptor, TβRII, in the cerebellum is consistent with a role in synapse formation in vitro and in vivo. It is low in the early postnatal days (P1–P9), increases after postnatal day 12 (P12), and remains high until adulthood (P30). We also found that granule neurons express the TGF-β receptor mRNA and protein, suggesting that they may be responsive to the synaptogenic effect of TGF-β1. Treatment of granular cell cultures with TGF-β1 increased the number of glutamatergic excitatory synapses by 100%, as shown by immunocytochemistry assays for presynaptic (synaptophysin) and post-synaptic (PSD-95) proteins. This effect was dependent on TβRI activation because addition of a pharmacological inhibitor of TGF-β, SB-431542, impaired the formation of synapses between granular neurons. Together, these findings suggest that TGF-β1 has a specific key function in the cerebellum through regulation of excitatory synapse formation between granule neurons. PMID:27199658

  7. The effects of early hypo- and hyperthyroidism on the development of rat cerebellar cortex. III. Kinetics of cell proliferation in the external granular layer.

    PubMed

    Lauder, J M

    1977-04-22

    The effects of early hypo- and hyperthyroidism on the rates of cell acquisition and proliferation have been studied in the external granular layer (EGL) of the developing rat cerebellar cortex at 10 days of age using quantitative autoradiographic methods. Both altered thyroid states reduce the rate of cell acquisition in the EGL, but appear to do so for different reasons. Hyperthyroidism shortens the average length of the cell cycle by decreasing the duration of the pre-DNA synthetic phase (G1), indicating that excess thyroxine may exert a direct effect on the EGL. This action involves the early onset of neuronal differentiation (cessation of proliferation)46 which presumably leads to the observed decrease in the rate of cell acquisition (increased doubling time). Such differentiating cells do not, however, leave the proliferative zone or the EGL prematurely, resulting in a reduced labeling index, mitotic index, and growth fraction as non-dividing cells dilute the proliferating cell population. Hypothyroidism, on the other hand, leads to no significant change in the length of the cell cycle or in the mitotic index, but causes a decreased labeling index and growth fraction, as well as a reduced rate of cell acquisition (increased doubling time). No significant change in the amount of cell death in the EGL could be found to explain this apparent discrepancy between the rate of cell proliferation (cell cycle length) and cell acqusiition. The answer to this puzzle appears to lie in the mitotic index, which is not affected to the same extent as the labeling index, although it is also slightly reduced. If cells were to remain longer in mitosis, this could result in a decreased labeling index and growth fraction but nearly normal mitotic index and cell cycle length (as measured using the % labeled mitoses method), since those cells dropping out of the cycling population would be counted as mitoses...

  8. Questioning the cerebellar doctrine.

    PubMed

    Galliano, Elisa; De Zeeuw, Chris I

    2014-01-01

    The basic principles of cerebellar function were originally described by Flourens, Cajal, and Marr/Albus/Ito, and they constitute the pillars of what can be considered to be the classic cerebellar doctrine. In their concepts, the main cerebellar function is to control motor behavior, Purkinje cells are the only cortical neuron receiving and integrating inputs from climbing fiber and mossy-parallel fiber pathways, and plastic modification at the parallel fiber synapses onto Purkinje cells constitutes the substrate of motor learning. Yet, because of recent technical advances and new angles of investigation, all pillars of the cerebellar doctrine now face regular re-examination. In this review, after summarizing the classic concepts and recent disputes, we attempt to synthesize an integrated view and propose a revisited version of the cerebellar doctrine. © 2014 Elsevier B.V. All rights reserved.

  9. Consensus Paper: Radiological Biomarkers of Cerebellar Diseases

    PubMed Central

    Baldarçara, Leonardo; Currie, Stuart; Hadjivassiliou, M.; Hoggard, Nigel; Jack, Allison; Jackowski, Andrea P.; Mascalchi, Mario; Parazzini, Cecilia; Reetz, Kathrin; Righini, Andrea; Schulz, Jörg B.; Vella, Alessandra; Webb, Sara Jane; Habas, Christophe

    2016-01-01

    Hereditary and sporadic cerebellar ataxias represent a vast and still growing group of diseases whose diagnosis and differentiation cannot only rely on clinical evaluation. Brain imaging including magnetic resonance (MR) and nuclear medicine techniques allows for characterization of structural and functional abnormalities underlying symptomatic ataxias. These methods thus constitute a potential source of radiological biomarkers, which could be used to identify these diseases and differentiate subgroups of them, and to assess their severity and their evolution. Such biomarkers mainly comprise qualitative and quantitative data obtained from MR including proton spectroscopy, diffusion imaging, tractography, voxel-based morphometry, functional imaging during task execution or in a resting state, and from SPETC and PET with several radiotracers. In the current article, we aim to illustrate briefly some applications of these neuroimaging tools to evaluation of cerebellar disorders such as inherited cerebellar ataxia, fetal developmental malformations, and immune-mediated cerebellar diseases and of neurodegenerative or early-developing diseases, such as dementia and autism in which cerebellar involvement is an emerging feature. Although these radiological biomarkers appear promising and helpful to better understand ataxia-related anatomical and physiological impairments, to date, very few of them have turned out to be specific for a given ataxia with atrophy of the cerebellar system being the main and the most usual alteration being observed. Consequently, much remains to be done to establish sensitivity, specificity, and reproducibility of available MR and nuclear medicine features as diagnostic, progression and surrogate biomarkers in clinical routine. PMID:25382714

  10. Cerebellar and Brainstem Malformations.

    PubMed

    Poretti, Andrea; Boltshauser, Eugen; Huisman, Thierry A G M

    2016-08-01

    The frequency and importance of the evaluation of the posterior fossa have increased significantly over the past 20 years owing to advances in neuroimaging. Conventional and advanced neuroimaging techniques allow detailed evaluation of the complex anatomic structures within the posterior fossa. A wide spectrum of cerebellar and brainstem malformations has been shown. Familiarity with the spectrum of cerebellar and brainstem malformations and their well-defined diagnostic criteria is crucial for optimal therapy, an accurate prognosis, and correct genetic counseling. This article discusses cerebellar and brainstem malformations, with emphasis on neuroimaging findings (including diagnostic criteria), neurologic presentation, systemic involvement, prognosis, and recurrence. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Cerebro-cerebellar circuits in autism spectrum disorder.

    PubMed

    D'Mello, Anila M; Stoodley, Catherine J

    2015-01-01

    The cerebellum is one of the most consistent sites of abnormality in autism spectrum disorder (ASD) and cerebellar damage is associated with an increased risk of ASD symptoms, suggesting that cerebellar dysfunction may play a crucial role in the etiology of ASD. The cerebellum forms multiple closed-loop circuits with cerebral cortical regions that underpin movement, language, and social processing. Through these circuits, cerebellar dysfunction could impact the core ASD symptoms of social and communication deficits and repetitive and stereotyped behaviors. The emerging topography of sensorimotor, cognitive, and affective subregions in the cerebellum provides a new framework for interpreting the significance of regional cerebellar findings in ASD and their relationship to broader cerebro-cerebellar circuits. Further, recent research supports the idea that the integrity of cerebro-cerebellar loops might be important for early cortical development; disruptions in specific cerebro-cerebellar loops in ASD might impede the specialization of cortical regions involved in motor control, language, and social interaction, leading to impairments in these domains. Consistent with this concept, structural, and functional differences in sensorimotor regions of the cerebellum and sensorimotor cerebro-cerebellar circuits are associated with deficits in motor control and increased repetitive and stereotyped behaviors in ASD. Further, communication and social impairments are associated with atypical activation and structure in cerebro-cerebellar loops underpinning language and social cognition. Finally, there is converging evidence from structural, functional, and connectivity neuroimaging studies that cerebellar right Crus I/II abnormalities are related to more severe ASD impairments in all domains. We propose that cerebellar abnormalities may disrupt optimization of both structure and function in specific cerebro-cerebellar circuits in ASD.

  12. Cerebro-cerebellar circuits in autism spectrum disorder

    PubMed Central

    D'Mello, Anila M.; Stoodley, Catherine J.

    2015-01-01

    The cerebellum is one of the most consistent sites of abnormality in autism spectrum disorder (ASD) and cerebellar damage is associated with an increased risk of ASD symptoms, suggesting that cerebellar dysfunction may play a crucial role in the etiology of ASD. The cerebellum forms multiple closed-loop circuits with cerebral cortical regions that underpin movement, language, and social processing. Through these circuits, cerebellar dysfunction could impact the core ASD symptoms of social and communication deficits and repetitive and stereotyped behaviors. The emerging topography of sensorimotor, cognitive, and affective subregions in the cerebellum provides a new framework for interpreting the significance of regional cerebellar findings in ASD and their relationship to broader cerebro-cerebellar circuits. Further, recent research supports the idea that the integrity of cerebro-cerebellar loops might be important for early cortical development; disruptions in specific cerebro-cerebellar loops in ASD might impede the specialization of cortical regions involved in motor control, language, and social interaction, leading to impairments in these domains. Consistent with this concept, structural, and functional differences in sensorimotor regions of the cerebellum and sensorimotor cerebro-cerebellar circuits are associated with deficits in motor control and increased repetitive and stereotyped behaviors in ASD. Further, communication and social impairments are associated with atypical activation and structure in cerebro-cerebellar loops underpinning language and social cognition. Finally, there is converging evidence from structural, functional, and connectivity neuroimaging studies that cerebellar right Crus I/II abnormalities are related to more severe ASD impairments in all domains. We propose that cerebellar abnormalities may disrupt optimization of both structure and function in specific cerebro-cerebellar circuits in ASD. PMID:26594140

  13. Acute cerebellar ataxia

    MedlinePlus

    ... swelling (inflammation) of the cerebellum (such as from multiple sclerosis). Cerebellar ataxia caused by a recent viral infection may not need treatment. Outlook (Prognosis) People whose condition was caused by ...

  14. Cerebellar Development and Disease

    PubMed Central

    Gleeson, Joseph G.

    2008-01-01

    Recent Advances The molecular control of cell type specification within the developing cerebellum as well as the genetic causes of the most common human developmental cerebellar disorders have long remained mysterious. Recent genetic lineage and loss-of-function data from mice have revealed unique and non-overlapping anatomical origins for GABAergic neurons from ventricular zone precursors and glutamatergic cell from rhombic lip precursors, mirroring distinct origins for these neurotransmitter-specific cell types in the cerebral cortex. Mouse studies elucidating the role of Ptf1a as a cerebellar ventricular zone GABerigic fate switch were actually preceded by the recognition that PTF1A mutations in humans cause cerebellar agenesis, a birth defect of the human cerebellum. Indeed, several genes for congenital human cerebellar malformations have recently been identified, including genes causing Joubert syndrome, Dandy-Walker malformation and Ponto-cerebellar hypoplasia. These studies have pointed to surprisingly complex roles for transcriptional regulation, mitochondrial function and neuronal cilia in patterning, homeostasis and cell proliferation during cerebellar development. Together mouse and human studies are synergistically advancing our understanding of the developmental mechanisms that generate the uniquely complex mature cerebellum. PMID:18513948

  15. Granulation of fine powder

    SciTech Connect

    Chen, Ching-Fong

    A mixture of fine powder including thorium oxide was converted to granulated powder by forming a first-green-body and heat treating the first-green-body at a high temperature to strengthen the first-green-body followed by granulation by crushing or milling the heat-treated first-green-body. The granulated powder was achieved by screening through a combination of sieves to achieve the desired granule size distribution. The granulated powder relies on the thermal bonding to maintain its shape and structure. The granulated powder contains no organic binder and can be stored in a radioactive or other extreme environment. The granulated powder was pressed and sintered to formmore » a dense compact with a higher density and more uniform pore size distribution.« less

  16. A Mild Form of COG5 Defect Showing Early-Childhood-Onset Friedreich's-Ataxia-Like Phenotypes with Isolated Cerebellar Atrophy.

    PubMed

    Kim, Young Ok; Yun, Misun; Jeong, Jae Ho; Choi, Seong Min; Kim, Seul Kee; Yoon, Woong; Park, Chungoo; Hong, Yeongjin; Woo, Young Jong

    2017-11-01

    Progressive cerebellar ataxias are rare diseases during childhood, especially under 6 years of age. In a single family, three affected siblings exhibited Friedreich's-ataxia-like phenotypes before 2 years of age. They had progressive cerebellar atrophy, intellectual disability, and scoliosis. Although their phenotypes were similar to those observed in patients with autosomal recessive cerebellar ataxias, other phenotypes (e.g., seizure, movement disorders, ophthalmologic disturbance, cardiomyopathy, and cutaneous disorders) were not noted in this family. Whole-exome sequencing of the family members revealed one potential heterozygous mutation (c.1209delG, NM_181733.2; p.Met403IlefsX3, NP_859422.2) of the gene encoding conserved oligomeric Golgi complex subunit 5 (COG5). The heterozygous deletion at the fifth base in exon 12 of COG5 caused a frameshift and premature stop. Western blotting of COG5 proteins in the skin tissues from an affected proband showed a significantly decreased level of full length COG5 and smaller, aberrant COG5 proteins. We reported a milder form of COG5 defect showing Friedreich's-ataxia-like phenotypes without hypotonia, microcephaly, and short stature that were observed in most patients with COG5 defect. © 2017 The Korean Academy of Medical Sciences.

  17. Cerebellar learning mechanisms

    PubMed Central

    Freeman, John H.

    2014-01-01

    The mechanisms underlying cerebellar learning are reviewed with an emphasis on old arguments and new perspectives on eyeblink conditioning. Eyeblink conditioning has been used for decades a model system for elucidating cerebellar learning mechanisms. The standard model of the mechanisms underlying eyeblink conditioning is that there two synaptic plasticity processes within the cerebellum that are necessary for acquisition of the conditioned response: 1) long-term depression (LTD) at parallel fiber-Purkinje cell synapses and 2) long-term potentiation (LTP) at mossy fiber-interpositus nucleus synapses. Additional Purkinje cell plasticity mechanisms may also contribute to eyeblink conditioning including LTP, excitability, and entrainment of deep nucleus activity. Recent analyses of the sensory input pathways necessary for eyeblink conditioning indicate that the cerebellum regulates its inputs to facilitate learning and maintain plasticity. Cerebellar learning during eyeblink conditioning is therefore a dynamic interactive process which maximizes responding to significant stimuli and suppresses responding to irrelevant or redundant stimuli. PMID:25289586

  18. Breakage and drying behaviour of granules in a continuous fluid bed dryer: Influence of process parameters and wet granule transfer.

    PubMed

    De Leersnyder, F; Vanhoorne, V; Bekaert, H; Vercruysse, J; Ghijs, M; Bostijn, N; Verstraeten, M; Cappuyns, P; Van Assche, I; Vander Heyden, Y; Ziemons, E; Remon, J P; Nopens, I; Vervaet, C; De Beer, T

    2018-03-30

    Although twin screw granulation has already been widely studied in recent years, only few studies addressed the subsequent continuous drying which is required after wet granulation and still suffers from a lack of detailed understanding. The latter is important for optimisation and control and, hence, a cost-effective practical implementation. Therefore, the aim of the current study is to increase understanding of the drying kinetics and the breakage and attrition phenomena during fluid bed drying after continuous twin screw granulation. Experiments were performed on a continuous manufacturing line consisting of a twin-screw granulator, a six-segmented fluid bed dryer, a mill, a lubricant blender and a tablet press. Granulation parameters were fixed in order to only examine the effect of drying parameters (filling time, drying time, air flow, drying air temperature) on the size distribution and moisture content of granules (both of the entire granulate and of size fractions). The wet granules were transferred either gravimetrically or pneumatically from the granulator exit to the fluid bed dryer. After a certain drying time, the moisture content reached an equilibrium. This drying time was found to depend on the applied airflow, drying air temperature and filling time. The moisture content of the granules decreased with an increasing drying time, airflow and drying temperature. Although smaller granules dried faster, the multimodal particle size distribution of the granules did not compromise uniform drying of the granules when the target moisture content was achieved. Extensive breakage of granules was observed during drying. Especially wet granules were prone to breakage and attrition during pneumatic transport, either in the wet transfer line or in the dry transfer line. Breakage and attrition of granules during transport and drying should be anticipated early on during process and formulation development by performing integrated experiments on the granulator

  19. Reevaluation of the Beam and Radial Hypotheses of Parallel Fiber Action in the Cerebellar Cortex

    PubMed Central

    Cramer, Samuel W.; Gao, Wangcai; Chen, Gang

    2013-01-01

    The role of parallel fibers (PFs) in cerebellar physiology remains controversial. Early studies inspired the “beam” hypothesis whereby granule cell (GC) activation results in PF-driven, postsynaptic excitation of beams of Purkinje cells (PCs). However, the “radial” hypothesis postulates that the ascending limb of the GC axon provides the dominant input to PCs and generates patch-like responses. Using optical imaging and single-cell recordings in the mouse cerebellar cortex in vivo, this study reexamines the beam versus radial controversy. Electrical stimulation of mossy fibers (MFs) as well as microinjection of NMDA in the granular layer generates beam-like responses with a centrally located patch-like response. Remarkably, ipsilateral forepaw stimulation evokes a beam-like response in Crus I. Discrete molecular layer lesions demonstrate that PFs contribute to the peripherally generated responses in Crus I. In contrast, vibrissal stimulation induces patch-like activation of Crus II and GABAA antagonists fail to convert this patch-like activity into a beam-like response, implying that molecular layer inhibition does not prevent beam-like responses. However, blocking excitatory amino acid transporters (EAATs) generates beam-like responses in Crus II. These beam-like responses are suppressed by focal inhibition of MF-GC synaptic transmission. Using EAAT4 reporter transgenic mice, we show that peripherally evoked patch-like responses in Crus II are aligned between parasagittal bands of EAAT4. This is the first study to demonstrate beam-like responses in the cerebellar cortex to peripheral, MF, and GC stimulation in vivo. Furthermore, the spatial pattern of the responses depends on extracellular glutamate and its local regulation by EAATs. PMID:23843513

  20. Control of a simulated arm using a novel combination of Cerebellar learning mechanisms

    NASA Technical Reports Server (NTRS)

    Assad, C.; Hartmann, M.; Paulin, M. G.

    2001-01-01

    We present a model of cerebellar cortex that combines two types of learning: feedforward predicitve association based on local Hebbian-type learning between granule cell ascending branch and parallel fiber inputs, and reinforcement learning with feedback error correction based on climbing fiber activity.

  1. Increased Excitatory Synaptic Transmission of Dentate Granule Neurons in Mice Lacking PSD-95-Interacting Adhesion Molecule Neph2/Kirrel3 during the Early Postnatal Period.

    PubMed

    Roh, Junyeop D; Choi, Su-Yeon; Cho, Yi Sul; Choi, Tae-Yong; Park, Jong-Sil; Cutforth, Tyler; Chung, Woosuk; Park, Hanwool; Lee, Dongsoo; Kim, Myeong-Heui; Lee, Yeunkum; Mo, Seojung; Rhee, Jeong-Seop; Kim, Hyun; Ko, Jaewon; Choi, Se-Young; Bae, Yong Chul; Shen, Kang; Kim, Eunjoon; Han, Kihoon

    2017-01-01

    Copy number variants and point mutations of NEPH2 (also called KIRREL3 ) gene encoding an immunoglobulin (Ig) superfamily adhesion molecule have been linked to autism spectrum disorders, intellectual disability and neurocognitive delay associated with Jacobsen syndrome, but the physiological roles of Neph2 in the mammalian brain remain largely unknown. Neph2 is highly expressed in the dentate granule (DG) neurons of the hippocampus and is localized in both dendrites and axons. It was recently shown that Neph2 is required for the formation of mossy fiber filopodia, the axon terminal structure of DG neurons forming synapses with GABAergic neurons of CA3. In contrast, however, it is unknown whether Neph2 also has any roles in the postsynaptic compartments of DG neurons. We here report that, through its C-terminal PDZ domain-binding motif, Neph2 directly interacts with postsynaptic density (PSD)-95, an abundant excitatory postsynaptic scaffolding protein. Moreover, Neph2 protein is detected in the brain PSD fraction and interacts with PSD-95 in synaptosomal lysates. Functionally, loss of Neph2 in mice leads to age-specific defects in the synaptic connectivity of DG neurons. Specifically, Neph2 -/- mice show significantly increased spontaneous excitatory synaptic events in DG neurons at postnatal week 2 when the endogenous Neph2 protein expression peaks, but show normal excitatory synaptic transmission at postnatal week 3. The evoked excitatory synaptic transmission and synaptic plasticity of medial perforant pathway (MPP)-DG synapses are also normal in Neph2 -/- mice at postnatal week 3, further confirming the age-specific synaptic defects. Together, our results provide some evidence for the postsynaptic function of Neph2 in DG neurons during the early postnatal period, which might be implicated in neurodevelopmental and cognitive disorders caused by NEPH2 mutations.

  2. The Changeable Nervous System: Studies On Neuroplasticity In Cerebellar Cultures

    PubMed Central

    Seil, Fredrick J.

    2014-01-01

    Circuit reorganization after injury was studied in a cerebellar culture model. When cerebellar cultures derived from newborn mice were exposed at explantation to a preparation of cytosine arabinoside that destroyed granule cells and oligodendrocytes and compromised astrocytes, Purkinje cells surviving in greater than usual numbers were unensheathed by astrocytic processes and received twice the control number of inhibitory axosomatic synapses. Purkinje cell axon collaterals sprouted and many of their terminals formed heterotypical synapses with other Purkinje cell dendritic spines. The resulting circuit reorganization preserved inhibition in the cerebellar cortex. Following this reorganization, replacement of the missing granule cells and glia was followed by a restitution of the normal circuitry. Most of these developmental and reconstructive changes were not dependent on neuronal activity, the major exception being inhibitory synaptogenesis. The full complement of inhibitory synapses did not develop in the absence of neuronal activity, which could be mitigated by application of exogenous TrkB receptor ligands. Inhibitory synaptogenesis could also be promoted by activity-induced release of endogenous TrkB receptor ligands or by antibody activation of the TrkB receptor. PMID:24933693

  3. Transient inhibition of the ERK pathway prevents cerebellar developmental defects and improves long-term motor functions in murine models of neurofibromatosis type 1.

    PubMed

    Kim, Edward; Wang, Yuan; Kim, Sun-Jung; Bornhorst, Miriam; Jecrois, Emmanuelle S; Anthony, Todd E; Wang, Chenran; Li, Yi E; Guan, Jun-Lin; Murphy, Geoffrey G; Zhu, Yuan

    2014-12-23

    Individuals with neurofibromatosis type 1 (NF1) frequently exhibit cognitive and motor impairments and characteristics of autism. The cerebellum plays a critical role in motor control, cognition, and social interaction, suggesting that cerebellar defects likely contribute to NF1-associated neurodevelopmental disorders. Here we show that Nf1 inactivation during early, but not late stages of cerebellar development, disrupts neuronal lamination, which is partially caused by overproduction of glia and subsequent disruption of the Bergmann glia (BG) scaffold. Specific Nf1 inactivation in glutamatergic neuronal precursors causes premature differentiation of granule cell (GC) precursors and ectopic production of unipolar brush cells (UBCs), indirectly disrupting neuronal migration. Transient MEK inhibition during a neonatal window prevents cerebellar developmental defects and improves long-term motor performance of Nf1-deficient mice. This study reveals essential roles of Nf1 in GC/UBC migration by generating correct numbers of glia and controlling GC/UBC fate-specification/differentiation, identifying a therapeutic prevention strategy for multiple NF1-associcated developmental abnormalities.

  4. Transient inhibition of the ERK pathway prevents cerebellar developmental defects and improves long-term motor functions in murine models of neurofibromatosis type 1

    PubMed Central

    Kim, Edward; Wang, Yuan; Kim, Sun-Jung; Bornhorst, Miriam; Jecrois, Emmanuelle S; Anthony, Todd E; Wang, Chenran; Li, Yi E; Guan, Jun-Lin; Murphy, Geoffrey G; Zhu, Yuan

    2014-01-01

    Individuals with neurofibromatosis type 1 (NF1) frequently exhibit cognitive and motor impairments and characteristics of autism. The cerebellum plays a critical role in motor control, cognition, and social interaction, suggesting that cerebellar defects likely contribute to NF1-associated neurodevelopmental disorders. Here we show that Nf1 inactivation during early, but not late stages of cerebellar development, disrupts neuronal lamination, which is partially caused by overproduction of glia and subsequent disruption of the Bergmann glia (BG) scaffold. Specific Nf1 inactivation in glutamatergic neuronal precursors causes premature differentiation of granule cell (GC) precursors and ectopic production of unipolar brush cells (UBCs), indirectly disrupting neuronal migration. Transient MEK inhibition during a neonatal window prevents cerebellar developmental defects and improves long-term motor performance of Nf1-deficient mice. This study reveals essential roles of Nf1 in GC/UBC migration by generating correct numbers of glia and controlling GC/UBC fate-specification/differentiation, identifying a therapeutic prevention strategy for multiple NF1-associcated developmental abnormalities. DOI: http://dx.doi.org/10.7554/eLife.05151.001 PMID:25535838

  5. The cell adhesion molecule CHL1 interacts with patched-1 to regulate apoptosis during postnatal cerebellar development.

    PubMed

    Katic, Jelena; Loers, Gabriele; Tosic, Jelena; Schachner, Melitta; Kleene, Ralf

    2017-08-01

    The immunoglobulin superfamily adhesion molecule close homolog of L1 (CHL1) plays important roles during nervous system development. Here, we identified the hedgehog receptor patched-1 (PTCH1) as a novel CHL1-binding protein and showed that CHL1 interacts with the first extracellular loop of PTCH1 via its extracellular domain. Colocalization and co-immunoprecipitation of CHL1 with PTCH1 suggest an association of CHL1 with this major component of the hedgehog signaling pathway. The trans -interaction of CHL1 with PTCH1 promotes neuronal survival in cultures of dissociated cerebellar granule cells and of organotypic cerebellar slices. An inhibitor of the PTCH1-regulated hedgehog signal transducer, smoothened (SMO), and inhibitors of RhoA and Rho-associated kinase (ROCK) 1 and 2 prevent CHL1-dependent survival of cultured cerebellar granule cells and survival of cerebellar granule and Purkinje cells in organotypic cultures. In histological sections from 10- and 14-day-old CHL1-deficient mice, enhanced apoptosis of granule, but not Purkinje, cells was observed. The results of the present study indicate that CHL1 triggers PTCH1-, SMO-, RhoA- and ROCK-dependent signal transduction pathways to promote neuronal survival after cessation of the major morphogenetic events during mouse cerebellar development. © 2017. Published by The Company of Biologists Ltd.

  6. Granule size control and targeting in pulsed spray fluid bed granulation.

    PubMed

    Ehlers, Henrik; Liu, Anchang; Räikkönen, Heikki; Hatara, Juha; Antikainen, Osmo; Airaksinen, Sari; Heinämäki, Jyrki; Lou, Honxiang; Yliruusi, Jouko

    2009-07-30

    The primary aim of the study was to investigate the effects of pulsed liquid feed on granule size. The secondary aim was to increase knowledge of this technique in granule size targeting. Pulsed liquid feed refers to the pump changing between on- and off-positions in sequences, called duty cycles. One duty cycle consists of one on- and off-period. The study was performed with a laboratory-scale top-spray fluid bed granulator with duty cycle length and atomization pressure as studied variables. The liquid feed rate, amount and inlet air temperature were constant. The granules were small, indicating that the powder has only undergone ordered mixing, nucleation and early growth. The effect of atomizing pressure on granule size depends on inlet air relative humidity, with premature binder evaporation as a reason. The duty cycle length was of critical importance to the end product attributes, by defining the extent of intermittent drying and rewetting. By varying only the duty cycle length, it was possible to control granule nucleation and growth, with a wider granule size target range in increased relative humidity. The present study confirms that pulsed liquid feed in fluid bed granulation is a useful tool in end product particle size targeting.

  7. Cerebellar degeneration following neuroleptic malignant syndrome.

    PubMed Central

    Lal, V.; Sardana, V.; Thussu, A.; Sawhney, I. M.; Prabhakar, S.

    1997-01-01

    A 55-year-old woman with a history of bipolar affective disorder developed hyperpyrexia, rigidity and depressed consciousness (neuroleptic malignant syndrome) after commencing neuroleptic therapy. On regaining consciousness, she was mute and had signs suggesting pancerebellar involvement. Hyperpyrexia, which is a cardinal feature of neuroleptic malignant syndrome, may have caused cerebellar damage. Neuroleptic malignant syndrome needs both early recognition and prompt treatment to obviate devastating complications. PMID:9519191

  8. Childhood cerebellar ataxia.

    PubMed

    Fogel, Brent L

    2012-09-01

    Childhood presentations of ataxia, an impairment of balance and coordination caused by damage to or dysfunction of the cerebellum, can often be challenging to diagnose. Presentations tend to be clinically heterogeneous, but key considerations may vary based on the child's age at onset, the course of illness, and subtle differences in phenotype. Systematic investigation is recommended for efficient diagnosis. In this review, we outline common etiologies and describe a comprehensive approach to the evaluation of both acquired and genetic cerebellar ataxia in children.

  9. Diagnosis and initial management of cerebellar infarction.

    PubMed

    Edlow, Jonathan A; Newman-Toker, David E; Savitz, Sean I

    2008-10-01

    Cerebellar infarction is an important cause of stroke that often presents with common and non-specific symptoms such as dizziness, nausea and vomiting, unsteady gait, and headache. Accurate diagnosis frequently relies on careful attention to patients' coordination, gait, and eye movements--components of the neurological physical examination that are sometimes omitted or abridged if cerebellar stroke is not specifically being considered. The differential diagnosis is broad, and includes many common and benign causes. Furthermore, early-stage posterior fossa ischaemia is rarely seen with brain CT--the most commonly available initial imaging test that is used for stroke. Insufficient examination and imaging can result in misdiagnosis. However, early correct diagnosis is crucial to help prevent treatable but potentially fatal complications, such as brainstem compression and obstructive hydrocephalus. The identification and treatment of the underlying vascular lesions at an early stage can also prevent subsequent occurrences of stroke and improve patients' outcomes. Here, we review the clinical presentation of cerebellar infarction, from diagnosis and misdiagnosis to patients' monitoring, treatment, and potential complications.

  10. Cerebellar abiotrophy in a miniature schnauzer.

    PubMed

    Berry, Michelle L; Blas-Machado, Uriel

    2003-08-01

    A 3.5-month-old miniature schnauzer was presented for signs of progressive cerebellar ataxia. Necropsy revealed cerebellar abiotrophy. This is the first reported case of cerebellar abiotrophy in a purebred miniature schnauzer.

  11. Cerebellar abiotrophy in a miniature schnauzer

    PubMed Central

    Berry, Michelle L.; Blas-Machado, Uriel

    2003-01-01

    A 3.5-month-old miniature schnauzer was presented for signs of progressive cerebellar ataxia. Necropsy revealed cerebellar abiotrophy. This is the first reported case of cerebellar abiotrophy in a purebred miniature schnauzer. PMID:13677598

  12. MicroRNAs Promote Granule Cell Expansion in the Cerebellum Through Gli2.

    PubMed

    Constantin, Lena; Wainwright, Brandon J

    2015-12-01

    MicroRNAs (miRNAs) are important regulators of cerebellar function and homeostasis. Their deregulation results in cerebellar neuronal degeneration and spinocerebellar ataxia type 1 and contributes to medulloblastoma. Canonical miRNA processing involves Dicer, which cleaves precursor miRNAs into mature double-stranded RNA duplexes. In order to address the role of miRNAs in cerebellar granule cell precursor development, loxP-flanked exons of Dicer1 were conditionally inactivated using the granule cell precursor-specific Atoh1-Cre recombinase. A reduction of 87% in Dicer1 transcript was achieved in this conditional Dicer knockdown model. Although knockdown resulted in normal survival, mice had disruptions to the cortical layering of the anterior cerebellum, which resulted from the premature differentiation of granule cell precursors in this region during neonatal development. This defect manifested as a thinner external granular layer with ectopic mature granule cells, and a depleted internal granular layer. We found that expression of the activator components of the Hedgehog-Patched pathway, the Gli family of transcription factors, was perturbed in conditional Dicer knockdown mice. We propose that loss of Gli2 mRNA mediated the anterior-restricted defect in conditional Dicer knockdown mice and, as proof of principle, were able to show that miR-106b positively regulated Gli2 mRNA expression. These findings confirm the importance of miRNAs as positive mediators of Hedgehog-Patched signalling during granule cell precursor development.

  13. Nicotinic receptor abnormalities in the cerebellar cortex in autism.

    PubMed

    Lee, M; Martin-Ruiz, C; Graham, A; Court, J; Jaros, E; Perry, R; Iversen, P; Bauman, M; Perry, E

    2002-07-01

    Autism is a common developmental disorder associated with structural and inferred neurochemical abnormalities of the brain. Cerebellar abnormalities frequently have been identified, based on neuroimaging or neuropathology. Recently, the cholinergic neurotransmitter system has been implicated on the basis of nicotinic receptor loss in the cerebral cortex. Cerebellar cholinergic activities were therefore investigated in autopsy tissue from a series of autistic individuals. The presynaptic cholinergic enzyme, choline acetyltransferase, together with nicotinic and muscarinic receptor subtypes were compared in the cerebellum from age-matched mentally retarded autistic (eight), normal control (10) and non-autistic mentally retarded individuals (11). The nicotinic receptor binding the agonist epibatidine (the high affinity receptor subtype, consisting primarily of alpha3 and alpha4, together with beta2 receptor subunits) was significantly reduced by 40-50% in the granule cell, Purkinje and molecular layers in the autistic compared with the normal group (P < 0.05). There was an opposite increase (3-fold) in the nicotinic receptor binding alpha-bungarotoxin (to the alpha7 subunit) which reached significance in the granule cell layer (P < 0.05). These receptor changes were paralleled by a significant reduction (P < 0.05) and non-significant increase, respectively, of alpha4 and alpha7 receptor subunit immunoreactivity measured using western blotting. Immunohistochemically loss of alpha(4 )reactivity was apparent from Purkinje and the other cell layers, with increased alpha7 reactivity in the granule cell layer. There were no significant changes in choline acetyltransferase activity, or in muscarinic M1 and M2 receptor subtypes in autism. In the non-autistic mentally retarded group, the only significant abnormality was a reduction in epibatidine binding in the granule cell and Purkinje layers. In two autistic cases examined histologically, Purkinje cell loss was observed in

  14. Childhood Cerebellar Ataxia

    PubMed Central

    Fogel, Brent L.

    2012-01-01

    Childhood presentations of ataxia, an impairment of balance and coordination caused by damage to or dysfunction of the cerebellum, can often be challenging to diagnose. Presentations tend to be clinically heterogeneous but key considerations may vary based on the child's age at onset, the course of illness, and subtle differences in phenotype. Systematic investigation is recommended for efficient diagnosis. In this review, we outline common etiologies and describe a comprehensive approach to the evaluation of both acquired and genetic cerebellar ataxia in children. PMID:22764177

  15. Cerebellar contribution to locomotor behavior: A neurodevelopmental perspective.

    PubMed

    Sathyanesan, Aaron; Gallo, Vittorio

    2018-04-30

    The developmental trajectory of the formation of cerebellar circuitry has significant implications for locomotor plasticity and adaptive learning at later stages. While there is a wealth of knowledge on the development of locomotor behavior in human infants, children, and adolescents, pre-clinical animal models have fallen behind on the study of the emergence of behavioral motifs in locomotor function across postnatal development. Since cerebellar development is protracted, it is subject to higher risk of genetic or environmental disruption, potentially leading to abnormal behavioral development. This highlights the need for more sophisticated and specific functional analyses of adaptive cerebellar behavior within the context of whole-body locomotion across the entire span of postnatal development. Here we review evidence on cerebellar contribution to adaptive locomotor behavior, highlighting methodologies employed to quantify and categorize behavior at different developmental stages, with the ultimate goal of following the course of early behavioral alterations in neurodevelopmental disorders. Since experimental paradigms used to study cerebellar behavior are lacking in both specificity and applicability to locomotor contexts, we highlight the use of the Erasmus Ladder - an advanced, computerized, fully automated system to quantify adaptive cerebellar learning in conjunction with locomotor function. Finally, we emphasize the need to develop objective, quantitative, behavioral tasks which can track changes in developmental trajectories rather than endpoint measurement at the adult stage of behavior. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Voltage-gated calcium channel autoimmune cerebellar degeneration

    PubMed Central

    McKasson, Marilyn; Clawson, Susan A.; Hill, Kenneth E.; Wood, Blair; Carlson, Noel; Bromberg, Mark; Greenlee, John E.

    2016-01-01

    Objectives: To describe response to treatment in a patient with autoantibodies against voltage-gated calcium channels (VGCCs) who presented with autoimmune cerebellar degeneration and subsequently developed Lambert-Eaton myasthenic syndrome (LEMS), and to study the effect of the patient's autoantibodies on Purkinje cells in rat cerebellar slice cultures. Methods: Case report and study of rat cerebellar slice cultures incubated with patient VGCC autoantibodies. Results: A 53-year-old man developed progressive incoordination with ataxic speech. Laboratory evaluation revealed VGCC autoantibodies without other antineuronal autoantibodies. Whole-body PET scans 6 and 12 months after presentation detected no malignancy. The patient improved significantly with IV immunoglobulin G (IgG), prednisone, and mycophenolate mofetil, but worsened after IV IgG was halted secondary to aseptic meningitis. He subsequently developed weakness with electrodiagnostic evidence of LEMS. The patient's IgG bound to Purkinje cells in rat cerebellar slice cultures, followed by neuronal death. Reactivity of the patient's autoantibodies with VGCCs was confirmed by blocking studies with defined VGCC antibodies. Conclusions: Autoimmune cerebellar degeneration associated with VGCC autoantibodies may precede onset of LEMS and may improve with immunosuppressive treatment. Binding of anti-VGCC antibodies to Purkinje cells in cerebellar slice cultures may be followed by cell death. Patients with anti-VGCC autoantibodies may be at risk of irreversible neurologic injury over time, and treatment should be initiated early. PMID:27088118

  17. Differential Effects of Intraventricular Hemorrhage and White Matter Injury on Preterm Cerebellar Growth

    PubMed Central

    Tam, Emily W.Y.; Miller, Steven P.; Studholme, Colin; Chau, Vann; Glidden, David; Poskitt, Kenneth J.; Ferriero, Donna M.; Barkovich, A. James

    2010-01-01

    Objective To hypothesize that detailed examination of early cerebellar volumes over time would distinguish differences in cerebellar growth associated with intraventricular hemorrhage (IVH) and white matter injury (WMI) in preterm infants. Study design Preterm newborns at the University of California San Francisco (n=57) and the University of British Columbia (n=115) were studied using serial MRI scans near birth and again at near term-equivalent age. Interactive semi-automated tools were used to determine volumes of the cerebellar hemispheres. Results Adjusting for supratentorial brain injury, cerebellar hemorrhage, and study site, cerebellar volume increased 1.7cm3/week postmenstrual age (95% CI 1.6–1.7, P<0.001). More severe supratentorial IVH was associated with slower growth of cerebellar volumes (P<0.001). Volumes by 40 weeks were 1.4 cm3 lower in premature infants with grade 1–2 IVH and 5.4 cm3 lower with grade 3–4 IVH. The same magnitude of decrease was found between ipsilateral and contralateral IVH. No association was found with severity of WMI (P=0.3). Conclusions Early effects of decreased cerebellar volume associated with supratentorial IVH in either hemisphere may be a result of concurrent cerebellar injury or direct effects of subarachnoid blood on cerebellar development. PMID:20961562

  18. The organization of plasticity in the cerebellar cortex: from synapses to control.

    PubMed

    D'Angelo, Egidio

    2014-01-01

    The cerebellum is thought to play a critical role in procedural learning, but the relationship between this function and the underlying cellular and synaptic mechanisms remains largely speculative. At present, at least nine forms of long-term synaptic and nonsynaptic plasticity (some of which are bidirectional) have been reported in the cerebellar cortex and deep cerebellar nuclei. These include long-term potentiation (LTP) and long-term depression at the mossy fiber-granule cell synapse, at the synapses formed by parallel fibers, climbing fibers, and molecular layer interneurons on Purkinje cells, and at the synapses formed by mossy fibers and Purkinje cells on deep cerebellar nuclear cells, as well as LTP of intrinsic excitability in granule cells, Purkinje cells, and deep cerebellar nuclear cells. It is suggested that the complex properties of cerebellar learning would emerge from the distribution of plasticity in the network and from its dynamic remodeling during the different phases of learning. Intrinsic and extrinsic factors may hold the key to explain how the different forms of plasticity cooperate to select specific transmission channels and to regulate the signal-to-noise ratio through the cerebellar cortex. These factors include regulation of neuronal excitation by local inhibitory networks, engagement of specific molecular mechanisms by spike bursts and theta-frequency oscillations, and gating by external neuromodulators. Therefore, a new and more complex view of cerebellar plasticity is emerging with respect to that predicted by the original "Motor Learning Theory," opening issues that will require experimental and computational testing. © 2014 Elsevier B.V. All rights reserved.

  19. Imaging of zymogen granules in fully wet cells: evidence for restricted mechanism of granule growth.

    PubMed

    Hammel, Ilan; Anaby, Debbie

    2007-09-01

    The introduction of wet SEM imaging technology permits electron microscopy of wet samples. Samples are placed in sealed specimen capsules and are insulated from the vacuum in the SEM chamber by an impermeable, electron-transparent membrane. The complete insulation of the sample from the vacuum allows direct imaging of fully hydrated, whole-mount tissue. In the current work, we demonstrate direct inspection of thick pancreatic tissue slices (above 400 mum). In the case of scanning of the pancreatic surface, the boundaries of intracellular features are seen directly. Thus no unfolding is required to ascertain the actual particle size distribution based on the sizes of the sections. This method enabled us to investigate the true granule size distribution and confirm early studies of improved conformity to a Poisson-like distribution, suggesting that the homotypic granule growth results from a mechanism, which favors the addition of a single unit granule to mature granules.

  20. Cerebellar liponeurocytoma with extracranial extension: case report.

    PubMed

    Ben Nsir, A; Ben Said, I; Hammami, N; Sebai, R; Jemel, H

    2014-01-01

    Cerebellar liponeurocytoma is a newly recognized, rare clinicopathological entity commonly described in the cerebellar hemispheres or the vermis. We present a rare case of cerebellar liponeurocytoma arising from the left cerebellar amygdala with extracranial extension. Such a condition has never been previously reported. Copyright © 2014 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  1. Current source density correlates of cerebellar Golgi and Purkinje cell responses to tactile input

    PubMed Central

    Tahon, Koen; Wijnants, Mike; De Schutter, Erik

    2011-01-01

    The overall circuitry of the cerebellar cortex has been known for over a century, but the function of many synaptic connections remains poorly characterized in vivo. We used a one-dimensional multielectrode probe to estimate the current source density (CSD) of Crus IIa in response to perioral tactile stimuli in anesthetized rats and to correlate current sinks and sources to changes in the spike rate of corecorded Golgi and Purkinje cells. The punctate stimuli evoked two distinct early waves of excitation (at <10 and ∼20 ms) associated with current sinks in the granular layer. The second wave was putatively of corticopontine origin, and its associated sink was located higher in the granular layer than the first trigeminal sink. The distinctive patterns of granular-layer sinks correlated with the spike responses of corecorded Golgi cells. In general, Golgi cell spike responses could be linearly reconstructed from the CSD profile. A dip in simple-spike activity of coregistered Purkinje cells correlated with a current source deep in the molecular layer, probably generated by basket cell synapses, interspersed between sparse early sinks presumably generated by synapses from granule cells. The late (>30 ms) enhancement of simple-spike activity in Purkinje cells was characterized by the absence of simultaneous sinks in the granular layer and by the suppression of corecorded Golgi cell activity, pointing at inhibition of Golgi cells by Purkinje axon collaterals as a likely mechanism of late Purkinje cell excitation. PMID:21228303

  2. Phenotypic outcomes in Mouse and Human Foxc1 dependent Dandy-Walker cerebellar malformation suggest shared mechanisms.

    PubMed

    Haldipur, Parthiv; Dang, Derek; Aldinger, Kimberly A; Janson, Olivia K; Guimiot, Fabien; Adle-Biasette, Homa; Dobyns, William B; Siebert, Joseph R; Russo, Rosa; Millen, Kathleen J

    2017-01-16

    FOXC1 loss contributes to Dandy-Walker malformation (DWM), a common human cerebellar malformation. Previously, we found that complete Foxc1 loss leads to aberrations in proliferation, neuronal differentiation and migration in the embryonic mouse cerebellum (Haldipur et al., 2014). We now demonstrate that hypomorphic Foxc1 mutant mice have granule and Purkinje cell abnormalities causing subsequent disruptions in postnatal cerebellar foliation and lamination. Particularly striking is the presence of a partially formed posterior lobule which echoes the posterior vermis DW 'tail sign' observed in human imaging studies. Lineage tracing experiments in Foxc1 mutant mouse cerebella indicate that aberrant migration of granule cell progenitors destined to form the posterior-most lobule causes this unique phenotype. Analyses of rare human del chr 6p25 fetal cerebella demonstrate extensive phenotypic overlap with our Foxc1 mutant mouse models, validating our DWM models and demonstrating that many key mechanisms controlling cerebellar development are likely conserved between mouse and human.

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

    PubMed

    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.

  4. Delayed reverberation through time windows as a key to cerebellar function.

    PubMed

    Kistler, W M; Leo van Hemmen, J

    1999-11-01

    We present a functional model of the cerebellum comprising cerebellar cortex, inferior olive, deep cerebellar nuclei, and brain stem nuclei. The discerning feature of the model being time coding, we consistently describe the system in terms of postsynaptic potentials, synchronous action potentials, and propagation delays. We show by means of detailed single-neuron modeling that (i) Golgi cells can fulfill a gating task in that they form short and well-defined time windows within which granule cells can reach firing threshold, thus organizing neuronal activity in discrete 'time slices', and that (ii) rebound firing in cerebellar nuclei cells is a robust mechanism leading to a delayed reverberation of Purkinje cell activity through cerebellar-reticular projections back to the cerebellar cortex. Computer simulations of the whole cerebellar network consisting of several thousand neurons reveal that reverberation in conjunction with long-term plasticity at the parallel fiber-Purkinje cell synapses enables the system to learn, store, and recall spatio-temporal patterns of neuronal activity. Climbing fiber spikes act both as a synchronization and as a teacher signal, not as an error signal. They are due to intrinsic oscillatory properties of inferior olivary neurons and to delayed reverberation within the network. In addition to clear experimental predictions the present theory sheds new light on a number of experimental observation such as the synchronicity of climbing fiber spikes and provides a novel explanation of how the cerebellum solves timing tasks on a time scale of several hundreds of milliseconds.

  5. Cerebellar contributions to spatial memory.

    PubMed

    Tomlinson, Simon P; Davis, Nick J; Morgan, Helen M; Bracewell, R Martyn

    2014-08-22

    There is mounting evidence for a role for the cerebellum in working memory (WM). The majority of relevant studies has examined verbal WM and has suggested specialisation of the right cerebellar hemisphere for language processing. Our study used theta burst stimulation (TBS) to examine whether there is a converse cerebellar hemispheric specialisation for spatial WM. We conducted two experiments to examine spatial WM performance before and after TBS to mid-hemispheric and lateral locations in the posterior cerebellum. Participants were required to recall the order of presentation of targets on a screen or the targets' order of presentation and their locations. We observed impaired recollection of target order after TBS to the mid left cerebellar hemisphere and reduced response speed after TBS to the left lateral cerebellum. We suggest that these results give evidence of the contributions of the left cerebellar cortex to the encoding and retrieval of spatial information. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. Excitatory Cerebellar Nucleocortical Circuit Provides Internal Amplification during Associative Conditioning.

    PubMed

    Gao, Zhenyu; Proietti-Onori, Martina; Lin, Zhanmin; Ten Brinke, Michiel M; Boele, Henk-Jan; Potters, Jan-Willem; Ruigrok, Tom J H; Hoebeek, Freek E; De Zeeuw, Chris I

    2016-02-03

    Closed-loop circuitries between cortical and subcortical regions can facilitate precision of output patterns, but the role of such networks in the cerebellum remains to be elucidated. Here, we characterize the role of internal feedback from the cerebellar nuclei to the cerebellar cortex in classical eyeblink conditioning. We find that excitatory output neurons in the interposed nucleus provide efference-copy signals via mossy fibers to the cerebellar cortical zones that belong to the same module, triggering monosynaptic responses in granule and Golgi cells and indirectly inhibiting Purkinje cells. Upon conditioning, the local density of nucleocortical mossy fiber terminals significantly increases. Optogenetic activation and inhibition of nucleocortical fibers in conditioned animals increases and decreases the amplitude of learned eyeblink responses, respectively. Our data show that the excitatory nucleocortical closed-loop circuitry of the cerebellum relays a corollary discharge of premotor signals and suggests an amplifying role of this circuitry in controlling associative motor learning. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Systemic inflammation combined with neonatal cerebellar haemorrhage aggravates long-term structural and functional outcomes in a mouse model.

    PubMed

    Tremblay, Sophie; Pai, Alex; Richter, Lindsay; Vafaei, Rod; Potluri, Praneetha; Ellegood, Jacob; Lerch, Jason P; Goldowitz, Daniel

    2017-11-01

    Despite the increased recognition of cerebellar injury in survivors of preterm birth, the neurodevelopmental consequences of isolated cerebellar injury have been largely unexplored and our current understanding of the functional deficits requires further attention in order to translate knowledge to best practices. Preterm infants are exposed to multiple stressors during their postnatal development including perinatal cerebellar haemorrhage (CBH) and postnatal infection, two major risk factors for neurodevelopmental impairments. We developed a translational mouse model of CBH and/or inflammation to measure the short- and long-term outcomes in cerebellar structure and function. Mice exposed to early combined insults of CBH and early inflammatory state (EIS) have a delay in grasping acquisition, neonatal motor deficits and deficient long-term memory. CBH combined with late inflammatory state (LIS) does not induce neonatal motor problems but leads to poor fine motor function and long-term memory deficits at adulthood. Early combined insults result in poor cerebellar growth from postnatal day 15 until adulthood shown by MRI, which are reflected in diminished volumes of cerebellar structures. There are also decreases in volumes of gray matter and hippocampus. Cerebellar microgliosis appears 24h after the combined insults and persists until postnatal day 15 in the cerebellar molecular layer and cerebellar nuclei in association with a disrupted patterning of myelin deposition, a delay of oligodendrocyte maturation and reduced white matter cerebellar volume. Together, these findings reveal poor outcomes in developing brains exposed to combined cerebellar perinatal insults in association with cerebellar hypoplasia, persistence of microgliosis and alterations of cerebellar white matter maturation and growth. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. [Cerebellar Infarction After Carbon Monoxide Poisoning and Hyperbaric Oxygen Therapy].

    PubMed

    Wick, Matthias; Schneiker, André; Bele, Sylvia; Pawlik, Michael; Meyringer, Helmut; Graf, Bernhard; Wendl, Christina; Kieninger, Martin

    2017-06-01

    We report on a patient who developed a space-occupying cerebellar infarction with occlusive hydrocephalus after a poisoning with carbon monoxide with the intention to commit suicide. A neurosurgical and intensive care therapy were needed. The patient's survival without severe neurological deficits could be secured due to the early detection of the intracerebral lesions. Georg Thieme Verlag KG Stuttgart · New York.

  9. Neurodevelopmental Outcomes in Children with Cerebellar Malformations: A Systematic Review

    ERIC Educational Resources Information Center

    Bolduc, Marie-Eve; Limperopoulos, Catherine

    2009-01-01

    Cerebellar malformations are increasingly diagnosed in the fetal period. Consequently, their consideration requires stressful and often critical decisions from both clinicians and families. This has resulted in an emergent need to understand better the impact of these early life lesions on child development. We performed a comprehensive literature…

  10. The Cerebellar-Cerebral Microstructure Is Disrupted at Multiple Sites in Very Preterm Infants with Cerebellar Haemorrhage.

    PubMed

    Neubauer, Vera; Djurdjevic, Tanja; Griesmaier, Elke; Biermayr, Marlene; Gizewski, Elke Ruth; Kiechl-Kohlendorfer, Ursula

    2018-01-01

    Recent advances in magnetic resonance imaging (MRI) techniques have prompted reconsideration of the anatomical correlates of adverse outcomes in preterm infants. The importance of the contribution made by the cerebellum is now increasingly appreciated. The effect of cerebellar haemorrhage (CBH) on the microstructure of the cerebellar-cerebral circuit is largely unexplored. To investigate the effect of CBH on the microstructure of cerebellar-cerebral connections in preterm infants aged <32 gestational weeks. Infants underwent diffusion tensor MRI at term-equivalent age. MRI was evaluated for CBH and additional supratentorial brain injury using a validated scoring system. Region of interest-based measures of brain microstructure (fractional anisotropy [FA] and apparent diffusion coefficient) were quantified in 5 vulnerable regions (the centrum semiovale, posterior limb of the internal capsule, corpus callosum, and superior and middle cerebellar peduncles). Group differences between infants with CBH and infants without CBH were assessed. There were 267 infants included in the study. Infants with CBH (isolated and combined) had significantly lower FA values in all regions investigated. Infants with isolated CBH showed lower FA in the middle and superior cerebellar peduncles and in the posterior limb of the internal capsule. This study provides evidence that CBH causes alterations in localised and remote WM pathways in the developing brain. The disruption of the cerebellar-cerebral microstructure at multiple sites adds further support for the concept of developmental diaschisis, which is propagated as an explanation for the consequences of early cerebellar injury on cognitive and affective domains. © 2017 S. Karger AG, Basel.

  11. [Cerebellar cognitive affective syndrome secondary to a cerebellar tumour].

    PubMed

    Domínguez-Carral, J; Carreras-Sáez, I; García-Peñas, J J; Fournier-Del Castillo, C; Villalobos-Reales, J

    2015-01-01

    Cerebellar cognitive affective syndrome is characterized by disturbances of executive function, impaired spatial cognition, linguistic difficulties, and personality change. The case of an 11 year old boy is presented, with behavior problems, learning difficulties and social interaction problems. In the physical examination he had poor visual contact, immature behavior, reduced expressive language and global motor disability with gait dyspraxia, with no defined cerebellar motor signs. In the neuropsychological evaluation he has a full scale overall intellectual quotient of 84, with signs of cerebellar cognitive affective syndrome. A tumour affecting inferior cerebellar vermis was observed in the magnetic resonance imaging, which had not significantly grown during 5 years of follow up. The cerebellum participates in controlling cognitive and affective functions. Cerebellar pathology must be considered in the differential diagnosis of children with cognitive or learning disorder with associated behavioral and emotional components. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  12. Cerebellar ataxia: abnormal control of interaction torques across multiple joints.

    PubMed

    Bastian, A J; Martin, T A; Keating, J G; Thach, W T

    1996-07-01

    each joint during the slow-accurate reaches and the fast-accurate reaches revealed that subjects with cerebellar lesions produced very different torque profiles compared with control subjects. In the slow-accurate condition, the cerebellar subjects produced abnormal elbow muscle torques that prevented the normal elbow extension early in the reach. In the fast-accurate condition, the cerebellar subjects produced inappropriate levels of shoulder muscle torque and also produced elbow muscle torques that did not very appropriately with the dynamic interaction torques that occurred at the elbow. Lack of appropriate muscle torque resulted in excessive contributions of the dynamic interaction torque during the fast-accurate reaches. 4. The inability to produce muscle torques that predict, accommodate, and compensate for the dynamic interaction torques appears to be an important cause of the classic kinematic deficits shown by cerebellar subjects during attempted reaching. These kinematic deficits include incoordination of the shoulder and the elbow joints, a curved trajectory, and overshoot. In the fast-accurate condition, cerebellar subjects often made inappropriate muscle torques relative to the dynamic interaction torques. Because of this, interaction torques often determined the pattern of incoordination of the elbow and shoulder that produced the curved trajectory and target overshoot. In the slow-accurate condition, we reason that the cerebellar subjects may use a decomposition strategy so as to simplify the movement and not have to control both joints simultaneously. From these results, we suggest that a major role of the cerebellum is in generating muscle torques at a joint that will predict the interaction torques being generated by other moving joints and compensate for them as they occur.

  13. The cerebellar Golgi cell and spatiotemporal organization of granular layer activity

    PubMed Central

    D'Angelo, Egidio; Solinas, Sergio; Mapelli, Jonathan; Gandolfi, Daniela; Mapelli, Lisa; Prestori, Francesca

    2013-01-01

    The cerebellar granular layer has been suggested to perform a complex spatiotemporal reconfiguration of incoming mossy fiber signals. Central to this role is the inhibitory action exerted by Golgi cells over granule cells: Golgi cells inhibit granule cells through both feedforward and feedback inhibitory loops and generate a broad lateral inhibition that extends beyond the afferent synaptic field. This characteristic connectivity has recently been investigated in great detail and been correlated with specific functional properties of these neurons. These include theta-frequency pacemaking, network entrainment into coherent oscillations and phase resetting. Important advances have also been made in terms of determining the membrane and synaptic properties of the neuron, and clarifying the mechanisms of activation by input bursts. Moreover, voltage sensitive dye imaging and multi-electrode array (MEA) recordings, combined with mathematical simulations based on realistic computational models, have improved our understanding of the impact of Golgi cell activity on granular layer circuit computations. These investigations have highlighted the critical role of Golgi cells in: generating dense clusters of granule cell activity organized in center-surround structures, implementing combinatorial operations on multiple mossy fiber inputs, regulating transmission gain, and cut-off frequency, controlling spike timing and burst transmission, and determining the sign, intensity and duration of long-term synaptic plasticity at the mossy fiber-granule cell relay. This review considers recent advances in the field, highlighting the functional implications of Golgi cells for granular layer network computation and indicating new challenges for cerebellar research. PMID:23730271

  14. Multiscale Mathematical Modeling in Dental Tissue Engineering: Toward Computer-Aided Design of a Regenerative System Based on Hydroxyapatite Granules, Focussing on Early and Mid-Term Stiffness Recovery

    PubMed Central

    Scheiner, Stefan; Komlev, Vladimir S.; Gurin, Alexey N.; Hellmich, Christian

    2016-01-01

    We here explore for the very first time how an advanced multiscale mathematical modeling approach may support the design of a provenly successful tissue engineering concept for mandibular bone. The latter employs double-porous, potentially cracked, single millimeter-sized granules packed into an overall conglomerate-type scaffold material, which is then gradually penetrated and partially replaced by newly grown bone tissue. During this process, the newly developing scaffold-bone compound needs to attain the stiffness of mandibular bone under normal physiological conditions. In this context, the question arises how the compound stiffness is driven by the key design parameters of the tissue engineering system: macroporosity, crack density, as well as scaffold resorption/bone formation rates. We here tackle this question by combining the latest state-of-the-art mathematical modeling techniques in the field of multiscale micromechanics, into an unprecedented suite of highly efficient, semi-analytically defined computation steps resolving several levels of hierarchical organization, from the millimeter- down to the nanometer-scale. This includes several types of homogenization schemes, namely such for porous polycrystals with elongated solid elements, for cracked matrix-inclusion composites, as well as for assemblies of coated spherical compounds. Together with the experimentally known stiffnesses of hydroxyapatite crystals and mandibular bone tissue, the new mathematical model suggests that early stiffness recovery (i.e., within several weeks) requires total avoidance of microcracks in the hydroxyapatite scaffolds, while mid-term stiffness recovery (i.e., within several months) is additionally promoted by provision of small granule sizes, in combination with high bone formation and low scaffold resorption rates. PMID:27708584

  15. The chromatin remodeling factor CHD7 controls cerebellar development by regulating reelin expression

    PubMed Central

    Whittaker, Danielle E.; Riegman, Kimberley L.H.; Kasah, Sahrunizam; Mohan, Conor; Yu, Tian; Sala, Blanca Pijuan; Hebaishi, Husam; Caruso, Angela; Marques, Ana Claudia; Michetti, Caterina; Smachetti, María Eugenia Sanz; Shah, Apar; Sabbioni, Mara; Kulhanci, Omer; Tee, Wee-Wei; Reinberg, Danny; Scattoni, Maria Luisa; McGonnell, Imelda; Wardle, Fiona C.; Fernandes, Cathy

    2017-01-01

    The mechanisms underlying the neurodevelopmental deficits associated with CHARGE syndrome, which include cerebellar hypoplasia, developmental delay, coordination problems, and autistic features, have not been identified. CHARGE syndrome has been associated with mutations in the gene encoding the ATP-dependent chromatin remodeler CHD7. CHD7 is expressed in neural stem and progenitor cells, but its role in neurogenesis during brain development remains unknown. Here we have shown that deletion of Chd7 from cerebellar granule cell progenitors (GCps) results in reduced GCp proliferation, cerebellar hypoplasia, developmental delay, and motor deficits in mice. Genome-wide expression profiling revealed downregulated expression of the gene encoding the glycoprotein reelin (Reln) in Chd7-deficient GCps. Recessive RELN mutations have been associated with severe cerebellar hypoplasia in humans. We found molecular and genetic evidence that reductions in Reln expression contribute to GCp proliferative defects and cerebellar hypoplasia in GCp-specific Chd7 mouse mutants. Finally, we showed that CHD7 is necessary for maintaining an open, accessible chromatin state at the Reln locus. Taken together, this study shows that Reln gene expression is regulated by chromatin remodeling, identifies CHD7 as a previously unrecognized upstream regulator of Reln, and provides direct in vivo evidence that a mammalian CHD protein can control brain development by modulating chromatin accessibility in neuronal progenitors. PMID:28165338

  16. Cerebellar infarction in the territory of the medial branch of the superior cerebellar artery.

    PubMed

    Sohn, Sung-Il; Lee, Hyung; Lee, Seong-Ryong; Baloh, Robert W

    2006-01-10

    The authors studied 14 patients with an isolated cerebellar infarct in the territory of the medial branch of the superior cerebellar artery (MSCA). The most common clinical finding was severe gait ataxia with sudden falling (n = 9) or severe veering (n = 2). Cerebellar dysarthria was found in 8 patients. Eight patients had a mild unilateral limb ataxia. These findings emphasize that MSCA territory cerebellar infarction presented with the prominent gait ataxia and cerebellar dysarthria.

  17. Roll compaction/dry granulation: comparison between roll mill and oscillating granulator in dry granulation.

    PubMed

    Sakwanichol, Jarunee; Puttipipatkhachorn, Satit; Ingenerf, Gernot; Kleinebudde, Peter

    2012-01-01

    Different experimental factorial designs were employed to evaluate granule properties obtained from oscillating granulator and roll mill. Four oscillating-granulator parameters were varied, i.e. rotor speed, oscillating angle, aperture of mesh screen and rotor type. Six roll-mill parameters that were throughput, speed ratio in both first and second stages, gap between roll pair in both stages and roll-surface texture were also investigated. Afterwards, the granule properties obtained from two milling types with similar median particle size were compared. All milling parameters in both milling types affected significantly the median particle size, size distribution and amount of fine particles (P < 0.05), except the rotor types of oscillating granulator on fines. Only three milling parameters influenced significantly the flowability (P < 0.05). These were the throughput and the gap size in the first stage of roll mill and the sieve size of oscillating granulator. In comparison between milling types, the differences of granule properties were not practically relevant. However, the roll mill had much higher capacity than the oscillating granulator about seven times, resulting in improving energy savings per unit of product. Consequently, the roll mill can be applied instead of oscillating granulator for roll compaction/dry granulation technique.

  18. Comparative neuronal morphology of the cerebellar cortex in afrotherians, carnivores, cetartiodactyls, and primates

    PubMed Central

    Jacobs, Bob; Johnson, Nicholas L.; Wahl, Devin; Schall, Matthew; Maseko, Busisiwe C.; Lewandowski, Albert; Raghanti, Mary A.; Wicinski, Bridget; Butti, Camilla; Hopkins, William D.; Bertelsen, Mads F.; Walsh, Timothy; Roberts, John R.; Reep, Roger L.; Hof, Patrick R.; Sherwood, Chet C.; Manger, Paul R.

    2014-01-01

    Although the basic morphological characteristics of neurons in the cerebellar cortex have been documented in several species, virtually nothing is known about the quantitative morphological characteristics of these neurons across different taxa. To that end, the present study investigated cerebellar neuronal morphology among eight different, large-brained mammalian species comprising a broad phylogenetic range: afrotherians (African elephant, Florida manatee), carnivores (Siberian tiger, clouded leopard), cetartiodactyls (humpback whale, giraffe) and primates (human, common chimpanzee). Specifically, several neuron types (e.g., stellate, basket, Lugaro, Golgi, and granule neurons; N = 317) of the cerebellar cortex were stained with a modified rapid Golgi technique and quantified on a computer-assisted microscopy system. There was a 64-fold variation in brain mass across species in our sample (from clouded leopard to the elephant) and a 103-fold variation in cerebellar volume. Most dendritic measures tended to increase with cerebellar volume. The cerebellar cortex in these species exhibited the trilaminate pattern common to all mammals. Morphologically, neuron types in the cerebellar cortex were generally consistent with those described in primates (Fox et al., 1967) and rodents (Palay and Chan-Palay, 1974), although there was substantial quantitative variation across species. In particular, Lugaro neurons in the elephant appeared to be disproportionately larger than those in other species. To explore potential quantitative differences in dendritic measures across species, MARSplines analyses were used to evaluate whether species could be differentiated from each other based on dendritic characteristics alone. Results of these analyses indicated that there were significant differences among all species in dendritic measures. PMID:24795574

  19. Oligodendrocyte ablation affects the coordinated interaction between granule and Purkinje neurons during cerebellum development

    SciTech Connect

    Collin, Ludovic; Doretto, Sandrine; Department of Psychiatry and Human Behavior, University of California Irvine, 3226 Gillespie Neuroscience Research Facility, Irvine CA 92697

    2007-08-01

    Oligodendrocytes (OLs) are the glial cells of the central nervous system (CNS) classically known to be devoted to the formation of myelin sheaths around most axons of the vertebrate brain. We have addressed the role of these cells during cerebellar development, by ablating OLs in vivo. Previous analyses had indicated that OL ablation during the first six postnatal days results into a striking cerebellar phenotype, whose major features are a strong reduction of granule neurons and aberrant Purkinje cells development. These two cell types are highly interconnected during cerebellar development through the production of molecules that help their proliferation, differentiationmore » and maintenance. In this article, we present data showing that OL ablation has major effects on the physiology of Purkinje (PC) and granule cells (GC). In particular, OL ablation results into a reduction of sonic hedgehog (Shh), Brain Derived Neurotrophic Factor (BDNF), and Reelin (Rln) expression. These results indicate that absence of OLs profoundly alters the normal cerebellar developmental program.« less

  20. Insights into cerebellar development and medulloblastoma.

    PubMed

    Bihannic, Laure; Ayrault, Olivier

    2016-01-01

    Cerebellar development is an extensive process that begins during early embryonic stages and persists more than one year after birth in human. Therefore, the cerebellum is susceptible to acquire various developmental abnormalities leading to numerous diseases such as medulloblastoma, the most common pediatric malignant brain tumor. One third of the patients with medulloblastoma are incurable and survivors have a poor quality of life due to the aggressiveness of the broad-spectrum treatments. Within the past few years, it has been highlighted that medulloblastoma is a heterogeneous disease that is divided in four molecular subgroups. This recent advance in the field, combined with the development of associated preclinical models for each subgroup, should enable, in the future, the discovery and use of targeted therapy in clinical treatments for each subtype of medulloblastoma. In this review, we first aim to show how deregulation of cerebellar development can lead to medulloblastoma formation and then to present the advances in the molecular subgrouping of medulloblastoma and the associated preclinical models. Copyright © 2015 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

  1. Orthostatic tremor: a cerebellar pathology?

    PubMed Central

    Popa, Traian; García-Lorenzo, Daniel; Valabregue, Romain; Legrand, André-Pierre; Apartis, Emmanuelle; Marais, Lea; Degos, Bertrand; Hubsch, Cecile; Fernández-Vidal, Sara; Bardinet, Eric; Roze, Emmanuel; Lehéricy, Stéphane; Meunier, Sabine; Vidailhet, Marie

    2016-01-01

    Abstract See Muthuraman et al. (doi:10.1093/aww164) for a scientific commentary on this article. Primary orthostatic tremor is characterized by high frequency tremor affecting the legs and trunk during the standing position. Cerebellar defects were suggested in orthostatic tremor without direct evidence. We aimed to characterize the anatomo-functional defects of the cerebellar motor pathways in orthostatic tremor. We used multimodal neuroimaging to compare 17 patients with orthostatic tremor and 17 age- and gender-matched healthy volunteers. Nine of the patients with orthostatic tremor underwent repetitive transcranial stimulation applied over the cerebellum during five consecutive days. We quantified the duration of standing position and tremor severity through electromyographic recordings. Compared to healthy volunteers, grey matter volume in patients with orthostatic tremor was (i) increased in the cerebellar vermis and correlated positively with the duration of the standing position; and (ii) increased in the supplementary motor area and decreased in the lateral cerebellum, which both correlated with the disease duration. Functional connectivity between the lateral cerebellum and the supplementary motor area was abnormally increased in patients with orthostatic tremor, and correlated positively with tremor severity. After repetitive transcranial stimulation, tremor severity and functional connectivity between the lateral cerebellum and the supplementary motor area were reduced. We provide an explanation for orthostatic tremor pathophysiology, and demonstrate the functional relevance of cerebello-thalamo-cortical connections in tremor related to cerebellar defects. PMID:27329770

  2. Multiple developmental programs are altered by loss of Zic1 and Zic4 to cause Dandy-Walker malformation cerebellar pathogenesis

    PubMed Central

    Blank, Marissa C.; Grinberg, Inessa; Aryee, Emmanuel; Laliberte, Christine; Chizhikov, Victor V.; Henkelman, R. Mark; Millen, Kathleen J.

    2011-01-01

    Heterozygous deletions encompassing the ZIC1;ZIC4 locus have been identified in a subset of individuals with the common cerebellar birth defect Dandy-Walker malformation (DWM). Deletion of Zic1 and Zic4 in mice produces both cerebellar size and foliation defects similar to human DWM, confirming a requirement for these genes in cerebellar development and providing a model to delineate the developmental basis of this clinically important congenital malformation. Here, we show that reduced cerebellar size in Zic1 and Zic4 mutants results from decreased postnatal granule cell progenitor proliferation. Through genetic and molecular analyses, we show that Zic1 and Zic4 have Shh-dependent function promoting proliferation of granule cell progenitors. Expression of the Shh-downstream genes Ptch1, Gli1 and Mycn was downregulated in Zic1/4 mutants, although Shh production and Purkinje cell gene expression were normal. Reduction of Shh dose on the Zic1+/−;Zic4+/− background also resulted in cerebellar size reductions and gene expression changes comparable with those observed in Zic1−/−;Zic4−/− mice. Zic1 and Zic4 are additionally required to pattern anterior vermis foliation. Zic mutant folial patterning abnormalities correlated with disrupted cerebellar anlage gene expression and Purkinje cell topography during late embryonic stages; however, this phenotype was Shh independent. In Zic1+/−;Zic4+/−;Shh+/−, we observed normal cerebellar anlage patterning and foliation. Furthermore, cerebellar patterning was normal in both Gli2-cko and Smo-cko mutant mice, where all Shh function was removed from the developing cerebellum. Thus, our data demonstrate that Zic1 and Zic4 have both Shh-dependent and -independent roles during cerebellar development and that multiple developmental disruptions underlie Zic1/4-related DWM. PMID:21307096

  3. Comparative sensitivity of rat cerebellar neurons to dysregulation of divalent cation homeostasis and cytotoxicity caused by methylmercury

    SciTech Connect

    Edwards, Joshua R.; Marty, M. Sue; Atchison, William D.

    2005-11-01

    The objective of the present study was to determine the relative effectiveness of methylmercury (MeHg) to alter divalent cation homeostasis and cause cell death in MeHg-resistant cerebellar Purkinje and MeHg-sensitive granule neurons. Application of 0.5-5 {mu}M MeHg to Purkinje and granule cells grown in culture caused a concentration- and time-dependent biphasic increase in fura-2 fluorescence. At 0.5 and 1 {mu}M MeHg, the elevations of fura-2 fluorescence induced by MeHg were biphasic in both cell types, but significantly delayed in Purkinje as compared to granule cells. Application of the heavy-metal chelator, TPEN, to Purkinje cells caused a precipitous decline in amore » proportion of the fura-2 fluorescence signal, indicating that MeHg causes release of Ca{sup 2+} and non-Ca{sup 2+} divalent cations. Purkinje cells were also more resistant than granule cells to the neurotoxic effects of MeHg. At 24.5 h after-application of 5 {mu}M MeHg, 97.7% of Purkinje cells were viable. At 3 {mu}M MeHg there was no detectable loss of Purkinje cell viability. In contrast, only 40.6% of cerebellar granule cells were alive 24.5 h after application of 3 {mu}M MeHg. In conclusion, Purkinje neurons in primary cultures appear to be more resistant to MeHg-induced dysregulation of divalent cation homeostasis and subsequent cell death when compared to cerebellar granule cells. There is a significant component of non-Ca{sup 2+} divalent cation released by MeHg in Purkinje neurons.« less

  4. Correlation between loose density and compactibility of granules prepared by various granulation methods.

    PubMed

    Murakami, H; Yoneyama, T; Nakajima, K; Kobayashi, M

    2001-03-23

    The objectives of this study were to prepare the lactose granules by various granulation methods using polyethylene glycol 6000 (PEG 6000) as a binder and to evaluate the effects of granulation methods on the compressibility and compactibility of granules in tabletting. Lactose was granulated by seven granulation methods -- four wet granulations including wet massing granulation, wet high-speed mixer granulation, wet fluidized bed granulation and wet tumbling fluidized bed granulation; and three melt granulations including melt high-speed mixer granulation, melt fluidized bed granulation and melt tumbling fluidized bed granulation. The loose density, angle of repose, granule size distribution, mean diameter of granules, and the tensile strength and porosity of tablets were evaluated. The compactibilities of granules were varied by the granulation methods. However, the difference in compactibility of granules could not be explained due to the difference in compressibility, since there was no difference in Heckel plots due to granulation methods. Among their granule properties, the loose density of granules seemed to have a correlation with the tablet strength regardless of the granulation methods.

  5. The Contribution of Brainstem and Cerebellar Pathways to Auditory Recognition

    PubMed Central

    McLachlan, Neil M.; Wilson, Sarah J.

    2017-01-01

    The cerebellum has been known to play an important role in motor functions for many years. More recently its role has been expanded to include a range of cognitive and sensory-motor processes, and substantial neuroimaging and clinical evidence now points to cerebellar involvement in most auditory processing tasks. In particular, an increase in the size of the cerebellum over recent human evolution has been attributed in part to the development of speech. Despite this, the auditory cognition literature has largely overlooked afferent auditory connections to the cerebellum that have been implicated in acoustically conditioned reflexes in animals, and could subserve speech and other auditory processing in humans. This review expands our understanding of auditory processing by incorporating cerebellar pathways into the anatomy and functions of the human auditory system. We reason that plasticity in the cerebellar pathways underpins implicit learning of spectrotemporal information necessary for sound and speech recognition. Once learnt, this information automatically recognizes incoming auditory signals and predicts likely subsequent information based on previous experience. Since sound recognition processes involving the brainstem and cerebellum initiate early in auditory processing, learnt information stored in cerebellar memory templates could then support a range of auditory processing functions such as streaming, habituation, the integration of auditory feature information such as pitch, and the recognition of vocal communications. PMID:28373850

  6. Aspm sustains postnatal cerebellar neurogenesis and medulloblastoma growth in mice

    PubMed Central

    Williams, Scott E.; Garcia, Idoia; Crowther, Andrew J.; Li, Shiyi; Stewart, Alyssa; Liu, Hedi; Lough, Kendall J.; O'Neill, Sean; Veleta, Katherine; Oyarzabal, Esteban A.; Merrill, Joseph R.; Shih, Yen-Yu Ian; Gershon, Timothy R.

    2015-01-01

    Alterations in genes that regulate brain size may contribute to both microcephaly and brain tumor formation. Here, we report that Aspm, a gene that is mutated in familial microcephaly, regulates postnatal neurogenesis in the cerebellum and supports the growth of medulloblastoma, the most common malignant pediatric brain tumor. Cerebellar granule neuron progenitors (CGNPs) express Aspm when maintained in a proliferative state by sonic hedgehog (Shh) signaling, and Aspm is expressed in Shh-driven medulloblastoma in mice. Genetic deletion of Aspm reduces cerebellar growth, while paradoxically increasing the mitotic rate of CGNPs. Aspm-deficient CGNPs show impaired mitotic progression, altered patterns of division orientation and differentiation, and increased DNA damage, which causes progenitor attrition through apoptosis. Deletion of Aspm in mice with Smo-induced medulloblastoma reduces tumor growth and increases DNA damage. Co-deletion of Aspm and either of the apoptosis regulators Bax or Trp53 (also known as p53) rescues the survival of neural progenitors and reduces the growth restriction imposed by Aspm deletion. Our data show that Aspm functions to regulate mitosis and to mitigate DNA damage during CGNP cell division, causes microcephaly through progenitor apoptosis when mutated, and sustains tumor growth in medulloblastoma. PMID:26450969

  7. Cerebellar Structure and Function in Male Wistar-Kyoto Hyperactive Rats

    PubMed Central

    Thanellou, Alexandra; Green, John T.

    2014-01-01

    Previous research has suggested that the Wistar-Kyoto Hyperactive (WKHA) rat strain may model some of the behavioral features associated with attention-deficit/hyperactivity disorder (ADHD). We have shown that, in cerebellar-dependent eyeblink conditioning, WKHA emit eyeblink CRs with shortened onset latencies. To further characterize the shortened CR onset latencies seen in WKHA rats, we examined 750-ms delay conditioning with either a tone CS or a light CS, we extended acquisition training, and we included Wistar rats as an additional, outbred control strain. Our results indicated that WKHAs learned more quickly and showed a shortened CR onset latency to a tone CS compared to both Wistar-Kyoto Hypertensive (WKHT) and Wistars. WKHAs and Wistars show a lengthening of CR onset latency over conditioning with a tone CS and an increasing confinement of CRs to the later part of the tone CS (inhibition of delay). WKHAs learned more quickly to a light CS only in comparison to WKHTs and showed a shortened CR onset latency only in comparison to Wistars. Wistars showed an increasing confinement of CRs to the late part of the light CS over conditioning. We used unbiased stereology to estimate the number of Purkinje and granule cells in the cerebellar cortex of the three strains. Our results indicated that WKHAs have more granule cells than Wistars and WKHTs and more Purkinje cells than Wistars. Results are discussed in terms of CS processing and cerebellar cortical contributions to EBC. PMID:23398437

  8. Cerebellar Abiotrophy Across Domestic Species.

    PubMed

    Scott, Erica Yuki; Woolard, Kevin Douglas; Finno, Carrie J; Murray, James D

    2018-06-01

    Cerebellar abiotrophy (CA) is a neurodegenerative disorder affecting the cerebellum and occurs in multiple species. Although CA is well researched in humans and mice, domestic species such as the dog, cat, sheep, cow, and horse receive little recognition. This may be due to few studies addressing the mechanism of CA in these species. However, valuable information can still be extracted from these cases. A review of the clinicohistologic phenotype of CA in these species and determining the various etiologies of CA may aid in determining conserved and required pathways necessary for proper cerebellar development and function. This review outlines research approaches of studies of CA in domestic species, compared to the approaches used in mice, with the objective of comparing CA in domestic species while identifying areas for further research efforts.

  9. Visuomotor learning in cerebellar patients.

    PubMed

    Timmann, D; Shimansky, Y; Larson, P S; Wunderlich, D A; Stelmach, G E; Bloedel, J R

    1996-11-01

    The aim of the present study was to demonstrate that patients with pathology affecting substantial regions of the cerebellum can improve their performance in a series of two-dimensional tracing tasks, thus supporting the view that this type of motor behavior can be acquired even when the integrity of this structure is compromised. Eight patients with chronic, isolated cerebellar lesions and eight age- and sex-matched healthy controls were tested. Three patients had mild, five had moderate upper limb ataxia. The experiment was divided into two parts. In the first, subjects traced an irregularly shaped outline over 20 consecutive trials ('Trace 1' task). Next, subjects were asked to redraw the object without any underlying template as a guide ('Memory 1' task). In the second part of the study, subjects were asked to trace a different, irregularly shaped outline over 20 consecutive trials ('Trace 2' task). Next, they were required to redraw it by memory with its axis rotated 90 degrees ('Memory 2' task). In each of the memory tasks the template was placed over the drawn image after each trial and shown to the subjects. The error of performance was determined by calculating three different measurements, each focused on different aspects of the task. Based on these measurements, the cerebellar patients showed improvement in both memory tasks. In the 'Memory 1' task the calculated error decreased significantly for the patients with mild ataxia. In the 'Memory 2' task all cerebellar patients improved their performance substantially enough to reduce significantly the magnitude of all three error measurements. The experiments demonstrate that patients with cerebellar lesions are capable of improving substantially their performance of a complex motor task involving the recall of memorized shapes and the visuomotor control of a tracing movement.

  10. Orthostatic tremor: a cerebellar pathology?

    PubMed

    Gallea, Cécile; Popa, Traian; García-Lorenzo, Daniel; Valabregue, Romain; Legrand, André-Pierre; Apartis, Emmanuelle; Marais, Lea; Degos, Bertrand; Hubsch, Cecile; Fernández-Vidal, Sara; Bardinet, Eric; Roze, Emmanuel; Lehéricy, Stéphane; Meunier, Sabine; Vidailhet, Marie

    2016-08-01

    SEE MUTHURAMAN ET AL DOI101093/AWW164 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Primary orthostatic tremor is characterized by high frequency tremor affecting the legs and trunk during the standing position. Cerebellar defects were suggested in orthostatic tremor without direct evidence. We aimed to characterize the anatomo-functional defects of the cerebellar motor pathways in orthostatic tremor. We used multimodal neuroimaging to compare 17 patients with orthostatic tremor and 17 age- and gender-matched healthy volunteers. Nine of the patients with orthostatic tremor underwent repetitive transcranial stimulation applied over the cerebellum during five consecutive days. We quantified the duration of standing position and tremor severity through electromyographic recordings. Compared to healthy volunteers, grey matter volume in patients with orthostatic tremor was (i) increased in the cerebellar vermis and correlated positively with the duration of the standing position; and (ii) increased in the supplementary motor area and decreased in the lateral cerebellum, which both correlated with the disease duration. Functional connectivity between the lateral cerebellum and the supplementary motor area was abnormally increased in patients with orthostatic tremor, and correlated positively with tremor severity. After repetitive transcranial stimulation, tremor severity and functional connectivity between the lateral cerebellum and the supplementary motor area were reduced. We provide an explanation for orthostatic tremor pathophysiology, and demonstrate the functional relevance of cerebello-thalamo-cortical connections in tremor related to cerebellar defects. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Cerebellar neuronal loss in amyotrophic lateral sclerosis cases with ATXN2 intermediate repeat expansions.

    PubMed

    Tan, Rachel H; Kril, Jillian J; McGinley, Ciara; Hassani, Mohammad; Masuda-Suzukake, Masami; Hasegawa, Masato; Mito, Remika; Kiernan, Matthew C; Halliday, Glenda M

    2016-02-01

    Despite evidence suggesting that the cerebellum may be targeted in amyotrophic lateral sclerosis (ALS), particularly in cases with repeat expansions in the ATXN2 and C9ORF72 genes, the integrity of cerebellar neurons has yet to be examined. The present study undertakes a histopathological analysis to assess the impact of these repeat expansions on cerebellar neurons and determine whether similar cerebellar pathology occurs in sporadic disease. Purkinje and granule cells were quantified in the vermis and lateral cerebellar hemispheres of ALS cases with repeat expansions in the ATXN2 and C9ORF72 genes, sporadic disease, and sporadic progressive muscular atrophy with only lower motor neuron degeneration. ALS cases with intermediate repeat expansions in the ATXN2 gene demonstrate a significant loss in Purkinje cells in the cerebellar vermis only. Despite ALS cases with expansions in the C9ORF72 gene having the highest burden of inclusion pathology, no neuronal loss was observed in this group. Neuronal numbers were also unchanged in sporadic ALS and sporadic PMA cases. The present study has established a selective loss of Purkinje cells in the cerebellar vermis of ALS cases with intermediate repeat expansions in the ATXN2 gene, suggesting a divergent pathogenic mechanism independent of upper and lower motor neuron degeneration in ALS. We discuss these findings in the context of large repeat expansions in ATXN2 and spinocerebellar ataxia type 2, providing evidence that intermediate repeats in ATXN2 cause significant, albeit less substantial, spinocerebellar damage compared with longer repeats in ATXN2. © 2016 American Neurological Association.

  12. Cerebellar mutism--report of four cases.

    PubMed

    Ozimek, A; Richter, S; Hein-Kropp, C; Schoch, B; Gorissen, B; Kaiser, O; Gizewski, E; Ziegler, W; Timmann, D

    2004-08-01

    The aim of the present study was to investigate the manifestations of mutism after surgery in children with cerebellar tumors. Speech impairment following cerebellar mutism in children was investigated based on standardized acoustic speech parameters and perceptual criteria. Mutistic and non-mutistic children after cerebellar surgery as well as orthopedic controls were tested pre-and postoperatively. Speech impairment was compared with the localization of cerebellar lesions (i. e. affected lobules and nuclei). Whereas both control groups showed no abnormalities in speech and behavior, the mutistic group could be divided into children with dysarthria in post mutistic phase and children with mainly behavioral disturbances. In the mutistic children involvement of dentate and fastigial nuclei tended to be more frequent and extended than in the nonmutistic cerebellar children. Cerebellar mutism is a complex phenomenon of at least two types. Dysarthric symptoms during resolution of mutism support the anarthria hypothesis, while mainly behavioral changes suggest an explanation independent from speech motor control.

  13. Cerebellar associative sensory learning defects in five mouse autism models

    PubMed Central

    Kloth, Alexander D; Badura, Aleksandra; Li, Amy; Cherskov, Adriana; Connolly, Sara G; Giovannucci, Andrea; Bangash, M Ali; Grasselli, Giorgio; Peñagarikano, Olga; Piochon, Claire; Tsai, Peter T; Geschwind, Daniel H; Hansel, Christian; Sahin, Mustafa; Takumi, Toru; Worley, Paul F; Wang, Samuel S-H

    2015-01-01

    Sensory integration difficulties have been reported in autism, but their underlying brain-circuit mechanisms are underexplored. Using five autism-related mouse models, Shank3+/ΔC, Mecp2R308/Y, Cntnap2−/−, L7-Tsc1 (L7/Pcp2Cre::Tsc1flox/+), and patDp(15q11-13)/+, we report specific perturbations in delay eyeblink conditioning, a form of associative sensory learning requiring cerebellar plasticity. By distinguishing perturbations in the probability and characteristics of learned responses, we found that probability was reduced in Cntnap2−/−, patDp(15q11-13)/+, and L7/Pcp2Cre::Tsc1flox/+, which are associated with Purkinje-cell/deep-nuclear gene expression, along with Shank3+/ΔC. Amplitudes were smaller in L7/Pcp2Cre::Tsc1flox/+ as well as Shank3+/ΔC and Mecp2R308/Y, which are associated with granule cell pathway expression. Shank3+/ΔC and Mecp2R308/Y also showed aberrant response timing and reduced Purkinje-cell dendritic spine density. Overall, our observations are potentially accounted for by defects in instructed learning in the olivocerebellar loop and response representation in the granule cell pathway. Our findings indicate that defects in associative temporal binding of sensory events are widespread in autism mouse models. DOI: http://dx.doi.org/10.7554/eLife.06085.001 PMID:26158416

  14. Deficiency of Starch Synthase IIIa and IVb Alters Starch Granule Morphology from Polyhedral to Spherical in Rice Endosperm1

    PubMed Central

    Toyosawa, Yoshiko; Kawagoe, Yasushi; Matsushima, Ryo; Ogawa, Masahiro; Fukuda, Masako; Kumamaru, Toshihiro; Okazaki, Yozo; Kusano, Miyako; Saito, Kazuki; Toyooka, Kiminori; Sato, Mayuko; Ai, Yongfeng; Fujita, Naoko

    2016-01-01

    Starch granule morphology differs markedly among plant species. However, the mechanisms controlling starch granule morphology have not been elucidated. Rice (Oryza sativa) endosperm produces characteristic compound-type granules containing dozens of polyhedral starch granules within an amyloplast. Some other cereal species produce simple-type granules, in which only one starch granule is present per amyloplast. A double mutant rice deficient in the starch synthase (SS) genes SSIIIa and SSIVb (ss3a ss4b) produced spherical starch granules, whereas the parental single mutants produced polyhedral starch granules similar to the wild type. The ss3a ss4b amyloplasts contained compound-type starch granules during early developmental stages, and spherical granules were separated from each other during subsequent amyloplast development and seed dehydration. Analysis of glucan chain length distribution identified overlapping roles for SSIIIa and SSIVb in amylopectin chain synthesis, with a degree of polymerization of 42 or greater. Confocal fluorescence microscopy and immunoelectron microscopy of wild-type developing rice seeds revealed that the majority of SSIVb was localized between starch granules. Therefore, we propose that SSIIIa and SSIVb have crucial roles in determining starch granule morphology and in maintaining the amyloplast envelope structure. We present a model of spherical starch granule production. PMID:26747287

  15. Cerebellar mutism syndrome and its relation to cerebellar cognitive and affective function: Review of the literature

    PubMed Central

    Yildiz, Ozlem; Kabatas, Serdar; Yilmaz, Cem; Altinors, Nur; Agaoglu, Belma

    2010-01-01

    Tumors of the cerebellum and brainstem account for half of all brain tumors in children. The realization that cerebellar lesions produce clinically relevant intellectual disability makes it important to determine whether neuropsychological abnormalities occur in long-term survivors of pediatric cerebellar tumors. Little is known about the neurobehavioral sequale resulting specifically from the resection of these tumors in this population. We therefore reviewed neuropsychological findings associated with postoperative cerebellar mutism syndrome and discuss the further implications for cerebellar cognitive function. PMID:20436742

  16. Modulation of p53 and met expression by Krüppel-like factor 8 regulates zebrafish cerebellar development.

    PubMed

    Tsai, Ming-Yuan; Lu, Yu-Fen; Liu, Yu-Hsiu; Lien, Huang-Wei; Huang, Chang-Jen; Wu, Jen-Leih; Hwang, Sheng-Ping L

    2015-09-01

    Krüppel-like factor 8 (Klf8) is a zinc-finger transcription factor implicated in cell proliferation, and cancer cell survival and invasion; however, little is known about its role in normal embryonic development. Here, we show that Klf8 is required for normal cerebellar development in zebrafish embryos. Morpholino knockdown of klf8 resulted in abnormal cerebellar primordium morphology and the induction of p53 in the brain region at 24 hours post-fertilization (hpf). Both p53-dependent reduction of cell proliferation and augmentation of apoptosis were observed in the cerebellar anlage of 24 hpf-klf8 morphants. In klf8 morphants, expression of ptf1a in the ventricular zone was decreased from 48 to 72 hpf; on the other hand, expression of atohla in the upper rhombic lip was unaffected. Consistent with this finding, Purkinje cell development was perturbed and granule cell number was reduced in 72 hpf-klf8 morphants; co-injection of p53 MO(sp) or klf8 mRNA substantially rescued development of cerebellar Purkinje cells in klf8 morphants. Hepatocyte growth factor/Met signaling is known to regulate cerebellar development in zebrafish and mouse. We observed decreased met expression in the tectum and rhombomere 1 of 24 hpf-klf8 morphants, which was largely rescued by co-injection with klf8 mRNA. Moreover, co-injection of met mRNA substantially rescued formation of Purkinje cells in klf8 morphants at 72 hpf. Together, these results demonstrate that Klf8 modulates expression of p53 and met to maintain ptf1a-expressing neuronal progenitors, which are required for the appropriate development of cerebellar Purkinje and granule cells in zebrafish embryos. © 2014 Wiley Periodicals, Inc.

  17. A severe form of epidermal nevus syndrome associated with brainstem and cerebellar malformations and neonatal medulloblastoma.

    PubMed

    Okumura, Akihisa; Lee, Tsubasa; Ikeno, Mitsuru; Shimojima, Keiko; Kajino, Kazunori; Inoue, Yuka; Yoshikawa, Naomi; Suganuma, Hiroki; Suzuki, Mitsuyoshi; Hisata, Ken; Shoji, Hiromichi; Takanashi, Jun-ichi; Barkovich, A James; Shimizu, Toshiaki; Yamamoto, Toshiyuki; Hayashi, Masaharu

    2012-11-01

    Here we report a boy with epidermal nevus syndrome associated with brainstem and cerebellar malformations and neonatal medulloblastoma. The patient had epidermal nevi and complicated brain malformations including macrocephaly with polymicrogyria, dysmorphic and enlarged midbrain tectum, enlarged cerebellar hemispheres with small and maloriented folia. The patient died after surgical resection of medulloblastoma which was newly recognized on MRI at 51 days of age. Postmortem pathological examinations showed very unique and bizarre malformation of the midbrain and hindbrain. The cerebellar cortex exhibited a coarse, irregular and bumpy surface, blurred border between the Purkinje cell layer and internal granule cell layer, and many foci of heterotopia in the cerebellar white matter. The brainstem showed multiple anomalies, including enlargement of superior colliculi, hypoplasia of pyramidal tracts and dysplasia of inferior olivary nuclei. The unusual constellation of brain malformations of our patient will widen the spectrum of epidermal nevus syndrome. Copyright © 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

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

    PubMed

    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.

  19. Magnetic resonance imaging depiction of acquired Dyke-Davidoff-Masson syndrome with crossed cerebro-cerebellar diaschisis: Report of two cases.

    PubMed

    Gupta, Ranjana; Joshi, Sandeep; Mittal, Amit; Luthra, Ishita; Mittal, Puneet; Verma, Vibha

    2015-01-01

    Acquired Dyke-Davidoff-Masson syndrome, also known as hemispheric atrophy, is characterized by loss of volume of one cerebral hemisphere from an insult in early life. Crossed cerebellar diaschisis refers to dysfunction/atrophy of cerebellar hemisphere which is secondary to contralateral supratentorial insult. We describe magnetic resonance imaging findings in two cases of acquired Dyke-Davidoff-Masson syndrome with crossed cerebro-cerebellar diaschisis.

  20. RNA in development: how ribonucleoprotein granules regulate the life cycles of pathogenic protozoa.

    PubMed

    Kramer, Susanne

    2014-01-01

    Ribonucleoprotein (RNP) granules are important posttranscriptional regulators of messenger RNA (mRNA) fate. Several types of RNP granules specifically regulate gene expression during development of multicellular organisms and are commonly referred to as germ granules. The function of germ granules is not entirely understood and probably diverse, but it is generally agreed that one main function is posttranscriptional regulation of gene expression during early development, when transcription is silent. One example is the translational repression of maternally derived mRNAs in oocytes. Here, I hope to show that the need for regulation of gene expression by RNP granules is not restricted to animal development, but plays an equally important role during the development of pathogenic protozoa. Apicomplexa and Trypanosomatidae have complex life cycles with frequent host changes. The need to quickly adapt gene expression to a new environment as well as the ability to suppress translation to survive latencies is critical for successful completion of life cycles. Posttranscriptional gene regulation is not necessarily simpler in protozoa. Apicomplexa surprise with the presence of micro RNA (miRNAs) and upstream open reading frames (µORFs). Trypanosomes have an unusually large repertoire of different RNP granule types. A better understanding of RNP granules in protozoa may help to gain insight into the evolutionary origin of RNP granules: Trypanosomes for example have two types of granules with interesting similarities to animal germ granules. © 2013 John Wiley & Sons, Ltd.

  1. The Cellular State Determines the Effect of Melatonin on the Survival of Mixed Cerebellar Cell Culture

    PubMed Central

    Franco, Daiane Gil; Markus, Regina P.

    2014-01-01

    The constitutive activation of nuclear factor-κB (NF-κB), a key transcription factor involved in neuroinflammation, is essential for the survival of neurons in situ and of cerebellar granule cells in culture. Melatonin is known to inhibit the activation of NF-κB and has a cytoprotective function. In this study, we evaluated whether the cytoprotective effect of melatonin depends on the state of activation of a mixed cerebellar culture that is composed predominantly of granule cells; we tested the effect of melatonin on cultured rat cerebellar cells stimulated or not with lipopolysaccharide (LPS). The addition of melatonin (0.1 nM–1 µM) reduced the survival of naïve cells while inhibiting LPS-induced cell death. Melatonin (100 nM) transiently (15 min) inhibited the nuclear translocation of both NF-κB dimers (p50/p50, p50/RelA) and, after 60 min, increased the activation of p50/RelA. Melatonin-induced p50/RelA activity in naïve cells resulted in the transcription of inducible nitric oxide synthase (iNOS) and the production of NO. Otherwise, in cultures treated with LPS, melatonin blocked the LPS-induced activation of p50/RelA and the reduction in p50/p50 levels and inhibited iNOS expression and NO synthesis. Therefore, melatonin in vehicle-treated cells induces cell death, while it protects against LPS-induced cytotoxicity. In summary, we confirmed that melatonin is a neuroprotective drug when cerebellar cells are challenged; however, melatonin can also lead to cell death when the normal balance of the NF-κB pathway is disturbed. Our data provide a mechanistic basis for understanding the influence of cell context on the final output response of melatonin. PMID:25184316

  2. Reorganization of the cerebro-cerebellar network of language production in patients with congenital left-hemispheric brain lesions.

    PubMed

    Lidzba, K; Wilke, M; Staudt, M; Krägeloh-Mann, I; Grodd, W

    2008-09-01

    Patients with congenital lesions of the left cerebral hemisphere may reorganize language functions into the right hemisphere. In these patients, language production is represented homotopically to the left-hemispheric language areas. We studied cerebellar activation in five patients with congenital lesions of the left cerebral hemisphere to assess if the language network is reorganized completely in these patients, i.e. including also cerebellar language functions. As compared to a group of controls matched for age, sex, and verbal IQ, the patients recruited an area not in the right but in the left cerebellar hemisphere. The extent of laterality of the cerebellar activation correlated significantly with the laterality of the frontal activation. We suggest that the developing brain reacts to early focal lesions in the left hemisphere with a mirror-image organization of the entire cerebro-cerebellar network engaged in speech production.

  3. Docking is not a prerequisite but a temporal constraint for fusion of secretory granules.

    PubMed

    Kasai, Kazuo; Fujita, Takuji; Gomi, Hiroshi; Izumi, Tetsuro

    2008-07-01

    We examined secretory granule dynamics using total internal reflection fluorescence microscopy in normal pancreatic beta cells and their mutants devoid of Rab27a and/or its effector, granuphilin, which play critical roles in the docking and recruitment of insulin granules to the plasma membrane. In the early phase of glucose stimulation in wild-type cells, we observed marked fusion of granules recruited from a relatively distant area, in parallel with that from granules located underneath the plasma membrane. Furthermore, despite a lack of granules directly attached to the plasma membrane, both spontaneous and evoked fusion was increased in granuphilin-null cells. In addition to these granuphilin-null phenotypes, Rab27a/granuphilin doubly deficient cells showed the decreases in granules located next to the docked area and in fusion from granules near the plasma membrane in the early phase of glucose-stimulated secretion, similar to Rab27a-mutated cells. Thus, the two proteins play nonoverlapping roles in insulin exocytosis: granuphilin acts on the granules underneath the plasma membrane, whereas Rab27a acts on those in a more distal area. These findings demonstrate that, in contrast to our conventional understanding, stable attachment of secretory granules to the plasma membrane is not prerequisite but temporally inhibitory for both spontaneous and evoked fusion.

  4. Clostridium perfringens epsilon toxin targets granule cells in the mouse cerebellum and stimulates glutamate release.

    PubMed

    Lonchamp, Etienne; Dupont, Jean-Luc; Wioland, Laetitia; Courjaret, Raphaël; Mbebi-Liegeois, Corinne; Jover, Emmanuel; Doussau, Frédéric; Popoff, Michel R; Bossu, Jean-Louis; de Barry, Jean; Poulain, Bernard

    2010-09-30

    Epsilon toxin (ET) produced by C. perfringens types B and D is a highly potent pore-forming toxin. ET-intoxicated animals express severe neurological disorders that are thought to result from the formation of vasogenic brain edemas and indirect neuronal excitotoxicity. The cerebellum is a predilection site for ET damage. ET has been proposed to bind to glial cells such as astrocytes and oligodendrocytes. However, the possibility that ET binds and attacks the neurons remains an open question. Using specific anti-ET mouse polyclonal antibodies and mouse brain slices preincubated with ET, we found that several brain structures were labeled, the cerebellum being a prominent one. In cerebellar slices, we analyzed the co-staining of ET with specific cell markers, and found that ET binds to the cell body of granule cells, oligodendrocytes, but not astrocytes or nerve endings. Identification of granule cells as neuronal ET targets was confirmed by the observation that ET induced intracellular Ca(2+) rises and glutamate release in primary cultures of granule cells. In cultured cerebellar slices, whole cell patch-clamp recordings of synaptic currents in Purkinje cells revealed that ET greatly stimulates both spontaneous excitatory and inhibitory activities. However, pharmacological dissection of these effects indicated that they were only a result of an increased granule cell firing activity and did not involve a direct action of the toxin on glutamatergic nerve terminals or inhibitory interneurons. Patch-clamp recordings of granule cell somata showed that ET causes a decrease in neuronal membrane resistance associated with pore-opening and depolarization of the neuronal membrane, which subsequently lead to the firing of the neuronal network and stimulation of glutamate release. This work demonstrates that a subset of neurons can be directly targeted by ET, suggesting that part of ET-induced neuronal damage observed in neuronal tissue is due to a direct effect of ET on

  5. Clostridium perfringens Epsilon Toxin Targets Granule Cells in the Mouse Cerebellum and Stimulates Glutamate Release

    PubMed Central

    Lonchamp, Etienne; Dupont, Jean-Luc; Wioland, Laetitia; Courjaret, Raphaël; Mbebi-Liegeois, Corinne; Jover, Emmanuel; Doussau, Frédéric; Popoff, Michel R.; Bossu, Jean-Louis; de Barry, Jean; Poulain, Bernard

    2010-01-01

    Epsilon toxin (ET) produced by C. perfringens types B and D is a highly potent pore-forming toxin. ET-intoxicated animals express severe neurological disorders that are thought to result from the formation of vasogenic brain edemas and indirect neuronal excitotoxicity. The cerebellum is a predilection site for ET damage. ET has been proposed to bind to glial cells such as astrocytes and oligodendrocytes. However, the possibility that ET binds and attacks the neurons remains an open question. Using specific anti-ET mouse polyclonal antibodies and mouse brain slices preincubated with ET, we found that several brain structures were labeled, the cerebellum being a prominent one. In cerebellar slices, we analyzed the co-staining of ET with specific cell markers, and found that ET binds to the cell body of granule cells, oligodendrocytes, but not astrocytes or nerve endings. Identification of granule cells as neuronal ET targets was confirmed by the observation that ET induced intracellular Ca2+ rises and glutamate release in primary cultures of granule cells. In cultured cerebellar slices, whole cell patch-clamp recordings of synaptic currents in Purkinje cells revealed that ET greatly stimulates both spontaneous excitatory and inhibitory activities. However, pharmacological dissection of these effects indicated that they were only a result of an increased granule cell firing activity and did not involve a direct action of the toxin on glutamatergic nerve terminals or inhibitory interneurons. Patch-clamp recordings of granule cell somata showed that ET causes a decrease in neuronal membrane resistance associated with pore-opening and depolarization of the neuronal membrane, which subsequently lead to the firing of the neuronal network and stimulation of glutamate release. This work demonstrates that a subset of neurons can be directly targeted by ET, suggesting that part of ET-induced neuronal damage observed in neuronal tissue is due to a direct effect of ET on neurons

  6. Acute cerebellar ataxia and infectious mononucleosis.

    PubMed Central

    Wadhwa, N. K.; Ghose, R. R.

    1983-01-01

    A 28-year-old man, who presented with acute cerebellar ataxia, was found to have haematological features of infectious mononucleosis. There was serological evidence of recent infection with Epstein-Barr virus. It is speculated that cerebellar dysfunction results from virus-induced inflammatory changes within the central nervous system. PMID:6312442

  7. Altered cerebellar feedback projections in Asperger syndrome.

    PubMed

    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 (p<0.001) and right superior cerebellar (output) peduncle (p<0.001) compared to controls; but no difference in the input tracts. Severity of social impairment, as measured by the Autistic Diagnostic Interview, was negatively correlated with diffusion anisotropy in the fibres of the left superior cerebellar peduncle. These findings suggest a vulnerability of specific cerebellar neural pathways in people with Asperger 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.

  8. Learning of Sensory Sequences in Cerebellar Patients

    ERIC Educational Resources Information Center

    Frings, Markus; Boenisch, Raoul; Gerwig, Marcus; Diener, Hans-Christoph; Timmann, Dagmar

    2004-01-01

    A possible role of the cerebellum in detecting and recognizing event sequences has been proposed. The present study sought to determine whether patients with cerebellar lesions are impaired in the acquisition and discrimination of sequences of sensory stimuli of different modalities. A group of 26 cerebellar patients and 26 controls matched for…

  9. Cytoplasmic RNA Granules in Somatic Maintenance.

    PubMed

    Moujaber, Ossama; Stochaj, Ursula

    2018-05-30

    Cytoplasmic RNA granules represent subcellular compartments that are enriched in protein-bound RNA species. RNA granules are produced by evolutionary divergent eukaryotes, including yeast, mammals, and plants. The functions of cytoplasmic RNA granules differ widely. They are dictated by the cell type and physiological state, which in turn is determined by intrinsic cell properties and environmental factors. RNA granules provide diverse cellular functions. However, all of the granules contribute to aspects of RNA metabolism. This is exemplified by transcription, RNA storage, silencing, and degradation, as well as mRNP remodeling and regulated translation. Several forms of cytoplasmic mRNA granules are linked to normal physiological processes. For instance, they may coordinate protein synthesis and thereby serve as posttranscriptional "operons". RNA granules also participate in cytoplasmic mRNA trafficking, a process particularly well understood for neurons. Many forms of RNA granules support the preservation of somatic cell performance under normal and stress conditions. On the other hand, severe insults or disease can cause the formation and persistence of RNA granules that contribute to cellular dysfunction, especially in the nervous system. Neurodegeneration and many other diseases linked to RNA granules are associated with aging. Nevertheless, information related to the impact of aging on the various types of RNA granules is presently very limited. This review concentrates on cytoplasmic RNA granules and their role in somatic cell maintenance. We summarize the current knowledge on different types of RNA granules in the cytoplasm, their assembly and function under normal, stress, or disease conditions. Specifically, we discuss processing bodies, neuronal granules, stress granules, and other less characterized cytoplasmic RNA granules. Our focus is primarily on mammalian and yeast models, because they have been critical to unravel the physiological role of various

  10. Pharmacological treatments of cerebellar ataxia.

    PubMed

    Ogawa, Masafumi

    2004-01-01

    The confirmed pharmacological treatment of cerebellar ataxia is still lacking. In a recent preliminary trial, we showed that D-cycloserine, a partial NMDA allosteric agonist, may relieve the symptoms. In this paper, major clinical trials to relieve ataxic symptoms are reviewed. Previous studies showed some efficacy of physostigmine in ataxic patients. However, physostigmine did not improve the ataxia in a recent double-blind crossover study. The replacement therapy of the deficient cholinergic system with choline or choline derivatives was tried in patients with Friedreich's ataxia and other ataxic patients, but the result was not definitive. A levorotatory form of hydroxytryptophan (a serotonin precursor), a serotoninergic 5-HT1A agonist, a serotoninergic 5-HT3 antagonist, and a serotonin reuptake inhibitor were also used for the therapy for ataxia. In a double-blind randomized study, buspirone, a 5-HT1A agonist was active in cerebellar ataxia, but the effect is partial and not major. The effects of the studies with the other serotoninergic drugs were not consistent. The effect of sulfamethoxazole-trimethoprim therapy in spinocerebellar ataxia type3/Machado-Joseph disease (MJD) was reported, although the therapy improved spasticity or rigidity, rather than ataxia. In contrast to previous studies, sulfamethoxazole-trimethoprim therapy in MJD had no effect in a 2001 double-blind crossover study. The thyrotropin-releasing hormone, D-cycloserine, and acetazolamide for SCA6 may have some efficacy. However, a well-designed double-blind crossover trial is needed to confirm the effect.

  11. Cellular and genetic regulation of the development of the cerebellar system.

    PubMed

    Sotelo, Constantino

    2004-04-01

    Recent advances in molecular biology have drastically changed our vision on the development of the nervous system, the cerebellum in particular. After a classical descriptive period, we are now in a modern mechanistic epoch as we begin to answer crucial questions in our quest to understand the mechanisms underlying the emergence of brain complexity. This review begins with an analysis of the role of the "isthmic organizer" in the induction and specification of the cerebellar territory and progresses through cerebellar development to the formation of cerebellar maps. It gathers information about the control of the proliferation of granule cell precursors by Purkinje cells and the role of Shh/Gli-patched signaling. The migratory routes for cerebellar and precerebellar neurons, together with the long-range and short-range cues guiding gliophilic and, particularly, neurophilic migrations, are also discussed. Because these cues are similar to those involved in axon guidance, both processes are under the same molecular constraints. Finally, using primarily the olivocerebellar projection as a model, the cellular and molecular mechanisms involved in the formation of cerebellar maps are discussed. During embryonic development, Purkinje cells in the cerebellum and neurons in the inferior olive follow a simultaneous, but independent, process of intrinsic parcellation, giving rise to subsets of biochemically different cortical compartments. The occurrence of positional information shared between olivary axons and their postsynaptic targets, the Purkinje cells, provides a molecular code for the formation of coarse-grained maps. Activity-dependent mechanisms are required for the transition from crude to fine-grained maps. This important refinement, which confers ultimate specificity to the maps, is under the regulation of parallel fiber-Purkinje cell synaptic activity.

  12. Pharmaceutical production of tableting granules in an ultra-small-scale high-shear granulator as a pre-formulation study.

    PubMed

    Ogawa, Tatsuya; Uchino, Tomohiro; Takahashi, Daisuke; Izumi, Tsuyoshi; Otsuka, Makoto

    2012-11-01

    In some of drug developments, the amount of bulk drug powder to use in early stages is limited and it is not easy to supply a sufficient drug amount for conventional preparation methods. Therefore, an ultra-small-scale high-shear granulator (less than 5 g) (USG) was developed and applied to small-scale granulation as a pre-formulation. The sample powder consisted of 66.5% lactose, 28.5% microcrystalline cellulose and 5.0% hydroxypropylcellulose. The granules were obtained to agitate 5 g of the sample powder with 1.0 mL of water at 300 rpm for 5 min after pre-powder mixing for 3 min by the USG and the manual hand (HM) methods. The granules were evaluated by the 10% and 90% accumulated particle size and the recoveries of the granules and the powder solid. Median particle size for the USG and the HM methods was 159.2 ± 2.3 and 270.9 ± 14.9 µm, respectively. The USG method had a narrower particle size distribution than those by the HM method. The recovery of the granules by USG was significantly larger than that by the HM method. Characteristics of all of the granules indicated that the USG method could produce higher quality granules within a shorter time than the HM methods.

  13. Neurotoxicological effects of nicotine on the embryonic development of cerebellar cortex of chick embryo during various stages of incubation.

    PubMed

    El-Beltagy, Abd El-Fattah B M; Abou-El-Naga, Amoura M; Sabry, Dalia M

    2015-10-01

    Long-acting nicotine is known to exert pathological effects on almost all tissues including the cerebellar cortex. The present work was designed to elucidate the effect of nicotine on the development of cerebellar cortex of chick embryo during incubation period. The fertilized eggs of hen (Gallus gallus domesticus) were injected into the air space by a single dose of long acting nicotine (1.6 mg/kg/egg) at the 4th day of incubation. The embryos were taken out of the eggs on days 8, 12 and 16 of incubation. The cerebellum of the control and treated embryos at above ages were processed for histopathological examination. The TEM were examined at 16th day of incubation. The results of the present study revealed that, exposure to long-acting nicotine markedly influence the histogenesis of cerebellar cortex of chick embryo during the incubation period. At 8th day of incubation, nicotine delayed the differentiation of the cerebellar analge; especially the external granular layer (EGL) and inner cortical layer (ICL). Furthermore, at 12th day of incubation, the cerebellar foliation was irregular and the Purkinje cells not recognized. By 16th day of incubation, the cerebellar foliations were irregular with interrupted cerebellar cortex and irregular arrangement of Purkinje cells. Immunohistochemical analysis for antibody P53 protein revealed that the cerebellar cortex in all stages of nicotine treated groups possessed a moderate to weak reaction for P53 protein however; this reaction was markedly stronger in the cerebellar cortex of control groups. Moreover, the flow cytometric analysis confirmed that the percentage of apoptosis in control group was significantly higher compared with that of nicotine treated group. At the TEM level, the cerebellar Purkinje cells of 16th day of treated groups showed multiple subcellular alterations in compared with those of the corresponding control group. Such changes represented by appearing of vacuolated mitochondria, cisternal

  14. Role of the Caenorhabditis elegans multidrug resistance gene, mrp-4, in gut granule differentiation.

    PubMed

    Currie, Erin; King, Brian; Lawrenson, Andrea L; Schroeder, Lena K; Kershner, Aaron M; Hermann, Greg J

    2007-11-01

    Caenorhabditis elegans gut granules are lysosome-related organelles with birefringent contents. mrp-4, which encodes an ATP-binding cassette (ABC) transporter homologous to mammalian multidrug resistance proteins, functions in the formation of gut granule birefringence. mrp-4(-) embryos show a delayed appearance of birefringent material in the gut granule but otherwise appear to form gut granules properly. mrp-4(+) activity is required for the extracellular mislocalization of birefringent material, body-length retraction, and NaCl sensitivity, phenotypes associated with defective gut granule biogenesis exhibited by embryos lacking the activity of GLO-1/Rab38, a putative GLO-1 guanine nucleotide exchange factor GLO-4, and the AP-3 complex. Multidrug resistance protein (MRP)-4 localizes to the gut granule membrane, consistent with it playing a direct role in the transport of molecules that compose and/or facilitate the formation of birefringent crystals within the gut granule. However, MRP-4 is also present in oocytes and early embryos, and our genetic analyses indicate that its site of action in the formation of birefringent material may not be limited to just the gut granule in embryos. In a search for genes that function similarly to mrp-4(+), we identified WHT-2, another ABC transporter that acts in parallel to MRP-4 for the formation of birefringent material in the gut granule.

  15. Origin, lineage and function of cerebellar glia.

    PubMed

    Buffo, Annalisa; Rossi, Ferdinando

    2013-10-01

    The glial cells of the cerebellum, and particularly astrocytes and oligodendrocytes, are characterized by a remarkable phenotypic variety, in which highly peculiar morphological features are associated with specific functional features, unique among the glial cells of the entire CNS. Here, we provide a critical report about the present knowledge of the development of cerebellar glia, including lineage relationships between cerebellar neurons, astrocytes and oligodendrocytes, the origins and the genesis of the repertoire of glial types, and the processes underlying their acquisition of mature morphological and functional traits. In parallel, we describe and discuss some fundamental roles played by specific categories of glial cells during cerebellar development. In particular, we propose that Bergmann glia exerts a crucial scaffolding activity that, together with the organizing function of Purkinje cells, is necessary to achieve the normal pattern of foliation and layering of the cerebellar cortex. Moreover, we discuss some of the functional tasks of cerebellar astrocytes and oligodendrocytes that are distinctive of cerebellar glia throughout the CNS. Notably, we report about the regulation of synaptic signalling in the molecular and granular layer mediated by Bergmann glia and parenchymal astrocytes, and the functional interaction between oligodendrocyte precursor cells and neurons. On the whole, this review provides an extensive overview of the available literature and some novel insights about the origin and differentiation of the variety of cerebellar glial cells and their function in the developing and mature cerebellum. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Granulated lead oxides with teflon

    SciTech Connect

    Nilsson, O.

    An improvement in the production of tube electrodes for lead storage batteries comprising mixing a small amount (0.1 to 3 weight percent) of polytetrafluoroethylene (Ptfe) with lead powder, the mixture is heated and shear stresses are applied thereto sufficient to convert substantially all of the ptfe in the mixture to fibrous form and to form a non-powdery dough. The dough is then granulated and the doughy granules about 100 mu to 500 mu in major dimension are used for filling tube elctrodes a lead-acid storage battery.

  17. Acute Cerebellar Ataxia Induced by Nivolumab

    PubMed Central

    Kawamura, Reina; Nagata, Eiichiro; Mukai, Masako; Ohnuki, Yoichi; Matsuzaki, Tomohiko; Ohiwa, Kana; Nakagawa, Tomoki; Kohno, Mitsutomo; Masuda, Ryota; Iwazaki, Masayuki; Takizawa, Shunya

    2017-01-01

    A 54-year-old woman with adenocarcinoma of the lung and lymph node metastasis experienced nystagmus and cerebellar ataxia 2 weeks after initiating nivolumab therapy. An evaluation for several autoimmune-related antibodies and paraneoplastic syndrome yielded negative results. We eventually diagnosed the patient with nivolumab-induced acute cerebellar ataxia, after excluding other potential conditions. Her ataxic gait and nystagmus resolved shortly after intravenous steroid pulse therapy followed by the administration of decreasing doses of oral steroids. Nivolumab, an immune checkpoint inhibitor, is known to induce various neurological adverse events. However, this is the first report of acute cerebellar ataxia associated with nivolumab treatment. PMID:29249765

  18. Thyroid hormone and cerebellar development.

    PubMed

    Anderson, Grant W

    2008-01-01

    Thyroid hormone (TH) plays a key role in mammalian brain development. The developing brain is sensitive to both TH deficiency and excess. Brain development in the absence of TH results in motor skill deficiencies and reduced intellectual development. These functional abnormalities can be attributed to maldevelopment of specific cell types and regions of the brain including the cerebellum. TH functions at the molecular level by regulating gene transcription. Therefore, understanding how TH regulates cerebellar development requires identification of TH-regulated gene targets and the cells expressing these genes. Additionally, the process of TH-dependent regulation of gene expression is tightly controlled by mechanisms including regulation of TH transport, TH metabolism, toxicologic inhibition of TH signaling, and control of the nuclear TH response apparatus. This review will describe the functional, cellular, and molecular effects of TH deficit in the developing cerebellum and emphasize the most recent findings regarding TH action in this important brain region.

  19. Cerebellar injury in preterm infants.

    PubMed

    Tam, Emily W Y

    2018-01-01

    Although preterm birth is best known to result in adverse neurodevelopmental outcomes through injury of the supratentorial structures, including intraventricular hemorrhage and periventricular leukomalacia, the cerebellum has become increasingly recognized as an important target for injury and adverse motor and cognitive outcomes. Undergoing the most dramatic growth during the preterm period, the cerebellum is vulnerable to large and small hemorrhages, as well as hypoplasia resulting from a number of potentially modifiable risk factors. These factors include contact with intraventricular blood, crossed cerebrocerebellar diaschisis, postnatal glucocorticoid exposure, pain and opioid exposure, nutrition and somatic growth, cardiorespiratory factors, and socioeconomic status. Strategies targeting these factors may result in prevention of the motor and cognitive deficits seen after cerebellar hemorrhage or hypoplasia. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Brainstem and cerebellar cavernous malformations.

    PubMed

    Atwal, Gursant S; Sarris, Christina E; Spetzler, Robert F

    2017-01-01

    Cavernous malformations are vascular lesions that occur throughout the central nervous system, most commonly in the supratentorial location, with brainstem and cerebellar cavernous malformations occurring more rarely. Cavernous malformations are associated with developmental venous anomalies that occur sporadically or in familial form. Patients with a cavernous malformation can present with headaches, seizures, sensorimotor disturbances, or focal neurologic deficits based on the anatomic location of the lesion. Patients with infratentorial lesions present more commonly with a focal neurologic deficit. Cavernous malformations are increasingly discovered incidentally due to the increasing use of magnetic resonance imaging. Understanding the natural history of these lesions is essential to their management. Observation and surgical resection are both reasonable options in the treatment of patients with these lesions. The clinical presentation of the patient, the location of the lesion, and the surgical risk assessment all play critical roles in management decision-making. © 2017 Elsevier B.V. All rights reserved.

  1. A realistic bi-hemispheric model of the cerebellum uncovers the purpose of the abundant granule cells during motor control.

    PubMed

    Pinzon-Morales, Ruben-Dario; Hirata, Yutaka

    2015-01-01

    The cerebellar granule cells (GCs) have been proposed to perform lossless, adaptive spatio-temporal coding of incoming sensory/motor information required by downstream cerebellar circuits to support motor learning, motor coordination, and cognition. Here we use a physio-anatomically inspired bi-hemispheric cerebellar neuronal network (biCNN) to selectively enable/disable the output of GCs and evaluate the behavioral and neural consequences during three different control scenarios. The control scenarios are a simple direct current motor (1 degree of freedom: DOF), an unstable two-wheel balancing robot (2 DOFs), and a simulation model of a quadcopter (6 DOFs). Results showed that adequate control was maintained with a relatively small number of GCs (< 200) in all the control scenarios. However, the minimum number of GCs required to successfully govern each control plant increased with their complexity (i.e., DOFs). It was also shown that increasing the number of GCs resulted in higher robustness against changes in the initialization parameters of the biCNN model (i.e., synaptic connections and synaptic weights). Therefore, we suggest that the abundant GCs in the cerebellar cortex provide the computational power during the large repertoire of motor activities and motor plants the cerebellum is involved with, and bring robustness against changes in the cerebellar microcircuit (e.g., neuronal connections).

  2. Phenotypic outcomes in Mouse and Human Foxc1 dependent Dandy-Walker cerebellar malformation suggest shared mechanisms

    PubMed Central

    Haldipur, Parthiv; Dang, Derek; Aldinger, Kimberly A; Janson, Olivia K; Guimiot, Fabien; Adle-Biasette, Homa; Dobyns, William B; Siebert, Joseph R; Russo, Rosa; Millen, Kathleen J

    2017-01-01

    FOXC1 loss contributes to Dandy-Walker malformation (DWM), a common human cerebellar malformation. Previously, we found that complete Foxc1 loss leads to aberrations in proliferation, neuronal differentiation and migration in the embryonic mouse cerebellum (Haldipur et al., 2014). We now demonstrate that hypomorphic Foxc1 mutant mice have granule and Purkinje cell abnormalities causing subsequent disruptions in postnatal cerebellar foliation and lamination. Particularly striking is the presence of a partially formed posterior lobule which echoes the posterior vermis DW 'tail sign' observed in human imaging studies. Lineage tracing experiments in Foxc1 mutant mouse cerebella indicate that aberrant migration of granule cell progenitors destined to form the posterior-most lobule causes this unique phenotype. Analyses of rare human del chr 6p25 fetal cerebella demonstrate extensive phenotypic overlap with our Foxc1 mutant mouse models, validating our DWM models and demonstrating that many key mechanisms controlling cerebellar development are likely conserved between mouse and human. DOI: http://dx.doi.org/10.7554/eLife.20898.001 PMID:28092268

  3. A dynamical system view of cerebellar function

    NASA Astrophysics Data System (ADS)

    Keeler, James D.

    1990-06-01

    First some previous theories of cerebellar function are reviewed, and deficiencies in how they map onto the neurophysiological structure are pointed out. I hypothesize that the cerebellar cortex builds an internal model, or prediction, of the dynamics of the animal. A class of algorithms for doing prediction based on local reconstruction of attractors are described, and it is shown how this class maps very well onto the structure of the cerebellar cortex. I hypothesize that the climbing fibers multiplex between different trajectories corresponding to different modes of operation. Then the vestibulo-ocular reflex is examined, and experiments to test the proposed model are suggested. The purpose of the presentation here is twofold: (1) To enlighten physiologists to the mathematics of a class of prediction algorithms that map well onto cerebellar architecture. (2) To enlighten dynamical system theorists to the physiological and anatomical details of the cerebellum.

  4. Genetics Home Reference: lissencephaly with cerebellar hypoplasia

    MedlinePlus

    ... on PubMed or Free article on PubMed Central Ross ME, Swanson K, Dobyns WB. Lissencephaly with cerebellar ... AA, Abdel-Salam G, Koeller HB, Ilkin Y, Ross ME, Dobyns WB, Gleeson JG. Identification of a ...

  5. Bax deficiency prolongs cerebellar neurogenesis, accelerates medulloblastoma formation and paradoxically increases both malignancy and differentiation.

    PubMed

    Garcia, I; Crowther, A J; Gama, V; Miller, C R; Miller, C Ryan; Deshmukh, M; Gershon, T R

    2013-05-02

    Neurogenesis requires negative regulation through differentiation of progenitors or their programmed cell death (PCD). Growth regulation is particularly important in the postnatal cerebellum, where excessive progenitor proliferation promotes medulloblastoma, the most common malignant brain tumor in children. We present evidence that PCD operates alongside differentiation to regulate cerebellar granule neuron progenitors (CGNPs) and to prevent medulloblastoma. Here, we show that genetic deletion of pro-apoptotic Bax disrupts regulation of cerebellar neurogenesis and promotes medulloblastoma formation. In Bax(-/-) mice, the period of neurogenesis was extended into the third week of postnatal life, and ectopic neurons and progenitors collected in the molecular layer of the cerebellum and adjacent tectum. Importantly, genetic deletion of Bax in medulloblastoma-prone ND2:SmoA1 transgenic mice greatly accelerated tumorigenesis. Bax-deficient medulloblastomas exhibited strikingly distinct pathology, with reduced apoptosis, increased neural differentiation and tectal migration. Comparing Bax(+/+) and Bax(-/-) medulloblastomas, we were able to identify upregulation of Bcl-2 and nuclear exclusion of p27 as tumorigenic changes that are required to mitigate the tumor suppressive effect of Bax. Studies on human tumors confirmed the importance of modulating Bax in medulloblastoma pathogenesis. Our results demonstrate that Bax-dependent apoptosis regulates postnatal cerebellar neurogenesis, suppresses medulloblastoma formation and imposes selective pressure on tumors that form. Functional resistance to Bax-mediated apoptosis, required for medulloblastoma tumorigenesis, may be a tumor-specific vulnerability to be exploited for therapeutic benefit.

  6. Robustness effect of gap junctions between Golgi cells on cerebellar cortex oscillations

    PubMed Central

    2011-01-01

    Background Previous one-dimensional network modeling of the cerebellar granular layer has been successfully linked with a range of cerebellar cortex oscillations observed in vivo. However, the recent discovery of gap junctions between Golgi cells (GoCs), which may cause oscillations by themselves, has raised the question of how gap-junction coupling affects GoC and granular-layer oscillations. To investigate this question, we developed a novel two-dimensional computational model of the GoC-granule cell (GC) circuit with and without gap junctions between GoCs. Results Isolated GoCs coupled by gap junctions had a strong tendency to generate spontaneous oscillations without affecting their mean firing frequencies in response to distributed mossy fiber input. Conversely, when GoCs were synaptically connected in the granular layer, gap junctions increased the power of the oscillations, but the oscillations were primarily driven by the synaptic feedback loop between GoCs and GCs, and the gap junctions did not change oscillation frequency or the mean firing rate of either GoCs or GCs. Conclusion Our modeling results suggest that gap junctions between GoCs increase the robustness of cerebellar cortex oscillations that are primarily driven by the feedback loop between GoCs and GCs. The robustness effect of gap junctions on synaptically driven oscillations observed in our model may be a general mechanism, also present in other regions of the brain. PMID:22330240

  7. Synchrony and neural coding in cerebellar circuits

    PubMed Central

    Person, Abigail L.; Raman, Indira M.

    2012-01-01

    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 circuits. PMID

  8. A Novel and Multivalent Role of Pax6 in Cerebellar Development

    PubMed Central

    Yeung, Joanna; Ha, Thomas J.; Swanson, Douglas J.

    2016-01-01

    Pax6 is a prominent gene in brain development. The deletion of Pax6 results in devastated development of eye, olfactory bulb, and cortex. However, it has been reported that the Pax6-null Sey cerebellum only has minor defects involving granule cells despite Pax6 being expressed throughout cerebellar development. The present work has uncovered a requirement of Pax6 in the development of all rhombic lip (RL) lineages. A significant downregulation of Tbr1 and Tbr2 expression is found in the Sey cerebellum, these are cell-specific markers of cerebellar nuclear (CN) neurons and unipolar brush cells (UBCs), respectively. The examination of Tbr1 and Lmx1a immunolabeling and Nissl staining confirmed the loss of CN neurons from the Sey cerebellum. CN neuron progenitors are produced in the mutant but there is an enhanced death of these neurons as shown by increased presence of caspase-3-positive cells. These data indicate that Pax6 regulates the survival of CN neuron progenitors. Furthermore, the analysis of experimental mouse chimeras suggests a cell-extrinsic role of Pax6 in CN neuron survival. For UBCs, using Tbr2 immunolabeling, these cells are significantly reduced in the Sey cerebellum. The loss of UBCs in the mutant is due partly to cell death in the RL and also to the reduced production of progenitors from the RL. These results demonstrate a critical role for Pax6 in regulating the generation and survival of UBCs. This and previous work from our laboratory demonstrate a seminal role of Pax6 in the development of all cerebellar glutamatergic neurons. SIGNIFICANCE STATEMENT Pax6 is a key molecule in development. Pax6 is best known as the master control gene in eye development with mutations causing aniridia in humans. Pax6 also plays important developmental roles in the cortex and olfactory bulb. During cerebellar development, Pax6 is robustly expressed in the germinal zone of all glutamatergic neurons [cerebellar nuclear (CN) neurons, granule cells, and unipolar brush

  9. Stimulus-Dependent State Transition between Synchronized Oscillation and Randomly Repetitive Burst in a Model Cerebellar Granular Layer

    PubMed Central

    Tanaka, Shigeru; Nagao, Soichi; Nishino, Tetsuro

    2011-01-01

    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. PMID:21779155

  10. Isolation of zymogen granules from rat pancreas.

    PubMed

    Rindler, Michael J

    2006-01-01

    This unit describes methods for preparing zymogen granules from rat pancreas. Zymogen granules are storage organelles in pancreatic acinar cells containing digestive enzymes that are released into the pancreatic duct. The protocols in this unit take advantage of the large size (up to 1 microm diameter) and high density (>1.20 g/cm(3) on sucrose gradients) of the granules as compared to other cellular organelles. They use a combination of differential sedimentation and density gradient separation to accomplish the purification. Similar procedures can be used to isolate zymogen granules from mouse pancreas and canine pancreas. A protocol for preparing zymogen granules from dog pancreas is also included.

  11. Relationship between ultrasound estimated fetal gestational age and cerebellar appearance in healthy pregnant Nigerian women.

    PubMed

    Adeyekun, Ademola A; Orji, Michael O

    2015-01-01

    Fetal biometry by ultrasound provides reliable and important information about fetal growth and wellbeing. Evaluation of the fetal posterior fossa is useful in the assessment of neural tube-defects. Studies on normal ultrasound fetal cerebellar appearance and diameter across gestational age (GA) are scanty in the Nigerian medical literature. This study was carried out to study normal fetal cerebellar appearance and diameter at various GAs among healthy pregnant Nigerian Africans. This was a prospective study of 450 healthy singleton pregnant women between 13 and 42 weeks gestation. A curvilinear probe with a 3.5 MHz transducer of a SonoAce X6 (Medison Inc., Korea 2010) scanner was used to assess fetal transcerebellar diameter (TCD) and appearance. GA was also determined using fetal biometric parameters such as the biparietal diameter, femur length, and abdominal circumference. Fetal cerebellar appearance was correlated against GA. The cerebellar appearance was graded into: Grade I: 164 fetuses (36.4%), Grade II; 102 fetuses (22.7%) and Grade III: 184 fetuses (40.9%). Mean GA and TCD was 21 weeks and 21.2 mm for Grade I; 28 weeks and 32.6 mm for Grade II; and 35 weeks and 47.1 mm for Grade III. There was significance difference among the cerebellar grades at the GA groups and transverse cerebellar diameter (P < 0.000). There is a gradual and steady change in ultrasonographic appearance of the fetal cerebellar and diameter appearance with advancing gestation. The changes ranged from anechoic, "pair of eye glass" appearance at second trimester to relatively echogenic, "dumb-bell" appearance at early third trimester, and solid, "fan-shape" in late third trimester.

  12. Specific cerebellar activation during Braille reading in blind subjects.

    PubMed

    Gizewski, Elke R; Timmann, Dagmar; Forsting, Michael

    2004-07-01

    The traditional view that the cerebellum is involved only in the control of movements has been changed recently. It has been suggested that the human cerebellum is involved in cognition and language. Likewise, besides cortical activity in sensorimotor and visual areas, an increased global activation of the cerebellum has been revealed during Braille reading in blind subjects. Our purpose was to investigate whether there is cerebellar activation during Braille reading by blind subjects other than sensorimotor activation related to finger movements. Early blind and normal sighted subjects were studied with functional magnetic resonance imaging (fMRI) during Braille reading, tactile discrimination of nonsense dots, dots forming symbols, and finger tapping. The experiments were done in block design. Echo planar imaging sequences were carried out on a 1.5-T MR scanner. All blind individuals reading Braille showed robust activation of the posterior and lateral aspects of cerebellar hemispheral lobules Crus I bilaterally but more predominately on the right side. Additionally, activation was present in the medial cerebellum within lobules IV, V, and VIIIA, predominantly on the right. Discriminating nonsense dots did not reveal any activation of Crus I, but did reveal activation within the medial part of lobules IV, V, and VIIIA, predominately on the right. Analysis of sighted subjects during reading of printed text revealed activation of the posterolateral cerebellar hemisphere in Crus I bilaterally, predominantly on the right. Tactile analysis of dots representing symbols revealed an activation in lobules IV and VIII and in right Crus II but not in Crus I. In conclusion, parts of cerebellar activation during Braille reading in blind subjects (i.e., within lobules IV, V, and VIII) overlap with the known hand representation within the cerebellum and are likely related to the sensorimotor part of the task. Cerebellar activation during Braille reading within bilateral Crus I

  13. EFFECTS OF ORGANOTINS ON RACTIVE OXYGEN SPECIES AND INTRACELLULAR CALCIUM IN CEREBELLAR GRANULE CELLS IN CULTURE.

    EPA Science Inventory

    Use of organotins has increased drastically in the past decade, including their use as stabilizers in polyvinylchloride pipes. Monomethyl- (MMT), dimethyl- (DMT), monobutyl- (MBT), and dibutyltin (DBT) have been found in home water samples and in human blood at concentrations up...

  14. CHANGES IN MITOGEN-ACTIVATED PROTEIN KINASE IN CEREBELLAR GRANULE NEURONAL CULTURES BY POLYBROMINATED DIPHENYL ETHERS.

    EPA Science Inventory

    Polybrominated diphenyl ethers (PBDEs) are used as additive flame-retardants and have been detected in human blood, adipose tissue, and breast milk; clarifying the nature of the risks posed is important for clean-up and remediation. Both in vitro and in vivo studies have shown t...

  15. STIMULATION OF [3H] ARACHIDONIC ACID RELEASE IN RAT CEREBELLAR GRANULE NEURONS BY POLYBROMINATED DIPHENYL.

    EPA Science Inventory

    Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in electronic equipment, plastics, textiles, and building materials. While the presence of other persistent organic pollutants, such as polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxin...

  16. ONTOGENY OF PROTEINS ASSOCIATED WITH NEURITE GROWTH AND SYNAPTOGENESIS IN CEREBELLAR GRANULE CELLS IN VITRO.

    EPA Science Inventory

    In vitro techniques may be useful in screening for effects of developmental neurotoxicants. Previously, we characterized changes in biochemical markers associated with neuronal development in a PC12 cell model of differentiation and growth. The current research extended these stu...

  17. Comparative effects of PBDEs and PCBs on intracellular signaling in rat cerebellar granule neurons

    EPA Science Inventory

    Polybrominated diphenyl ethers (PBDEs) are synthetic chemicals that do not occur in nature and are structurally similar to polychlorinated biphenyls (PCBs; Figure I) and several chlorinated pesticides. They are comprised of two phenyl rings linked by oxygen and are resistant to p...

  18. Cerebellar models of associative memory: Three papers from IEEE COMPCON spring 1989

    NASA Technical Reports Server (NTRS)

    Raugh, Michael R. (Editor)

    1989-01-01

    Three papers are presented on the following topics: (1) a cerebellar-model associative memory as a generalized random-access memory; (2) theories of the cerebellum - two early models of associative memory; and (3) intelligent network management and functional cerebellum synthesis.

  19. Evolution of the cerebellar cortex: the selective expansion of prefrontal-projecting cerebellar lobules.

    PubMed

    Balsters, J H; Cussans, E; Diedrichsen, J; Phillips, K A; Preuss, T M; Rilling, J K; Ramnani, N

    2010-02-01

    It has been suggested that interconnected brain areas evolve in tandem because evolutionary pressures act on complete functional systems rather than on individual brain areas. The cerebellar cortex has reciprocal connections with both the prefrontal cortex and motor cortex, forming independent loops with each. Specifically, in capuchin monkeys cerebellar cortical lobules Crus I and Crus II connect with prefrontal cortex, whereas the primary motor cortex connects with cerebellar lobules V, VI, VIIb, and VIIIa. Comparisons of extant primate species suggest that the prefrontal cortex has expanded more than cortical motor areas in human evolution. Given the enlargement of the prefrontal cortex relative to motor cortex in humans, our hypothesis would predict corresponding volumetric increases in the parts of the cerebellum connected to the prefrontal cortex, relative to cerebellar lobules connected to the motor cortex. We tested the hypothesis by comparing the volumes of cerebellar lobules in structural MRI scans in capuchins, chimpanzees and humans. The fractions of cerebellar volume occupied by Crus I and Crus II were significantly larger in humans compared to chimpanzees and capuchins. Our results therefore support the hypothesis that in the cortico-cerebellar system, functionally related structures evolve in concert with each other. The evolutionary expansion of these prefrontal-projecting cerebellar territories might contribute to the evolution of the higher cognitive functions of humans. Copyright (c) 2009 Elsevier Inc. All rights reserved.

  20. Components of action potential repolarization in cerebellar parallel fibres.

    PubMed

    Pekala, Dobromila; Baginskas, Armantas; Szkudlarek, Hanna J; Raastad, Morten

    2014-11-15

    Repolarization of the presynaptic action potential is essential for transmitter release, excitability and energy expenditure. Little is known about repolarization in thin, unmyelinated axons forming en passant synapses, which represent the most common type of axons in the mammalian brain's grey matter.We used rat cerebellar parallel fibres, an example of typical grey matter axons, to investigate the effects of K(+) channel blockers on repolarization. We show that repolarization is composed of a fast tetraethylammonium (TEA)-sensitive component, determining the width and amplitude of the spike, and a slow margatoxin (MgTX)-sensitive depolarized after-potential (DAP). These two components could be recorded at the granule cell soma as antidromic action potentials and from the axons with a newly developed miniaturized grease-gap method. A considerable proportion of fast repolarization remained in the presence of TEA, MgTX, or both. This residual was abolished by the addition of quinine. The importance of proper control of fast repolarization was demonstrated by somatic recordings of antidromic action potentials. In these experiments, the relatively broad K(+) channel blocker 4-aminopyridine reduced the fast repolarization, resulting in bursts of action potentials forming on top of the DAP. We conclude that repolarization of the action potential in parallel fibres is supported by at least three groups of K(+) channels. Differences in their temporal profiles allow relatively independent control of the spike and the DAP, whereas overlap of their temporal profiles provides robust control of axonal bursting properties.

  1. Changes in the cerebellar and cerebro-cerebellar circuit in type 2 diabetes.

    PubMed

    Fang, Peng; An, Jie; Tan, Xin; Zeng, Ling-Li; Shen, Hui; Qiu, Shijun; Hu, Dewen

    2017-04-01

    Currently, 422 million adults suffer from diabetes worldwide, leading to tremendous disabilities and a great burden to families and society. Functional and structural MRIs have demonstrated that patients with type 2 diabetes mellitus (T2DM) exhibit abnormalities in brain regions in the cerebral cortex. However, the changes of cerebellar anatomical connections in diabetic patients remains unclear. In the current study, diffusion tensor imaging deterministic tractography and statistical analysis were employed to investigate abnormal cerebellar anatomical connections in diabetic patients. This is the first study to investigate the altered cerebellar anatomical connectivity in T2DM patients. Decreased anatomical connections were found in the cerebellar and cerebro-cerebellar circuits of T2DM patients, providing valuable new insights into the potential neuro-pathophysiology of diabetes-related motor and cognitive deficits. Copyright © 2017. Published by Elsevier Inc.

  2. Effect of two medium chain triglycerides-supplemented diets on synaptic morphology in the cerebellar cortex of late-adult rats.

    PubMed

    Balietti, Marta; Fattoretti, Patrizia; Giorgetti, Belinda; Casoli, Tiziana; Di Stefano, Giuseppina; Platano, Daniela; Aicardi, Giorgio; Lattanzio, Fabrizia; Bertoni-Freddari, Carlo

    2009-12-01

    Ketogenic diets (KDs) have shown beneficial effects in experimental models of neurodegeneration, designating aged individuals as possible recipients. However, few studies have investigated their consequences on aging brain. Here, late-adult rats (19 months of age) were fed for 8 weeks with two medium chain triglycerides-supplemented diets (MCT-SDs) and the average area (S), numeric density (Nv(s)), and surface density (S(v)) of synapses, as well as the average volume (V), numeric density (Nv(m)), and volume density (V(v)) of synaptic mitochondria were evaluated in granule cell layer of the cerebellar cortex (GCL-CCx) by computer-assisted morphometric methods. MCT content was 10 or 20%. About 10%MCT-SD induced the early appearance of senescent patterns (decreased Nv(s) and Nv(m); increased V), whereas 20%MCT-SD caused no changes. Recently, we have shown that both MCT-SDs accelerate aging in the stratum moleculare of CA1 (SM CA1), but are "antiaging" in the outer molecular layer of dentate gyrus (OML DG). Since GCL-CCx is more vulnerable to age than OML DG but less than SM CA1, present and previous results suggest that the effects of MCT-SDs in the aging brain critically depend on neuronal vulnerability to age, besides MCT percentage.

  3. Comparative analysis of cadherin expression and connectivity patterns in the cerebellar system of ferret and mouse.

    PubMed

    Neudert, Franziska; Nuernberger, Krishna-K Monique; Redies, Christoph

    2008-12-20

    The cerebellum shows remarkable variations in the relative size of its divisions among vertebrate species. In the present study, we compare the cerebella of two mammals (ferret and mouse) by mapping the expression of three cadherins (cadherin-8, protocadherin-7, and protocadherin-10) at similar postnatal stages. The three cadherins are expressed differentially in parasagittal stripes in the cerebellar cortex, in the portions of the deep cerebellar nuclei, in the divisions of the inferior olivary nucleus, and in the lateral vestibular nucleus. The expression profiles suggest that the cadherin-positive structures are interconnected. The expression patterns resemble each other in ferret and mouse, although some differences can be observed. The general resemblance indicates that cerebellar organization is based on a common set of embryonic divisions in the two species. Consequently, the large differences in cerebellar morphology between the two species are more likely caused by differential growth of these embryonic divisions than by differences in early embryonic patterning. Based on the cadherin expression patterns, a model of corticonuclear projection territories in ferret and mouse is proposed. In summary, our results indicate that the cerebellar systems of rodents and carnivores display a relatively large degree of similarity in their molecular and functional organization.

  4. Laterality and the evolution of the prefronto-cerebellar system in anthropoids.

    PubMed

    Smaers, Jeroen B; Steele, James; Case, Charleen R; Amunts, Katrin

    2013-06-01

    There is extensive evidence for an early vertebrate origin of lateralized motor behavior and of related asymmetries in underlying brain systems. We investigate human lateralized motor functioning in a broad comparative context of evolutionary neural reorganization. We quantify evolutionary trends in the fronto-cerebellar system (involved in motor learning) across 46 million years of divergent primate evolution by comparing rates of evolution of prefrontal cortex, frontal motor cortex, and posterior cerebellar hemispheres along individual branches of the primate tree of life. We provide a detailed evolutionary model of the neuroanatomical changes leading to modern human lateralized motor functioning, demonstrating an increased role for the fronto-cerebellar system in the apes dating to their evolutionary divergence from the monkeys (∼30 million years ago (Mya)), and a subsequent shift toward an increased role for prefrontal cortex over frontal motor cortex in the fronto-cerebellar system in the Homo-Pan ancestral lineage (∼10 Mya) and in the human ancestral lineage (∼6 Mya). We discuss these results in the context of cortico-cerebellar functions and their likely role in the evolution of human tool use and speech. © 2013 New York Academy of Sciences.

  5. Mechanism of the formation of hollow spherical granules using a high shear granulator.

    PubMed

    Asada, Takumi; Nishikawa, Mitsunori; Ochiai, Yasushi; Noguchi, Shuji; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

    2018-05-30

    Recently, we have developed a novel granulation technology to manufacture hollow spherical granules (HSGs) for controlled-release formulations; however, the mechanism of the granulation is still unclear. The aim of this study is to determine the mechanism of the formation of the HSGs using a high shear granulator. Samples of granulated material were collected at various times during granulation and were investigated using scanning electron microscope and X-ray computed tomography. It was observed that the granulation proceeded by drug layering to the polymer, followed by formation of a hollow in the granule. In addition, it was also found that generation of a crack in the adhered drug layer and air flow into the granules might be involved in forming the hollow in the structure. Observation of the granulation of formulations with different types of drugs and polymers indicated that negative pressure in the granules occurred and the granules caved in when the hollow was formed. The hollow-forming speed and the shell density of the hollow granules depended on the particular drug and polymer. Taken together, the granulation mechanism of HSGs was determined and this information will be valuable for HSGs technology development. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Tubulin-related cerebellar dysplasia: definition of a distinct pattern of cerebellar malformation.

    PubMed

    Romaniello, Romina; Arrigoni, Filippo; Panzeri, Elena; Poretti, Andrea; Micalizzi, Alessia; Citterio, Andrea; Bedeschi, Maria Francesca; Berardinelli, Angela; Cusmai, Raffaella; D'Arrigo, Stefano; Ferraris, Alessandro; Hackenberg, Annette; Kuechler, Alma; Mancardi, Margherita; Nuovo, Sara; Oehl-Jaschkowitz, Barbara; Rossi, Andrea; Signorini, Sabrina; Tüttelmann, Frank; Wahl, Dagmar; Hehr, Ute; Boltshauser, Eugen; Bassi, Maria Teresa; Valente, Enza Maria; Borgatti, Renato

    2017-12-01

    To determine the neuroimaging pattern of cerebellar dysplasia (CD) and other posterior fossa morphological anomalies associated with mutations in tubulin genes and to perform clinical and genetic correlations. Twenty-eight patients harbouring 23 heterozygous pathogenic variants (ten novel) in tubulin genes TUBA1A (n = 10), TUBB2B (n = 8) or TUBB3 (n = 5) were studied by a brain MRI scan performed either on a 1.5 T (n = 10) or 3 T (n = 18) MR scanner with focus on the posterior fossa. Cerebellar anomalies were detected in 24/28 patients (86%). CD was recognised in 19/28 (68%) including cortical cerebellar dysplasia (CCD) in 18/28, either involving only the cerebellar hemispheres (12/28) or associated with vermis dysplasia (6/28). CCD was located only in the right hemisphere in 13/18 (72%), including four TUBB2B-, four TUBB3- and five TUBA1A-mutated patients, while in the other five TUBA1A cases it was located only in the left hemisphere or in both hemispheres. The postero-superior region of the cerebellar hemispheres was most frequently affected. The cerebellar involvement in tubulinopathies shows specific features that may be labelled as 'tubulin-related CD'. This pattern is unique and differs from other genetic causes of cerebellar dysplasia. • Cortical cerebellar dysplasia without cysts is suggestive of tubulin-related disorder. • Cerebellar dysplasia in tubulinopathies shows specific features labelled as 'tubulin-related CD'. • Focal and unilateral involvement of cerebellar hemispheres has important implications for counselling.

  7. The Cerebellar Mossy Fiber Synapse as a Model for High-Frequency Transmission in the Mammalian CNS.

    PubMed

    Delvendahl, Igor; Hallermann, Stefan

    2016-11-01

    The speed of neuronal information processing depends on neuronal firing frequency. Here, we describe the evolutionary advantages and ubiquitous occurrence of high-frequency firing within the mammalian nervous system in general. The highest firing frequencies so far have been observed at the cerebellar mossy fiber to granule cell synapse. The mechanisms enabling high-frequency transmission at this synapse are reviewed and compared with other synapses. Finally, information coding of high-frequency signals at the mossy fiber synapse is discussed. The exceptionally high firing frequencies and amenability to high-resolution technical approaches both in vitro and in vivo establish the cerebellar mossy fiber synapse as an attractive model to investigate high-frequency signaling from the molecular up to the network level. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. A multicohort, longitudinal study of cerebellar development in attention deficit hyperactivity disorder.

    PubMed

    Shaw, Philip; Ishii-Takahashi, Ayaka; Park, Min Tae; Devenyi, Gabriel A; Zibman, Chava; Kasparek, Steven; Sudre, Gustavo; Mangalmurti, Aman; Hoogman, Martine; Tiemeier, Henning; von Polier, Georg; Shook, Devon; Muetzel, Ryan; Chakravarty, M Mallar; Konrad, Kerstin; Durston, Sarah; White, Tonya

    2018-04-25

    The cerebellum supports many cognitive functions disrupted in attention deficit hyperactivity disorder (ADHD). Prior neuroanatomic studies have been often limited by small sample sizes, inconsistent findings, and a reliance on cross-sectional data, limiting inferences about cerebellar development. Here, we conduct a multicohort study using longitudinal data, to characterize cerebellar development. Growth trajectories of the cerebellar vermis, hemispheres and white matter were estimated using piecewise linear regression from 1,656 youth; of whom 63% had longitudinal data, totaling 2,914 scans. Four cohorts participated, all contained childhood data (age 4-12 years); two had adolescent data (12-25 years). Growth parameters were combined using random-effects meta-analysis. Diagnostic differences in growth were confined to the corpus medullare (cerebellar white matter). Here, the ADHD group showed slower growth in early childhood compared to the typically developing group (left corpus medullare z = 2.49, p = .01; right z = 2.03, p = .04). This reversed in late childhood, with faster growth in ADHD in the left corpus medullare (z = 2.06, p = .04). Findings held when gender, intelligence, comorbidity, and psychostimulant medication were considered. Across four independent cohorts, containing predominately longitudinal data, we found diagnostic differences in the growth of cerebellar white matter. In ADHD, slower white matter growth in early childhood was followed by faster growth in late childhood. The findings are consistent with the concept of ADHD as a disorder of the brain's structural connections, formed partly by developing cortico-cerebellar white matter tracts. © 2018 Association for Child and Adolescent Mental Health.

  9. Protein Mobility within Secretory Granules

    PubMed Central

    Weiss, Annita Ngatchou; Bittner, Mary A.; Holz, Ronald W.; Axelrod, Daniel

    2014-01-01

    We investigated the basis for previous observations that fluorescent-labeled neuropeptide Y (NPY) is usually released within 200 ms after fusion, whereas labeled tissue plasminogen activator (tPA) is often discharged over many seconds. We found that tPA and NPY are endogenously expressed in small and different subpopulations of bovine chromaffin cells in culture. We measured the mobility of these proteins (tagged with fluorophore) within the lumen of individual secretory granules in living chromaffin cells, and related their mobilities to postfusion release kinetics. A method was developed that is not limited by standard optical resolution, in which a bright flash of strongly decaying evanescent field (∼64 nm exponential decay constant) produced by total internal reflection (TIR) selectively bleaches cerulean-labeled protein proximal to the glass coverslip within individual granules. Fluorescence recovery occurred as unbleached protein from distal regions within the 300 nm granule diffused into the bleached proximal regions. The fractional bleaching of tPA-cerulean (tPA-cer) was greater when subsequently probed with TIR excitation than with epifluorescence, indicating that tPA-cer mobility was low. The almost equal NPY-cer bleaching when probed with TIR and epifluorescence indicated that NPY-cer equilibrated within the 300 ms bleach pulse, and therefore had a greater mobility than tPA-cer. TIR-fluorescence recovery after photobleaching revealed a significant recovery of tPA-cer (but not NPY-cer) fluorescence within several hundred milliseconds after bleaching. Numerical simulations, which take into account bleach duration, granule diameter, and the limited number of fluorophores in a granule, are consistent with tPA-cer being 100% mobile, with a diffusion coefficient of 2 × 10−10 cm2/s (∼1/3000 of that for a protein of similar size in aqueous solution). However, the low diffusive mobility of tPA cannot alone explain its slow postfusion release. In the

  10. The effect of the chopper on granules from wet high-shear granulation using a PMA-1 granulator.

    PubMed

    Briens, Lauren; Logan, Ryan

    2011-12-01

    Chopper presence and then chopper speed was varied during wet high shear granulation of a placebo formulation using a PMA-1 granulator while also varying the impeller speed. The granules were extensively analyzed for differences due to the chopper. The effect of the chopper on the granules varied with impeller speed from no effect at a low impeller speed of 300 rpm to flow interruptions at an impeller speed of 700 rpm to minimal impact at very high impeller speeds as caking at the bowl perimeter obscured the effect of the chopper on the flow pattern. Differences in the granule flowability were minimal. However, it was concluded that the largest fraction of optimal granules would be obtained at an impeller speed of 700 rpm with the chopper at 1,000 rpm allowing balances between flow establishment, segregation, and centrifugal forces.

  11. Gestational lead exposure induces developmental abnormalities and up-regulates apoptosis of fetal cerebellar cells in rats.

    PubMed

    Mousa, Alyaa M; Al-Fadhli, Ameera S; Rao, Muddanna S; Kilarkaje, Narayana

    2015-01-01

    Lead (Pb), a known environmental toxicant, adversely affects almost all organ systems. In this study, we investigated the effects of maternal lead exposure on fetal rat cerebellum. Female Sprague-Dawley rats were given lead nitrate in drinking water (0, 0.5, and 1%) for two weeks before conception, and during pregnancy. Fetuses were collected by caesarian section on gestational day 21 and observed for developmental abnormalities. The fetal cerebellar sections from control and 1% lead group were stained with cresyl violet. Immunohistochemical expressions of p53, Bax, Bcl-2, and caspase 3 were quantified by AnalySIS image analyzer (Life Science, Germany). Lead exposure induced developmental abnormalities of eyes, ear, limbs, neck and ventral abdominal wall; however, these abnormalities were commonly seen in the 1% lead-treated group. In addition, lead also caused fetal mortality and reduced body growth in both dose groups and reduced brain weight in the 1% lead-treated group. The fetal cerebella from the 1% lead-treated group showed unorganized cerebellar cortical layers, and degenerative changes in granule and Purkinje cells such as the formation of clumps of Nissl granules. An increase in Bax and caspase 3, and a decrease in Bcl-2 (p < 0.05), but not in p53, showed apoptosis of the neurons. In conclusion, gestational lead exposure in rats induces fetal toxicity and developmental abnormalities. The lead exposure also impairs development of cerebellar layers, induces structural changes, and apoptosis in the fetal cerebellar cortex. These results suggest that lead exposure during gestation is extremely toxic to developing cerebellum in rats.

  12. A theory of cerebellar cortex and adaptive motor control based on two types of universal function approximation capability.

    PubMed

    Fujita, Masahiko

    2016-03-01

    Lesions of the cerebellum result in large errors in movements. The cerebellum adaptively controls the strength and timing of motor command signals depending on the internal and external environments of movements. The present theory describes how the cerebellar cortex can control signals for accurate and timed movements. A model network of the cerebellar Golgi and granule cells is shown to be equivalent to a multiple-input (from mossy fibers) hierarchical neural network with a single hidden layer of threshold units (granule cells) that receive a common recurrent inhibition (from a Golgi cell). The weighted sum of the hidden unit signals (Purkinje cell output) is theoretically analyzed regarding the capability of the network to perform two types of universal function approximation. The hidden units begin firing as the excitatory inputs exceed the recurrent inhibition. This simple threshold feature leads to the first approximation theory, and the network final output can be any continuous function of the multiple inputs. When the input is constant, this output becomes stationary. However, when the recurrent unit activity is triggered to decrease or the recurrent inhibition is triggered to increase through a certain mechanism (metabotropic modulation or extrasynaptic spillover), the network can generate any continuous signals for a prolonged period of change in the activity of recurrent signals, as the second approximation theory shows. By incorporating the cerebellar capability of two such types of approximations to a motor system, in which learning proceeds through repeated movement trials with accompanying corrections, accurate and timed responses for reaching the target can be adaptively acquired. Simple models of motor control can solve the motor error vs. sensory error problem, as well as the structural aspects of credit (or error) assignment problem. Two physiological experiments are proposed for examining the delay and trace conditioning of eyelid responses, as

  13. Longitudinal volumetric and 2D assessment of cerebellar atrophy in a large cohort of children with phosphomannomutase deficiency (PMM2-CDG).

    PubMed

    de Diego, Víctor; Martínez-Monseny, Antonio F; Muchart, Jordi; Cuadras, Daniel; Montero, Raquel; Artuch, Rafael; Pérez-Cerdá, Celia; Pérez, Belén; Pérez-Dueñas, Belén; Poretti, Andrea; Serrano, Mercedes

    2017-09-01

    We aim to delineate the progression of cerebellar atrophy (the primary neuroimaging finding) in children with phosphomannomutase-deficiency (PMM2-CDG) by analyzing longitudinal MRI studies and performing cerebellar volumetric analysis and a 2D cerebellar measurement. Statistical analysis was used to compare MRI measurements [midsagittal vermis relative diameter (MVRD) and volume] of children with PMM2-CDG and sex- and age-matched controls, and to determine the rate of progression of cerebellar atrophy at different ages. Fifty MRI studies of 33 PMM2-CDG patients were used for 2D evaluation, and 19 MRI studies were available for volumetric analysis. Results from a linear regression model showed that patients have a significantly lower MVRD and cerebellar volume compared to controls (p < 0.001 and p < 0.001 respectively). There was a significant negative correlation between age and MVRD for patients (p = 0.014). The rate of cerebellar atrophy measured by the loss of MVRD and cerebellar volume per year was higher at early ages (r = -0.578, p = 0.012 and r = -0.323, p = 0.48 respectively), particularly in patients under 11 years (p = 0.004). There was a significant positive correlation between MVRD and cerebellar volume in PMM2-CDG patients (r = 0.669, p = 0.001). Our study quantifies a progression of cerebellar atrophy in PMM2-CDG patients, particularly during the first decade of life, and suggests a simple and reliable measure, the MVRD, to monitor cerebellar atrophy. Quantitative measurement of MVRD and cerebellar volume are essential for correlation with phenotype and outcome, natural follow-up, and monitoring in view of potential therapies in children with PMM2-CDG.

  14. Postoperative cerebellar mutism and autistic spectrum disorder.

    PubMed

    Tasdemiroğlu, Erol; Kaya, Miktat; Yildirim, Can Hakan; Firat, Levent

    2011-06-01

    I read the article "An Inside View of Autism" written by a 44-year-old autistic woman who had a successful international career designing livestock equipment. In this article, she wrote about her life, disease, and experiences as an autistic individual. She stated that "It is interesting that my speech resembled the stressed speech in young children who have had tumors removed from the cerebellum". In this article, we intend to review and extensively document both postoperative cerebellar mutism and autistic spectrum disorder. We reviewed the clinical and neurological findings, etio-pathogenesis, neuroanatomy, mechanisms of development, and similarities between the etio-pathogenesis of both diseases. Cerebellar lesions can produce mutism and dysarthria, symptoms sometimes seen in autistic spectrum disorder. In mammals, cerebellar lesions disturb motivated behavior and reduce social interactions, functions that are disturbed in autistic spectrum disorder and cerebellar mutism. The cerebellum and two regions within the frontal lobes are active in certain language tasks. Language is abnormal in autistic spectrum disorder and cerebellar mutism.

  15. Downregulation of immediate-early genes linking to suppression of neuronal plasticity in rats after 28-day exposure to glycidol

    SciTech Connect

    Akane, Hirotoshi; Saito, Fumiyo; Shiraki, Ayako

    2014-09-01

    We previously found that the 28-day oral toxicity study of glycidol at 200 mg/kg/day in rats resulted in axonopathy in both the central and peripheral nervous systems and aberrations in the late-stage of hippocampal neurogenesis targeting the process of neurite extension. To capture the neuronal parameters in response to glycidol toxicity, these animals were subjected to region-specific global gene expression profiling in four regions of cerebral and cerebellar architectures, followed by immunohistochemical analysis of selected gene products. Expression changes of genes related to axonogenesis and synaptic transmission were observed in the hippocampal dentate gyrus, cingulate cortex and cerebellar vermis atmore » 200 mg/kg showing downregulation in most genes. In the corpus callosum, genes related to growth, survival and functions of glial cells fluctuated their expression. Immunohistochemically, neurons expressing gene products of immediate-early genes, i.e., Arc, Fos and Jun, decreased in their number in the dentate granule cell layer, cingulate cortex and cerebellar vermis. We also applied immunohistochemical analysis in rat offspring after developmental exposure to glycidol through maternal drinking water. The results revealed increases of Arc{sup +} neurons at 1000 ppm and Fos{sup +} neurons at ≥ 300 ppm in the dentate granule cell layer of offspring only at the adult stage. These results suggest that glycidol suppressed neuronal plasticity in the brain after 28-day exposure to young adult animals, in contrast to the operation of restoration mechanism to increase neuronal plasticity at the adult stage in response to aberrations in neurogenesis after developmental exposure. - Highlights: • Neuronal toxicity parameters after 28-day glycidol treatment were examined in rats. • Region-specific global gene expression profiling was conducted in brain regions. • Cortical tissues downregulated genes on axonogenesis and synaptic transmission. • Cortical

  16. Neurodevelopmental malformations of the cerebellar vermis in genetically engineered rats

    EPA Science Inventory

    The cerebellar vermis is particularly vulnerable to neurodevelopmental malformations in humans and rodents. Sprague-Dawley, and Long-Evans rats exhibit spontaneous cerebellar malformations consisting of heterotopic neurons and glia in the molecular layer of the vermis. Malformati...

  17. Cerebellar contribution to feedforward control of locomotion.

    PubMed

    Pisotta, Iolanda; Molinari, Marco

    2014-01-01

    The cerebellum is an important contributor to feedforward control mechanisms of the central nervous system, and sequencing-the process that allows spatial and temporal relationships between events to be recognized-has been implicated as the fundamental cerebellar mode of operation. By adopting such a mode and because cerebellar activity patterns are sensitive to a variety of sensorimotor-related tasks, the cerebellum is believed to support motor and cognitive functions that are encoded in the frontal and parietal lobes of the cerebral cortex. In this model, the cerebellum is hypothesized to make predictions about the consequences of a motor or cognitive command that originates from the cortex to prepare the entire system to cope with ongoing changes. In this framework, cerebellar predictive mechanisms for locomotion are addressed, focusing on sensorial and motoric sequencing. The hypothesis that sequence recognition is the mechanism by which the cerebellum functions in gait control is presented and discussed.

  18. Cerebellar contribution to feedforward control of locomotion

    PubMed Central

    Pisotta, Iolanda; Molinari, Marco

    2014-01-01

    The cerebellum is an important contributor to feedforward control mechanisms of the central nervous system, and sequencing—the process that allows spatial and temporal relationships between events to be recognized—has been implicated as the fundamental cerebellar mode of operation. By adopting such a mode and because cerebellar activity patterns are sensitive to a variety of sensorimotor-related tasks, the cerebellum is believed to support motor and cognitive functions that are encoded in the frontal and parietal lobes of the cerebral cortex. In this model, the cerebellum is hypothesized to make predictions about the consequences of a motor or cognitive command that originates from the cortex to prepare the entire system to cope with ongoing changes. In this framework, cerebellar predictive mechanisms for locomotion are addressed, focusing on sensorial and motoric sequencing. The hypothesis that sequence recognition is the mechanism by which the cerebellum functions in gait control is presented and discussed. PMID:25009490

  19. Vertigo in brainstem and cerebellar strokes.

    PubMed

    Choi, Kwang-Dong; Lee, Hyung; Kim, Ji-Soo

    2013-02-01

    The aim of this study is to review the recent findings on the prevalence, clinical features, and diagnosis of vertigo from brainstem and cerebellar strokes. Patients with isolated vertigo are at higher risk for stroke than the general population. Strokes involving the brainstem and cerebellum may manifest as acute vestibular syndrome, and acute isolated audiovestibular loss may herald impending infarction in the territory of the anterior inferior cerebellar artery. Appropriate bedside evaluation is superior to MRI for detecting central vestibular syndromes. Recording of vestibular-evoked myogenic potentials is useful for evaluation of the central otolithic pathways in brainstem and cerebellar strokes. Accurate identification of isolated vascular vertigo is very important since misdiagnosis of acute stroke may result in significant morbidity and mortality, whereas overdiagnosis of vascular vertigo would lead to unnecessary costly work-ups and medication.

  20. Spontaneous Cerebellar Hematoma: Decision Making in Conscious Adults.

    PubMed

    Alkosha, Hazem M; Ali, Nabil Mansour

    2017-06-01

    To detect predictors of the clinical course and outcome of cerebellar hematoma in conscious patients that may help in decision making. This study entails retrospective and prospective review and collection of the demographic, clinical, and radiologic data of 92 patients with cerebellar hematoma presented conscious and initially treated conservatively. Primary outcome was deterioration lower than a Glasgow Coma Scale score of 14 and secondary outcome was Glasgow Outcome Scale score at discharge and 3 months later. Relevant data to primary outcome were used to create a prediction model and derive a risk score. The model was validated using a bootstrap technique and performance measures of the score were presented. Surgical interventions and secondary outcomes were correlated to the score to explore its use in future decision making. Demographic and clinical data showed no relevance to outcome. The relevant initial computed tomography criteria were used to build up the prediction model. A score was derived after the model proved to be valid using internal validation with bootstrapping technique. The score (0-6) had a cutoff value of ≥2, with sensitivity of 93.3% and specificity of 88.0%. It was found to have a significant negative association with the onset of neurologic deterioration, end point Glasgow Coma Scale scores and the Glasgow Outcome Scale scores at discharge. The score was positively correlated to the aggressiveness of surgical interventions and the length of hospital stay. Early definitive management is critical in conscious patients with cerebellar hematomas and can improve outcome. Our proposed score is a simple tool with high discrimination power that may help in timely decision making in those patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Regular tracheostomy tube changes to prevent formation of granulation tissue.

    PubMed

    Yaremchuk, Kathleen

    2003-01-01

    Tracheostomy is a commonly performed operative procedure that has been described since 2000 B.C. The early indications for tracheostomy were for upper airway obstruction, usually occurring in young people as a result of an infectious process. Recently, tracheostomies are more commonly performed in the critically ill patient to assist in long-term ventilatory support. Granulation tissue at the stoma and the trachea has been described as a late complication resulting in bleeding, drainage, and difficulty with maintaining mechanical ventilatory support. The present report is of an observational study of a newly implemented policy that required regular changing of tracheostomy tubes. Comparable groups of patients were compared before and after this procedural change to document complications. Data collection consisted of chart reviews of all admissions for 1 year before the policy change and the subsequent 2 years. Complication rates were compared using standard statistical techniques. A policy change was instituted that required all tracheostomy tubes to be changed every 2 weeks in conjunction with a detailed evaluation of the tracheostomy stoma. Charts were reviewed the year before the change in policy and in the subsequent 2 years to determine the incidence of granulation tissue requiring operative intervention. The number of patients requiring surgical intervention secondary to granulation tissue showed a statistically significant decrease (P =.02). A review of policies and procedures from the six largest hospitals in southeastern Michigan had no recommendations for routine tracheostomy tube changes. A policy requiring a routine change of tracheostomy tubes results in fewer complications from granulation tissue. Tracheostomy tube changes to prevent granulation tissue and its complications.

  2. Lewis M. Rutherfurd and the First Photograph of Solar Granulation

    NASA Astrophysics Data System (ADS)

    Harvey, J. W.; Briggs, John W.; Prosser, Sian

    2017-08-01

    A major astronomical controversy of the mid-19th century was discordant descriptions of the small scale structure of the solar surface. Visual observers contradicted each other by describing the surface as consisting of “corrugations”, “willow leaves”, “rice grains”, “cumuli”, “thatch”, “granules”, etc. Early photographs of the solar surface were not good enough to settle the controversy. The French astronomer Jules Janssen is credited with the first 1876 photographs that clearly showed what we now call solar granulation (1876, CRAS 82, 1363). Upon seeing these images, New Yorker Lewis M. Rutherfurd (1878, MNRAS 38, 410) praised the high quality of Janssen’s images but asserted that he had also photographed granulation as early as 1871 using collodion wet plates. He sent copies of his best photograph to the Royal Astronomical Society to support his assertion. Curious about his claim, Briggs and Harvey set up Rutherfurd’s 13-inch achromatic refractor on Kitt Peak and found that it easily showed well-resolved solar granulation, so his claim might well have been justified. But without his plates we could not confirm the claim. For 140 years the copies of Rutherfurd’s best solar photograph remained in the archives of the Royal Astronomical Society and were recently discovered by Prosser (RAS Photographs A3/001B and A3/002). By coincidence a few days later, Briggs found the original August 11, 1871 plate. Despite poor condition these photographs show solar granulation. There are at least two other possible early claimants (Reade; Vogel) but their plates are almost certainly lost. Rutherfurd was a master of astronomical instrumentation and photography. He was reticent about his work, letting results speak for themselves, so it is satisfying to find that he was justified in making his claim of priority.

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

    ERIC Educational Resources Information Center

    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…

  4. Mutant ataxin1 disrupts cerebellar development in spinocerebellar ataxia type 1.

    PubMed

    Edamakanti, Chandrakanth Reddy; Do, Jeehaeh; Didonna, Alessandro; Martina, Marco; Opal, Puneet

    2018-06-01

    Spinocerebellar ataxia type 1 (SCA1) is an adult-onset neurodegenerative disease caused by a polyglutamine expansion in the protein ATXN1, which is involved in transcriptional regulation. Although symptoms appear relatively late in life, primarily from cerebellar dysfunction, pathogenesis begins early, with transcriptional changes detectable as early as a week after birth in SCA1-knockin mice. Given the importance of this postnatal period for cerebellar development, we asked whether this region might be developmentally altered by mutant ATXN1. We found that expanded ATXN1 stimulates the proliferation of postnatal cerebellar stem cells in SCA1 mice. These hyperproliferating stem cells tended to differentiate into GABAergic inhibitory interneurons rather than astrocytes; this significantly increased the GABAergic inhibitory interneuron synaptic connections, disrupting cerebellar Purkinje cell function in a non-cell autonomous manner. We confirmed the increased basket cell-Purkinje cell connectivity in human SCA1 patients. Mutant ATXN1 thus alters the neural circuitry of the developing cerebellum, setting the stage for the later vulnerability of Purkinje cells to SCA1. We propose that other late-onset degenerative diseases may also be rooted in subtle developmental derailments.

  5. Epidermal growth factor receptor expression is related to post-mitotic events in cerebellar development: regulation by thyroid hormone.

    PubMed

    Carrasco, Emilce; Blum, Mariann; Weickert, Cynthia Shannon; Casper, Diana

    2003-01-10

    It has been established that thyroid hormone and neurotrophic factors both orchestrate developmental events in the brain. However, it is not clear how these two influences are related. In this study, we investigated the effects of thyroid hormone on cerebellar development and the coincident expression of transforming growth factor-alpha (TGF-alpha), a ligand in the epidermal growth factor (EGF) family, and the epidermal growth factor receptor (EGFR). Profiles of thyroid hormone expression were measured in postnatal animals and were found to peak at postnatal day 15 (P15). These levels dropped below detectable levels when mice were made hypothyroid with propylthiouracil (PTU). TGF-alpha and EGFR expression, as determined by RNAse protection assay, was maximal at P6 in normal animals, but remained low in hypothyroid animals, suggesting that thyroid hormone was responsible for their induction. In situ hybridization and immunohistochemical analysis of EGFR expression revealed that this receptor was present on granule cells within the inner zone of the external granule cell layer (EGL), suggesting that EGFR-ligands were not inducing granule cell proliferation. The persistence of EGFR expression on migrating granule cells and subsequent down-regulation of expression in the internal granule cell layer (IGL) implicates a role for EGFR-ligands in differentiation and/or migration. In hypothyroid animals, we observed a delayed progression of granule cell migration, consistent with the persistence of EGFR labeling in the EGL, and in the 'pile-up' of labeled cells at the interface between the molecular layer and the Purkinje cell layer. Taken together, these results implicate thyroid hormone in the coordinated expression of TGF-alpha and EGFR, which are positioned to play a role in post-mitotic developmental events in the cerebellum.

  6. Improving cerebellar segmentation with statistical fusion

    NASA Astrophysics Data System (ADS)

    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.

  7. Remote cerebellar hemorrhage following supratentorial craniotomy.

    PubMed

    Huang, Chih-Yuan; Lee, Po-Hsuan; Lin, Sheng-Hsiang; Chuang, Ming-Tsung; Sun, Yuan-Ting; Hung, Yu-Chang; Lee, E-Jian

    2012-06-01

    Cerebellar hemorrhage remote from the site of surgery may complicate neurosurgical procedure. The exact pathophysiology of this type of hemorrhage is poorly understood. We retrospectively compared 16 patients who had remote cerebellar hemorrhage (RCH) with a case-matched control cohort, to determine the significance of perisurgical and surgical factors that may predispose patients to such bleeding events. From 1 June 2005 to 31 December 2008, postoperative routine head computed tomographic (CT) scan was performed in our institution and 16 patients with RCH after supratentorial neurosurgical procedure were identified. The medical charts of these 16 cases and a control cohort of 64 patients were recorded. All parameters were analyzed with regards to various variables. The incidence RCH after supratentorial craniotomy increased after postoperative computed tomographic scan. The mechanism of cerebellar hemorrhage in this series of patients is most likely multifactorial. Several variables showed a significant association with the occurrence of RCH. Multivariate analysis indicated that the following two factors independently correlated with occurrence of RCH: (1) postoperative epidural drainage amount; and (2) history of previous cerebrovascular accident (CVA) with cerebral atrophy. All cases with RCH underwent medical treatment and no neurological sequelae associated with RCH. Postoperative epidural drainage amount and history of previous CVA with cerebral atrophy can reliably predict the occurrence of cerebellar hemorrhage after supratentorial craniotomy. One of the most important strategies to minimize hazardous complications is to be aware of these potential risk factors and to take action to prevent them.

  8. Inverse Stochastic Resonance in Cerebellar Purkinje Cells

    PubMed Central

    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

  9. Vergence Deficits in Patients with Cerebellar Lesions

    ERIC Educational Resources Information Center

    Sander, T.; Sprenger, A.; Neumann, G.; Machner, B.; Gottschalk, S.; Rambold, H.; Helmchen, C.

    2009-01-01

    The cerebellum is part of the cortico-ponto-cerebellar circuit for conjugate eye movements. Recent animal data suggest an additional role of the cerebellum for the control of binocular alignment and disconjugate, i.e. vergence eye movements. The latter is separated into two different components: fast vergence (to step targets) and slow vergence…

  10. Differences between Spinocerebellar Ataxias and Multiple System Atrophy-Cerebellar Type on Proton Magnetic Resonance Spectroscopy

    PubMed Central

    Chen, Hung-Chieh; Soong, Bing-Wen; Guo, Wan Yuo; Wu, Hsiu-Mei; Chang, Cheng-Yen

    2012-01-01

    Purpose A broad spectrum of diseases can manifest cerebellar ataxia. In this study, we investigated whether proton magnetic resonance spectroscopy (MRS) may help differentiate spinocerebellar ataxias (SCA) from multiple systemic atrophy- cerebellar type (MSA-C). Material and Methods This prospective study recruited 156 patients with ataxia, including spinocerebellar ataxia (SCA) types 1, 2, 3, 6 and 17 (N = 94) and MSA-C (N = 62), and 44 healthy controls. Single voxel proton MRS in the cerebellar hemispheres and vermis were measured. The differences were evaluated using nonparametric statistic tests. Results When compared with healthy controls, the cerebellar and vermis NAA/Cr and NAA/Cho were lower in all patients(p<0.002). The Cho/Cr was lower in SCA2 and MSA-C (p<0.0005). The NAA/Cr and Cho/Cr were lower in MSA-C or SCA2 comparing with SCA3 or SCA6. The MRS features of SCA1 were in between (p<0.018). The cerebellar NAA/Cho was lower in SCA2 than SCA1, SCA3 or SCA6 (p<0.04). The cerebellar NAA/Cho in MSA-C was lower than SCA3 (p<0.0005). In the early stages of diseases (SARA score<10), significant lower NAA/Cr and NAA/Cho in SCA2, SCA3, SCA6 or MSA-C were observed comparing with healthy controls (p<0.017). The Cho/Cr was lower in MSA-C or SCA2 (p<0.0005). Patients with MSA-C and SCA2 had lower NAA/Cr and Cho/Cr than SCA3 or SCA6 (p<0.016). Conclusion By using MRS, significantly lower NAA/Cr, Cho/Cr and NAA/Cho in the cerebellar hemispheres and vermis were found in patients with ataxia (SCAs and MSA-C). Rapid neuronal degeneration and impairment of membrane activities were observed more often in patients with MSA-C than those with SCA, even in early stages. MRS could also help distinguish between SCA2 and other subtypes of SCAs. MRS ratios may be of use as biomarkers in early stages of disease and should be further assessed in a longitudinal study. PMID:23118909

  11. Cerebellar Hypoplasia and Dysmorphia in Neurofibromatosis Type 1.

    PubMed

    Toelle, Sandra P; Poretti, Andrea; Weber, Peter; Seute, Tatjana; Bromberg, Jacoline E C; Scheer, Ianina; Boltshauser, Eugen

    2015-12-01

    Unidentified bright objects (UBO) and tumors are well-known cerebellar abnormalities in neurofibromatosis type 1 (NF1). Literature reports on malformative cerebellar anomalies in neurofibromatosis type 1 (NF1), however, are scant. We retrospectively studied the clinical and neuroimaging findings of 5 patients with NF1 (4 females, age 6 to 29 years at last follow-up) and cerebellar anomalies. Cerebellar symptoms on neurological examination were mild or even not evident whereas learning disabilities were more or less pronounced in four patients. Two patients had cerebellar hypoplasia (diffusely enlarged cerebellar interfoliar spaces) and three cerebellar dysmorphias involving mainly one cerebellar hemisphere. In NF1, malformative cerebellar anomalies are rare (estimated prevalence of about 1%), but most likely underestimated and easily overlooked, because physicians tend to focus on more prevalent, obvious, and well-known findings such as optic pathway gliomas, other tumors, and UBO. This kind of cerebellar anomaly in NF1 has most likely a malformative origin, but the exact pathogenesis is unknown. The individual clinical significance is difficult to determine. We suggest that cerebellar anomalies should be systematically evaluated in neuroimaging studies of NF1 patients.

  12. Cerebellar contribution to mental rotation: a cTBS study.

    PubMed

    Picazio, Silvia; Oliveri, Massimiliano; Koch, Giacomo; Caltagirone, Carlo; Petrosini, Laura

    2013-12-01

    A cerebellar role in spatial information processing has been advanced even in the absence of physical manipulation, as occurring in mental rotation. The present study was aimed at investigating the specific involvement of left and right cerebellar hemispheres in two tasks of mental rotation. We used continuous theta burst stimulation to downregulate cerebellar hemisphere excitability in healthy adult subjects performing two mental rotation tasks: an Embodied Mental Rotation (EMR) task, entailing an egocentric strategy, and an Abstract Mental Rotation (AMR) task entailing an allocentric strategy. Following downregulation of left cerebellar hemisphere, reaction times were slower in comparison to sham stimulation in both EMR and AMR tasks. Conversely, identical reaction times were obtained in both tasks following right cerebellar hemisphere and sham stimulations. No effect of cerebellar stimulation side was found on response accuracy. The present findings document a specialization of the left cerebellar hemisphere in mental rotation regardless of the kind of stimulus to be rotated.

  13. Improved segmentation of cerebellar structures in children

    PubMed Central

    Narayanan, Priya Lakshmi; Boonazier, Natalie; Warton, Christopher; Molteno, Christopher D; Joseph, Jesuchristopher; Jacobson, Joseph L; Jacobson, Sandra W; Zöllei, Lilla; Meintjes, Ernesta M

    2016-01-01

    Background Consistent localization of cerebellar cortex in a standard coordinate system is important for functional studies and detection of anatomical alterations in studies of morphometry. To date, no pediatric cerebellar atlas is available. New method The probabilistic Cape Town Pediatric Cerebellar Atlas (CAPCA18) was constructed in the age-appropriate National Institute of Health Pediatric Database asymmetric template space using manual tracings of 16 cerebellar compartments in 18 healthy children (9–13 years) from Cape Town, South Africa. The individual atlases of the training subjects were also used to implement multi atlas label fusion using multi atlas majority voting (MAMV) and multi atlas generative model (MAGM) approaches. Segmentation accuracy in 14 test subjects was compared for each method to ‘gold standard’ manual tracings. Results Spatial overlap between manual tracings and CAPCA18 automated segmentation was 73% or higher for all lobules in both hemispheres, except VIIb and X. Automated segmentation using MAGM yielded the best segmentation accuracy over all lobules (mean Dice Similarity Coefficient 0.76; range 0.55–0.91). Comparison with existing methods In all lobules, spatial overlap of CAPCA18 segmentations with manual tracings was similar or higher than those obtained with SUIT (spatially unbiased infra-tentorial template), providing additional evidence of the benefits of an age appropriate atlas. MAGM segmentation accuracy was comparable to values reported recently by Park et al. (2014) in adults (across all lobules mean DSC = 0.73, range 0.40–0.89). Conclusions CAPCA18 and the associated multi atlases of the training subjects yield improved segmentation of cerebellar structures in children. PMID:26743973

  14. Isolation of new polar granule components in Drosophila reveals P body and ER associated proteins

    PubMed Central

    Thomson, Travis; Liu, Niankun; Arkov, Alexey; Lehmann, Ruth; Lasko, Paul

    2008-01-01

    Germ plasm, a specialized cytoplasm present at the posterior of the early Drosophila embryo, is necessary and sufficient for germ cell formation. Germ plasm is rich in mitochondria and contains electron dense structures called polar granules. To identify novel polar granule components we isolated proteins that associate in early embryos with Vasa (VAS) and Tudor (TUD), two known polar granule associated molecules. We identified Maternal expression at 31B (ME31B), eIF4A, Aubergine (AUB) and Transitional Endoplasmic Reticulum 94 (TER94) as components of both VAS and TUD complexes and confirmed their localization to polar granules by immuno-electron microscopy. ME31B, eIF4A and AUB are also present in processing (P) bodies, suggesting that polar granules, which are necessary for germ line formation, might be related to P bodies. Our recovery of ER associated proteins TER94 and ME31B confirms that polar granules are closely linked to the translational machinery and to mRNP assembly. PMID:18590813

  15. Dendritic excitation–inhibition balance shapes cerebellar output during motor behaviour

    PubMed Central

    Jelitai, Marta; Puggioni, Paolo; Ishikawa, Taro; Rinaldi, Arianna; Duguid, Ian

    2016-01-01

    Feedforward excitatory and inhibitory circuits regulate cerebellar output, but how these circuits interact to shape the somatodendritic excitability of Purkinje cells during motor behaviour remains unresolved. Here we perform dendritic and somatic patch-clamp recordings in vivo combined with optogenetic silencing of interneurons to investigate how dendritic excitation and inhibition generates bidirectional (that is, increased or decreased) Purkinje cell output during self-paced locomotion. We find that granule cells generate a sustained depolarization of Purkinje cell dendrites during movement, which is counterbalanced by variable levels of feedforward inhibition from local interneurons. Subtle differences in the dendritic excitation–inhibition balance generate robust, bidirectional changes in simple spike (SSp) output. Disrupting this balance by selectively silencing molecular layer interneurons results in unidirectional firing rate changes, increased SSp regularity and disrupted locomotor behaviour. Our findings provide a mechanistic understanding of how feedforward excitatory and inhibitory circuits shape Purkinje cell output during motor behaviour. PMID:27976716

  16. Influence of metronidazole particle properties on granules prepared in a high-shear mixer-granulator.

    PubMed

    Di Martino, Piera; Censi, Roberta; Malaj, Ledjan; Martelli, Sante; Joiris, Etienne; Barthélémy, Christine

    2007-02-01

    Metronidazole is a good example of high-dose drug substance with poor granulating and tableting properties. Tablets are generally produced by liquid granulation; however, the technological process failure is quite frequent. In order to verify how the metronidazole particle characteristics can influence granule properties, three metronidazole batches differing for crystal habit, mean particle size, BET surface area and wettability were selected, primarily designed according to their different elongation ratio: needle-shaped, stick-shaped, and isodimensional. In the presence of lactose monohydrate and pregelatinized maize starch, respectively as diluent and binder, they were included in a formula for wet granulation in a high-shear mixer-granulator. In order to render the process comparable as far as possible, all parameters and experimental conditions were maintained constant. Four granule batches were obtained: granules from placebo (G-placebo), granules from needle-shaped crystals (G-needle-shaped), granules from stick-shaped crystals (G-stick-shaped), and granules from isodimensional crystals (G-isodimensional). Different granule properties were considered, in particular concerning porosity, friability, loss on drying (LOD), and flowability. In order to study their tabletability and compressibility, the different granules obtained were then compressed in a rotary press. The best tabletability was obtained with the isodimensional batch, while the poorest was exhibited by the stick-shaped one. Differences in tabletability are in good accordance with compressibility results: to a better tabletability corresponds an important granule ability to undergo a volume reduction as a result of an applied pressure. In particular, it was proposed that the greatest compressibility of the G-isodimensional must be related to the greatest granule porosity percentage.

  17. Correlative microscopy of detergent granules.

    PubMed

    van Dalen, G; Nootenboom, P; Heussen, P C M

    2011-03-01

    The microstructure of detergent products for textile cleaning determines to a large extent the physical properties of these products. Correlative microscopy was used to reveal the microstructure by reconciling images obtained by scanning electron microscopy with energy dispersive X-ray analysis, X-ray microtomography and Fourier transform infrared microscopy. These techniques were applied on the same location of a subsample of a spray-dried detergent base powder embedded in polyacrylate. In this way, the three-dimensional internal and external structure of detergent granules could be investigated from milli to nano scale with detailed spatial information about the components present. This will generate knowledge how to design optimal microstructures for laundry products to obtain product properties demanded by the market. This method is also very useful for other powder systems used in a large variety of industries (e.g. for pharmaceutical, food, ceramic and metal industries). © 2010 The Authors Journal of Microscopy © 2010 The Royal Microscopical Society.

  18. NEDDylation promotes stress granule assembly

    PubMed Central

    Jayabalan, Aravinth Kumar; Sanchez, Anthony; Park, Ra Young; Yoon, Sang Pil; Kang, Gum-Yong; Baek, Je-Hyun; Anderson, Paul; Kee, Younghoon; Ohn, Takbum

    2016-01-01

    Stress granules (SGs) harbour translationally stalled messenger ribonucleoproteins and play important roles in regulating gene expression and cell fate. Here we show that neddylation promotes SG assembly in response to arsenite-induced oxidative stress. Inhibition or depletion of key components of the neddylation machinery concomitantly inhibits stress-induced polysome disassembly and SG assembly. Affinity purification and subsequent mass-spectrometric analysis of Nedd8-conjugated proteins from translationally stalled ribosomal fractions identified ribosomal proteins, translation factors and RNA-binding proteins (RBPs), including SRSF3, a previously known SG regulator. We show that SRSF3 is selectively neddylated at Lys85 in response to arsenite. A non-neddylatable SRSF3 (K85R) mutant do not prevent arsenite-induced polysome disassembly, but fails to support the SG assembly, suggesting that the neddylation pathway plays an important role in SG assembly. PMID:27381497

  19. NEDDylation promotes stress granule assembly.

    PubMed

    Jayabalan, Aravinth Kumar; Sanchez, Anthony; Park, Ra Young; Yoon, Sang Pil; Kang, Gum-Yong; Baek, Je-Hyun; Anderson, Paul; Kee, Younghoon; Ohn, Takbum

    2016-07-06

    Stress granules (SGs) harbour translationally stalled messenger ribonucleoproteins and play important roles in regulating gene expression and cell fate. Here we show that neddylation promotes SG assembly in response to arsenite-induced oxidative stress. Inhibition or depletion of key components of the neddylation machinery concomitantly inhibits stress-induced polysome disassembly and SG assembly. Affinity purification and subsequent mass-spectrometric analysis of Nedd8-conjugated proteins from translationally stalled ribosomal fractions identified ribosomal proteins, translation factors and RNA-binding proteins (RBPs), including SRSF3, a previously known SG regulator. We show that SRSF3 is selectively neddylated at Lys85 in response to arsenite. A non-neddylatable SRSF3 (K85R) mutant do not prevent arsenite-induced polysome disassembly, but fails to support the SG assembly, suggesting that the neddylation pathway plays an important role in SG assembly.

  20. Long-term supratentorial brain structure and cognitive function following cerebellar tumour resections in childhood.

    PubMed

    Moberget, T; Andersson, S; Lundar, T; Due-Tønnessen, B J; Heldal, A; Endestad, T; Westlye, L T

    2015-03-01

    The cerebellum is connected to extensive regions of the cerebrum, and cognitive deficits following cerebellar lesions may thus be related to disrupted cerebello-cerebral connectivity. Moreover, early cerebellar lesions could affect distal brain development, effectively inducing long-term changes in brain structure and cognitive function. Here, we characterize supratentorial brain structure and cognitive function in 20 adult patients treated for cerebellar tumours in childhood (mean age at surgery: 7.1 years) and 26 matched controls. Relative to controls, patients showed reduced cognitive function and increased grey matter density in bilateral cingulum, left orbitofrontal cortex and the left hippocampus. Within the patient group, increased grey matter density in these regions was associated with decreased performance on tests of processing speed and executive function. Further, diffusion tensor imaging revealed widespread alterations in white matter microstructure in patients. While current ventricle volume (an index of previous hydrocephalus severity it patients) was associated with grey matter density and white matter microstructure in patients, this could only partially account for the observed group differences in brain structure and cognitive function. In conclusion, our results show distal effects of cerebellar lesions on cerebral integrity and wiring, likely caused by a combination of neurodegenerative processes and perturbed neurodevelopment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Optogenetic Modulation and Multi-Electrode Analysis of Cerebellar Networks In Vivo

    PubMed Central

    Kruse, Wolfgang; Krause, Martin; Aarse, Janna; Mark, Melanie D.; Manahan-Vaughan, Denise; Herlitze, Stefan

    2014-01-01

    The firing patterns of cerebellar Purkinje cells (PCs), as the sole output of the cerebellar cortex, determine and tune motor behavior. PC firing is modulated by various inputs from different brain regions and by cell-types including granule cells (GCs), climbing fibers and inhibitory interneurons. To understand how signal integration in PCs occurs and how subtle changes in the modulation of PC firing lead to adjustment of motor behaviors, it is important to precisely record PC firing in vivo and to control modulatory pathways in a spatio-temporal manner. Combining optogenetic and multi-electrode approaches, we established a new method to integrate light-guides into a multi-electrode system. With this method we are able to variably position the light-guide in defined regions relative to the recording electrode with micrometer precision. We show that PC firing can be precisely monitored and modulated by light-activation of channelrhodopsin-2 (ChR2) expressed in PCs, GCs and interneurons. Thus, this method is ideally suited to investigate the spatio/temporal modulation of PCs in anesthetized and in behaving mice. PMID:25144735

  2. Information processing in the hemisphere of the cerebellar cortex for control of wrist movement

    PubMed Central

    Tomatsu, Saeka; Ishikawa, Takahiro; Tsunoda, Yoshiaki; Lee, Jongho; Hoffman, Donna S.

    2015-01-01

    A region of cerebellar lobules V and VI makes strong loop connections with the primary motor (M1) and premotor (PM) cortical areas and is assumed to play essential roles in limb motor control. To examine its functional role, we compared the activities of its input, intermediate, and output elements, i.e., mossy fibers (MFs), Golgi cells (GoCs), and Purkinje cells (PCs), in three monkeys performing wrist movements in two different forearm postures. The results revealed distinct steps of information processing. First, MF activities displayed temporal and directional properties that were remarkably similar to those of M1/PM neurons, suggesting that MFs relay near copies of outputs from these motor areas. Second, all GoCs had a stereotyped pattern of activity independent of movement direction or forearm posture. Instead, GoC activity resembled an average of all MF activities. Therefore, inhibitory GoCs appear to provide a filtering function that passes only prominently modulated MF inputs to granule cells. Third, PCs displayed highly complex spatiotemporal patterns of activity, with coordinate frames distinct from those of MF inputs and directional tuning that changed abruptly before movement onset. The complexity of PC activities may reflect rapidly changing properties of the peripheral motor apparatus during movement. Overall, the cerebellar cortex appears to transform a representation of outputs from M1/PM into different movement representations in a posture-dependent manner and could work as part of a forward model that predicts the state of the peripheral motor apparatus. PMID:26467515

  3. A probabilistic atlas of the cerebellar white matter.

    PubMed

    van Baarsen, K M; Kleinnijenhuis, M; Jbabdi, S; Sotiropoulos, S N; Grotenhuis, J A; van Cappellen van Walsum, A M

    2016-01-01

    Imaging of the cerebellar cortex, deep cerebellar nuclei and their connectivity are gaining attraction, due to the important role the cerebellum plays in cognition and motor control. Atlases of the cerebellar cortex and nuclei are used to locate regions of interest in clinical and neuroscience studies. However, the white matter that connects these relay stations is of at least similar functional importance. Damage to these cerebellar white matter tracts may lead to serious language, cognitive and emotional disturbances, although the pathophysiological mechanism behind it is still debated. Differences in white matter integrity between patients and controls might shed light on structure-function correlations. A probabilistic parcellation atlas of the cerebellar white matter would help these studies by facilitating automatic segmentation of the cerebellar peduncles, the localization of lesions and the comparison of white matter integrity between patients and controls. In this work a digital three-dimensional probabilistic atlas of the cerebellar white matter is presented, based on high quality 3T, 1.25mm resolution diffusion MRI data from 90 subjects participating in the Human Connectome Project. The white matter tracts were estimated using probabilistic tractography. Results over 90 subjects were symmetrical and trajectories of superior, middle and inferior cerebellar peduncles resembled the anatomy as known from anatomical studies. This atlas will contribute to a better understanding of cerebellar white matter architecture. It may eventually aid in defining structure-function correlations in patients with cerebellar disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Impact of screw configuration on the particle size distribution of granules produced by twin screw granulation.

    PubMed

    Vercruysse, J; Burggraeve, A; Fonteyne, M; Cappuyns, P; Delaet, U; Van Assche, I; De Beer, T; Remon, J P; Vervaet, C

    2015-02-01

    Twin screw granulation (TSG) has been reported by different research groups as an attractive technology for continuous wet granulation. However, in contrast to fluidized bed granulation, granules produced via this technique typically have a wide and multimodal particle size distribution (PSD), resulting in suboptimal flow properties. The aim of the current study was to evaluate the impact of granulator screw configuration on the PSD of granules produced by TSG. Experiments were performed using a 25 mm co-rotating twin screw granulator, being part of the ConsiGma™-25 system (a fully continuous from-powder-to-tablet manufacturing line from GEA Pharma Systems). Besides the screw elements conventionally used for TSG (conveying and kneading elements), alternative designs of screw elements (tooth-mixing-elements (TME), screw mixing elements (SME) and cutters) were investigated using an α-lactose monohydrate formulation granulated with distilled water. Granulation with only conveying elements resulted in wide and multimodal PSD. Using kneading elements, the width of the PSD could be partially narrowed and the liquid distribution was more homogeneous. However, still a significant fraction of oversized agglomerates was obtained. Implementing additional kneading elements or cutters in the final section of the screw configuration was not beneficial. Furthermore, granulation with only TME or SME had limited impact on the width of the PSD. Promising results were obtained by combining kneading elements with SME, as for these configurations the PSD was narrower and shifted to the size fractions suitable for tableting. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Polyhydroxyalkanoate (PHA) Granules Have no Phospholipids.

    PubMed

    Bresan, Stephanie; Sznajder, Anna; Hauf, Waldemar; Forchhammer, Karl; Pfeiffer, Daniel; Jendrossek, Dieter

    2016-05-25

    Polyhydroxybutyrate (PHB) granules, also designated as carbonosomes, are supra-molecular complexes in prokaryotes consisting of a PHB polymer core and a surface layer of structural and functional proteins. The presence of suspected phospholipids in the surface layer is based on in vitro data of isolated PHB granules and is often shown in cartoons of the PHB granule structure in reviews on PHB metabolism. However, the in vivo presence of a phospholipid layer has never been demonstrated. We addressed this topic by the expression of fusion proteins of DsRed2EC and other fluorescent proteins with the phospholipid-binding domain (LactC2) of lactadherin in three model organisms. The fusion proteins specifically localized at the cell membrane of Ralstonia eutropha but did not co-localize with PHB granules. The same result was obtained for Pseudomonas putida, a species that accumulates another type of polyhydroxyalkanoate (PHA) granules related to PHB. Notably, DsRed2EC-LactC2 expressed in Magnetospirillum gryphiswaldense was detected at the position of membrane-enclosed magnetosome chains and at the cytoplasmic membrane but not at PHB granules. In conclusion, the carbonosomes of representatives of α-proteobacteria, β-proteobacteria and γ-proteobacteria have no phospholipids in vivo and we postulate that the PHB/PHA granule surface layers in natural producers generally are free of phospholipids and consist of proteins only.

  6. Polyhydroxyalkanoate (PHA) Granules Have no Phospholipids

    PubMed Central

    Bresan, Stephanie; Sznajder, Anna; Hauf, Waldemar; Forchhammer, Karl; Pfeiffer, Daniel; Jendrossek, Dieter

    2016-01-01

    Polyhydroxybutyrate (PHB) granules, also designated as carbonosomes, are supra-molecular complexes in prokaryotes consisting of a PHB polymer core and a surface layer of structural and functional proteins. The presence of suspected phospholipids in the surface layer is based on in vitro data of isolated PHB granules and is often shown in cartoons of the PHB granule structure in reviews on PHB metabolism. However, the in vivo presence of a phospholipid layer has never been demonstrated. We addressed this topic by the expression of fusion proteins of DsRed2EC and other fluorescent proteins with the phospholipid-binding domain (LactC2) of lactadherin in three model organisms. The fusion proteins specifically localized at the cell membrane of Ralstonia eutropha but did not co-localize with PHB granules. The same result was obtained for Pseudomonas putida, a species that accumulates another type of polyhydroxyalkanoate (PHA) granules related to PHB. Notably, DsRed2EC-LactC2 expressed in Magnetospirillum gryphiswaldense was detected at the position of membrane-enclosed magnetosome chains and at the cytoplasmic membrane but not at PHB granules. In conclusion, the carbonosomes of representatives of α-proteobacteria, β-proteobacteria and γ-proteobacteria have no phospholipids in vivo and we postulate that the PHB/PHA granule surface layers in natural producers generally are free of phospholipids and consist of proteins only. PMID:27222167

  7. Cerebellar Ataxia, Seizures, Premature Death, and Cardiac Abnormalities in Mice with Targeted Disruption of the Cacna2d2 Gene

    PubMed Central

    Ivanov, Sergey V.; Ward, Jerrold M.; Tessarollo, Lino; McAreavey, Dorothea; Sachdev, Vandana; Fananapazir, Lameh; Banks, Melissa K.; Morris, Nicole; Djurickovic, Draginja; Devor-Henneman, Deborah E.; Wei, Ming-Hui; Alvord, Gregory W.; Gao, Boning; Richardson, James A.; Minna, John D.; Rogawski, Michael A.; Lerman, Michael I.

    2004-01-01

    CACNA2D2 is a putative tumor suppressor gene located in the human chromosome 3p21.3 region that shows frequent allelic imbalances in lung, breast, and other cancers. The α2δ-2 protein encoded by the gene is a regulatory subunit of voltage-dependent calcium channels and is expressed in brain, heart, and other tissues. Here we report that mice homozygous for targeted disruption of the Cacna2d2 gene exhibit growth retardation, reduced life span, ataxic gait with apoptosis of cerebellar granule cells followed by Purkinje cell depletion, enhanced susceptibility to seizures, and cardiac abnormalities. The Cacna2d2tm1NCIF null phenotype has much in common with that of Cacna1a mutants, such as cerebellar neuro-degeneration associated with ataxia, seizures, and premature death. A tendency to bradycardia and limited response of null mutants to isoflurane implicate α2δ-2 in sympathetic regulation of cardiac function. In summary, our findings provide genetic evidence that the α2δ-2 subunit serves in vivo as a component of P/Q-type calcium channels, is indispensable for the central nervous system function, and may be involved in hereditary cerebellar ataxias and epileptic disorders in humans. PMID:15331424

  8. Analysis of the release process of phenylpropanolamine hydrochloride from ethylcellulose matrix granules V. Release properties of ethylcellulose layered matrix granules.

    PubMed

    Fukui, Atsuko; Fujii, Ryuta; Yonezawa, Yorinobu; Sunada, Hisakazu

    2008-04-01

    In the pharmaceutical preparation of a controlled release drug, it is very important and necessary to understand the release properties. In previous papers, a combination of the square-root time law and cube-root law equations was confirmed to be a useful equation for qualitative treatment. It was also confirmed that the combination equation could analyze the release properties of layered granules as well as matrix granules. The drug release property from layered granules is different from that of matrix granules. A time lag occurs before release, and the entire release property of layered granules was analyzed using the combination of the square-root time law and cube-root law equations. It is considered that the analysis method is very useful and efficient for both matrix and layered granules. Comparing the granulation methods, it is easier to control the manufacturing process by tumbling granulation (method B) than by tumbling-fluidized bed granulation (method C). Ethylcellulose (EC) layered granulation by a fluidized bed granulator might be convenient for the preparation of controlled release dosage forms as compared with a tumbling granulator, because the layered granules prepared by the fluidized bed granulator can granulate and dry at the same time. The time required for drying by the fluidized bed granulator is shorter than that by the tumbling granulator, so the fluidized bed granulator is convenient for preparation of granules in handling and shorter processing time than the tumbling granulator. It was also suggested that the EC layered granules prepared by the fluidized bed granulator were suitable for a controlled release system as well as the EC matrix granules.

  9. Influence of granulating method on physical and mechanical properties, compression behavior, and compactibility of lactose and microcrystalline cellulose granules.

    PubMed

    Horisawa, E; Danjo, K; Sunada, H

    2000-06-01

    The physical and mechanical properties of lactose (LC) and microcrystalline cellulose (MCC) granules prepared by various granulating methods were determined, and their effects on the compression and strength of the tablets were examined. From the force-displacement curve obtained in a crushing test on a single granule, all LC granules appeared brittle, and MCC granules were somewhat plastically deformable. Inter-granular porosity epsilon inter clearly decreased with greater spherical granule shape for both materials. Decrease in intragranular porosity epsilon intra enhanced the crushing force of a single granule Fg. Agitating granulation brought about the most compactness and hardness of granules. In granule compression tests, the initial slope of Heckel plots K1 appeared closely related to ease of filling voids in a granule bed by the slippage or rolling of granules. The reciprocal of the slope in the succeeding step 1/K2 in compression of MCC granules indicated positive correlation to Fg, while in LC granules, no such obvious relation was evident. 1/K2 differed only slightly among granulating methods. Tensile strength of tablets Tt obtained by compression of various LC granules was low as a whole and was little influenced by granulating method. For MCC granules, which are plastically deformable, tablet strength greatly depended on granulation. Granules prepared by extruding or dry granulation gave strong tablets. Tablets prepared from granules made by the agitating method showed particularly low Tt. From stereomicroscopic observation, the contact area between granule particles in a tablet appeared smaller; this would explain the decrease in inter-granular bond formation.

  10. Neuroligin-1 overexpression in newborn granule cells in vivo.

    PubMed

    Schnell, Eric; Bensen, Aesoon L; Washburn, Eric K; Westbrook, Gary L

    2012-01-01

    Adult-born dentate granule cells integrate into the hippocampal network, extend neurites and form synapses in otherwise mature tissue. Excitatory and inhibitory inputs innervate these new granule cells in a stereotyped, temporally segregated manner, which presents a unique opportunity to study synapse development in the adult brain. To examine the role of neuroligins as synapse-inducing molecules in vivo, we infected dividing neural precursors in adult mice with a retroviral construct that increased neuroligin-1 levels during granule cell differentiation. By 21 days post-mitosis, exogenous neuroligin-1 was expressed at the tips of dendritic spines and increased the number of dendritic spines. Neuroligin-1-overexpressing cells showed a selective increase in functional excitatory synapses and connection multiplicity by single afferent fibers, as well as an increase in the synaptic AMPA/NMDA receptor ratio. In contrast to its synapse-inducing ability in vitro, neuroligin-1 overexpression did not induce precocious synapse formation in adult-born neurons. However, the dendrites of neuroligin-1-overexpressing cells did have more thin protrusions during an early period of dendritic outgrowth, suggesting enhanced filopodium formation or stabilization. Our results indicate that neuroligin-1 expression selectively increases the degree, but not the onset, of excitatory synapse formation in adult-born neurons.

  11. Convergent evolution of germ granule nucleators: A hypothesis.

    PubMed

    Kulkarni, Arpita; Extavour, Cassandra G

    2017-10-01

    Germ cells have been considered "the ultimate stem cell" because they alone, during normal development of sexually reproducing organisms, are able to give rise to all organismal cell types. Morphological descriptions of a specialized cytoplasm termed 'germ plasm' and associated electron dense ribonucleoprotein (RNP) structures called 'germ granules' within germ cells date back as early as the 1800s. Both germ plasm and germ granules are implicated in germ line specification across metazoans. However, at a molecular level, little is currently understood about the molecular mechanisms that assemble these entities in germ cells. The discovery that in some animals, the gene products of a small number of lineage-specific genes initiate the assembly (also termed nucleation) of germ granules and/or germ plasm is the first step towards facilitating a better understanding of these complex biological processes. Here, we draw on research spanning over 100years that supports the hypothesis that these nucleator genes may have evolved convergently, allowing them to perform analogous roles across animal lineages. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

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

    PubMed

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

    2016-02-27

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Isolated rhomboencephalosynapsis - a rare cerebellar anomaly.

    PubMed

    Paprocka, Justyna; Jamroz, Ewa; Scieszka, Ewa; Kluczewska, Ewa

    2012-01-01

    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.

  15. Marijuana alters the human cerebellar clock.

    PubMed

    O'Leary, Daniel S; Block, Robert I; Turner, Beth M; Koeppel, Julie; Magnotta, Vincent A; Ponto, Laura Boles; Watkins, G Leonard; Hichwa, Richard D; Andreasen, Nancy C

    2003-06-11

    The effects of marijuana on brain perfusion and internal timing were assessed using [15O] water PET in occasional and chronic users. Twelve volunteers who smoked marijuana recreationally about once weekly, and 12 volunteers who smoked daily for a number of years performed a self-paced counting task during PET imaging, before and after smoking marijuana and placebo cigarettes. Smoking marijuana increased rCBF in the ventral forebrain and cerebellar cortex in both groups, but resulted in significantly less frontal lobe activation in chronic users. Counting rate increased after smoking marijuana in both groups, as did a behavioral measure of self-paced tapping, and both increases correlated with rCBF in the cerebellum. Smoking marijuana appears to accelerate a cerebellar clock altering self-paced behaviors.

  16. Cerebellar interaction with the acoustic reflex.

    PubMed

    Jastreboff, P J

    1981-01-01

    The involvement of the cerebellar vermis in the acoustic reflex was analyzed in 12 cats, decerebrated or in pentobarbital anesthesia. Anatomical data suggested the existence of a connection of lobules VIII with the ventral cochlear nucleus. Single cell recording and evoked potential techniques demonstrated the existence of the acoustic projection to lobulus VIII. Electrical stimulation of this area changed the tension of the middle ear muscle and caused evoked potential responses in the caudal part of the ventral cochlear nucleus. Electrical stimulation of the motor nucleus of the facial nerve evoked a slow wave in the recording taken from the surrounding of the cochlear round window. A hypothesis is proposed which postulates the involvement of the acoustic reflex in space localization of acoustic stimuli and the action of cerebellar vermis in order to assure the stability and plasticity of the acoustic reflex arc.

  17. Ebola Virus Does Not Induce Stress Granule Formation during Infection and Sequesters Stress Granule Proteins within Viral Inclusions.

    PubMed

    Nelson, Emily V; Schmidt, Kristina M; Deflubé, Laure R; Doğanay, Sultan; Banadyga, Logan; Olejnik, Judith; Hume, Adam J; Ryabchikova, Elena; Ebihara, Hideki; Kedersha, Nancy; Ha, Taekjip; Mühlberger, Elke

    2016-08-15

    many viruses. We show that EBOV does not induce formation of stress granules (SGs) in infected cells and is therefore unrestricted by their concomitant translational arrest. We identified SG proteins sequestered within viral inclusions, which did not impair protein translation. We further show that EBOV is unable to block SG formation triggered by exogenous stress early in infection. These findings provide insight into potential targets of therapeutic intervention. Additionally, we identified a novel function of the interferon antagonist VP35, which is able to disrupt SG formation. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  18. Cerebellar malformations alter regional cerebral development.

    PubMed

    Bolduc, Marie-Eve; Du Plessis, Adre J; Evans, Alan; Guizard, Nicolas; Zhang, Xun; Robertson, Richard L; Limperopoulos, Catherine

    2011-12-01

    The aim of this study was to compare total and regional cerebral volumes in children with isolated cerebellar malformations (CBMs) with those in typically developing children, and to examine the extent to which cerebellar volumetric reductions are associated with total and regional cerebral volumes. This is a case-control study of children diagnosed with isolated CBMs. Each child was matched on age and sex to two typically developing children. Using advanced three-dimensional volumetric magnetic resonance imaging, the cerebrum was segmented into tissue classes and partitioned into eight regions. Analysis of variance was used to compare cerebral volumes between children with CBMs and control children, and linear regressions to examine the impact of cerebellar volume reduction on cerebral volumes. Magnetic resonance imaging was performed at a mean age of 27 months in 20 children (10 males, 10 females) with CBMs and 40 typically developing children. Children with CBMs showed significantly smaller deep grey matter nuclei (p < 0.001), subgenual white matter (p = 0.03), midtemporal white matter (p = 0.02), and inferior occipital grey matter (p = 0.03) volumes than typically developing children. Greater cerebellar volumetric reduction in children with CBMs was associated with decreased total cerebral volume and deep grey matter nuclei (p = 0.02), subgenual white/grey matter (p = 0.001), midtemporal white (p = 0.02) and grey matter (p = 0.01), and parieto-occipital grey matter (p = 0.004). CBMs are associated with impaired regional cerebral growth, suggesting deactivation of principal cerebello-cerebral pathways. © The Authors. Developmental Medicine & Child Neurology © 2011 Mac Keith Press.

  19. Right side neglect in right cerebellar lesion

    PubMed Central

    Silveri, M; Misciagna, S; Terrezza, G

    2001-01-01

    A patient is described who developed right side hemineglect after a right cerebellar lesion. This spatial disorder was interpreted as a secondary effect of a deficit of the motor organisation in the right hemispace due to left frontal diaschisis. The pathological base may be the interruption of a highly integrated system which includes the lateral cerebellum and the contralateral frontal lobe.

 PMID:11413276

  20. Hydroxyurea Treatment and Development of the Rat Cerebellum: Effects on the Neurogenetic Profiles and Settled Patterns of Purkinje Cells and Deep Cerebellar Nuclei Neurons.

    PubMed

    Martí, Joaquín; Santa-Cruz, M C; Serra, Roger; Hervás, José P

    2016-11-01

    The current paper analyzes the development of the male and female rat cerebellum exposed to hydroxyurea (HU) (300 or 600 mg/kg) as embryo and collected at postnatal day 90. Our study reveals that the administration of this drug compromises neither the cytoarchitecture of the cerebellar cortex nor deep nuclei (DCN). However, in comparison with the saline group, we observed that several cerebellar parameters were lower in the HU injected groups. These parameters included area of the cerebellum, cerebellar cortex length, molecular layer area, Purkinje cell number, granule cell counts, internal granular layer, white matter and cerebellar nuclei areas, and number of deep cerebellar nuclei neurons. These features were larger in the rats injected with saline, smaller in those exposed to 300 mg/kg of HU and smallest in the group receiving 600 mg/kg of this agent. No sex differences in the effect of the HU were observed. In addition, we infer the neurogenetic timetables and the neurogenetic gradients of PCs and DCN neurons in rats exposed to either saline or HU as embryos. For this purpose, 5-bromo-2'-deoxyuridine was injected into pregnant rats previously administered with saline or HU. This thymidine analog was administered following a progressively delayed cumulative labeling method. The data presented here show that systematic differences exist in the pattern of neurogenesis and in the spatial location of cerebellar neurons between rats injected with saline or HU. No sex differences in the effect of the HU were observed. These findings have implications for the administration of this compound to women in gestation as the effects of HU on the development of the cerebellum might persist throughout their offsprings' life.

  1. Cerebellar cortex development in the weaver condition presents regional and age-dependent abnormalities without differences in Purkinje cells neurogenesis.

    PubMed

    Martí, Joaquín; Santa-Cruz, María C; Hervás, José P; Bayer, Shirley A; Villegas, Sandra

    2016-01-01

    Ataxias are neurological disorders associated with the degeneration of Purkinje cells (PCs). Homozygous weaver mice (wv/wv) have been proposed as a model for hereditary cerebellar ataxia because they present motor abnormalities and PC loss. To ascertain the physiopathology of the weaver condition, the development of the cerebellar cortex lobes was examined at postnatal day (P): P8, P20 and P90. Three approaches were used: 1) quantitative determination of several cerebellar features; 2) qualitative evaluation of the developmental changes occurring in the cortical lobes; and 3) autoradiographic analyses of PC generation and placement. Our results revealed a reduction in the size of the wv/wv cerebellum as a whole, confirming previous results. However, as distinguished from these reports, we observed that quantified parameters contribute differently to the abnormal growth of the wv/wv cerebellar lobes. Qualitative analysis showed anomalies in wv/wv cerebellar cytoarchitecture, depending on the age and lobe analyzed. Such abnormalities included the presence of the external granular layer after P20 and, at P90, ectopic cells located in the molecular layer following several placement patterns. Finally, we obtained autoradiographic evidence that wild-type and wv/wv PCs presented similar neurogenetic timetables, as reported. However, the innovative character of this current work lies in the fact that the neurogenetic gradients of wv/wv PCs were not modified from P8 to P90. A tendency for the accumulation of late-formed PCs in the anterior and posterior lobes was found, whereas early-generated PCs were concentrated in the central and inferior lobes. These data suggested that wv/wv PCs may migrate properly to their final destinations. The extrapolation of our results to patients affected with cerebellar ataxias suggests that all cerebellar cortex lobes are affected with several age-dependent alterations in cytoarchitectonics. We also propose that PC loss may be regionally

  2. Compressibility and compactibility of granules produced by wet and dry granulation.

    PubMed

    Bacher, C; Olsen, P M; Bertelsen, P; Sonnergaard, J M

    2008-06-24

    The bulk properties, compactibility and compressibility of granules produced by wet and dry granulation were compared applying a rotary tablet press, three different morphological forms of calcium carbonate and two particle sizes of sorbitol. Granules from both granulation methods possessed acceptable flow properties; however, the ground (Mikhart) and cubic (Scoralite) calcium carbonate demonstrated better die-filling abilities in the tablet press than the scalenhedral calcium carbonate (Sturcal). The wet processed granules showed in general larger compression properties. This was explained as these granules were mechanical stronger and had a higher initial porosity. In some cases, a large particle surface area of calcium carbonate and sorbitol resulted in a small, insignificant improvement of the consolidation characteristics. A correlation between the compression and compaction characteristics was demonstrated.

  3. Distribution of binder in granules produced by means of twin screw granulation.

    PubMed

    Fonteyne, Margot; Fussell, Andrew Luke; Vercruysse, Jurgen; Vervaet, Chris; Remon, Jean Paul; Strachan, Clare; Rades, Thomas; De Beer, Thomas

    2014-02-28

    According to the quality by design principle processes may not remain black-boxes and full process understanding is required. The granule size distribution of granules produced via twin screw granulation is often found to be bimodal. The aim of this study was to gain a better understanding of binder distribution within granules produced via twin screw granulation in order to investigate if an inhomogeneous spread of binder is causing this bimodal size distribution. Theophylline-lactose-polyvinylpyrrolidone K30 (PVP) (30-67.5-2.5%, w/w) was used as a model formulation. The intra-granular distribution of PVP was evaluated by means of hyperspectral coherent anti-Stokes Raman scattering (CARS) microscopy. For the evaluated formulation, no PVP rich zones were detected when applying a lateral spatial resolution of 0.5 μm, indicating that PVP is homogenously distributed within the granules. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Application of tumbling melt granulation (TMG) method to prepare controlled-release fine granules.

    PubMed

    Maejima, T; Kubo, M; Osawa, T; Nakajima, K; Kobayashi, M

    1998-03-01

    The tumbling melt granulation (TMG) method was applied to prepare controlled-release fine granules of diltiazem hydrochloride (DH). The entire process, from the preparation of the cores by the adherence of DH to the sucrose crystal to the subsequent coating of the controlled-release layer, was performed without using any solvent. A mixture of meltable material, talc, and ethylcellulose was used for the controlled-release layer and controlled-release fine granules approximately 400 microns in diameter were obtained with excellent producibility. The dissolution rate of DH from these fine granules was similar to that of a once-a-day dosage form obtained in the market; further, the dependency of the dissolution profile on pH of the media was less. Thus, it was concluded that this TMG method was very useful for preparing not only controlled-release beads of granule size (usually 500 to 1400 microns) but also fine granules.

  5. Differentiating Cerebellar Impact on Thalamic Nuclei.

    PubMed

    Gornati, Simona V; Schäfer, Carmen B; Eelkman Rooda, Oscar H J; Nigg, Alex L; De Zeeuw, Chris I; Hoebeek, Freek E

    2018-05-29

    The cerebellum plays a role in coordination of movements and non-motor functions. Cerebellar nuclei (CN) axons connect to various parts of the thalamo-cortical network, but detailed information on the characteristics of cerebello-thalamic connections is lacking. Here, we assessed the cerebellar input to the ventrolateral (VL), ventromedial (VM), and centrolateral (CL) thalamus. Confocal and electron microscopy showed an increased density and size of CN axon terminals in VL compared to VM or CL. Electrophysiological recordings in vitro revealed that optogenetic CN stimulation resulted in enhanced charge transfer and action potential firing in VL neurons compared to VM or CL neurons, despite that the paired-pulse ratio was not significantly different. Together, these findings indicate that the impact of CN input onto neurons of different thalamic nuclei varies substantially, which highlights the possibility that cerebellar output differentially controls various parts of the thalamo-cortical network. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  6. Modification of drug release from acetaminophen granules by melt granulation technique - consideration of release kinetics.

    PubMed

    Uhumwangho, M U; Okor, R S

    2006-01-01

    Acetaminophen granules have been formed by a melt granulation process with the objective of retarding drug release for prolonged action formulations. The waxes used were goat wax, carnuba wax and glyceryl monostearate. In the melt granulation procedure, acetaminophen powder was triturated with the melted waxes and passed through a sieve of mesh 10 (aperture size 710 microm). The content of wax in resulting granules ranged from 10 to 40%w/w. Acetaminophen granules were also formed by the convectional method of wet granulation with starch mucilage (20%w/w). The granules were subjected to in-vitro drug release tests. The release data were subjected to analysis by three different well-established mathematical models (release kinetics) namely, - zero order flux, first order, and the Higuchi square root of time relationship. The convectional granules exhibited an initial zero order flux (first 55%) followed by a first order release profile (the remaining 45%). The pattern of drug release from the melt granulations was consistent with the first order kinetic and the Higuchi square root of time relationship, indicating a diffusion-controlled release mechanism. The first order release rate constant of the convectional granules was 1.95 +/- 0.02 h(-1). After melt granulation (wax content, 20%w/w) the rate constants dropped drastically to 0.130+/-0.001 h(-1) (goat wax), 0.120+/-0.003 h(-1) (carnuba wax), and 0.130+/-0.002 h(-1) (glyceryl monosterate) indicating that all three waxes were equivalent in retarding drug release from the melt granulations.

  7. [Cerebellar atrophy in Minamata disease: comparison with spino-cerebellar degeneration on MR images].

    PubMed

    Ikeda, O; Okajima, T; Korogi, Y; Kitajima, M; Uchino, M; Takahasi, M

    1997-02-01

    We evaluated atrophic patterns of the cerebellar vermis in seven patients with Minamata disease (MD) and nine patients with spino-cerebellar degeneration (SCD) on MR images. Twenty-five control subjects were also examined. The cerebellar vermis was divided into superior, middle, and inferior parts by the primary fissure and the prepyramidal fissure on the median sagittal T1-weighted MR image. The length and area of each part were measured. In the patients with SCD, there were no significant differences in the degree of atrophy among the three parts. However, MR images of the patients with MD showed more severe atrophy in the middle and inferior parts than in the superior part. Atrophy of the superior part was less frequently observed in MD patients.

  8. Acute bilateral cerebellar infarction in the territory of the medial branches of posterior inferior cerebellar arteries.

    PubMed

    Gurer, G; Sahin, G; Cekirge, S; Tan, E; Saribas, O

    2001-10-01

    The most frequent type of cerebellar infarcts involved the posterior inferior cerebellar artery (PICA) and superior cerebellar artery territories but bilateral involvement of lateral or medial branches of PICA is extremely rare. In this report, we present a 55-year-old male who admitted to hospital with vomiting, nausea and dizziness. On examination left-sided hemiparesia and ataxic gait were detected. Infarct on bilateral medial branch of PICA artery territories was found out with cranial magnetic resonance imaging (MRI) technique and 99% stenosis of the left vertebral artery was found out with digital subtraction arteriography. The patient was put on heparin treatment. After 3 weeks, his complaints and symptoms had disappeared except for mild gait ataxia.

  9. Exome Sequencing in the Clinical Diagnosis of Sporadic or Familial Cerebellar Ataxia

    PubMed Central

    Fogel, Brent L.; Lee, Hane; Deignan, Joshua L.; Strom, Samuel P.; Kantarci, Sibel; Wang, Xizhe; Quintero-Rivera, Fabiola; Vilain, Eric; Grody, Wayne W.; Perlman, Susan; Geschwind, Daniel H.; Nelson, Stanley F.

    2015-01-01

    IMPORTANCE Cerebellar ataxias are a diverse collection of neurologic disorders with causes ranging from common acquired etiologies to rare genetic conditions. Numerous genetic disorders have been associated with chronic progressive ataxia and this consequently presents a diagnostic challenge for the clinician regarding how to approach and prioritize genetic testing in patients with such clinically heterogeneous phenotypes. Additionally, while the value of genetic testing in early-onset and/or familial cases seems clear, many patients with ataxia present sporadically with adult onset of symptoms and the contribution of genetic variation to the phenotype of these patients has not yet been established. OBJECTIVE To investigate the contribution of genetic disease in a population of patients with predominantly adult- and sporadic-onset cerebellar ataxia. DESIGN, SETTING, AND PARTICIPANTS We examined a consecutive series of 76 patients presenting to a tertiary referral center for evaluation of chronic progressive cerebellar ataxia. MAIN OUTCOMES AND MEASURES Next-generation exome sequencing coupled with comprehensive bioinformatic analysis, phenotypic analysis, and clinical correlation. RESULTS We identified clinically relevant genetic information in more than 60% of patients studied (n = 46), including diagnostic pathogenic gene variants in 21% (n = 16), a notable yield given the diverse genetics and clinical heterogeneity of the cerebellar ataxias. CONCLUSIONS AND RELEVANCE This study demonstrated that clinical exome sequencing in patients with adult-onset and sporadic presentations of ataxia is a high-yield test, providing a definitive diagnosis in more than one-fifth of patients and suggesting a potential diagnosis in more than one-third to guide additional phenotyping and diagnostic evaluation. Therefore, clinical exome sequencing is an appropriate consideration in the routine genetic evaluation of all patients presenting with chronic progressive cerebellar ataxia

  10. Cerebellar Hematoma Location: Implications for the Underlying Microangiopathy.

    PubMed

    Pasi, Marco; Marini, Sandro; Morotti, Andrea; Boulouis, Gregoire; Xiong, Li; Charidimou, Andreas; Ayres, Alison M; Lee, Myung Joo; Biffi, Alessandro; Goldstein, Joshua N; Rosand, Jonathan; Gurol, M Edip; Greenberg, Steven M; Viswanathan, Anand

    2018-01-01

    Spontaneous cerebellar intracerebral hemorrhage (ICH) has been reported to be mainly associated with vascular changes secondary to hypertension. However, a subgroup of cerebellar ICH seems related to vascular amyloid deposition (cerebral amyloid angiopathy). We sought to determine whether location of hematoma in the cerebellum (deep and superficial regions) was suggestive of a particular hemorrhage-prone small-vessel disease pathology (cerebral amyloid angiopathy or hypertensive vasculopathy). Consecutive patients with cerebellar ICH from a single tertiary care medical center were recruited. Based on data from pathological reports, patients were divided according to the location of the primary cerebellar hematoma (deep versus superficial). Location of cerebral microbleeds (CMBs; strictly lobar, strictly deep, and mixed CMB) was evaluated on magnetic resonance imaging. One-hundred and eight patients (84%) had a deep cerebellar hematoma, and 20 (16%) a superficial cerebellar hematoma. Hypertension was more prevalent in deep than in patients with superficial cerebellar ICH (89% versus 65%, respectively; P <0.05). Among patients who underwent magnetic resonance imaging, those with superficial cerebellar ICH had higher prevalence of strictly lobar CMB (43%) and lower prevalence of strictly deep or mixed CMB (0%) compared with those with deep superficial cerebellar ICH (6%, 17%, and 38%, respectively). In a multivariable model, presence of strictly lobar CMB was associated with superficial cerebellar ICH (odds ratio, 3.8; 95% confidence interval, 1.5-8.5; P =0.004). Our study showed that superficial cerebellar ICH is related to the presence of strictly lobar CMB-a pathologically proven marker of cerebral amyloid angiopathy. Cerebellar hematoma location may thus help to identify those patients likely to have cerebral amyloid angiopathy pathology. © 2017 American Heart Association, Inc.

  11. Gastroretentive extended-release floating granules prepared using a novel fluidized hot melt granulation (FHMG) technique.

    PubMed

    Zhai, H; Jones, D S; McCoy, C P; Madi, A M; Tian, Y; Andrews, G P

    2014-10-06

    The objective of this work was to investigate the feasibility of using a novel granulation technique, namely, fluidized hot melt granulation (FHMG), to prepare gastroretentive extended-release floating granules. In this study we have utilized FHMG, a solvent free process in which granulation is achieved with the aid of low melting point materials, using Compritol 888 ATO and Gelucire 50/13 as meltable binders, in place of conventional liquid binders. The physicochemical properties, morphology, floating properties, and drug release of the manufactured granules were investigated. Granules prepared by this method were spherical in shape and showed good flowability. The floating granules exhibited sustained release exceeding 10 h. Granule buoyancy (floating time and strength) and drug release properties were significantly influenced by formulation variables such as excipient type and concentration, and the physical characteristics (particle size, hydrophilicity) of the excipients. Drug release rate was increased by increasing the concentration of hydroxypropyl cellulose (HPC) and Gelucire 50/13, or by decreasing the particle size of HPC. Floating strength was improved through the incorporation of sodium bicarbonate and citric acid. Furthermore, floating strength was influenced by the concentration of HPC within the formulation. Granules prepared in this way show good physical characteristics, floating ability, and drug release properties when placed in simulated gastric fluid. Moreover, the drug release and floating properties can be controlled by modification of the ratio or physical characteristics of the excipients used in the formulation.

  12. Laughing headache with giant pacchionian granulations.

    PubMed

    Giraud, Pierric; Segal, Olivier; Chauvet, Sylvie

    2013-04-01

    Laughing is recognized as a provoking factor for headache, certainly underestimated among the general population and few cases have been published to date. We report a single case of severe headache, provoked almost exclusively by outbursts of laughing, where venous magnetic resonance imaging revealed the presence of giant Pacchioni granulations in both right and transverse sinuses. Reviewing published cases of laughing headache, we discuss possible mechanisms of pain and the role of giant Pacchionian granulations. © 2013 American Headache Society.

  13. Decreased cerebellar-cerebral connectivity contributes to complex task performance

    PubMed Central

    Knops, André

    2016-01-01

    The cerebellum's role in nonmotor processes is now well accepted, but cerebellar interaction with cerebral targets is not well understood. Complex cognitive tasks activate cerebellar, parietal, and frontal regions, but the effective connectivity between these regions has never been tested. To this end, we used psycho-physiological interactions (PPI) analysis to test connectivity changes of cerebellar and parietal seed regions in complex (2-digit by 1-digit multiplication, e.g., 12 × 3) vs. simple (1-digit by 1-digit multiplication, e.g., 4 × 3) task conditions (“complex − simple”). For cerebellar seed regions (lobule VI, hemisphere and vermis), we found significantly decreased cerebellar-parietal, cerebellar-cingulate, and cerebellar-frontal connectivity in complex multiplication. For parietal seed regions (PFcm, PFop, PFm) we found significantly increased parietal-parietal and parietal-frontal connectivity in complex multiplication. These results suggest that decreased cerebellar-cerebral connectivity contributes to complex task performance. Interestingly, BOLD activity contrasts revealed partially overlapping parietal areas of increased BOLD activity but decreased cerebellar-parietal PPI connectivity. PMID:27334957

  14. Prostaglandin E2 is an endogenous modulator of cerebellar development and complex behavior during a sensitive postnatal period.

    PubMed

    Dean, Shannon L; Knutson, Jessica F; Krebs-Kraft, Desiree L; McCarthy, Margaret M

    2012-04-01

    Prostaglandins are lipid-derived molecules that mediate the generation of fever in the central nervous system. In addition to their proinflammatory role, prostaglandins also impact neuronal development and synaptic plasticity, sometimes in a sex-specific manner. The cerebellum has a high expression of prostaglandin receptors during development, but the role that these molecules play during normal cerebellar maturation is unknown. We demonstrate here that disrupting prostaglandin synthesis with cyclo-oxygenase inhibitors during a time-sensitive window in early postnatal life alters cerebellar Purkinje cell development in rats, resulting in initially increased dendritic growth in both sexes. We show that this results in later cerebellar atrophy in males only, resulting in a sex-specific loss of cerebellar volume. Further, although performance in motor tasks is spared, social interaction and the sensory threshold are altered in males developmentally exposed to cyclo-oxygenase inhibitors. This work demonstrates a previously unknown role for prostaglandins in cerebellar development and emphasizes the role that the cerebellum plays outside motor tasks, in cognitive and sensory domains that may help to explain its connection to complex neurodevelopmental disorders such as autism. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  15. Cerebro-Cerebellar Functional Connectivity is Associated with Cerebellar Excitation-Inhibition Balance in Autism Spectrum Disorder.

    PubMed

    Hegarty, John P; Weber, Dylan J; Cirstea, Carmen M; Beversdorf, David Q

    2018-05-23

    Atypical functional connectivity (FC) and an imbalance of excitation-to-inhibition (E/I) have been previously reported in cerebro-cerebellar circuits in autism spectrum disorder (ASD). The current investigation used resting state fMRI and proton magnetic resonance spectroscopy ( 1 H-MRS) to examine the relationships between E/I (glutamate + glutamine/GABA) and FC of the dorsolateral prefrontal cortex and posterolateral cerebellar hemisphere from 14 adolescents/adults with ASD and 12 age/sex/IQ-matched controls. In this pilot sample, cerebro-cerebellar FC was positively associated with cerebellar E/I and listening comprehension abilities in individuals with ASD but not controls. Additionally, a subgroup of individuals with ASD and low FC (n = 5) exhibited reduced E/I and impaired listening comprehension. Thus, altered functional coherence of cerebro-cerebellar circuits in ASD may be related with a cerebellar E/I imbalance.

  16. Phasins, Multifaceted Polyhydroxyalkanoate Granule-Associated Proteins

    PubMed Central

    Mezzina, Mariela P.

    2016-01-01

    Phasins are the major polyhydroxyalkanoate (PHA) granule-associated proteins. They promote bacterial growth and PHA synthesis and affect the number, size, and distribution of the granules. These proteins can be classified in 4 families with distinctive characteristics. Low-resolution structural studies and in silico predictions were performed in order to elucidate the structure of different phasins. Most of these proteins share some common structural features, such as a preponderant α-helix composition, the presence of disordered regions that provide flexibility to the protein, and coiled-coil interacting regions that form oligomerization domains. Due to their amphiphilic nature, these proteins play an important structural function, forming an interphase between the hydrophobic content of PHA granules and the hydrophilic cytoplasm content. Phasins have been observed to affect both PHA accumulation and utilization. Apart from their role as granule structural proteins, phasins have a remarkable variety of additional functions. Different phasins have been determined to (i) activate PHA depolymerization, (ii) increase the expression and activity of PHA synthases, (iii) participate in PHA granule segregation, and (iv) have both in vivo and in vitro chaperone activities. These properties suggest that phasins might play an active role in PHA-related stress protection and fitness enhancement. Due to their granule binding capacity and structural flexibility, several biotechnological applications have been developed using different phasins, increasing the interest in the study of these remarkable proteins. PMID:27287326

  17. Phasins, Multifaceted Polyhydroxyalkanoate Granule-Associated Proteins.

    PubMed

    Mezzina, Mariela P; Pettinari, M Julia

    2016-09-01

    Phasins are the major polyhydroxyalkanoate (PHA) granule-associated proteins. They promote bacterial growth and PHA synthesis and affect the number, size, and distribution of the granules. These proteins can be classified in 4 families with distinctive characteristics. Low-resolution structural studies and in silico predictions were performed in order to elucidate the structure of different phasins. Most of these proteins share some common structural features, such as a preponderant α-helix composition, the presence of disordered regions that provide flexibility to the protein, and coiled-coil interacting regions that form oligomerization domains. Due to their amphiphilic nature, these proteins play an important structural function, forming an interphase between the hydrophobic content of PHA granules and the hydrophilic cytoplasm content. Phasins have been observed to affect both PHA accumulation and utilization. Apart from their role as granule structural proteins, phasins have a remarkable variety of additional functions. Different phasins have been determined to (i) activate PHA depolymerization, (ii) increase the expression and activity of PHA synthases, (iii) participate in PHA granule segregation, and (iv) have both in vivo and in vitro chaperone activities. These properties suggest that phasins might play an active role in PHA-related stress protection and fitness enhancement. Due to their granule binding capacity and structural flexibility, several biotechnological applications have been developed using different phasins, increasing the interest in the study of these remarkable proteins. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  18. Physicochemical characteristics of insulin secretion granules

    PubMed Central

    Coore, H. G.; Hellman, B.; Pihl, E.; Täljedal, I.-B.

    1969-01-01

    β-Granules were prepared from micro-dissected pancreatic islets of obese–hyperglycaemic mice. This fraction contained 60% of the insulin, 30% of the cytochrome oxidase, 16% of the acid phosphatase activity and 20% of the protein present in whole islets. The isolated granules retained a heavy metal during fractionation. Optimum conditions for granule stability were low ionic strength and pH6, the granules being unexpectedly fragile at pH7·4. The stability of the granules was unaffected by sucrose in the concentration range 50–320mm, but 1% (w/v) sodium deoxycholate released all insulin. A solubilizing effect was also noted with ATP and citrate. Spinning through 1·6m-sucrose yielded a further purification in relation to mitochondria and acid-phosphatase-carrying particles but virtually no purification in relation to protein. Electron microscopy revealed that the major contaminants were rough-surfaced vesicles and membranes. A separation of granules from acid phosphatase was achieved by phase distribution in polyethylene glycol and dextran. The location of the enzyme to the interphase was so pronounced in systems buffered with lithium phosphate that the technique may be used for future purification of acid-phosphatase-carrying particles from the β-cells. ImagesPLATE 1 PMID:4887194

  19. Genome-wide analysis of alternative splicing in medulloblastoma identifies splicing patterns characteristic of normal cerebellar development

    PubMed Central

    Menghi, Francesca; Jacques, Thomas S.; Barenco, Martino; Schwalbe, Ed C.; Clifford, Steven C.; Hubank, Mike; Ham, Jonathan

    2011-01-01

    Alternative splicing is an important mechanism for the generation of protein diversity at a post-transcriptional level. Modifications in the splicing patterns of several genes have been shown to contribute to the malignant transformation of different tissue types. In this study, we used the Affymetrix Exon arrays to investigate patterns of differential splicing between paediatric medulloblastomas and normal cerebellum on a genome-wide scale. Of the 1262 genes identified as potentially generating tumour-associated splice forms, we selected 14 examples of differential splicing of known cassette exons and successfully validated 11 of them by RT-PCR. The pattern of differential splicing of three validated events was characteristic for the molecular subset of Sonic Hedgehog (Shh)-driven medulloblastomas, suggesting that their unique gene signature includes the expression of distinctive transcript variants. Generally, we observed that tumour and normal fetal cerebellar samples shared significantly lower exon inclusion rates compared to normal adult cerebellum. We investigated whether tumour-associated splice forms were expressed in primary cultures of Shh-dependent mouse cerebellar granule cell precursors (GCPs) and found that Shh caused a decrease in the cassette exon inclusion rate of five out of the seven tested genes. Furthermore, we observed a significant increase in exon inclusion between post-natal days 7 and 14 of mouse cerebellar development, at the time when GCPs mature into post-mitotic neurons. We conclude that inappropriate splicing frequently occurs in human medulloblastomas and may be linked to the activation of developmental signalling pathways and a failure of cerebellar precursor cells to differentiate. PMID:21248070

  20. The morphology of solar granulations and dark networks

    NASA Astrophysics Data System (ADS)

    Graves, J. Elon; Pierce, A. Keith

    1986-08-01

    Solar granules are classified into four groups based on shape and splitting by sharp rifts crossing them. Grains are classified as: single granules varying in size from 1/8 to 3 in., single granules embayed by a broad dark area or possessing a central darkening, single granules split by very narrow rifts which are significantly narrower than the intergranular lanes, and complexes of granules displaying a daisy pattern. The formation and growth of 'white-light dark networks' are also discussed

  1. Detection of component segregation in granules manufactured by high shear granulation with over-granulation conditions using near-infrared chemical imaging.

    PubMed

    Koide, Tatsuo; Nagato, Takuya; Kanou, Yoshiyuki; Matsui, Kou; Natsuyama, Susumu; Kawanishi, Toru; Hiyama, Yukio

    2013-01-30

    The objective of this study was to evaluate the high shear granulation process using near-infrared (NIR) chemical imaging technique and to make the findings available for pharmaceutical development. We prepared granules and tablets made under appropriate- and over-granulation conditions with high shear granulation and observed these granules and tablets using NIR chemical imaging system. We found an interesting phenomenon: lactose agglomeration and segregation of ingredients occurred in experimental tablets when over-granulation conditions, including greater impeller rotation speeds and longer granulation times, were employed. Granules prepared using over-granulation conditions were larger and had progressed to the consolidation stage; segregation between ethenzamide and lactose occurred within larger granules. The segregation observed here is not detectable using conventional analytical technologies such as high pressure liquid chromatography (HPLC) because the content of the granules remained uniform despite the segregation. Therefore, granule visualization using NIR chemical imaging is an effective method for investigating and evaluating the granulation process. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Neurochemical deficits in the cerebellar vermis in child offspring of parents with bipolar disorder.

    PubMed

    Singh, Manpreet K; Spielman, Daniel; Libby, Allison; Adams, Elizabeth; Acquaye, Tenah; Howe, Meghan; Kelley, Ryan; Reiss, Allan; Chang, Kiki D

    2011-03-01

    We aimed to compare concentrations of N-acetyl aspartate, myo-inositol, and other neurometabolites in the cerebellar vermis of offspring at risk for bipolar disorder (BD) and healthy controls to examine whether changes in these neuronal metabolite concentrations occur in at-risk offspring prior to the onset of mania. A total of 22 children and adolescents aged 9-17 years with a familial risk for bipolar I or II disorder [at-risk offspring with non-bipolar I disorder mood symptoms (AR)], and 25 healthy controls (HC) were examined using proton magnetic resonance spectroscopy at 3T to study metabolite concentrations in an 8-cc voxel in the cerebellar vermis. Decreased myo-inositol and choline concentrations in the vermis were seen in the AR group compared to HC (p<0.01). Decreased cellular metabolism and interference with second messenger pathways may be present in the cerebellar vermis in youth at risk for BD as evident by decreased myo-inositol and choline concentrations in this region. These results may be limited by a cross-sectional design, co-occurring diagnoses, and medication exposure. Longitudinal studies are necessary to determine whether early neurochemical changes can predict the development of mania. Improved methods for identifying children with certain neurochemical vulnerabilities may inform preventive and early intervention strategies prior to the onset of mania. © 2011 John Wiley and Sons A/S.

  3. Neurochemical deficits in the cerebellar vermis in child offspring of parents with bipolar disorder

    PubMed Central

    Singh, Manpreet K; Spielman, Daniel; Libby, Allison; Adams, Elizabeth; Acquaye, Tenah; Howe, Meghan; Kelley, Ryan; Reiss, Allan; Chang, Kiki D

    2011-01-01

    Objectives We aimed to compare concentrations of N-acetyl aspartate, myo-inositol, and other neurometabolites in the cerebellar vermis of offspring at risk for bipolar disorder (BD) and healthy controls to examine whether changes in these neuronal metabolite concentrations occur in at-risk offspring prior to the onset of mania. Methods A total of 22 children and adolescents aged 9–17 years with a familial risk for bipolar I or II disorder [at-risk offspring with non-bipolar I disorder mood symptoms (AR)], and 25 healthy controls (HC) were examined using proton magnetic resonance spectroscopy at 3T to study metabolite concentrations in an 8-cc voxel in the cerebellar vermis. Results Decreased myo-inositol and choline concentrations in the vermis were seen in the AR group compared to HC (p < 0.01). Conclusions Decreased cellular metabolism and interference with second messenger pathways may be present in the cerebellar vermis in youth at risk for BD as evident by decreased myo-inositol and choline concentrations in this region. These results may be limited by a cross-sectional design, co-occurring diagnoses, and medication exposure. Longitudinal studies are necessary to determine whether early neurochemical changes can predict the development of mania. Improved methods for identifying children with certain neurochemical vulnerabilities may inform preventive and early intervention strategies prior to the onset of mania. PMID:21443573

  4. Investigation of Physicochemical Drug Properties to Prepare Fine Globular Granules Composed of Only Drug Substance in Fluidized Bed Rotor Granulation.

    PubMed

    Mise, Ryohei; Iwao, Yasunori; Kimura, Shin-Ichiro; Osugi, Yukiko; Noguchi, Shuji; Itai, Shigeru

    2015-01-01

    The effect of some drug properties (wettability and particle size distribution) on granule properties (mean particle size, particle size distribution, sphericity, and granule strength) were investigated in a high (>97%) drug-loading formulation using fluidized bed rotor granulation. Three drugs: acetaminophen (APAP); ibuprofen (IBU); and ethenzamide (ETZ) were used as model drugs based on their differences in wettability and particle size distribution. Granules with mean particle sizes of 100-200 µm and a narrow particle size distribution (PSD) could be prepared regardless of the drug used. IBU and ETZ granules showed a higher sphericity than APAP granules, while APAP and ETZ granules exhibited higher granule strength than IBU. The relationship between drug and granule properties suggested that the wettability and the PSD of the drugs were critical parameters affecting sphericity and granule strength, respectively. Furthermore, the dissolution profiles of granules prepared with poorly water-soluble drugs (IBU and ETZ) showed a rapid release (80% release in 20 min) because of the improved wettability with granulation. The present study demonstrated for the first time that fluidized bed rotor granulation can prepare high drug-loaded (>97%) globular granules with a mean particle size of less than 200 µm and the relationship between physicochemical drug properties and the properties of the granules obtained could be readily determined, indicating the potential for further application of this methodology to various drugs.

  5. Anti-Hu Antibody Associated Paraneoplastic Cerebellar Degeneration in Head and Neck Cancer.

    PubMed

    Huemer, Florian; Melchardt, Thomas; Tränkenschuh, Wolfgang; Neureiter, Daniel; Moser, Gerhard; Magnes, Teresa; Weiss, Lukas; Schlattau, Alexander; Hufnagl, Clemens; Ricken, Gerda; Höftberger, Romana; Greil, Richard; Egle, Alexander

    2015-12-22

    Paraneoplastic syndromes are most frequently associated with small cell lung carcinoma, hematologic and gynecologic malignancies while reports in head and neck cancer are rare. We present the case of a 60-year old female patient who developed paraneoplastic cerebellar degeneration upon locoregional recurrence of a poorly differentiated spindle cell carcinoma of the nasal cavity and paranasal sinus. The neurological symptoms, especially ataxia, stabilized after resection of tumor recurrence and concomitant chemoradiotherapy whereas anti-Hu-antibodies remained positive. Despite the unfavorable prognosis of paraneoplastic neurological disorders associated with onconeural antibodies, the patient achieved long-standing stabilization of neurological symptoms. We report the first patient with anti-Hu antibodies and paraneoplastic cerebellar degeneration associated with a spindle cell carcinoma of the head and neck. We recommend that evaluation of neurological symptoms in patients with this tumor entity should also include paraneoplastic syndromes as differential diagnoses and suggest early extensive screening for onconeural antibodies.

  6. The effects of exercise and stress on the survival and maturation of adult-generated granule cells

    PubMed Central

    Snyder, Jason S.; Glover, Lucas R.; Sanzone, Kaitlin M.; Kamhi, J. Frances; Cameron, Heather A.

    2009-01-01

    Stress strongly inhibits proliferation of granule cell precursors in the dentate gyrus, while voluntary running has the opposite effect. Few studies, however, have examined the possible effects of these environmental manipulations on the maturation and survival of young granule cells. We examined number of surviving granule cells and the proportion of young neurons that were functionally mature, as defined by seizure-induced immediate-early gene expression, in 14 and 21 day-old granule cells in mice that were given access to a running wheel, restrained daily for 2 hours, or given no treatment during this period. Importantly, treatments began two days after BrdU injection, to isolate effects on survival from those on cell proliferation. We found a large increase in granule cell survival in running mice compared with controls at both time points. In addition, running increased the proportion of granule cells expressing the immediate-early gene Arc in response to seizures, suggesting that it speeds incorporation into circuits, i.e., functional maturation. Stressed mice showed no change in Arc expression, compared to control animals, but, surprisingly, showed a transient increase in survival of 14-day-old granule cells, which was gone 7 days later. Examination of cell proliferation, using the endogenous mitotic marker proliferating cell nuclear antigen (PCNA) showed an increase in cell proliferation after 12 days of running but not after 19 days of running. The number of proliferating cells was unchanged 24 hours after the 12th or 19th episode of daily restraint stress. These findings demonstrate that running has strong effects on survival and maturation of young granule cells as well as their birth and that stress can have positive but short-lived effects on granule cell survival. PMID:19156854

  7. Segregation of large granules from close-packed cluster of small granules due to buoyancy.

    PubMed

    Yang, Xian-qing; Zhou, Kun; Qiu, Kang; Zhao, Yue-min

    2006-03-01

    Segregation of large granules in a vibrofluidized granular bed with inhomogeneous granular number density distribution is studied by an event-driven algorithm. Simulation results show that the mean vertical position of large granules decreases with the increase of the density ration of the large granules to the small ones. This conclusion is consistent with the explanation that the net pressure due to the small surrounding particle impacts balances the large granular weight, and indict that the upward movement of the large granules is driven by the buoyancy. The values of temperature, density, and pressure of the systems are also computed by changing the conditions such as heating temperature on the bottom and restitution coefficient of particles. These results indicate that the segregation of large granules also happen in the systems with density inversion or even close-packed cluster of particles floating on a low-density fluid, due to the buoyancy. An equation of state is proposed to explain the buoyancy.

  8. Rhythmic finger tapping reveals cerebellar dysfunction in essential tremor.

    PubMed

    Buijink, A W G; Broersma, M; van der Stouwe, A M M; van Wingen, G A; Groot, P F C; Speelman, J D; Maurits, N M; van Rootselaar, A F

    2015-04-01

    Cerebellar circuits are hypothesized to play a central role in the pathogenesis of essential tremor. Rhythmic finger tapping is known to strongly engage the cerebellar motor circuitry. We characterize cerebellar and, more specifically, dentate nucleus function, and neural correlates of cerebellar output in essential tremor during rhythmic finger tapping employing functional MRI. Thirty-one propranolol-sensitive essential tremor patients with upper limb tremor and 29 healthy controls were measured. T2*-weighted EPI sequences were acquired. The task consisted of alternating rest and finger tapping blocks. A whole-brain and region-of-interest analysis was performed, the latter focusing on the cerebellar cortex, dentate nucleus and inferior olive nucleus. Activations were also related to tremor severity. In patients, dentate activation correlated positively with tremor severity as measured by the tremor rating scale part A. Patients had reduced activation in widespread cerebellar cortical regions, and additionally in the inferior olive nucleus, and parietal and frontal cortex, compared to controls. The increase in dentate activation with tremor severity supports involvement of the dentate nucleus in essential tremor. Cortical and cerebellar changes during a motor timing task in essential tremor might point to widespread changes in cerebellar output in essential tremor. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Dystonia and Cerebellar Degeneration in the Leaner Mouse Mutant

    PubMed Central

    Raike, Robert S.; Hess, Ellen J.; Jinnah, H.A.

    2015-01-01

    Cerebellar degeneration is traditionally associated with ataxia. Yet, there are examples of both ataxia and dystonia occurring in individuals with cerebellar degeneration. There is also substantial evidence suggesting that cerebellar dysfunction alone may cause dystonia. The types of cerebellar defects that may cause ataxia, dystonia, or both have not been delineated. In the current study, we explored the relationship between cerebellar degeneration and dystonia using the leaner mouse mutant. Leaner mice have severe dystonia that is associated with dysfunctional and degenerating cerebellar Purkinje cells. Whereas the density of Purkinje cells was not significantly reduced in 4 week-old leaner mice, approximately 50% of the neurons were lost by 34 weeks of age. On the other hand, the dystonia and associated functional disability became significantly less severe during this same interval. In other words, dystonia improved as Purkinje cells were lost, suggesting that dysfunctional Purkinje cells, rather than Purkinje cell loss, contribute to the dystonia. These results provide evidence that distorted cerebellar function may cause dystonia and support the concept that different types of cerebellar defects can have different functional consequences. PMID:25791619

  10. Distinct Critical Cerebellar Subregions for Components of Verbal Working Memory

    ERIC Educational Resources Information Center

    Cooper, Freya E.; Grube, Manon; Von Kriegstein, Katharina; Kumar, Sukhbinder; English, Philip; Kelly, Thomas P.; Chinnery, Patrick F.; Griffiths, Timothy D.

    2012-01-01

    A role for the cerebellum in cognition has been proposed based on studies suggesting a profile of cognitive deficits due to cerebellar stroke. Such studies are limited in the determination of the detailed organisation of cerebellar subregions that are critical for different aspects of cognition. In this study we examined the correlation between…

  11. Humor and laughter in patients with cerebellar degeneration.

    PubMed

    Frank, B; Propson, B; Göricke, S; Jacobi, H; Wild, B; Timmann, D

    2012-06-01

    Humor is a complex behavior which includes cognitive, affective and motor responses. Based on observations of affective changes in patients with cerebellar lesions, the cerebellum may support cerebral and brainstem areas involved in understanding and appreciation of humorous stimuli and expression of laughter. The aim of the present study was to examine if humor appreciation, perception of humorous stimuli, and the succeeding facial reaction differ between patients with cerebellar degeneration and healthy controls. Twenty-three adults with pure cerebellar degeneration were compared with 23 age-, gender-, and education-matched healthy control subjects. No significant difference in humor appreciation and perception of humorous stimuli could be found between groups using the 3 Witz-Dimensionen Test, a validated test asking for funniness and aversiveness of jokes and cartoons. Furthermore, while observing jokes, humorous cartoons, and video sketches, facial expressions of subjects were videotaped and afterwards analysed using the Facial Action Coding System. Using depression as a covariate, the number, and to a lesser degree, the duration of facial expressions during laughter were reduced in cerebellar patients compared to healthy controls. In sum, appreciation of humor appears to be largely preserved in patients with chronic cerebellar degeneration. Cerebellar circuits may contribute to the expression of laughter. Findings add to the literature that non-motor disorders in patients with chronic cerebellar disease are generally mild, but do not exclude that more marked disorders may show up in acute cerebellar disease and/or in more specific tests of humor appreciation.

  12. The Cerebellum and Language: Evidence from Patients with Cerebellar Degeneration

    ERIC Educational Resources Information Center

    Stoodley, Catherine J.; Schmahmann, Jeremy D.

    2009-01-01

    Clinical and imaging studies suggest that the cerebellum is involved in language tasks, but the extent to which slowed language production in cerebellar patients contributes to their poor performance on these tasks is not clear. We explored this relationship in 18 patients with cerebellar degeneration and 16 healthy controls who completed measures…

  13. Developmental Subchronic Exposure to Diphenylarsinic Acid Induced Increased Exploratory Behavior, Impaired Learning Behavior, and Decreased Cerebellar Glutathione Concentration in Rats

    PubMed Central

    Negishi, Takayuki; Matsunaga, Yuki

    2013-01-01

    In Japan, people using water from the well contaminated with high-level arsenic developed neurological, mostly cerebellar, symptoms, where diphenylarsinic acid (DPAA) was a major compound. Here, we investigated the adverse effects of developmental exposure to 20mg/l DPAA in drinking water (early period [0–6 weeks of age] and/or late period [7–12]) on behavior and cerebellar development in male rats. In the open field test at 6 weeks of age, early exposure to DPAA significantly increased exploratory behaviors. At 12 weeks of age, late exposure to DPAA similarly increased exploratory behavior independent of the early exposure although a 6-week recovery from DPAA could reverse that change. In the passive avoidance test at 6 weeks of age, early exposure to DPAA significantly decreased the avoidance performance. Even at 12 weeks of age, early exposure to DPAA significantly decreased the test performance, which was independent of the late exposure to DPAA. These results suggest that the DPAA-induced increase in exploratory behavior is transient, whereas the DPAA-induced impairment of passive avoidance is long lasting. At 6 weeks of age, early exposure to DPAA significantly reduced the concentration of cerebellar total glutathione. At 12 weeks of age, late, but not early, exposure to DPAA also significantly reduced the concentration of cerebellar glutathione, which might be a primary cause of oxidative stress. Early exposure to DPAA induced late-onset suppressed expression of NMDAR1 and PSD95 protein at 12 weeks of age, indicating impaired glutamatergic system in the cerebellum of rats developmentally exposed to DPAA. PMID:24008832

  14. Developmental subchronic exposure to diphenylarsinic acid induced increased exploratory behavior, impaired learning behavior, and decreased cerebellar glutathione concentration in rats.

    PubMed

    Negishi, Takayuki; Matsunaga, Yuki; Kobayashi, Yayoi; Hirano, Seishiro; Tashiro, Tomoko

    2013-12-01

    In Japan, people using water from the well contaminated with high-level arsenic developed neurological, mostly cerebellar, symptoms, where diphenylarsinic acid (DPAA) was a major compound. Here, we investigated the adverse effects of developmental exposure to 20mg/l DPAA in drinking water (early period [0-6 weeks of age] and/or late period [7-12]) on behavior and cerebellar development in male rats. In the open field test at 6 weeks of age, early exposure to DPAA significantly increased exploratory behaviors. At 12 weeks of age, late exposure to DPAA similarly increased exploratory behavior independent of the early exposure although a 6-week recovery from DPAA could reverse that change. In the passive avoidance test at 6 weeks of age, early exposure to DPAA significantly decreased the avoidance performance. Even at 12 weeks of age, early exposure to DPAA significantly decreased the test performance, which was independent of the late exposure to DPAA. These results suggest that the DPAA-induced increase in exploratory behavior is transient, whereas the DPAA-induced impairment of passive avoidance is long lasting. At 6 weeks of age, early exposure to DPAA significantly reduced the concentration of cerebellar total glutathione. At 12 weeks of age, late, but not early, exposure to DPAA also significantly reduced the concentration of cerebellar glutathione, which might be a primary cause of oxidative stress. Early exposure to DPAA induced late-onset suppressed expression of NMDAR1 and PSD95 protein at 12 weeks of age, indicating impaired glutamatergic system in the cerebellum of rats developmentally exposed to DPAA.

  15. Cerebellar lesions in tuberous sclerosis complex: neurobehavioral and neuroimaging correlates.

    PubMed

    Eluvathingal, Thomas J; Behen, Michael E; Chugani, Harry T; Janisse, James; Bernardi, Bruno; Chakraborty, Pulak; Juhasz, Csaba; Muzik, Otto; Chugani, Diane C

    2006-10-01

    We assessed the structural and functional imaging features of cerebellar lesions and their neurobehavioral correlates in a large cohort of patients with tuberous sclerosis complex. A consecutive series of 78 patients with tuberous sclerosis complex underwent magnetic resonance imaging (MRI) and positron emission tomography (PET) studies with [(18)F]fluorodeoxyglucose (FDG) and alpha-[(11)C]methyl-l-tryptophan (AMT) as part of their evaluation for epilepsy surgery. Neurobehavioral assessment included the Gilliam Autism Rating Scales (GARS) and the Vineland Adaptive Behavior Scales (VABS). Twenty-one patients (27%) had cerebellar lesions (10 boys; mean age 9 +/- 8 years; 9 had right-sided, 10 had left-sided, and 2 had bilateral cerebellar lesions). The lesions showed decreased glucose metabolism (0.79 +/- 0.10) and increased (1.04 +/- 0.10) AMT uptake compared with the normal (nonlesional) cerebellar cortex. Comparisons between patients with (n = 20) and without (n = 57) a cerebellar lesion on neurobehavioral functioning, controlling for the number and location of cortical tubers, revealed that the cerebellar lesion group had higher overall autistic symptomatology. Within-group analyses of the cerebellar lesion group revealed that children with right-sided cerebellar lesions had higher social isolation and communicative and developmental disturbance compared with children with left-sided cerebellar lesions. The side of the cerebellar lesion was not related to adaptive behavior functioning. These findings provide additional empiric support for a role of the cerebellum in autistic symptomatology. Further investigation of the potential role of the right cerebellum in autism, particularly with regard to the dentatothalamofrontal circuit, is warranted.

  16. Onset of Tlx-3 expression in the chick cerebellar cortex correlates with the morphological development of fissures and delineates a posterior transverse boundary.

    PubMed

    Logan, Cairine; Millar, Cassie; Bharadia, Vinay; Rouleau, Katherine

    2002-06-24

    Recent studies have shown that the mammalian cerebellar cortex can be subdivided into a reproducible array of zones and stripes. In particular, discontinuous patterns of gene expression together with mutational analysis suggest that there are at least four distinct transverse zones along the rostrocaudal axis in mouse: the anterior zone (lobules I-V), the central zone (lobules VI and VII), the posterior zone (lobules VIII and IX), and the nodular zone (lobule X). Here we show that the divergent homeobox-containing transcription factor, Tlx- 3 (also known as Hox11L2 or Rnx) is transiently expressed in external granule cells in a distinct transverse domain of the developing chick cerebellar cortex. Expression is first detected at Hamburger and Hamilton (HH) stage 35. Interestingly, Tlx-3 mRNA expression is initially confined to, and coincident with, the morphological development of fissures. Slightly later, at HH stage 38, expression extends throughout the developing external granular layer (EGL) of lobules I-IXab. Notably, no Tlx-3 expression was detected in lobules IXc and X at any developmental time point examined. Expression is noticeably stronger in nonproliferating cells located in the deep layer of the EGL. Tlx-3 expression is downregulated as granule cells migrate inward to form the internal granule layer and is undetectable shortly after birth. These results suggest that Tlx-3 is expressed as granule cells become postmitotic and suggest that Tlx-3 may play a role in the differentiation of distinct neuronal populations in the cerebellum. Copyright 2002 Wiley-Liss, Inc.

  17. The combined effect of wet granulation process parameters and dried granule moisture content on tablet quality attributes.

    PubMed

    Gabbott, Ian P; Al Husban, Farhan; Reynolds, Gavin K

    2016-09-01

    A pharmaceutical compound was used to study the effect of batch wet granulation process parameters in combination with the residual moisture content remaining after drying on granule and tablet quality attributes. The effect of three batch wet granulation process parameters was evaluated using a multivariate experimental design, with a novel constrained design space. Batches were characterised for moisture content, granule density, crushing strength, porosity, disintegration time and dissolution. Mechanisms of the effect of the process parameters on the granule and tablet quality attributes are proposed. Water quantity added during granulation showed a significant effect on granule density and tablet dissolution rate. Mixing time showed a significant effect on tablet crushing strength, and mixing speed showed a significant effect on the distribution of tablet crushing strengths obtained. The residual moisture content remaining after granule drying showed a significant effect on tablet crushing strength. The effect of moisture on tablet tensile strength has been reported before, but not in combination with granulation parameters and granule properties, and the impact on tablet dissolution was not assessed. Correlations between the energy input during granulation, the density of granules produced, and the quality attributes of the final tablets were also identified. Understanding the impact of the granulation and drying process parameters on granule and tablet properties provides a basis for process optimisation and scaling. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Development of the cerebellar afferent system in the shark Scyliorhinus canicula: insights into the basal organization of precerebellar nuclei in gnathostomes.

    PubMed

    Pose-Méndez, Sol; Candal, Eva; Adrio, Fátima; Rodríguez-Moldes, Isabel

    2014-01-01

    The cerebellum is recognized as an evolutionary innovation of jawed vertebrates, whose most primitive group is represented by the chondrichthyans, or cartilaginous fishes. A comprehensive knowledge of cerebellar connections in these fishes might shed light on the basal organization of the cerebellar system. Although the organization of the precerebellar system is known in adults, developmental studies are essential for understanding the origin and evolution of precerebellar nuclei. In the present work we performed a developmental study of cerebellar connections in embryos and juveniles of an advanced shark species, Scyliorhinus canicula, by application of tract tracing in combination with immunohistochemical techniques. Main precerebellar cell populations were located in the diencephalon (pretectum and thalamus), mesencephalon (reticular formation and nucleus ruber), rhombencephalon (cerebellar nucleus, reticular formation, and inferior olive), and spinal cord (ventral horn). The order of arrival of cerebellar afferent projections throughout development revealed a common pattern with other jawed vertebrates, which was helpful for comparison of stages of cerebellar development. The neurochemical study of the inferior olive and other precerebellar nuclei revealed many shared features with other gnathostomes. Furthermore, because many precerebellar nuclei originate from rhombic lips, the first analysis of neuronal migrations from these lips was performed with markers of neuroblasts. The shared features of development and organization of precerebellar connections observed between sharks and amniotes suggest that their basic pattern was established early in gnathostome evolution. Copyright © 2013 Wiley Periodicals, Inc.

  19. Antimicrobial-Coated Granules for Disinfecting Water

    NASA Technical Reports Server (NTRS)

    Akse, James R.; Holtsnider, John T.; Kliestik, Helen

    2011-01-01

    Methods of preparing antimicrobialcoated granules for disinfecting flowing potable water have been developed. Like the methods reported in the immediately preceding article, these methods involve chemical preparation of substrate surfaces (in this case, the surfaces of granules) to enable attachment of antimicrobial molecules to the surfaces via covalent bonds. A variety of granular materials have been coated with a variety of antimicrobial agents that include antibiotics, bacteriocins, enzymes, bactericides, and fungicides. When employed in packed beds in flowing water, these antimicrobial-coated granules have been proven effective against gram-positive bacteria, gram-negative bacteria, fungi, and viruses. Composite beds, consisting of multiple layers containing different granular antimicrobial media, have proven particularly effective against a broad spectrum of microorganisms. These media have also proven effective in enhancing or potentiating the biocidal effects of in-line iodinated resins and of very low levels of dissolved elemental iodine.

  20. Measuring stellar granulation during planet transits

    NASA Astrophysics Data System (ADS)

    Chiavassa, A.; Caldas, A.; Selsis, F.; Leconte, J.; Von Paris, P.; Bordé, P.; Magic, Z.; Collet, R.; Asplund, M.

    2017-01-01

    Context. Stellar activity and convection-related surface structures might cause bias in planet detection and characterization that use these transits. Surface convection simulations help to quantify the granulation signal. Aims: We used realistic three-dimensional (3D) radiative hydrodynamical (RHD) simulations from the Stagger grid and synthetic images computed with the radiative transfer code Optim3D to model the transits of three prototype planets: a hot Jupiter, a hot Neptune, and a terrestrial planet. Methods: We computed intensity maps from RHD simulations of the Sun and a K-dwarf star at different wavelength bands from optical to far-infrared that cover the range of several ground- and space-based telescopes which observe exoplanet transits. We modeled the transit using synthetic stellar-disk images obtained with a spherical-tile imaging method and emulated the temporal variation of the granulation intensity generating random images covering a granulation time-series of 13.3 h. We measured the contribution of the stellar granulation on the light curves during the planet transit. Results: We identified two types of granulation noise that act simultaneously during the planet transit: (I) the intrinsic change in the granulation pattern with timescale (e.g., 10 min for solar-type stars assumed in this work) is smaller than the usual planet transit ( hours as in our prototype cases); and (II) the fact that the transiting planet occults isolated regions of the photosphere that differ in local surface brightness as a result of convective-related surface structures. First, we showed that our modeling approach returns granulation timescale fluctuations that are comparable with what has been observed for the Sun. Then, our statistical approach shows that the granulation pattern of solar and K-dwarf-type stars have a non-negligible effect of the light curve depth during the transit, and, consequentially on the determination of the planet transit parameters such as the

  1. Misdiagnosis of cerebellar hemorrhage - features of 'pseudo-gastroenteritis' clinical presentations to the ED and primary care.

    PubMed

    Lee, Seung-Han; Stanton, Victoria; Rothman, Richard E; Crain, Barbara; Wityk, Robert; Wang, Zheyu; Newman-Toker, David E

    2017-03-01

    Early-stage cerebellar hemorrhage can present with nausea or vomiting absent other neurological symptoms or signs, potentially leading to an incorrect diagnosis of gastroenteritis. We sought to determine the frequency of gastroenteritis-like presentations and delayed or missed diagnoses among patients with spontaneous cerebellar hemorrhage. This is a retrospective, case-control analysis of atraumatic, primary cerebellar hemorrhages derived from a systematic search of surgical pathology and autopsy databases at two large urban, academic medical centers from 1984 to 2006. Hospital visit and clinical symptom data were abstracted from electronic and paper medical records for included patients. Delayed or missed diagnoses were defined as those at least one previous visit for relevant clinical symptoms in the 7 days prior to the correct diagnosis being confirmed. Among 254 records captured by our search filter, we identified 35 cases of pathologically proven primary cerebellar hemorrhage. Four patients (11%) were misdiagnosed initially - three with "gastroenteritis" and one with "hypertension". In this small sample, misdiagnosed patients presented more often with normal mental state (100% vs. 35%, p=0.07) and nausea/vomiting (100% vs. 58%, p=0.22). Although patients deteriorated clinically after the initial misdiagnosis, and potentially dangerous diagnostic tests and treatment strategies were instituted as a result of misdiagnosis, none of the misdiagnosed patients died or suffered major permanent harms due to diagnostic delay. Our study is limited by the small number of identified cases. Nevertheless, it appears that patients with cerebellar hemorrhages can present with relatively unimpressive clinical findings without obvious neurological manifestations. Such individuals are sometimes misdiagnosed with gastroenteritis or other benign disorders initially, possibly when neurologic examination, particularly gait testing, is omitted or abridged. A careful search for subtle

  2. Chromospheric impact of an exploding solar granule

    NASA Astrophysics Data System (ADS)

    Fischer, C. E.; Bello González, N.; Rezaei, R.

    2017-06-01

    Context. Observations of multi-wavelength and therefore height-dependent information following events throughout the solar atmosphere and unambiguously assigning a relation between these rapidly evolving layers are rare and difficult to obtain. Yet, they are crucial for our understanding of the physical processes that couple the different regimes in the solar atmosphere. Aims: We characterize the exploding granule event with simultaneous observations of Hinode spectroplarimetric data in the solar photosphere and Hinode broadband Ca II H images combined with Interface Region Imaging Spectrograph (IRIS) slit spectra. We follow the evolution of an exploding granule and its connectivity throughout the atmosphere and analyze the dynamics of a magnetic element that has been affected by the abnormal granule. Methods: In addition to magnetic flux maps we use a local correlation tracking method to infer the horizontal velocity flows in the photosphere and apply a wavelet analysis on several IRIS chromospheric emission features such as Mg II k2v and Mg II k3 to detect oscillatory phenomena indicating wave propagation. Results: During the vigorous expansion of the abnormal granule we detect radially outward horizontal flows, causing, together with the horizontal flows from the surrounding granules, the magnetic elements in the bordering intergranular lanes to be squeezed and elongated. In reaction to the squeezing, we detect a chromospheric intensity and velocity oscillation pulse which we identify as an upward traveling hot shock front propagating clearly through the IRIS spectral line diagnostics of Mg II h&k. Conclusions: Exploding granules can trigger upward-propagating shock fronts that dissipate in the chromosphere. Movies associated to Figs. A.1 and A.2 are available in electronic form at http://www.aanda.org

  3. GRANULATION IN THE PHOTOSPHERE OF {zeta} CYGNI

    SciTech Connect

    Gray, David F., E-mail: dfgray@uwo.ca

    2012-05-15

    A series of 35 high-resolution spectra are used to measure the third-signature plot of the G8 III star, {zeta} Cygni, which shows convective velocities only 8% larger than the Sun. Bisector mapping yields a flux deficit, a measure of granulation contrast, typical of other giants. The observations also give radial velocities with errors {approx}30 m s{sup -1} and allow the orbit to be refined. Velocity excursions relative to the smooth orbital motion, possibly from the granulation, have values exceeding 200 m s{sup -1}. Temperature variations were looked for using line-depth ratios, but none were found.

  4. Continuous melt granulation: Influence of process and formulation parameters upon granule and tablet properties.

    PubMed

    Monteyne, Tinne; Vancoillie, Jochem; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas

    2016-10-01

    The pharmaceutical industry has a growing interest in alternative manufacturing models allowing automation and continuous production in order to improve process efficiency and reduce costs. Implementing a switch from batch to continuous processing requires fundamental process understanding and the implementation of quality-by-design (QbD) principles. The aim of this study was to examine the relationship between formulation-parameters (type binder, binder concentration, drug-binder miscibility), process-parameters (screw speed, powder feed rate and granulation temperature), granule properties (size, size distribution, shape, friability, true density, flowability) and tablet properties (tensile strength, friability, dissolution rate) of four different drug-binder formulations using Design of experiments (DOE). Two binders (polyethylene glycol (PEG) and Soluplus®) with a different solid state, semi-crystalline vs amorphous respectively, were combined with two model-drugs, metoprolol tartrate (MPT) and caffeine anhydrous (CAF), both having a contrasting miscibility with the binders. This research revealed that the granule properties of miscible drug-binder systems depended on the powder feed rate and barrel filling degree of the granulator whereas the granule properties of immiscible systems were mainly influenced by binder concentration. Using an amorphous binder, the tablet tensile strength depended on the granule size. In contrast, granule friability was more important for tablet quality using a brittle binder. However, this was not the case for caffeine-containing blends, since these phenomena were dominated by the enhanced compression properties of caffeine Form I, which was formed during granulation. Hence, it is important to gain knowledge about formulation behavior during processing since this influences the effect of process parameters onto the granule and tablet properties. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. High-shear granulation as a manufacturing method for cocrystal granules.

    PubMed

    Rehder, Sönke; Christensen, Niels Peter Aae; Rantanen, Jukka; Rades, Thomas; Leopold, Claudia S

    2013-11-01

    Cocrystal formation allows the tailoring of physicochemical as well as of mechanical properties of an API. However, there is a lack of large-scale manufacturing methods of cocrystals. Therefore, the objective of this work was to examine the suitability of high-shear wet granulation as a manufacturing method for cocrystal granules on a batch scale. Furthermore, the cocrystal granules were characterized regarding their mechanical properties as well as their dissolution behavior. High-shear wet granulation was found to be a feasible manufacturing method for cocrystal granules. Cocrystal formation depended on the exposure time of the solids to the granulation liquid (water), the amount of liquid, the impeller speed of the granulator, and on the excipients (hydroxyl propylcellulose, microcrystalline cellulose, calcium hydrogenphosphate) used in the formulation. Storage stability was strongly influenced by the excipients, since in presence of calcium hydrogenphosphate, the poorly water-soluble salt calcium tartrate monohydrate was formed at high relative humidity. Interestingly, compactability was increased by cocrystal formation compared to that of the reference granules (piracetam and the respective excipients). The drug release was slightly decreased by cocrystal formation, most likely due to the lower solubility of the cocrystal. In the presence of calcium hydrogenphosphate however, no influence of cocrystal formation on either compactability or on drug release were observed, compared with the reference tablets. It was concluded that high-shear wet granulation is a valuable, however complex, manufacturing method for cocrystals. Cocrystal formation may influence compactability and drug release and thus affect drug performance and should be investigated during pre-formulation. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. NK cells converge lytic granules to promote cytotoxicity and prevent bystander killing

    PubMed Central

    Hsu, Hsiang-Ting; Viswanath, Dixita I.; Önfelt, Björn

    2016-01-01

    Natural killer (NK) cell activation triggers sequential cellular events leading to destruction of diseased cells. We previously identified lytic granule convergence, a dynein- and integrin signal–dependent movement of lysosome-related organelles to the microtubule-organizing center, as an early step in the cell biological process underlying NK cell cytotoxicity. Why lytic granules converge during NK cell cytotoxicity, however, remains unclear. We experimentally controlled the availability of human ligands to regulate NK cell signaling and promote granule convergence with either directed or nondirected degranulation. By the use of acoustic trap microscopy, we generated specific effector–target cell arrangements to define the impact of the two modes of degranulation. NK cells with converged granules had greater targeted and less nonspecific “bystander” killing. Additionally, NK cells in which dynein was inhibited or integrin blocked under physiological conditions demonstrated increased nondirected degranulation and bystander killing. Thus, NK cells converge lytic granules and thereby improve the efficiency of targeted killing and prevent collateral damage to neighboring healthy cells. PMID:27903610

  7. Pten Knockdown in vivo Increases Excitatory Drive onto Dentate Granule Cells

    PubMed Central

    Luikart, Bryan W.; Schnell, Eric; Washburn, Eric K.; Bensen, AeSoon L.; Tovar, Kenneth R.; Westbrook, Gary L.

    2011-01-01

    Some cases of autism spectrum disorder (ASD) have mutations in the lipid phosphatase, Pten (phosphatase and tensin homolog on chromosome 10). Tissue specific deletion of Pten in the hippocampus and cortex of mice causes anatomical and behavioral abnormalities similar to human autism. However, the impact of reductions in Pten on synaptic and circuit function remains unexplored. We used in vivo stereotaxic injections of lentivirus expressing an shRNA to knockdown Pten in mouse neonatal and young adult dentate granule cells. We then assessed the morphology and synaptic physiology between two weeks and four months later. Confocal imaging of the hippocampus revealed a marked increase in granule cell size and an increase in dendritic spine density. The onset of morphological changes occurred earlier in neonatal mice than in young adults. We used whole-cell recordings from granule cells in acute slices to assess synaptic function following Pten knockdown. Consistent with the increase in dendritic spines, the frequency of excitatory miniature and spontaneous postsynaptic currents increased. However, there was little or no effect on inhibitory postsynaptic currents. Thus Pten knockdown results in an imbalance between excitatory and inhibitory synaptic activity. Because reductions in Pten affected mature granule cells as well as developing granule cells, we suggest that the disruption of circuit function by Pten hypofunction may be ongoing well beyond early development. PMID:21411674

  8. Cellular stress induces cytoplasmic RNA granules in fission yeast.

    PubMed

    Nilsson, Daniel; Sunnerhagen, Per

    2011-01-01

    Severe stress causes plant and animal cells to form large cytoplasmic granules containing RNA and proteins. Here, we demonstrate the existence of stress-induced cytoplasmic RNA granules in Schizosaccharomyces pombe. Homologs to several known protein components of mammalian processing bodies and stress granules are found in fission yeast RNA granules. In contrast to mammalian cells, poly(A)-binding protein (Pabp) colocalizes in stress-induced granules with decapping protein. After glucose deprivation, protein kinase A (PKA) is required for accumulation of Pabp-positive granules and translational down-regulation. This is the first demonstration of a role for PKA in RNA granule formation. In mammals, the translation initiation protein eIF2α is a key regulator of formation of granules containing poly(A)-binding protein. In S. pombe, nonphosphorylatable eIF2α does not block but delays granule formation and subsequent clearance after exposure to hyperosmosis. At least two separate pathways in S. pombe appear to regulate stress-induced granules: pka1 mutants are fully proficient to form granules after hyperosmotic shock; conversely, eIF2α does not affect granule formation in glucose starvation. Further, we demonstrate a Pka1-dependent link between calcium perturbation and RNA granules, which has not been described earlier in any organism.

  9. ELLI-1, a novel germline protein, modulates RNAi activity and P-granule accumulation in Caenorhabditis elegans

    PubMed Central

    Andralojc, Karolina M.; Kelly, Ashley L.; Tanner, Paige C.

    2017-01-01

    Germ cells contain non-membrane bound cytoplasmic organelles that help maintain germline integrity. In C. elegans they are called P granules; without them, the germline undergoes partial masculinization and aberrant differentiation. One key P-granule component is the Argonaute CSR-1, a small-RNA binding protein that antagonizes accumulation of sperm-specific transcripts in developing oocytes and fine-tunes expression of proteins critical to early embryogenesis. Loss of CSR-1 complex components results in a very specific, enlarged P-granule phenotype. In a forward screen to identify mutants with abnormal P granules, ten alleles were recovered with a csr-1 P-granule phenotype, eight of which contain mutations in known components of the CSR-1 complex (csr-1, ego-1, ekl-1, and drh-3). The remaining two alleles are in a novel gene now called elli-1 (enlarged germline granules). ELLI-1 is first expressed in primordial germ cells during mid-embryogenesis, and continues to be expressed in the adult germline. While ELLI-1 forms cytoplasmic aggregates, they occasionally dock, but do not co-localize with P granules. Instead, the majority of ELLI-1 aggregates accumulate in the shared germline cytoplasm. In elli-1 mutants, several genes that promote RNAi and P-granule accumulation are upregulated, and embryonic lethality, sterility, and RNAi resistance in a hypomorphic drh-3 allele is enhanced, suggesting that ELLI-1 functions with CSR-1 to modulate RNAi activity, P-granule accumulation, and post-transcriptional expression in the germline. PMID:28182654

  10. Fractal dimension values of cerebral and cerebellar activity in rats loaded with aluminium.

    PubMed

    Kekovic, Goran; Culic, Milka; Martac, Ljiljana; Stojadinovic, Gordana; Capo, Ivan; Lalosevic, Dusan; Sekulic, Slobodan

    2010-07-01

    Aluminium interferes with a variety of cellular metabolic processes in the mammalian nervous system and its intake might increase a risk of developing Alzheimer's disease (AD). While cerebral involvement even at the early stages of intoxication is well known, the role of cerebellum is underestimated. Our aim was to investigate cerebral and cerebellar electrocortical activity in adult male rats exposed to chronic aluminium treatment by nonlinear analytic tools. The adult rats in an aluminium-treated group were injected by AlCl(3), intraperitoneally (2 mg Al/kg, daily for 4 weeks). Fractal analysis of brain activity was performed off-line using Higuchi's algorithm. The average fractal dimension of electrocortical activity in aluminium-treated animals was lower than the average fractal dimension of electrocortical activity in the control rats, at cerebral but not at cerebellar level. The changes in the stationary and nonlinear properties of time series were more expressed in cerebral electrocortical activity than in cerebellar activity. This can be useful for developing effective diagnostic and therapeutic strategies in neurodegenerative diseases.

  11. Clinical, biochemical and molecular aspects of cerebellar ataxia and Coenzyme Q10 deficiency.

    PubMed

    Montero, Raquel; Pineda, Mercé; Aracil, Asun; Vilaseca, Maria-Antonia; Briones, Paz; Sánchez-Alcázar, José-Antonio; Navas, Plácido; Artuch, Rafael

    2007-01-01

    Coenzyme Q(10) (CoQ) deficiency is an autosomal recessive disorder presenting five phenotypes: a myopathic form, a severe infantile neurological syndrome associated with nephritic syndrome, an ataxic variant, Leigh syndrome and a pure myopathic form. The third is the most common phenotype related with CoQ deficiency and it will be the focus of this review. This new syndrome presents muscle CoQ deficiency associated with cerebellar ataxia and cerebellar atrophy as the main neurological signs. Biochemically, the hallmark of CoQ deficiency syndrome is a decreased CoQ concentration in muscle and/or fibroblasts. There is no molecular evidence of the enzyme or gene involved in primary CoQ deficiencies associated with cerebellar ataxia, although recently a family has been reported with mutations at COQ2 gene who present a distinct phenotype. Patients with primary CoQ deficiency may benefit from CoQ supplementation, although the clinical response to this therapy varies even among patients with similar phenotypes. Some present an excellent response to CoQ while others show only a partial improvement of some symptoms and signs. CoQ deficiency is the mitochondrial encephalomyopathy with the best clinical response to CoQ supplementation, highlighting the importance of an early identification of this disorder.

  12. Subclavian steal syndrome decreases neurogenesis in the cerebellar cortex and affects cognitive function in rabbits.

    PubMed

    Fu, Xiao-Yang; Zhang, Zhi-Dong; Liang, Kai; Shi, Shuai-Tao; Wang, Guo-Quan; Zhang, Ke-Wei; Li, Kun; Li, Wei-Xiao; Li, Tian-Xiao; Zhai, Shui-Ting

    2015-10-01

    Subclavian steal syndrome (SSS) is a condition characterized by a steno-occlusive impairment of the proximal subclavian artery. The majority of patients with SSS are asymptomatic, while symptomatic patients present with neurological symptoms. SSS is a risk factor for cerebral ischemia, which reacts badly upon cognitive function; however, it remains unknown whether SSS is able to cause progressive cognitive impairment. In the present study, the potential effects of SSS on cognitive function were investigated using atherosclerotic rabbits as a model of SSS. A total of 48 male New Zealand rabbits were divided into the control, sham and SSS groups. The results of eyeblink experiments indicated no significant differences among the three groups; however, SSS did appear to exert a negative impact on neurogenesis in the cerebellar cortex. In order to further clarify the mechanisms underlying this SSS-mediated reduction in cell proliferation, the energy metabolism, immune function and oxidative stress statuses were evaluated by determining the levels of adenosine triphosphate (ATP), adenosine, interleukin (IL)-1β, IL-6, malondialdehyde, 8-hydroxy-2'-deoxyguanosine, CuZn-superoxide dismutase and catalase. The results showed that the levels of extracellular ATP in the cerebellar cortex had decreased, while levels of adenosine had also decreased. These findings suggest that SSS is able to inhibit neurogenesis in the cerebellar cortex by decreasing the extracellular ATP levels. Furthermore, these changes may result in an impairment of the cognition of the rabbits. The early diagnosis and treatment of SSS may, therefore, prevent or mitigate cognitive impairment in the future.

  13. Effect of edaravone on acute brainstem-cerebellar infarction with vertigo and sudden hearing loss.

    PubMed

    Inoue, Yuta; Yabe, Takao; Okada, Kazunari; Nakamura, Yuka

    2014-06-01

    We report 2 cases with acute brainstem and brainstem-cerebellar infarction showed improvement of their signs and symptoms after administration of edaravone. Case 1, a 74-year-old woman who experienced sudden vertigo, also had dysarthria and left hemiplegia. Magnetic resonance imaging (MRI) showed an abnormal region in the right ventrolateral medulla oblongata. The patient's vertigo and hemiplegia improved completely after treatment. Case 2, a 50-year-old man who experienced sudden vertigo and sensorineural hearing loss (SNHL), developed dysarthria after admission. MRI revealed acute infarction in the right cerebellar hemisphere. Magnetic resonance angiography revealed dissection of the basilar artery and occlusion of the right anterior inferior cerebellar artery. The patient's vertigo and hearing remarkably improved. We have described 2 patients whose early symptoms were vertigo and sudden SNHL, but who were later shown to have ischemic lesions of the central nervous system. Edaravone is neuroprotective drug with free radical-scavenging actions. Free radicals in the ear are responsible for ischemic damage. Edaravone, a free radical scavenger, may be useful in the treatment of vertigo and SNHL. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Mutations in SNX14 Cause a Distinctive Autosomal-Recessive Cerebellar Ataxia and Intellectual Disability Syndrome

    PubMed Central

    Thomas, Anna C.; Williams, Hywel; Setó-Salvia, Núria; Bacchelli, Chiara; Jenkins, Dagan; O’Sullivan, Mary; Mengrelis, Konstantinos; Ishida, Miho; Ocaka, Louise; Chanudet, Estelle; James, Chela; Lescai, Francesco; Anderson, Glenn; Morrogh, Deborah; Ryten, Mina; Duncan, Andrew J.; Pai, Yun Jin; Saraiva, Jorge M.; Ramos, Fabiana; Farren, Bernadette; Saunders, Dawn; Vernay, Bertrand; Gissen, Paul; Straatmaan-Iwanowska, Anna; Baas, Frank; Wood, Nicholas W.; Hersheson, Joshua; Houlden, Henry; Hurst, Jane; Scott, Richard; Bitner-Glindzicz, Maria; Moore, Gudrun E.; Sousa, Sérgio B.; Stanier, Philip

    2014-01-01

    Intellectual disability and cerebellar atrophy occur together in a large number of genetic conditions and are frequently associated with microcephaly and/or epilepsy. Here we report the identification of causal mutations in Sorting Nexin 14 (SNX14) found in seven affected individuals from three unrelated consanguineous families who presented with recessively inherited moderate-severe intellectual disability, cerebellar ataxia, early-onset cerebellar atrophy, sensorineural hearing loss, and the distinctive association of progressively coarsening facial features, relative macrocephaly, and the absence of seizures. We used homozygosity mapping and whole-exome sequencing to identify a homozygous nonsense mutation and an in-frame multiexon deletion in two families. A homozygous splice site mutation was identified by Sanger sequencing of SNX14 in a third family, selected purely by phenotypic similarity. This discovery confirms that these characteristic features represent a distinct and recognizable syndrome. SNX14 encodes a cellular protein containing Phox (PX) and regulator of G protein signaling (RGS) domains. Weighted gene coexpression network analysis predicts that SNX14 is highly coexpressed with genes involved in cellular protein metabolism and vesicle-mediated transport. All three mutations either directly affected the PX domain or diminished SNX14 levels, implicating a loss of normal cellular function. This manifested as increased cytoplasmic vacuolation as observed in cultured fibroblasts. Our findings indicate an essential role for SNX14 in neural development and function, particularly in development and maturation of the cerebellum. PMID:25439728

  15. Mutations in SNX14 cause a distinctive autosomal-recessive cerebellar ataxia and intellectual disability syndrome.

    PubMed

    Thomas, Anna C; Williams, Hywel; Setó-Salvia, Núria; Bacchelli, Chiara; Jenkins, Dagan; O'Sullivan, Mary; Mengrelis, Konstantinos; Ishida, Miho; Ocaka, Louise; Chanudet, Estelle; James, Chela; Lescai, Francesco; Anderson, Glenn; Morrogh, Deborah; Ryten, Mina; Duncan, Andrew J; Pai, Yun Jin; Saraiva, Jorge M; Ramos, Fabiana; Farren, Bernadette; Saunders, Dawn; Vernay, Bertrand; Gissen, Paul; Straatmaan-Iwanowska, Anna; Baas, Frank; Wood, Nicholas W; Hersheson, Joshua; Houlden, Henry; Hurst, Jane; Scott, Richard; Bitner-Glindzicz, Maria; Moore, Gudrun E; Sousa, Sérgio B; Stanier, Philip

    2014-11-06

    Intellectual disability and cerebellar atrophy occur together in a large number of genetic conditions and are frequently associated with microcephaly and/or epilepsy. Here we report the identification of causal mutations in Sorting Nexin 14 (SNX14) found in seven affected individuals from three unrelated consanguineous families who presented with recessively inherited moderate-severe intellectual disability, cerebellar ataxia, early-onset cerebellar atrophy, sensorineural hearing loss, and the distinctive association of progressively coarsening facial features, relative macrocephaly, and the absence of seizures. We used homozygosity mapping and whole-exome sequencing to identify a homozygous nonsense mutation and an in-frame multiexon deletion in two families. A homozygous splice site mutation was identified by Sanger sequencing of SNX14 in a third family, selected purely by phenotypic similarity. This discovery confirms that these characteristic features represent a distinct and recognizable syndrome. SNX14 encodes a cellular protein containing Phox (PX) and regulator of G protein signaling (RGS) domains. Weighted gene coexpression network analysis predicts that SNX14 is highly coexpressed with genes involved in cellular protein metabolism and vesicle-mediated transport. All three mutations either directly affected the PX domain or diminished SNX14 levels, implicating a loss of normal cellular function. This manifested as increased cytoplasmic vacuolation as observed in cultured fibroblasts. Our findings indicate an essential role for SNX14 in neural development and function, particularly in development and maturation of the cerebellum. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Abnormal cerebellar morphometry in abstinent adolescent marijuana users

    PubMed Central

    Medina, Krista Lisdahl; Nagel, Bonnie J.; Tapert, Susan F.

    2010-01-01

    Background Functional neuroimaging data from adults have, in general, found frontocerebellar dysfunction associated with acute and chronic marijuana (MJ) use (Loeber & Yurgelun-Todd, 1999). One structural neuroimaging study found reduced cerebellar vermis volume in young adult MJ users with a history of heavy polysubstance use (Aasly et al., 1993). The goal of this study was to characterize cerebellar volume in adolescent chronic MJ users following one month of monitored abstinence. Method Participants were MJ users (n=16) and controls (n=16) aged 16-18 years. Extensive exclusionary criteria included history of psychiatric or neurologic disorders. Drug use history, neuropsychological data, and structural brain scans were collected after 28 days of monitored abstinence. Trained research staff defined cerebellar volumes (including three cerebellar vermis lobes and both cerebellar hemispheres) on high-resolution T1-weighted magnetic resonance images. Results Adolescent MJ users demonstrated significantly larger inferior posterior (lobules VIII-X) vermis volume (p<.009) than controls, above and beyond effects of lifetime alcohol and other drug use, gender, and intracranial volume. Larger vermis volumes were associated with poorer executive functioning (p’s<.05). Conclusions Following one month of abstinence, adolescent MJ users had significantly larger posterior cerebellar vermis volumes than non-using controls. These greater volumes are suggested to be pathological based on linkage to poorer executive functioning. Longitudinal studies are needed to examine typical cerebellar development during adolescence and the influence of marijuana use. PMID:20413277

  17. Contribution of Cerebellar Sensorimotor Adaptation to Hippocampal Spatial Memory

    PubMed Central

    Passot, Jean-Baptiste; Sheynikhovich, Denis; Duvelle, Éléonore; Arleo, Angelo

    2012-01-01

    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. PMID:22485133

  18. Vaccine adjuvants: Tailor-made mast-cell granules

    NASA Astrophysics Data System (ADS)

    Gunzer, Matthias

    2012-03-01

    Mast cells induce protective immune responses through secretion of stimulatory granules. Microparticles modelled after mast-cell granules are now shown to replicate and enhance the functions of their natural counterparts and to direct the character of the resulting immunity.

  19. Impaired Cerebellar Maturation, Growth Restriction, and Circulating Insulin-Like Growth Factor 1 in Preterm Rabbit Pups

    PubMed Central

    Sveinsdóttir, Kristbjörg; Länsberg, John-Kalle; Sveinsdóttir, Snjólaug; Garwicz, Martin; Ohlsson, Lennart; Hellström, Ann; Smith, Lois; Gram, Magnus; Ley, David

    2018-01-01

    Cerebellar growth is impeded following very preterm birth in human infants and the observed reduction in cerebellar volume is associated with neurodevelopmental impairment. Decreased levels of circulating insulin-like growth factor 1 (IGF-1) are associated with decreased cerebellar volume. The relationship between preterm birth, circulating IGF-1, and key cell populations supporting cerebellar proliferation is unknown. The aim of this study was to evaluate the effect of preterm birth on postnatal growth, circulating IGF-1, and cerebellar maturation in a preterm rabbit pup model. Preterm rabbit pups (PT) were delivered by cesarean section at day 29 of gestation, cared for in closed incubators with humidified air, and gavage fed with formula. Control term pups (T) delivered by spontaneous vaginal delivery at day 32 of gestation were housed and fed by their lactating doe. In vivo perfusion-fixation for immunohistochemical evaluation of cerebellar proliferation, cell maturation, and apoptosis was performed at repeated time points in PT and T pups. Results show that the mean weight of the pups and circulating IGF-1 protein levels were lower in the PT group at all time points (p < 0.05) than in the T group. Postnatal weight development correlated with circulating IGF-1 (r2 = 0.89) independently of gestational age at birth and postnatal age. The proliferative (Ki-67-positive) portion of the external granular layer (EGL) was decreased in the PT group at postnatal day 2 (P2) compared to in the T group (p = 0.01). Purkinje cells exhibited decreased calbindin staining at P0 (p = 0.003), P2 (p = 0.004), and P5 (p = 0.04) in the PT group compared to in the T group. Staining for sonic hedgehog was positive in neuronal EGL progenitors and Purkinje cells at early time points but was restricted to a well-defined Purkinje cell monolayer at later time points. Preterm birth in rabbit pups is associated with lower circulating levels of IGF-1, decreased postnatal growth, and decreased

  20. Nystagmus in SCA territory cerebellar infarction: pattern and a possible mechanism.

    PubMed

    Lee, Hyung; Kim, Hyun-Ah

    2013-04-01

    To investigate the frequency and pattern of nystagmus associated with isolated cerebellar infarction in the territory of the superior cerebellar artery (SCA) and to discuss its possible mechanism. We identified 41 consecutive patients with isolated SCA territory cerebellar infarction diagnosed by MRI. Each patient completed a standardised dizziness questionnaire and underwent neurotological evaluations. Eye movements were recorded using 3-dimensional video-oculography during the acute period. Approximately half (19/41) of the patients experienced true vertigo early in the course of the SCA distribution infarct. 11 (27%) of the 41 patients showed spontaneous nystagmus (SN) or direction changed bidirectional gaze-evoked nystagmus (GEN). SN was observed in 10 patients (24%) and the horizontal component of SN was predominant in most case (80%, 8/10) and always beat towards the lesion side. Direction changed bidirectional GEN was observed in five patients and was mostly (4/5) accompanied by SN. Lesion subtraction analyses revealed that damage to the rostral anterior cerebellum including the ala of the central lobule and part of the quadrangular lobule was more frequent in patients with nystagmus compared to patients without nystagmus (9/11, 82% vs 11/30, 37%) (p=0.015). In most (82%, 9/11) patients with SN or GEN, the nystagmus subsided within 1 week after hospitalisation. Vertigo and nystagmus in SCA territory cerebellar infarction are more common than previously thought. Ipsilesional SN may result from damage to the anterior lobe of the cerebellum, which transmits the vestibular output to the fastigial nucleus.

  1. A New Mouse Allele of Glutamate Receptor Delta 2 with Cerebellar Atrophy and Progressive Ataxia

    PubMed Central

    Miyoshi, Yuka; Yoshioka, Yoshichika; Suzuki, Kinuko; Miyazaki, Taisuke; Koura, Minako; Saigoh, Kazumasa; Kajimura, Naoko; Monobe, Yoko; Kusunoki, Susumu; Matsuda, Junichiro; Watanabe, Masahiko; Hayasaka, Naoto

    2014-01-01

    Spinocerebellar degenerations (SCDs) are a large class of sporadic or hereditary neurodegenerative disorders characterized by progressive motion defects and degenerative changes in the cerebellum and other parts of the CNS. Here we report the identification and establishment from a C57BL/6J mouse colony of a novel mouse line developing spontaneous progressive ataxia, which we refer to as ts3. Frequency of the phenotypic expression was consistent with an autosomal recessive Mendelian trait of inheritance, suggesting that a single gene mutation is responsible for the ataxic phenotype of this line. The onset of ataxia was observed at about three weeks of age, which slowly progressed until the hind limbs became entirely paralyzed in many cases. Micro-MRI study revealed significant cerebellar atrophy in all the ataxic mice, although individual variations were observed. Detailed histological analyses demonstrated significant atrophy of the anterior folia with reduced granule cells (GC) and abnormal morphology of cerebellar Purkinje cells (PC). Study by ultra-high voltage electron microscopy (UHVEM) further indicated aberrant morphology of PC dendrites and their spines, suggesting both morphological and functional abnormalities of the PC in the mutants. Immunohistochemical studies also revealed defects in parallel fiber (PF)–PC synapse formation and abnormal distal extension of climbing fibers (CF). Based on the phenotypic similarities of the ts3 mutant with other known ataxic mutants, we performed immunohistological analyses and found that expression levels of two genes and their products, glutamate receptor delta2 (grid2) and its ligand, cerebellin1 (Cbln1), are significantly reduced or undetectable. Finally, we sequenced the candidate genes and detected a large deletion in the coding region of the grid2 gene. Our present study suggests that ts3 is a new allele of the grid2 gene, which causes similar but different phenotypes as compared to other grid2 mutants. PMID

  2. Sodium phenylbutyrate coated granules (Pheburane). Defective urea synthesis: a welcome formulation.

    PubMed

    2015-02-01

    Compared with Ammonaps granules, Pheburane coated granules mask the unpleasant taste of sodium phenylbutyrate. A more precise dosing device is provided with the coated granules than with the uncoated granules (Ammonaps).

  3. Detection and Analysis of the Quality of Ibuprofen Granules

    NASA Astrophysics Data System (ADS)

    Yu-bin, Ji; Xin, LI; Guo-song, Xin; Qin-bing, Xue

    2017-12-01

    The Ibuprofen Granules comprehensive quality testing to ensure that it is in accordance with the provisions of Chinese pharmacopoeia. With reference of Chinese pharmacopoeia, the Ibuprofen Granules is tested by UV, HPLC, in terms of grain size checking, volume deviation, weight loss on drying detection, dissolution rate detection, and quality evaluation. Results indicated that Ibuprofen Granules conform to the standards. The Ibuprofen Granules are qualified and should be permitted to be marketed.

  4. 21 CFR 520.1468 - Naproxen granules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1468 Naproxen granules. (a... musculoskeletal system of the horse. (2)(i) For oral maintenance therapy following initial intravenous dosage...

  5. Cerebellar abiotrophy in a family of Border Collie dogs.

    PubMed

    Sandy, J R; Slocombe, R E; Mitten, R W; Jedwab, D

    2002-11-01

    Cerebellar abiotrophies have a nonsex-linked, autosomal, recessively inherited basis in a number of species, and lesions typically reflect profound and progressive loss of Purkinje cells. In this report, an unusual form of abiotrophy is described for two sibling Border Collies. Extensive loss of the cerebellar granular cell layer was present with relative sparing of Purkinje cells of two female pups. The biochemical basis for this form of cerebellar abiotrophy is unknown, but the lack of disease in other siblings supports an autosomal recessive mode of inheritance.

  6. Lissencephaly with brainstem and cerebellar hypoplasia and congenital cataracts.

    PubMed

    Abumansour, Iman S; Wrogemann, Jens; Chudley, Albert E; Chodirker, Bernard N; Salman, Michael S

    2014-06-01

    Classical lissencephaly may be associated with cerebellar hypoplasia and when significant cerebellar abnormalities occur, defects in proteins encoded by TUBA1A, RELN, and very-low-density lipoprotein receptor (VLDLR) genes have been reported. We present a neonate with a severe neurologic phenotype associated with hypotonia, oropharyngeal incoordination that required a gastric tube for feeding, intractable epilepsy, and congenital cataracts. Her brain magnetic resonance imaging (MRI) showed classical lissencephaly, ventriculomegaly, absent corpus callosum, globular and vertical hippocampi, and severe cerebellar and brainstem hypoplasia. She died at 6 weeks of age. No specific molecular diagnosis was made. This likely represents a previously undescribed genetic lissencephaly syndrome. © The Author(s) 2013.

  7. Heat stroke induced cerebellar dysfunction: A “forgotten syndrome”

    PubMed Central

    Kosgallana, Athula D; Mallik, Shreyashee; Patel, Vishal; Beran, Roy G

    2013-01-01

    We report a case of heat stroke induced acute cerebellar dysfunction, a rare neurological disease characterized by gross cerebellar dysfunction with no acute radiographic changes, in a 61 years old ship captain presenting with slurred speech and gait ataxia. A systematic review of the literature on heat stroke induced cerebellar dysfunction was performed, with a focus on investigations, treatment and outcomes. After review of the literature and detailed patient investigation it was concluded that this patient suffered heat stroke at a temperature less than that quoted in the literature. PMID:24340279

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

    PubMed Central

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

    2017-01-01

    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

  9. Gene expression signature of cerebellar hypoplasia in a mouse model of Down syndrome during postnatal development

    PubMed Central

    Laffaire, Julien; Rivals, Isabelle; Dauphinot, Luce; Pasteau, Fabien; Wehrle, Rosine; Larrat, Benoit; Vitalis, Tania; Moldrich, Randal X; Rossier, Jean; Sinkus, Ralph; Herault, Yann; Dusart, Isabelle; Potier, Marie-Claude

    2009-01-01

    Background Down syndrome is a chromosomal disorder caused by the presence of three copies of chromosome 21. The mechanisms by which this aneuploidy produces the complex and variable phenotype observed in people with Down syndrome are still under discussion. Recent studies have demonstrated an increased transcript level of the three-copy genes with some dosage compensation or amplification for a subset of them. The impact of this gene dosage effect on the whole transcriptome is still debated and longitudinal studies assessing the variability among samples, tissues and developmental stages are needed. Results We thus designed a large scale gene expression study in mice (the Ts1Cje Down syndrome mouse model) in which we could measure the effects of trisomy 21 on a large number of samples (74 in total) in a tissue that is affected in Down syndrome (the cerebellum) and where we could quantify the defect during postnatal development in order to correlate gene expression changes to the phenotype observed. Statistical analysis of microarray data revealed a major gene dosage effect: for the three-copy genes as well as for a 2 Mb segment from mouse chromosome 12 that we show for the first time as being deleted in the Ts1Cje mice. This gene dosage effect impacts moderately on the expression of euploid genes (2.4 to 7.5% differentially expressed). Only 13 genes were significantly dysregulated in Ts1Cje mice at all four postnatal development stages studied from birth to 10 days after birth, and among them are 6 three-copy genes. The decrease in granule cell proliferation demonstrated in newborn Ts1Cje cerebellum was correlated with a major gene dosage effect on the transcriptome in dissected cerebellar external granule cell layer. Conclusion High throughput gene expression analysis in the cerebellum of a large number of samples of Ts1Cje and euploid mice has revealed a prevailing gene dosage effect on triplicated genes. Moreover using an enriched cell population that is thought

  10. Functional recovery after cerebellar damage is related to GAP-43-mediated reactive responses of pre-cerebellar and deep cerebellar nuclei.

    PubMed

    Burello, Lorena; De Bartolo, Paola; Gelfo, Francesca; Foti, Francesca; Angelucci, Francesco; Petrosini, Laura

    2012-01-01

    Since brain injuries in adulthood are a leading cause of long-term disabilities, the development of rehabilitative strategies able to impact on functional outcomes requires detailing adaptive neurobiological responses. Functional recovery following brain insult is mainly ascribed to brain neuroplastic properties although the close linkage between neuronal plasticity and functional recovery is not yet fully clarified. The present study analyzed the reactive responses of pre-cerebellar (inferior olive, lateral reticular nucleus and pontine nuclei) and deep cerebellar nuclei after a hemicerebellectomy, considering the great plastic potential of the cerebellar system in physiological and pathological conditions. The time course of the plastic reorganization following cerebellar lesion was investigated by monitoring the Growth Associated Protein-43 (GAP-43) immunoreactivity. The time course of recovery from cerebellar symptoms was also assessed to parallel behavioral and neurobiological parameters. A key role of GAP-43 in neuronal reactive responses was evidenced. Neurons that underwent an axotomy as consequence of the right hemicerebellectomy (neurons of left inferior olive, right lateral reticular nucleus and left pontine nuclei) exhibited enhanced GAP-43 immunoreactivity and cell death. As for the not-axotomized neurons, we found enhanced GAP-43 immunoreactivity only in right pontine nuclei projecting to the spared (left) hemicerebellum. GAP-43 levels augmented also in the three deep cerebellar nuclei of the spared hemicerebellum, indicating the ponto-cerebellar circuit as crucially involved in functional recovery. Interestingly, each nucleus showed a distinct time course in GAP-43 immunoreactivity. GAP-43 levels peaked during the first post-operative week in the fastigial and interposed nuclei and after one month in the dentate nucleus. These results suggest that the earlier plastic events of the fastigial and interposed nuclei were driving compensation of the

  11. Granule fraction inhomogeneity of calcium carbonate/sorbitol in roller compacted granules.

    PubMed

    Bacher, C; Olsen, P M; Bertelsen, P; Sonnergaard, J M

    2008-02-12

    The granule fraction inhomogeneity of roller compacted granules was examined on mixtures of three different morphologic forms of calcium carbonate and three particle sizes of sorbitol. The granule fraction inhomogeneity was determined by the distribution of the calcium carbonate in each of the 10 size fractions between 0 and 2000 microm and by calculating the demixing potential. Significant inhomogeneous occurrence of calcium carbonate in the size fractions was demonstrated, depending mostly on the particles sizes of sorbitol but also on the morphological forms of calcium carbonate. The heterogeneous distribution of calcium carbonate was related to the decrease in compactibility of roller compacted granules in comparison to the ungranulated materials. This phenomenon was explained by a mechanism where fracturing of the ribbon during granulation occurred at the weakest interparticulate bonds (the calcium carbonate: calcium carbonate bonds) and consequently exposed the weakest areas of bond formation on the surface of the granules. Accordingly, the non-uniform allocation of the interparticulate attractive forces in a tablet would cause a lowering of the compactibility. Furthermore, the ability of the powder to agglomerate in the roller compactor was demonstrated to be related to the ability of the powder to be compacted into a tablet, thus the most compactable calcium carbonate and the smallest sized sorbitol improved the homogeneity by decreasing the demixing potential.

  12. Wave granulation in the Venus' atmosphere

    NASA Astrophysics Data System (ADS)

    Kochemasov, G.

    2007-08-01

    In unique venusian planetary system the solid body rotates very slowly and the detached massive atmosphere very rapidly. However both together orbit Sun and their characteristic orbital frequency -1/ 0.62 year - places them in the regular row of planets assigning them characteristic only for Venus wave produced granulation with a granule size πR/6 [1& others]. Remind other bodies in the row with their granule sizes inversely proportional to their orbital frequencies: solar photosphere πR/60, Mercury πR/16, Venus πR/6, Earth πR/4, Mars πR/2, asteroids πR/1 (R-a body radius). Three planets have atmospheres with wave granulations having sizes equal to their lithospheric granules. But Venus, unlike Earth and Mars, has the detached atmosphere that can be considered as a separate body with its own orbital frequency around the center of the Venus' system. According to the correlation between an orbital frequency and a wave granule size the venusian wave granule will be πR/338 (a scale can be Earth: orbital frequency 1/ 1year, granule size πR/4 or Sun: frequency 1/1month, granule size πR/60). So, πR/338 = 57 km. This theoretical size is rather close to that observed by Galileo SC through a violet filter "the filamentary dark features. . . are here revealed to be composed of several dark nodules, like beads on a string, each about 60 miles across" (PIA00072). Actually all Venus' disc seen from a distance π1.7mln.miles is peppered with these fine features seen on a limit of resolution. So, the Venus' atmosphere has two main frequencies in the solar system with corresponding wave granulations: around Sun 1/225 days (granule πR/6) and around Venus 1/ 4 days (granule πR/338). As was done for the Moon, Phobos, Titan and other icy satellites of Saturn [2, 3, 4 & others] one can apply the wave modulation technique also for the atmosphere of Venus. The lower frequency modulates the higher one by dividing and multiplying it thus getting two side frequencies and

  13. Wave granulation in the Venus' atmosphere

    NASA Astrophysics Data System (ADS)

    Kochemasov, G.

    2007-08-01

    In unique venusian planetary system the solid body rotates very slowly and the detached massive atmosphere very rapidly. However both together orbit Sun and their characteristic orbital frequency -1/ 0.62 year - places them in the regular row of planets assigning them characteristic only for Venus wave produced granulation with a granule size πR/6 [1& others]. Remind other bodies in the row with their granule sizes inversely proportional to their orbital frequencies: solar photosphere πR/60, Mercury πR/16, Venus πR/6, Earth πR/4, Mars πR/2, asteroids πR/1 (R-a body radius). Three planets have atmospheres with wave granulations having sizes equal to their lithospheric granules. But Venus, unlike Earth and Mars, has the detached atmosphere that can be considered as a separate body with its own orbital frequency around the center of the Venus' system. According to the correlation between an orbital frequency and a wave granule size the venusian wave granule will be πR/338 (a scale can be Earth: orbital frequency 1/ 1year, granule size πR/4 or Sun: frequency 1/1month, granule size πR/60). So, πR/338 = 57 km. This theoretical size is rather close to that observed by Galileo SC through a violet filter "the filamentary dark features. . . are here revealed to be composed of several dark nodules, like beads on a string, each about 60 miles across" (PIA00072). Actually all Venus' disc seen from a distance ~1.7mln.miles is peppered with these fine features seen on a limit of resolution. So, the Venus' atmosphere has two main frequencies in the solar system with corresponding wave granulations: around Sun 1/225 days (granule πR/6) and around Venus 1/ 4 days (granule πR/338). As was done for the Moon, Phobos, Titan and other icy satellites of Saturn [2, 3, 4 & others] one can apply the wave modulation technique also for the atmosphere of Venus. The lower frequency modulates the higher one by dividing and multiplying it thus getting two side frequencies and

  14. [Preparation and evaluation of taste masked orally disintegrating tablets with granules made by the wet granulation method].

    PubMed

    Kawano, Yayoi; Ito, Akihiko; Sasatsu, Masanaho; Machida, Yoshiharu; Onishi, Hiraku

    2010-12-01

    Using furosemide (FU) as a model drug, we examined the wet granulation method as a way to improve the taste masking and physical characteristics of orally disintegrating tablets (ODTs). In the wet granulation method, yogurt powder (YO) was used as a corrective and maltitol (MA) was used as a binding agent. The taste masked FU tablets were prepared using the direct compression method. Microcrystalline cellulose (Avicel® PH-302) and mannitol were added as excipients at a mixing ratio of 1/1 by weight. Based on the results of sensory test on taste, the prepared granules markedly improved the taste of FU, and a sufficient masking effect was obtained at the YO/FU ratio of 1 or more. Furthermore, it was found that the masking effect achieved by YO granules made with the wet granulation method was similar to or better than that produced by the granules made with dry granulation method. All types of tablets displayed sufficient hardness (over 3.5×10(-2) kN), and rapidly disintegrating tablets were obtained with YO granules produced at a mixing ratio of FU/YO=1/1, which disintegrated within 20 s. Disintegration time lengthened as the mixing ratio of YO to FU increased. In the mixing ratio of FU/YO=1/1, the hardness of tablets with granules made by the wet granulation method exceeded that of tablets with granules made by the dry granulation method, with minimal differences in disintegration time. The hardness and disintegration time of the tablets with granules made by the wet granulation method could be controlled by varying the compression force. In conclusion, YO was found to be a useful additive for masking unpleasant tastes. FU ODTs with improved taste, rapid disintegration and greater hardness could be prepared with YO-containing granules made by the wet granulation method using MA as a binding agent.

  15. Comparative Analysis of Zearalenone Effects on Thyroid Receptor Alpha (TRα) and Beta (TRβ) Expression in Rat Primary Cerebellar Cell Cultures.

    PubMed

    Kiss, David Sandor; Ioja, Eniko; Toth, Istvan; Barany, Zoltan; Jocsak, Gergely; Bartha, Tibor; Horvath, Tamas L; Zsarnovszky, Attila

    2018-05-11

    Thyroid receptors play an important role in postnatal brain development. Zearalenone (ZEN), a major mycotoxin of Fusarium fungi, is well known to cause serious health problems in animals and humans through various mechanisms, including the physiological pathways of thyroid hormone (TH). In the present study, we aimed to investigate the expression of thyroid receptors α (TRα) and β (TRβ) in primary cerebellar neurons in the presence or absence of glia and following ZEN treatment, using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot. Primary cerebellar granule cells were treated with low doses of ZEN (0.1 nM) in combination with physiologically relevant concentrations of l-thyroxine (T4), 3,3',5-triiodo-l-thyronine (T3) and 17β-estradiol (E2). Expression levels of TRα and TRβ at mRNA and protein levels were slightly modified by ZEN administered alone; however, along with thyroid and steroid hormones, modelling the physiological conditions, expression levels of TRs varied highly depending on the given treatment. Gene expression levels were also highly modulated by the presence or absence of glial cells, with mostly contrasting effects. Our results demonstrate divergent transcriptional and translational mechanisms involved in the expression of TRs implied by ZEN and hormonal milieu, as well as culturing conditions.

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

    PubMed

    Itoh, K; Korogi, Y; Tomiguchi, S; Takahashi, M; Okajima, T; Sato, H

    2001-04-01

    We looked at regional cerebellar blood flow in patients with Minamata disease (MD) using technetium-99m 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.

  17. Late Onset of Cerebellar Abiotrophy in a Boxer Dog

    PubMed Central

    Gumber, Sanjeev; Cho, Doo-Youn; Morgan, Timothy W.

    2010-01-01

    Cerebellar abiotrophy is a degenerative disorder of the central nervous system and has been reported in humans and animals. This case report documents clinical, histopathological, and immunohistochemical findings of cerebellar abiotrophy in an adult Boxer dog. A 3.5-year-old, female, tan Boxer dog presented with a six-week history of left-sided head tilt. Neurological examination and additional diagnostics during her three subsequent visits over 4.5 months revealed worsening of neurological signs including marked head pressing, severe proprioceptive deficits in all the four limbs, loss of menace response and palpebral reflex in the left eye, and a gradual seizure lasting one hour at her last visit. Based on the immunohistochemical staining for glial fibrillary acidic protein and histopathological examination of cerebellum, cerebellar cortical abiotrophy was diagnosed. This is the first reported case of cerebellar abiotrophy in a Boxer dog to our knowledge. PMID:21151662

  18. Past, Present and Future Therapeutics for Cerebellar Ataxias

    PubMed Central

    Marmolino, D; Manto, M

    2010-01-01

    Cerebellar ataxias are a group of disabling neurological disorders. Patients exhibit a cerebellar syndrome and can also present with extra-cerebellar deficits, namely pigmentary retinopathy, extrapyramidal movement disorders, pyramidal signs, cortical symptoms (seizures, cognitive impairment/behavioural symptoms), and peripheral neuropathy. Recently, deficits in cognitive operations have been unraveled. Cerebellar ataxias are heterogeneous both at the phenotypic and genotypic point of view. Therapeutical trials performed during these last 4 decades have failed in most cases, in particular because drugs were not targeting a deleterious pathway, but were given to counteract putative defects in neurotransmission. The identification of the causative mutations of many hereditary ataxias, the development of relevant animal models and the recent identifications of the molecular mechanisms underlying ataxias are impacting on the development of new drugs. We provide an overview of the pharmacological treatments currently used in the clinical practice and we discuss the drugs under development. PMID:20808545

  19. Cerebellar theta-burst stimulation selectively enhances lexical associative priming.

    PubMed

    Argyropoulos, Giorgos P

    2011-09-01

    Recent research in cerebellar cognitive and linguistic functions makes plausible the idea that the cerebellum is involved in processing temporally contiguous linguistic input. In order to assess this hypothesis, a simple lexical decision task was constructed to study whether the effect of transcranial magnetic stimulation on two different cerebellar sites would have a selective impact on associative as opposed to semantic priming. This is the first experiment applying transcranial magnetic stimulation of the cerebellum to a linguistic task. The results show a selective drop in lexical decision accuracy after stimulation of a medial cerebellar site in the first session of participation. Most importantly, they also demonstrate a selective increase of associative priming sizes after stimulation of the same site that cannot be attributed to changes in sensorimotor performance or in accuracy rates. The finding is discussed within the context of domain-general associative cerebellar computations.

  20. Effect of suspension property on granule morphology and compaction behavior

    SciTech Connect

    Hae-Weon Lee, Guesup Song, In-Sik Suk

    1995-12-31

    Granule morphology is an important factor during dry pressing, since it has great influences on die flowability, compaction ratio, and resulting green microstructure. Granule morphology and packing structure of ultrafine Si{sub 3}N{sub 4} particles in the granule were optimized during spray drying by adjusting the suspension structure. The particle packing structure of spray-dried granule was investigated with suspension structure. The effects of granule morphology and its particle packing structure on compaction and resultant sintering behavior were evaluated.

  1. Friedreich and dominant ataxias: quantitative differences in cerebellar dysfunction measurements.

    PubMed

    Tanguy Melac, Audrey; Mariotti, Caterina; Filipovic Pierucci, Antoine; Giunti, Paola; Arpa, Javier; Boesch, Sylvia; Klopstock, Thomas; Müller Vom Hagen, Jennifer; Klockgether, Thomas; Bürk, Katrin; Schulz, Jörg B; Reetz, Kathrin; Pandolfo, Massimo; Durr, Alexandra; Tezenas du Montcel, Sophie

    2018-06-01

    Sensitive outcome measures for clinical trials on cerebellar ataxias are lacking. Most cerebellar ataxias progress very slowly and quantitative measurements are required to evaluate cerebellar dysfunction. We evaluated two scales for rating cerebellar ataxias: the Composite Cerebellar Functional Severity (CCFS) Scale and Scale for the Assessment and Rating of Ataxia (SARA), in patients with spinocerebellar ataxia (SCA) and controls. We evaluated these scales for different diseases and investigated the factors governing the scores obtained. All patients were recruited prospectively. There were 383 patients with Friedreich's ataxia (FRDA), 205 patients with SCA and 168 controls. In FRDA, 31% of the variance of cerebellar signs with the CCFS and 41% of that with SARA were explained by disease duration, age at onset and the shorter abnormal repeat in the FXN gene. Increases in CCFS and SARA scores per year were lower for FRDA than for SCA (CCFS index: 0.123±0.123 per year vs 0.163±0.179, P<0.001; SARA index: 1.5±1.2 vs 1.7±1.7, P<0.001), indicating slower cerebellar dysfunction indexes for FRDA than for SCA. Patients with SCA2 had higher CCFS scores than patients with SCA1 and SCA3, but similar SARA scores. Cerebellar dysfunction, as measured with the CCFS and SARA scales, was more severe in FRDA than in patients with SCA, but with lower progression indexes, within the limits of these types of indexes. Ceiling effects may occur at late stages, for both scales. The CCFS scale is rater-independent and could be used in a multicentre context, as it is simple, rapid and fully automated. ClinicalTrials.gov: NCT02069509. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  2. Network-targeted cerebellar transcranial magnetic stimulation improves attentional control

    PubMed Central

    Esterman, Michael; Thai, Michelle; Okabe, Hidefusa; DeGutis, Joseph; Saad, Elyana; Laganiere, Simon E.; Halko, Mark A.

    2018-01-01

    Developing non-invasive brain stimulation interventions to improve attentional control is extremely relevant to a variety of neurologic and psychiatric populations, yet few studies have identified reliable biomarkers that can be readily modified to improve attentional control. One potential biomarker of attention is functional connectivity in the core cortical network supporting attention - the dorsal attention network (DAN). We used a network-targeted cerebellar transcranial magnetic stimulation (TMS) procedure, intended to enhance cortical functional connectivity in the DAN. Specifically, in healthy young adults we administered intermittent theta burst TMS (iTBS) to the midline cerebellar node of the DAN and, as a control, the right cerebellar node of the default mode network (DMN). These cerebellar targets were localized using individual resting-state fMRI scans. Participants completed assessments of both sustained (gradual onset continuous performance task, gradCPT) and transient attentional control (attentional blink) immediately before and after stimulation, in two sessions (cerebellar DAN and DMN). Following cerebellar DAN stimulation, participants had significantly fewer attentional lapses (lower commission error rates) on the gradCPT. In contrast, stimulation to the cerebellar DMN did not affect gradCPT performance. Further, in the DAN condition, individuals with worse baseline gradCPT performance showed the greatest enhancement in gradCPT performance. These results suggest that temporarily increasing functional connectivity in the DAN via network-targeted cerebellar stimulation can enhance sustained attention, particularly in those with poor baseline performance. With regard to transient attention, TMS stimulation improved attentional blink performance across both stimulation sites, suggesting increasing functional connectivity in both networks can enhance this aspect of attention. These findings have important implications for intervention applications

  3. Acute and critical care management of a pediatric patient with medullo-cerebellar impaling.

    PubMed

    Sherr, Gregory T; Beal, Alan; Irwin, Eric; Roach, Robert; Dyste, Gregg

    2009-09-01

    The authors present a child with an accidental cervical medullo-cerebellar impaling by an aluminum rod. Careful planning for safe removal of the rod as well as vigilant attention to early cardiac instability and flash neurogenic pulmonary edema were paramount to her successful recovery. This patient illustrates that it is possible to survive impaling of the brainstem but it requires both innovation and collaboration by multiple specialists across different departments. The value of well coordinated and collaborative neuro surgical intensive care is demonstrated in this young girl's nearly complete recovery from the accident.

  4. Granulation of snow: From tumbler experiments to discrete element simulations

    NASA Astrophysics Data System (ADS)

    Steinkogler, Walter; Gaume, Johan; Löwe, Henning; Sovilla, Betty; Lehning, Michael

    2015-06-01

    It is well known that snow avalanches exhibit granulation phenomena, i.e., the formation of large and apparently stable snow granules during the flow. The size distribution of the granules has an influence on flow behavior which, in turn, affects runout distances and avalanche velocities. The underlying mechanisms of granule formation are notoriously difficult to investigate within large-scale field experiments, due to limitations in the scope for measuring temperatures, velocities, and size distributions. To address this issue we present experiments with a concrete tumbler, which provide an appropriate means to investigate granule formation of snow. In a set of experiments at constant rotation velocity with varying temperatures and water content, we demonstrate that temperature has a major impact on the formation of granules. The experiments showed that granules only formed when the snow temperature exceeded -1∘C. No evolution in the granule size was observed at colder temperatures. Depending on the conditions, different granulation regimes are obtained, which are qualitatively classified according to their persistence and size distribution. The potential of granulation of snow in a tumbler is further demonstrated by showing that generic features of the experiments can be reproduced by cohesive discrete element simulations. The proposed discrete element model mimics the competition between cohesive forces, which promote aggregation, and impact forces, which induce fragmentation, and supports the interpretation of the granule regime classification obtained from the tumbler experiments. Generalizations, implications for flow dynamics, and experimental and model limitations as well as suggestions for future work are discussed.

  5. The biological significance of storage granules in rat parathyroid cells.

    PubMed

    Setoguti, T; Inoue, Y; Wild, P

    1995-10-01

    Both prosecretory and storage granules are concomitantly formed at the trans Golgi network including the innermost Golgi cisterna. Prosecretory granules develop into small secretory granules that release their contents by exocytosis finely regulated by a complex mechanism for maintaining calcium homeostasis. In the rat parathyroid cells, storage granules are large secretory granules storing parathyroid hormone for an emergency supply. The hormone is rapidly discharged by exocytosis when serum calcium concentration is decreased. The granules are constantly produced even under conditions of low serum calcium concentration in the regions of 8 mg/dl. The granule content is constantly hydrolyzed when not discharged, leading to a decreased core and finally to the formation of vacuolar bodies. The fate of the vacuolar bodies is unknown. Hypercalcemic conditions accelerate hydrolysis. The threshold value of calcium concentration required for the release of storage granule contents is between 8.0 and 7.5 mg/dl and that of calcium concentration for accelerating degradation of storage granules is about 11.5 mg/dl. Sympathetic stimulation causes storage granules to be discharged regardless of hypercalcemia or hypocalcemia. Parasympathetic stimulation accelerates hydrolysis. The degradation of storage granules seems to be closely associated with an intracellular regulatory mechanism for parathyroid hormone secretion.

  6. Aberrant cerebellar connectivity in bipolar disorder with psychosis.

    PubMed

    Shinn, Ann K; Roh, Youkyung S; Ravichandran, Caitlin T; Baker, Justin T; Öngür, Dost; Cohen, Bruce M

    2017-07-01

    The cerebellum, which modulates affect and cognition in addition to motor functions, may contribute substantially to the pathophysiology of mood and psychotic disorders, such as bipolar disorder. A growing literature points to cerebellar abnormalities in bipolar disorder. However, no studies have investigated the topographic representations of resting state cerebellar networks in bipolar disorder, specifically their functional connectivity to cerebral cortical networks. Using a well-defined cerebral cortical parcellation scheme as functional connectivity seeds, we compared ten cerebellar resting state networks in 49 patients with bipolar disorder and a lifetime history of psychotic features and 55 healthy control participants matched for age, sex, and image signal-to-noise ratio. Patients with psychotic bipolar disorder showed reduced cerebro-cerebellar functional connectivity in somatomotor A, ventral attention, salience, and frontoparietal control A and B networks relative to healthy control participants. These findings were not significantly correlated with current symptoms. Patients with psychotic bipolar disorder showed evidence of cerebro-cerebellar dysconnectivity in selective networks. These disease-related changes were substantial and not explained by medication exposure or substance use. Therefore, they may be mechanistically relevant to the underlying susceptibility to mood dysregulation and psychosis. Cerebellar mechanisms deserve further exploration in psychiatric conditions, and this study's findings may have value in guiding future studies on pathophysiology and treatment of mood and psychotic disorders, in particular.

  7. Anticoagulation therapy is harmful to large-sized cerebellar infarction.

    PubMed

    Zhang, She-Qing; Wang, Wei; Ma, Xiao-Long; Xia, Yu-Ye; Liu, Ai-Jun

    2014-09-01

    Anticoagulants are commonly used to treat ischemic stroke. Its impact on cerebellar infarction has not been fully understood. In the clinical study, we reviewed a consecutive series of patients with large-sized cerebellar infarction (diameter > 3 cm, n = 30) treated with or without anticoagulation. In animal study, cerebellar infarction operation was performed in 12 Cynomolgus monkeys. Then the animals were administrated with low molecular weight heparin (LMWH) or vehicle for 14 days. Six patients died during the following treatment. All the subjects that died received anticoagulation therapy, while nobody in the survival group received such a therapy. Compared with sham-operated animals, all monkeys with cerebellar infarction have obvious neurological deficits. The number and size of the Purkinje cells in the cerebellar area were also reduced. Two animals in the LMWH group (33%) died, while all animals in the vehicle control group survived. Compared with the vehicle group, the neurological score in the LMWH group was significantly increased (P < 0.05). The water content in the cerebella was also significantly higher (P < 0.05). Edema, hemorrhage, and subarachnoid hemorrhage occurred in the cerebella as well as brainstem of all the LMWH treated animals. These results indicated the harmful effects of anticoagulation therapy on large-sized cerebellar infarction. © 2014 John Wiley & Sons Ltd.

  8. Primary Cerebellar Gliosarcoma with Extracranial Metastases: An Orphan Differential Diagnosis.

    PubMed

    Ben Nsir, Atef; Thai, Quoc-Anh; Kassar, Alia Zhani; Ben Said, Imed; Jemel, Hafedh

    2015-12-01

    Gliosarcomas are rare, malignant primary brain tumors, most commonly located in the temporal lobe, that contain both glial and mesenchymal elements. Gliosarcomas located within the cerebellum are exceedingly rare. The previously unreported finding of a cerebellar gliosarcoma concurrently with an extracranial metastasis to the lungs is discussed here. A 57-year-old man presented with a 3-month history of chest pain, weight loss, headaches, and vomiting. Physical examination revealed a left cerebellar dysfunction, and the radiological work-up revealed a 6 × 6-cm right apical pulmonary tumor and a 4 × 3.5 × 3.8-cm peripherally enhancing left cerebellar mass. On the basis of a smoking history in the setting of a lung lesion and cerebellar mass, the presumptive diagnosis was primary lung cancer with metastasis to the cerebellum. Gross total resection of a firm pseudo-encapsulated cerebellar mass was performed. The microscopic features and the immunohistochemical profile confirmed the diagnosis of Gliosarcoma. The thoracic lesion was removed subsequently, and pathology confirmed it as an extracranial metastasis from the cerebellar gliosarcoma. Adjuvant radiation and chemotherapy were then administered. No clinical or radiographic evidence of recurrence was observed during one year of follow-up monitoring. To the best of our knowledge, a primary infratentorial gliosarcoma with extracranial metastases has not been previously described. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Neurodevelopmental Malformations of the Cerebellar Vermis in Genetically Engineered Rats.

    PubMed

    Ramos, Raddy L; Van Dine, Sarah E; Gilbert, Mary E; Leheste, Joerg R; Torres, German

    2015-12-01

    The cerebellar vermis is particularly vulnerable to neurodevelopmental malformations in humans and rodents. Sprague-Dawley, and Long-Evans rats exhibit spontaneous cerebellar malformations consisting of heterotopic neurons and glia in the molecular layer of the vermis. Malformations are almost exclusively found along the primary fissure and are indicative of deficits of neuronal migration during cerebellar development. In the present report, we test the prediction that genetically engineered rats on Sprague-Dawley or Long-Evans backgrounds will also exhibit the same cerebellar malformations. Consistent with our hypothesis, we found that three different transgenic lines on two different backgrounds had cerebellar malformations. Heterotopia in transgenic rats had identical cytoarchitecture as that observed in wild-type rats including altered morphology of Bergmann glia. In light of the possibility that heterotopia could affect results from behavioral studies, these data suggest that histological analyses be performed in studies of cerebellar function or development when using genetically engineered rats on these backgrounds in order to have more careful interpretation of experimental findings.

  10. Factors associated with the misdiagnosis of cerebellar infarction.

    PubMed

    Masuda, Yoko; Tei, Hideaki; Shimizu, Satoru; Uchiyama, Shinichiro

    2013-10-01

    Cerebellar infarction is easily misdiagnosed or underdiagnosed. In this study, we investigated factors leading to misdiagnosis of cerebellar infarction in patients with acute ischemic stroke. Data on neurological and radiological findings from 114 consecutive patients with acute cerebellar infarction were analyzed. We investigated factors associated with misdiagnosis from the data on clinical findings. Thirty-two (28%) patients were misdiagnosed on admission. Misdiagnosis was significantly more frequent in patients below 60 years of age and in patients with vertebral artery dissection, and significantly less frequent in patients with dysarthria. It tended to be more frequent in patients with the medial branch of posterior inferior cerebellar artery territory infarction, and infrequent in patients with the medial branch of the superior cerebellar artery territory infarction. Thirty out of 32 (94%) misdiagnosed patients were seen by physicians that were not neurologists at the first visit. Twenty-four of 32 (75%) misdiagnosed patients were screened only by brain CT. However, patients were not checked by brain MRI or follow-up CT until their conditions worsened. Patients below 60 years of age and patients with vertebral artery dissection are more likely to have a cerebellar infarction misdiagnosed by physicians other than neurologists. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  11. Altered soleus responses to magnetic stimulation in pure cerebellar ataxia.

    PubMed

    Kurokawa-Kuroda, Tomomi; Ogata, Katsuya; Suga, Rie; Goto, Yoshinobu; Taniwaki, Takayuki; Kira, Jun-Ichi; Tobimatsu, Shozo

    2007-06-01

    Transcranial magnetic stimulation (TMS) over the leg motor area elicits a soleus primary response (SPR) and a soleus late response (SLR). We evaluated the influence of the cerebellofugal pathway on the SPR and SLR in patients with 'pure' cerebellar ataxia. SPRs and SLRs were recorded from 11 healthy subjects and 9 patients with 'pure' cerebellar cortical degeneration; 5 with spinocerebellar ataxia type 6 (SCA6), and 4 with late cortical cerebellar ataxia (LCCA). In addition, three patients with localized cerebellar lesions were tested. The SPR latency was significantly longer in patients than in controls, but primary responses in the tibialis anterior muscle were normal. The frequency of abnormal SLR was 38.9% in the supine position and 83.3% in the standing position. Two out of three patients with localized cerebellar lesions also showed abnormal SLR. Altered SPRs in patients may result from a dysfunction of the primary motor cortex caused by crossed cerebello-cerebral diaschisis. In addition, our results suggest that 'pure' cerebellar degeneration involves the mechanism responsible for evoking SLR which is related to the control of posture. SLR can be a useful neurophysiological parameter for evaluating cerebellofugal function.

  12. Comparison of PC12 and Cerebellar Granule Cell Cultures for Evaluating Neurite Outgrowth Using High Content Screening

    EPA Science Inventory

    Development of high-throughput assays for chemical screening and hazard identification is a pressing priority worldwide. One approach uses in vitro, cell-based assays which recapitulate biological events observed in vivo. Neurite outgrowth is one such critical cellular process un...

  13. APOPTOSIS OF CEREBELLAR GRANULE CELLS INDUCED BY ORGANOTIN COMPOUNDS FOUND IN DRINKING WATER: INVOLVEMENT OF MAP KINASES.

    EPA Science Inventory

    Mono- and dialkyl organotins have been found in drinking water in homes and businesses served by PVC pipes. Because the structurally related trialkyl organotins (eg. trimethyltin, tributyltin) are well known neurotoxicants, there is concern over the potential for the mono- and di...

  14. COMPARISON OF NEUROSCREEN-1 AND CEREBELLAR GRANULE CELL CULTURES FOR EVALUATING NEURITE OUTGROWTH USING THE ARRAYSCAN HIGH CONTENT ANALYSIS SYSTEM

    EPA Science Inventory

    A major challenge facing the Environmental Protection Agency is the development of high-throughput screening assays amendable to resource-efficient developmental neurotoxicity for chemical screening and toxicity prioritization. One approach uses in vitro, cell-based assays which...

  15. The absence of pleiotrophin modulates gene expression in the hippocampus in vivo and in cerebellar granule cells in vitro.

    PubMed

    González-Castillo, Celia; Ortuño-Sahagún, Daniel; Guzmán-Brambila, Carolina; Márquez-Aguirre, Ana Laura; Raisman-Vozari, Rita; Pallás, Mercé; Rojas-Mayorquín, Argelia E

    2016-09-01

    Pleiotrophin (PTN) is a secreted growth factor recently proposed to act as a neuromodulatory peptide in the Central Nervous System. PTN appears to be involved in neurodegenerative diseases and neural disorders, and it has also been implicated in learning and memory. Specifically, PTN-deficient mice exhibit a lower threshold for LTP induction in the hippocampus, which is attenuated in mice overexpressing PTN. However, there is little information about the signaling systems recruited by PTN to modulate neural activity. To address this issue, the gene expression profile in hippocampus of mice lacking PTN was analyzed using microarrays of 22,000 genes. In addition, we corroborated the effect of the absence of PTN on the expression of these genes by silencing this growth factor in primary neuronal cultures in vitro. The microarray analysis identified 102 genes that are differentially expressed (z-score>3.0) in PTN null mice, and the expression of eight of those modified in the hippocampus of KO mice was also modified in vitro after silencing PTN in cultured neurons with siRNAs. The data obtained indicate that the absence of PTN affects AKT pathway response and modulates the expression of genes related with neuroprotection (Mgst3 and Estrogen receptor 1, Ers 1) and cell differentiation (Caspase 6, Nestin, and Odz4), both in vivo and in vitro. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. THE SYNTHESIS OF THE STARCH GRANULE.

    PubMed

    Smith, A. M.; Denyer, K.; Martin, C.

    1997-06-01

    This review describes and discusses the implications of recent discoveries about how starch polymers are synthesized and organized to form a starch granule. Three issues are highlighted. 1. The role and importance of ADPglucose pyrophosphorylase in the generation of ADPglucose as the substrate for polymer synthesis. 2. The contributions of isoforms of starch-branching enzyme, starch synthase, and debranching enzyme to the synthesis and ordered packing of amylopectin molecules. 3. The requirements for and regulation of the synthesis of amylose.

  17. Activation of the cerebellar cortex and the dentate nucleus in a prism adaptation fMRI study.

    PubMed

    Küper, Michael; Wünnemann, Meret J S; Thürling, Markus; Stefanescu, Roxana M; Maderwald, Stefan; Elles, Hans G; Göricke, Sophia; Ladd, Mark E; Timmann, Dagmar

    2014-04-01

    During prism adaptation two types of learning processes can be distinguished. First, fast strategic motor control responses are predominant in the early course of prism adaptation to achieve rapid error correction within few trials. Second, slower spatial realignment occurs among the misaligned visual and proprioceptive sensorimotor coordinate system. The aim of the present ultra-highfield (7T) functional magnetic resonance imaging (fMRI) study was to explore cerebellar cortical and dentate nucleus activation during the course of prism adaptation in relation to a similar visuomotor task without prism exposure. Nineteen young healthy participants were included into the study. Recently developed normalization procedures were applied for the cerebellar cortex and the dentate nucleus. By means of subtraction analysis (early prism adaptation > visuomotor, early prism adaptation > late prism adaptation) we identified ipsilateral activation associated with strategic motor control responses within the posterior cerebellar cortex (lobules VIII and IX) and the ventro-caudal dentate nucleus. During the late phase of adaptation we observed pronounced activation of posterior parts of lobule VI, although subtraction analyses (late prism adaptation > visuomotor) remained negative. These results are in good accordance with the concept of a representation of non-motor functions, here strategic control, within the ventro-caudal dentate nucleus. Copyright © 2013 Wiley Periodicals, Inc.

  18. Infantile onset progressive cerebellar atrophy and anterior horn cell degeneration--a late onset variant of PCH-1?

    PubMed

    Lev, Dorit; Michelson-Kerman, Marina; Vinkler, Chana; Blumkin, Lubov; Shalev, Stavit A; Lerman-Sagie, Tally

    2008-03-01

    Despite major recent advances in our understanding of developmental cerebellar disorders, classification and delineation of these disorders remains difficult. The term pontocerebellar hypoplasia is used when there is a structural defect, originating in utero of both pons and cerebellar hemispheres. The term olivopontocerebellar atrophy is used when the disorder starts later in life and the process is a primary degeneration of cerebellar neurons. Pontocerebellar hypoplasia type 1 is associated with spinal anterior horn cell degeneration, congenital contractures, microcephaly, polyhydramnion and respiratory insufficiency leading to early death. However, anterior horn cell degeneration has also been described in cases with later onset pontocerebellar atrophy and recently the spectrum has even been further extended to include the association of anterior horn cell degeneration and cerebellar atrophy without pontine involvement. We describe two siblings from a consanguineous Moslem Arabic family who presented with progressive degeneration of both the cerebellum and the anterior horn cells. The patients presented after 1 year of age with a slow neurodegenerative course that included both cognitive and motor functions. There is considerable phenotypic variability; the sister shows a much milder course. Both children are still alive at 6 and 9 years. The sister could still crawl and speak two word sentences at the age of 3 years while the brother was bedridden and only uttered guttural sounds at the same age. Our cases further extend the phenotype of the cerebellar syndromes with anterior horn cell involvement to include a childhood onset and protracted course and further prove that this neurodegenerative disorder may start in utero or later in life.

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

    PubMed Central

    Parthier, Daniel; Frings, Stephan; Möhrlen, Frank

    2015-01-01

    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. PMID:26558388

  20. Smaller Cerebellar Growth and Poorer Neurodevelopmental Outcomes in Very Preterm Infants exposed to morphine

    PubMed Central

    Zwicker, Jill G; Miller, Steven P; Grunau, Ruth E; Chau, Vann; Brant, Rollin; Studholme, Colin; Liu, Mengyuan; Synnes, Anne; Poskitt, Kenneth J; Stiver, Mikaela L; Tam, Emily WY

    2017-01-01

    Objective To examine the relationship between morphine exposure and growth of the cerebellum and cerebrum in very preterm neonates from early in life to term-equivalent age, as well as to examine morphine exposure and brain volumes in relation to neurodevelopmental outcomes at 18 months corrected age (CA). Study design A prospective cohort of 136 very preterm neonates (24–32 weeks gestational age) was serially scanned with MRI near birth and at term-equivalent age for volumetric measurements of the cerebellum and cerebrum. Motor outcomes were assessed with the Peabody Scales of Motor Development-2 and cognitive outcomes with the Bayley-III at 18 months CA. Generalized least squares models and linear regression models were used to assess relationships between morphine exposure, brain volumes, and neurodevelopmental outcomes. Results A 10-fold increase in morphine exposure was associated with a 5.5% decrease in cerebellar volume, after adjustment for multiple clinical confounders and total brain volume (P=0.04). When infants exposed to glucocorticoids were excluded, the association of morphine was more pronounced, with an 8.2% decrease in cerebellar volume. Morphine exposure was not associated with cerebral volume (P=0.30). Greater morphine exposure also predicted poorer motor (P<0.001) and cognitive outcomes (P=0.006) at 18 months CA, an association mediated, in part, by slower brain growth. Conclusions Morphine exposure in very preterm neonates is independently associated with impaired cerebellar growth in the neonatal period and poorer neurodevelopmental outcomes in early childhood. Alternatives to better manage pain in preterm neonates that optimize brain development and functional outcomes are urgently needed. PMID:26763312

  1. Second Harmonic Generation Mediated by Aligned Water in Starch Granules.

    PubMed

    Cisek, Richard; Tokarz, Danielle; Krouglov, Serguei; Steup, Martin; Emes, Michael J; Tetlow, Ian J; Barzda, Virginijus

    2014-12-26

    The origin of second harmonic generation (SHG) in starch granules was investigated using ab initio quantum mechanical modeling and experimentally examined using polarization-in, polarization-out (PIPO) second harmonic generation microscopy. Ab initio calculations revealed that the largest contribution to the SHG signal from A- and B-type allomorphs of starch originates from the anisotropic organization of hydroxide and hydrogen bonds mediated by aligned water found in the polymers. The hypothesis was experimentally tested by imaging maize starch granules under various hydration and heat treatment conditions that alter the hydrogen bond network. The highest SHG intensity was found in fully hydrated starch granules, and heat treatment diminished the SHG intensity. The PIPO SHG imaging showed that dried starch granules have a much higher nonlinear optical susceptibility component ratio than fully hydrated granules. In contrast, deuterated starch granules showed a smaller susceptibility component ratio demonstrating that SHG is highly sensitive to the organization of the hydroxyl and hydrogen bond network. The polarization SHG imaging results of potato starch granules, representing starch allomorph B, were compared to those of maize starch granules representing allomorph A. The results showed that the amount of aligned water was higher in the maize granules. Nonlinear microscopy of starch granules provides evidence that varying hydration conditions leads to significant changes in the nonlinear susceptibility ratio as well as the SHG intensity, supporting the hypothesis from ab initio calculations that the dominant contribution to SHG is due to the ordered hydroxide and hydrogen bond network.

  2. The influence of granulation on super disintegrant performance.

    PubMed

    Zhao, Na; Augsburger, Larry L

    2006-02-01

    The purpose of this study is to identify the causes of efficiency loss of super disintegrants following granulation or reworking. Two processes, precompression and prewetting, were proposed to simulate the processes during dry and wet granulation, respectively. The disintegration efficiency of the resulting disintegrant granules was tested in model formulations composed of dicalcium phosphate and lactose with the unprocessed disintegrants as controls. No significant difference was shown in the intrinsic swelling and the water uptake abilities of all super disintegrants following dry granulation. However, a significant decrease was observed for both Primojel and Polyplasdone XL10 in the rate of water being absorbed into the tablet matrix following wet granulation, but not for Ac-Di-Sol. United States Pharmacopeia (USP) disintegration testing without disc revealed a significant increase in disintegration time for tablets formulated with dry granulated Primojel and Polyplasdone XL10 and all wet granulated disintegrants. The increase in particle size following granulation appears to be the cause of the loss in disintegration efficiency. In conclusion, Ac-Di-Sol is less affected by both precompression and prewetting. The efficiency of Primojel and Polyplasdone XL10 is highly dependent on their particle size. Descreasing the particle size tends to increase their efficiency. Due to the size increase following granulation, a higher addition level of super disintegrant is required to ensure fast and uniform disintegration of tablets prepared by granulation.

  3. Microvascular anatomy of the cerebellar parafloccular perforating space.

    PubMed

    Sosa, Pablo; Dujovny, Manuel; Onyekachi, Ibe; Sockwell, Noressia; Cremaschi, Fabián; Savastano, Luis E

    2016-02-01

    The cerebellopontine angle is a common site for tumor growth and vascular pathologies requiring surgical manipulations that jeopardize cranial nerve integrity and cerebellar and brainstem perfusion. To date, a detailed study of vessels perforating the cisternal surface of the middle cerebellar peduncle-namely, the paraflocculus or parafloccular perforating space-has yet to be published. In this report, the perforating vessels of the anterior inferior cerebellar artery (AICA) in the parafloccular space, or on the cisternal surface of the middle cerebellar peduncle, are described to elucidate their relevance pertaining to microsurgery and the different pathologies that occur at the cerebellopontine angle. Fourteen cadaveric cerebellopontine cisterns (CPCs) were studied. Anatomical dissections and analysis of the perforating arteries of the AICA and posterior inferior cerebellar artery at the parafloccular space were recorded using direct visualization by surgical microscope, optical histology, and scanning electron microscope. A comprehensive review of the English-language and Spanish-language literature was also performed, and findings related to anatomy, histology, physiology, neurology, neuroradiology, microsurgery, and endovascular surgery pertaining to the cerebellar flocculus or parafloccular spaces are summarized. A total of 298 perforating arteries were found in the dissected specimens, with a minimum of 15 to a maximum of 26 vessels per parafloccular perforating space. The average outer diameter of the cisternal portion of the perforating arteries was 0.11 ± 0.042 mm (mean ± SD) and the average length was 2.84 ± 1.2 mm. Detailed schematics and the surgical anatomy of the perforating vessels at the CPC and their clinical relevance are reported. The parafloccular space is a key entry point for many perforating vessels toward the middle cerebellar peduncle and lateral brainstem, and it must be respected and protected during surgical approaches to the

  4. Effect of Valsartan on Cerebellar Adrenomedullin System Dysregulation During Hypertension.

    PubMed

    Figueira, Leticia; Israel, Anita

    2017-02-01

    Adrenomedullin (AM) and its receptors components, calcitonin-receptor-like receptor (CRLR), and receptor activity-modifying protein (RAMP1, RAMP2, and RAMP3) are expressed in cerebellum. Cerebellar AM, AM binding sites and receptor components are altered during hypertension, suggesting a role for cerebellar AM in blood pressure regulation. Thus, we assessed the effect of valsartan, on AM and its receptor components expression in the cerebellar vermis of Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Additionally, we evaluated AM action on superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activity, and thiobarbituric acid reactive substances (TBARS) production in cerebellar vermis. Animals were treated with valsartan or vehicle for 11 days. Rats were sacrificed by decapitation; cerebellar vermis was dissected; and AM, CRLR, RAMP1, RAMP2, and RAMP3 expression was quantified by Western blot analysis. CAT, SOD, and GPx activity was determined spectrophotometrically and blood pressure by non-invasive plethysmography. We demonstrate that AM and RAMP2 expression was lower in cerebellum of SHR rats, while CRLR, RAMP1, and RAMP3 expression was higher than those of WKY rats. AM reduced cerebellar CAT, SOD, GPx activities, and TBARS production in WKY rats, but not in SHR rats. Valsartan reduced blood pressure and reversed the altered expression of AM and its receptors components, as well the loss of AM capacity to reduce antioxidant enzyme activity and TBARS production in SHR rats. These findings demonstrate that valsartan is able to reverse the dysregulation of cerebellar adrenomedullinergic system; and they suggest that altered AM system in the cerebellum could represent the primary abnormality leading to hypertension.

  5. Glucocorticoid Effects on Cerebellar Development in a Chicken Embryo Model: Exploring Changes in PAX6 and Metalloproteinase-9 After Exposure to Dexamethasone.

    PubMed

    Austdal, L P E; Bjørnstad, S; Mathisen, G H; Aden, P K; Mikkola, I; Paulsen, R E; Rakkestad, K E

    2016-12-01

    The developing cerebellum is vulnerable to effects of glucocorticoids and cerebellar dysfunction is associated with neurodevelopmental disorders (e.g. autism). Transcription factor PAX6 and matrix metalloproteinase-9 (MMP-9) are critical for normal cerebellar development and are highly expressed in migrating neurones. Alterations in MMP-9 and PAX6 are associated with altered cerebellar development. In the present study, we characterised the growth rate and development of the cortical layers, and further investigated how the levels of PAX6 and MMP-9, as well as glucocorticoid receptor (GR) and proliferating cell nuclear antigen (PCNA), change in the cerebellum during the foetal period [embryonic day (E)12-21] in chicken, which corresponds to the human perinatal period. Dexamethasone (DEX) was administered in ovo at E13 and E16, aiming to investigate how prenatal exposure to glucocorticoids interferes with normal development. DEX reduced foetal and cerebellar weight at E17 in a dose-dependent manner linked to a reduced level of PCNA and, over time, down-regulation of GR. We report that promoter activity of PAX6 and MMP-9 increased as a result of GR-stimulation in vitro. Prenatal DEX increased the protein level of PAX6 in a transient manner. PAX6 is reduced in mature granule neurones, and this occurred earlier in embryos exposed to DEX than in non-exposed controls. DEX exposure also led to a slow-onset down-regulation of MMP-9. Taken together, these findings indicate that excess prenatal glucocorticoid stimulation disturbs normal development of the cerebellum through mechanisms associated with reduced proliferation and accelerated maturation where PAX6 and MMP-9 play important roles. © 2016 British Society for Neuroendocrinology.

  6. Importance of genetics in fetal alcohol effects: null mutation of the nNOS gene worsens alcohol-induced cerebellar neuronal losses and behavioral deficits

    PubMed Central

    Bonthius, Daniel J.; Winters, Zachary; Karacay, Bahri; Bousquet, Samantha Larimer; Bonthius, Daniel J.

    2014-01-01

    The cerebellum is a major target of alcohol-induced damage in the developing brain. However, the cerebella of some children are much more seriously affected than others by prenatal alcohol exposure. As a consequence of in utero alcohol exposure, some children have substantial reductions in cerebellar volume and corresponding neurodevelopmental problems, including microencephaly, ataxia, and balance deficits, while other children who were exposed to similar alcohol quantities are spared. One factor that likely plays a key role in determining the impact of alcohol on the fetal cerebellum is genetics. However, no specific gene variant has yet been identified that worsens cerebellar function as a consequence of developmental alcohol exposure. Previous studies have revealed that mice carrying a homozygous mutation of the gene for neuronal nitric oxide synthase (nNOS−/− mice) have more severe acute alcohol-induced neuronal losses from the cerebellum than wild type mice. Therefore, the goals of this study were to determine whether alcohol induces more severe cerebellum-based behavioral deficits in nNOS−/− mice than in wild type mice and to determine whether these worsened behavior deficits are associated with worsened cerebellar neuronal losses. nNOS−/− mice and their wild type controls received alcohol (0.0, 2.2, or 4.4 mg/g) daily over postnatal days 4–9. In adulthood, the mice underwent behavioral testing, followed by neuronal quantification. Alcohol caused dose-related deficits in rotarod and balance beam performance in both nNOS−/− and wild type mice. However, the alcohol-induced behavioral deficits were substantially worse in the nNOS−/− mice than in wild type. Likewise, alcohol exposure led to losses of Purkinje cells and cerebellar granule cells in mice of both genotypes, but the cell losses were more severe in the nNOS−/− mice than in wild type. Behavioral performances were correlated with neuronal number in the nNOS−/− mice, but not

  7. Distributed Cerebellar Motor Learning: A Spike-Timing-Dependent Plasticity Model

    PubMed Central

    Luque, Niceto R.; Garrido, Jesús A.; Naveros, Francisco; Carrillo, Richard R.; D'Angelo, Egidio; Ros, Eduardo

    2016-01-01

    Deep cerebellar nuclei neurons receive both inhibitory (GABAergic) synaptic currents from Purkinje cells (within the cerebellar cortex) and excitatory (glutamatergic) synaptic currents from mossy fibers. Those two deep cerebellar nucleus inputs are thought to be also adaptive, embedding interesting properties in the framework of accurate movements. We show that distributed spike-timing-dependent plasticity mechanisms (STDP) located at different cerebellar sites (parallel fibers to Purkinje cells, mossy fibers to deep cerebellar nucleus cells, and Purkinje cells to deep cerebellar nucleus cells) in close-loop simulations provide an explanation for the complex learning properties of the cerebellum in motor learning. Concretely, we propose a new mechanistic cerebellar spiking model. In this new model, deep cerebellar nuclei embed a dual functionality: deep cerebellar nuclei acting as a gain adaptation mechanism and as a facilitator for the slow memory consolidation at mossy fibers to deep cerebellar nucleus synapses. Equipping the cerebellum with excitatory (e-STDP) and inhibitory (i-STDP) mechanisms at deep cerebellar nuclei afferents allows the accommodation of synaptic memories that were formed at parallel fibers to Purkinje cells synapses and then transferred to mossy fibers to deep cerebellar nucleus synapses. These adaptive mechanisms also contribute to modulate the deep-cerebellar-nucleus-output firing rate (output gain modulation toward optimizing its working range). PMID:26973504

  8. Formation of artificial granules for proving gelation as the main mechanism of aerobic granulation in biological wastewater treatment.

    PubMed

    Li, Yun; Yang, Shu-Fang; Zhang, Jian-Jun; Li, Xiao-Yan

    2014-01-01

    In this study, gelation-facilitated biofilm formation as a new mechanism is proposed for the phenomenon of aerobic granulation in biological wastewater treatment. To obtain an experimental proof for the gelation-based theory, the granulation process was simulated in a chemical system using latex particles for bacterial cells and organic polymers (alginate and peptone) for extracellular polymeric substances (EPS) in a solution with the addition of cations (Ca²⁺, Mg²⁺ and Fe³⁺). The results showed that at a low alginate content (70 mg g⁻¹ mixed liquid suspended solids (MLSS)) flocculation was observed in the suspension with loose flocs. At a higher alginate content (180 mg g⁻¹ MLSS), together with discharge of small flocs, formation of artificial gel granules was successfully achieved leading to granulation. The artificial granules show a morphological property similar to that of actual microbial granules. However, if the protein content increased, granulation became difficult with little gel formation. The experimental work demonstrates the importance of the bonding interactions between EPS functional groups and cations in gel formation and granulation. The laboratory results on the formation of artificial granules provide a sound proof for the theory of gelation-facilitated biofilm formation as the main mechanism for aerobic granulation in sludge suspensions.

  9. Visualization and understanding of the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging.

    PubMed

    Vercruysse, Jurgen; Toiviainen, Maunu; Fonteyne, Margot; Helkimo, Niko; Ketolainen, Jarkko; Juuti, Mikko; Delaet, Urbain; Van Assche, Ivo; Remon, Jean Paul; Vervaet, Chris; De Beer, Thomas

    2014-04-01

    Over the last decade, there has been increased interest in the application of twin screw granulation as a continuous wet granulation technique for pharmaceutical drug formulations. However, the mixing of granulation liquid and powder material during the short residence time inside the screw chamber and the atypical particle size distribution (PSD) of granules produced by twin screw granulation is not yet fully understood. Therefore, this study aims at visualizing the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging. In first instance, the residence time of material inside the barrel was investigated as function of screw speed and moisture content followed by the visualization of the granulation liquid distribution as function of different formulation and process parameters (liquid feed rate, liquid addition method, screw configuration, moisture content and barrel filling degree). The link between moisture uniformity and granule size distributions was also studied. For residence time analysis, increased screw speed and lower moisture content resulted to a shorter mean residence time and narrower residence time distribution. Besides, the distribution of granulation liquid was more homogenous at higher moisture content and with more kneading zones on the granulator screws. After optimization of the screw configuration, a two-level full factorial experimental design was performed to evaluate the influence of moisture content, screw speed and powder feed rate on the mixing efficiency of the powder and liquid phase. From these results, it was concluded that only increasing the moisture content significantly improved the granulation liquid distribution. This study demonstrates that NIR chemical imaging is a fast and adequate measurement tool for allowing process visualization and hence for providing better process understanding of a continuous twin screw granulation system. Copyright © 2013 Elsevier B.V. All

  10. Differential timing of granule cell production during cerebellum development underlies generation of the foliation pattern.

    PubMed

    Legué, Emilie; Gottshall, Jackie L; Jaumouillé, Edouard; Roselló-Díez, Alberto; Shi, Wei; Barraza, Luis Humberto; Washington, Senna; Grant, Rachel L; Joyner, Alexandra L

    2016-09-08

    The mouse cerebellum (Cb) has a remarkably complex foliated three-dimensional (3D) structure, but a stereotypical cytoarchitecture and local circuitry. Little is known of the cellular behaviors and genes that function during development to determine the foliation pattern. In the anteroposterior axis the mammalian cerebellum is divided by lobules with distinct sizes, and the foliation pattern differs along the mediolateral axis defining a medial vermis and two lateral hemispheres. In the vermis, lobules are further grouped into four anteroposterior zones (anterior, central, posterior and nodular zones) based on genetic criteria, and each has distinct lobules. Since each cerebellar afferent group projects to particular lobules and zones, it is critical to understand how the 3D structure of the Cb is acquired. During cerebellar development, the production of granule cells (gcs), the most numerous cell type in the brain, is required for foliation. We hypothesized that the timing of gc accumulation is different in the four vermal zones during development and contributes to the distinct lobule morphologies. In order to test this idea, we used genetic inducible fate mapping to quantify accumulation of gcs in each lobule during the first two postnatal weeks in mice. The timing of gc production was found to be particular to each lobule, and delayed in the central zone lobules relative to the other zones. Quantification of gc proliferation and differentiation at three time-points in lobules representing different zones, revealed the delay involves a later onset of maximum differentiation and prolonged proliferation of gc progenitors in the central zone. Similar experiments in Engrailed mutants (En1 (-/+) ;En2 (-/-) ), which have a smaller Cb and altered foliation pattern preferentially outside the central zone, showed that gc production, proliferation and differentiation are altered such that the differences between zones are attenuated compared to wild-type mice. Our

  11. Preparation and evaluation of gelling granules to improve oral administration.

    PubMed

    Ito, Ikumi; Ito, Akihiko; Unezaki, Sakae

    2015-06-01

    We investigated the preparation of oral granules that are solid when stored and that will swell and gel via water absorption, to address problems experienced by patients when taking medication. Important physical properties of gelling granules include elasticity that is normally smooth, quick water absorption and swelling properties that allow easy swallowing. We selected gelatin (GEL), succinylated gelatin (SUC-GEL) and ι-carrageenan (CAR) as matrix polymers that can undergo gelation at room temperature or at cold temperatures. Saccharide and polyethylene glycol (PEG) were added to prepare the experimental granules. The best matrix gelling granule was SUC-GEL. When xylitol (XYL), sorbitol (SOR) and maltitol (MAL) were added, elasticity was improved, and PEG improved the granule's water absorption behavior, which is an important element involved in gelation. The best granules were prepared by selecting SUC-GEL as the matrix and adding a small amount of PEG and XYL in amounts equal to that of SUC-GEL.

  12. Adsorption mechanism for xanthene dyes to cellulose granules.

    PubMed

    Tabara, Aya; Yamane, Chihiro; Seguchi, Masaharu

    2012-01-01

    The xanthene dyes, erythrosine, phloxine, and rose bengal, were adsorbed to charred cellulose granules. The charred cellulose granules were preliminarily steeped in ionic (NaOH, NaCl, KOH, KCl, and sodium dodecyl sulfate (SDS)), nonionic (glucose, sucrose, and ethanol), and amphipathic sucrose fatty acid ester (SFAE) solutions, and adsorption tests on the dye to the steeped and charred cellulose granules were conducted. Almost none of the dye was adsorbed when the solutions of ionic and amphipathic molecules were used, but were adsorbed in the case of steeping in the nonionic molecule solutions. Thin-layer chromatography (TLC) and the Fourier transform infra-red (FT-IR) profiles of SFAE which was adsorbed to the charred cellulose granules and extracted by ethyl ether suggested the presence of hydrophobic sites on the surface of the charred cellulose granules. We confirmed that the xanthene dyes could bind to the charred cellulose granules by ionic and hydrophobic bonds.

  13. Specific lignin accumulation in granulated juice sacs of Citrus maxima.

    PubMed

    Wu, Jia-Ling; Pan, Teng-Fei; Guo, Zhi-Xiong; Pan, Dong-Ming

    2014-12-17

    Juice sac granulation occurring in pummelo fruits [Citrus maxima (Burm.) Merr.] is an undesirable trait, and the underlying mechanism remains unresolved. Previous studies have shown that lignin metabolism is closely associated with the process of juice sac granulation. Here, a method suitable for lignin isolation from pummelo tissues is established. Acetylated lignins from different pummelo tissues and cultivars were analyzed by HSQC NMR. The results showed that lignins in granulated juice sacs were characterized by an extremely high abundance of guaiacyl units (91.13-96.82%), in contrast to lignins from other tissues, including leaves, stems, and segment membranes. The abnormally accumulated lignins in granulated juice sacs were specific and mainly polymerized from coniferyl alcohol. No significant difference was found in lignin types among various cultivars. These findings indicated that the mechanism of juice sac granulation might be similar among various cultivars, although very different degrees of juice sac granulation can be observed.

  14. Membrane interactions between secretion granules and plasmalemma in three exocrine glands

    PubMed Central

    Tanaka, Y; De Camilli, P; Meldolesi, J

    1980-01-01

    Three types of membrane interactions were studied in three exocrine systems (the acinar cells of the rat parotid, rat lacrimal gland, and guinea pig pancrease) by freeze- fracture and thin-section electron microscopy: exocytosis, induced in vivo by specific pharmacological stimulations; the mutual apposition of secretory granule membranes in the intact cell; membrane appositions induced in vitro by centrifugation of the isolated granules. In all three glandular cells, the distribution of intramembrane particles (IMP) on the fracture faces of the luminal plasmagranule membrane particles (IMP) on the fracture faces of the lumenal plasmalemma appeared random before stimulation. However, after injection of secretagogues, IMP were rapidly clearly from the areas of granule- plasmalemma apposition in the parotid cells and, especially, in lacrimocytes. In the latter, the cleared areas appeared as large bulges toward the lumen, whereas in the parotid they were less pronounced. Exocytotic openings were usually large and the fracture faces of their rims were covered with IMP. In contrast, in stimulated pancreatic acinar cells, the IMP distribution remained apparently random after stimulation. Exocytoses were established through the formation of narrown necks, and no images which might correspond to early stages of membrane fusion were revealed. Within the cytoplasm of parotid and lacrimal cells (but not in the pancreas), both at rest and after stimulation, secretion granules were often closely apposed by means of flat, circular areas, also devoid of IMP. In thin sections, the images corresponding to IMP-free areas were close granule-granule and granule-plasmalemma appositions, sometimes with focal merging of the membrane outer layers to yield pentalaminar structures. Isolated secretion granules were forced together in vitro by centrifugation. Under these conditions, increasing the centrifugal force from 1,600 to 50,000 g for 10 min resulted in a progressive, statistically

  15. Extended-release mesalamine granules for ulcerative colitis.

    PubMed

    Love, Bryan L; Miller, April D

    2012-11-01

    To evaluate the efficacy and safety of extended-release mesalamine granules in the maintenance of remission in ulcerative colitis (UC). Literature was obtained through searches of MEDLINE (1990-June 2012) using the terms mesalamine granules, ulcerative colitis, Apriso, and Salofalk. Bibliographies from retrieved articles were searched for additional citations. All English-language articles reporting on use of extended-release mesalamine granules in humans identified through the search were evaluated and included. The preferred initial treatment for induction and maintenance of remission in mild to moderate UC is agents from the 5-aminosalicylate class (balsalazide, mesalamine, olsalazine, sulfasalazine). Mesalamine granules are available as an encapsulated product in the US and as a nonencapsulated formulation in Europe. Data evaluating encapsulated mesalamine granules for induction of remission are lacking; however, the European mesalamine granule formulation has been evaluated for induction of remission. Patients receiving mesalamine granules for induction achieved clinical and endoscopic remission more frequently than those receiving placebo. Two pivotal, randomized, double-blind, placebo-controlled, multicenter studies have evaluated encapsulated mesalamine granules for maintenance in 562 adults in remission from UC. In both studies, the proportion of patients who remained relapse-free at 6 months was higher for those receiving encapsulated mesalamine granules than placebo. Mesalamine granules are well tolerated, with headache, nausea, and upper respiratory infections being the most frequently reported adverse effects. Current evidence supports the use of extended-release mesalamine granules for maintenance of remission in mild to moderate UC. Further studies are necessary to examine the ideal dose and regimen of encapsulated mesalamine granules for induction of remission in UC.

  16. Beta phase synchronization in the frontal-temporal-cerebellar network during auditory-to-motor rhythm learning.

    PubMed

    Edagawa, Kouki; Kawasaki, Masahiro

    2017-02-22

    Rhythm is an essential element of dancing and music. To investigate the neural mechanisms underlying how rhythm is learned, we recorded electroencephalographic (EEG) data during a rhythm-reproducing task that asked participants to memorize an auditory stimulus and reproduce it via tapping. Based on the behavioral results, we divided the participants into Learning and No-learning groups. EEG analysis showed that error-related negativity (ERN) in the Learning group was larger than in the No-learning group. Time-frequency analysis of the EEG data showed that the beta power in right and left temporal area at the late learning stage was smaller than at the early learning stage in the Learning group. Additionally, the beta power in the temporal and cerebellar areas in the Learning group when learning to reproduce the rhythm were larger than in the No Learning group. Moreover, phase synchronization between frontal and temporal regions and between temporal and cerebellar regions at late stages of learning were larger than at early stages. These results indicate that the frontal-temporal-cerebellar beta neural circuits might be related to auditory-motor rhythm learning.

  17. Rab3A, a possible marker of cortical granules, participates in cortical granule exocytosis in mouse eggs

    SciTech Connect

    Bello, Oscar Daniel; Cappa, Andrea Isabel; Paola, Matilde de

    Fusion of cortical granules with the oocyte plasma membrane is the most significant event to prevent polyspermy. This particular exocytosis, also known as cortical reaction, is regulated by calcium and its molecular mechanism is still not known. Rab3A, a member of the small GTP-binding protein superfamily, has been implicated in calcium-dependent exocytosis and is not yet clear whether Rab3A participates in cortical granules exocytosis. Here, we examine the involvement of Rab3A in the physiology of cortical granules, particularly, in their distribution during oocyte maturation and activation, and their participation in membrane fusion during cortical granule exocytosis. Immunofluorescence and Western blotmore » analysis showed that Rab3A and cortical granules have a similar migration pattern during oocyte maturation, and that Rab3A is no longer detected after cortical granule exocytosis. These results suggested that Rab3A might be a marker of cortical granules. Overexpression of EGFP-Rab3A colocalized with cortical granules with a Pearson correlation coefficient of +0.967, indicating that Rab3A and cortical granules have almost a perfect colocalization in the egg cortical region. Using a functional assay, we demonstrated that microinjection of recombinant, prenylated and active GST-Rab3A triggered cortical granule exocytosis, indicating that Rab3A has an active role in this secretory pathway. To confirm this active role, we inhibited the function of endogenous Rab3A by microinjecting a polyclonal antibody raised against Rab3A prior to parthenogenetic activation. Our results showed that Rab3A antibody microinjection abolished cortical granule exocytosis in parthenogenetically activated oocytes. Altogether, our findings confirm that Rab3A might function as a marker of cortical granules and participates in cortical granule exocytosis in mouse eggs. - Highlights: • Rab3A has a similar migration pattern to cortical granules in mouse oocytes. • Rab3A can be a

  18. Microbial granulation for lactic acid production.

    PubMed

    Kim, Dong-Hoon; Lee, Mo-Kwon; Hwang, Yuhoon; Im, Wan-Taek; Yun, Yeo-Myeong; Park, Chul; Kim, Mi-Sun

    2016-01-01

    This work investigated the formation of microbial granules to boost the productivity of lactic acid (LA). The flocculated form of LA-producing microbial consortium, dominated by Lactobacillus sp. (91.5% of total sequence), was initially obtained in a continuous stirred-tank reactor (CSTR), which was fed with 2% glucose and operated at a hydraulic retention time (HRT) of 12 h and pH 5.0 ± 0.1 under a thermophilic condition (50°C). The mixed liquor in the CSTR was then transferred to an up-flow anaerobic sludge blanket reactor (UASB). The fermentation performance and granulation process were monitored with a gradual decrease of HRT from 8.0 to 0.17 h, corresponding to an increase in the substrate loading from 60 to 2,880 g glucose L(-1) d(-1) . As the operation continued, the accumulation of biomass in the UASB was clearly observed, which changed from flocculent to granular form with decrease in HRT. Up to the HRT decrease to 0.5 h, the LA concentration was maintained at 19-20 g L(-1) with over 90% of substrate removal efficiency. However, further decrease of HRT resulted in a decrease of LA concentration with increase in residual glucose. Nevertheless, the volumetric LA productivity continuously increased, reaching 67 g L-fermenter (-1) h(-1) at HRT 0.17 h. The size of LA-producing granules and hydrophobicity gradually increased with decrease in HRT, reaching 6.0 mm and 60%, respectively. These biogranules were also found to have high settling velocities and low porosities, ranging 2.69-4.73 cm s(-1) and 0.39-0.92, respectively. © 2015 Wiley Periodicals, Inc.

  19. Carbon granule probe microphone for leak detection. [recovery boilers

    NASA Technical Reports Server (NTRS)

    Parthasarathy, S. P. (Inventor)

    1985-01-01

    A microphone which is not subject to corrosion is provided by employing carbon granules to sense sound waves. The granules are packed into a ceramic tube and no diaphragm is used. A pair of electrodes is located in the tube adjacent the carbon granules and are coupled to a sensing circuit. Sound waves cause pressure changes on the carbon granules which results in a change in resistance in the electrical path between the electrodes. This change in resistance is detected by the sensing circuit. The microphone is suitable for use as a leak detection probe in recovery boilers, where it provides reliable operation without corrosion problems associated with conventional microphones.

  20. Identification of SNAREs that mediate zymogen granule exocytosis

    SciTech Connect

    Pickett, James A.; Campos-Toimil, Manuel; Thomas, Paul

    2007-08-03

    A secretagogue-stimulated pancreatic acinar cell releases digestive enzymes from its apical pole. We attempted to identify the SNAREs involved in zymogen granule exocytosis. Antibodies against syntaxins 2 and 3, SNAP-23 and VAMP 8, and the corresponding recombinant SNAREs, inhibited amylase secretion from streptolysin O-permeabilised acini; other anti-SNARE antibodies and SNAREs had no effect. Botulinum neurotoxin C, which cleaved syntaxin 2 and (to a lesser extent) syntaxin 3, but not syntaxins 4, 7 or 8, also inhibited exocytosis. We propose that syntaxin 2, SNAP-23 and VAMP 8 mediate primary granule-plasma membrane fusion. Syntaxin 3 may be involved in secondary granule-granule fusion.