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Sample records for cerebellar granule neurons

  1. Cultures of Cerebellar Granule Neurons

    OpenAIRE

    sprotocols

    2014-01-01

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

  2. File list: Unc.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

  3. File list: Unc.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

  4. File list: Unc.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

  5. File list: DNS.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Neu.20.AllAg.Cerebellar_granule_neurons mm9 DNase-seq Neural Cerebellar granule... neurons SRX685885,SRX685882,SRX685880 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available His.Neu.50.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule n...eurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  7. File list: DNS.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Neu.50.AllAg.Cerebellar_granule_neurons mm9 DNase-seq Neural Cerebellar granule... neurons SRX685885,SRX685882,SRX685880 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  8. File list: Oth.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.05.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.20.AllAg.Cerebellar_granule_neurons mm9 All antigens Neural Cerebellar gran...ule neurons SRX685885,SRX685882,SRX685880 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available DNS.Neu.10.AllAg.Cerebellar_granule_neurons mm9 DNase-seq Neural Cerebellar granule... neurons SRX685882,SRX685880,SRX685883,SRX685885,SRX685877,SRX685878 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  11. File list: Oth.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.50.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  12. File list: His.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.10.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule n...eurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  13. File list: Pol.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

  14. File list: Pol.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

  15. File list: Unc.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

  16. File list: ALL.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.50.AllAg.Cerebellar_granule_neurons mm9 All antigens Neural Cerebellar gran...ule neurons SRX685885,SRX685882,SRX685880 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  17. File list: ALL.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.05.AllAg.Cerebellar_granule_neurons mm9 All antigens Neural Cerebellar gran...ule neurons SRX685885,SRX685878,SRX685882,SRX685877,SRX685880,SRX685883 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  18. File list: Oth.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.10.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  19. File list: ALL.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Neu.10.AllAg.Cerebellar_granule_neurons mm9 All antigens Neural Cerebellar gran...ule neurons SRX685882,SRX685880,SRX685883,SRX685885,SRX685877,SRX685878 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.20.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  1. File list: His.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.05.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule n...eurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  2. File list: Pol.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

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

  3. File list: DNS.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.Neu.05.AllAg.Cerebellar_granule_neurons mm9 DNase-seq Neural Cerebellar granule... neurons SRX685885,SRX685878,SRX685882,SRX685877,SRX685880,SRX685883 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  4. File list: His.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.20.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule n...eurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

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

    Lifescience Database Archive (English)

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

  6. File list: NoD.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Neu.10.AllAg.Cerebellar_granule_neurons mm9 No description Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

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

    Lifescience Database Archive (English)

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

  8. File list: NoD.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Neu.05.AllAg.Cerebellar_granule_neurons mm9 No description Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

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

    Lifescience Database Archive (English)

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

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

    Lifescience Database Archive (English)

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

  11. File list: NoD.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Neu.20.AllAg.Cerebellar_granule_neurons mm9 No description Neural Cerebellar gran...ule neurons http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/NoD.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  12. Nitric oxide promotes survival of cerebellar granule neurons cultured in vitro through the Akt pathway

    Institute of Scientific and Technical Information of China (English)

    Lin Wang; Mei Li; Lihua Zhou

    2011-01-01

    In this study, cerebellar granule neurons were used to examine the role of nitric oxide on cell survival. The N-methyl-D-aspartic acid receptor antagonist, MK-801, and the soluble guanylate cyclase antagonist, 1H-[1, 2, 4]oxadiazolo-[4, 3-a] quinoxalin-1-one, decreased cell viability, induced caspase-3, and decreased phosphorylated-Akt levels, suggesting that blockade of nitric oxide production promotes apoptosis of differentiating cerebellar granule neurons. After administration of sodium nitroprusside, an endogenous nitric oxide donor, cell viability recovered,caspase-3 expression was decreased, and phosphorylated-Akt levels increased. This study provides direct evidence that nitric oxide can sustain the survival of developing cerebellar granule neurons in vitro through the nitric oxide-Akt pathway. Moreover, endogenous nitric oxide exerts these effects in a cyclic guanosine monophosphate-dependent manner while exogenous nitric oxide does so in a cyclic guanosine monophosphate-independent manner.

  13. Nuclear Factor I and Cerebellar Granule Neuron Development: An Intrinsic–Extrinsic Interplay

    OpenAIRE

    Kilpatrick, Daniel L.; Wang, Wei; Gronostajski, Richard; Litwack, E. David

    2012-01-01

    Granule neurons have a central role in cerebellar function via their synaptic interactions with other neuronal cell types both within and outside this structure. Establishment of these synaptic connections and its control is therefore essential to their function. Both intrinsic as well as environmental mechanisms are required for neuronal development and formation of neuronal circuits, and a key but poorly understood question is how these various events are coordinated and integrated in matur...

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

    Directory of Open Access Journals (Sweden)

    Mafra R.A.

    2003-01-01

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

    Science.gov (United States)

    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.

  16. Agonists of fibroblast growth factor receptor induce neurite outgrowth and survival of cerebellar granule neurons

    DEFF Research Database (Denmark)

    Li, Shizhong; Christensen, Claus; Køhler, Lene B;

    2009-01-01

    Fibroblast growth factor receptor (FGFR) signaling is pivotal in the regulation of neurogenesis, neuronal differentiation and survival, and synaptic plasticity both during development and in adulthood. In order to develop low molecular weight agonists of FGFR, seven peptides, termed hexafins...... phosphorylation, indicating that hexafins act as partial agonists. Hexafin2, 3, 8, 10, and 17 (but not 1 or 9) induced neurite outgrowth from cerebellar granule neurons (CGNs), an effect that was abolished by two inhibitors of FGFR, SU5402 and inositol hexaphosphate (IP6) and a diacylglycerol lipase inhibitor...

  17. Talpid3-binding centrosomal protein Cep120 is required for centriole duplication and proliferation of cerebellar granule neuron progenitors.

    Directory of Open Access Journals (Sweden)

    Chuanqing Wu

    Full Text Available Granule neuron progenitors (GNPs are the most abundant neuronal type in the cerebellum. GNP proliferation and thus cerebellar development require Sonic hedgehog (Shh secreted from Purkinje cells. Shh signaling occurs in primary cilia originating from the mother centriole. Centrioles replicate only once during a typical cell cycle and are responsible for mitotic spindle assembly and organization. Recent studies have linked cilia function to cerebellar morphogenesis, but the role of centriole duplication in cerebellar development is not known. Here we show that centrosomal protein Cep120 is asymmetrically localized to the daughter centriole through its interaction with Talpid3 (Ta3, another centrosomal protein. Cep120 null mutant mice die in early gestation with abnormal heart looping. Inactivation of Cep120 in the central nervous system leads to both hydrocephalus, due to the loss of cilia on ependymal cells, and severe cerebellar hypoplasia, due to the failed proliferation of GNPs. The mutant GNPs lack Hedgehog pathway activity. Cell biological studies show that the loss of Cep120 results in failed centriole duplication and consequently ciliogenesis, which together underlie Cep120 mutant cerebellar hypoplasia. Thus, our study for the first time links a centrosomal protein necessary for centriole duplication to cerebellar morphogenesis.

  18. Reactive oxygen species are related to ionic fluxes and volume decrease in apoptotic cerebellar granule neurons: role of NOX enzymes.

    Science.gov (United States)

    Hernández-Enríquez, Berenice; Guemez-Gamboa, Alicia; Morán, Julio

    2011-05-01

    Reactive oxygen species (ROS) are produced early during apoptosis of cerebellar granule neurons induced by low potassium (K5) and staurosporine (Sts). In addition, K5 and Sts activate NADPH oxidases (NOX). Recently, we described that K5 and Sts induce apoptotic volume decrease (AVD) at a time when ROS generation and NOX activity occur. In the present study, we evaluated the relationship between ROS generation and ionic fluxes during AVD. Here, we showed that K5- and Sts-induced AVD was inhibited by antioxidants and that direct ROS production induced AVD. Moreover, NOX inhibitors eliminated AVD induced by both K5 and Sts. Sts, but not K5, failed to induce AVD in cerebellar granule neurons from NOX2 knockout mice. These findings suggest that K5- and Sts-induced AVD is largely mediated by ROS produced by NOX. On the other hand, we also found that the blockage of ionic fluxes involved in AVD inhibited both ROS generation and NOX activity. These findings suggest that ROS generation and NOX activity are involved in ionic fluxes activation, which in turn could maintain ROS generation by activating NOX, leading to a self-amplifying cycle.

  19. Role of glutamate receptors in tetrabrominated diphenyl ether (BDE-47) neurotoxicity in mouse cerebellar granule neurons.

    Science.gov (United States)

    Costa, Lucio G; Tagliaferri, Sara; Roqué, Pamela J; Pellacani, Claudia

    2016-01-22

    The polybrominated diphenyl ether (PBDE) flame retardants are developmental neurotoxicants, as evidenced by numerous in vitro, animal and human studies. PBDEs can alter the homeostasis of thyroid hormone and directly interact with brain cells. Induction of oxidative stress, leading to DNA damage and apoptotic cell death is a prominent mechanism of PBDE neurotoxicity, though other mechanisms have also been suggested. In the present study we investigated the potential role played by glutamate receptors in the in vitro neurotoxicity of the tetrabromodiphenyl ether BDE-47, one of the most abundant PBDE congeners. Toxicity of BDE-47 in mouse cerebellar neurons was diminished by antagonists of glutamate ionotropic receptors, but not by antagonists of glutamate metabotropic receptors. Antagonists of NMDA and AMPA/Kainate receptors also inhibited BDE-47-induced oxidative stress and increases in intracellular calcium. The calcium chelator BAPTA-AM also inhibited BDE-47 cytotoxicity and oxidative stress. BDE-47 caused a rapid increase of extracellular glutamate levels, which was not antagonized by any of the compounds tested. The results suggest that BDE-47, by still unknown mechanisms, increases extracellular glutamate which in turn activates ionotropic glutamate receptors leading to increased calcium levels, oxidative stress, and ultimately cell death. PMID:26640238

  20. Neuritin Activates Insulin Receptor Pathway to Up-regulate Kv4.2-mediated Transient Outward K+ Current in Rat Cerebellar Granule Neurons*

    OpenAIRE

    Yao, Jin-jing; Gao, Xiao-Fei; Chow, Chi-Wing; Zhan, Xiao-Qin; Hu, Chang-Long; Mei, Yan-ai

    2012-01-01

    Neuritin is a new neurotrophic factor discovered in a screen to identify genes involved in activity-dependent synaptic plasticity. Neuritin also plays multiple roles in the process of neural development and synaptic plasticity. The receptors for binding neuritin and its downstream signaling effectors, however, remain unclear. Here, we report that neuritin specifically increases the densities of transient outward K+ currents (I A) in rat cerebellar granule neurons (CGNs) in a time- and concent...

  1. GDF-15 enhances intracellular Ca2+ by increasing Cav1.3 expression in rat cerebellar granule neurons

    Science.gov (United States)

    Lu, Jun-Mei; Wang, Chang-Ying; Hu, Changlong; Fang, Yan-Jia; Mei, Yan-Ai

    2016-01-01

    GDF-15 (growth/differentiation factor 15) is a novel member of the TGF (transforming growth factor)-β superfamily that has critical roles in the central and peripheral nervous systems. We reported previously that GDF-15 increased delayed rectifier outward K+ currents and Kv2.1 α subunit expression through TβRII (TGF-β receptor II) to activate Src kinase and Akt/mTOR (mammalian target of rapamycin) signalling in rat CGNs (cerebellar granule neurons). In the present study, we found that treatment of CGNs with GDF-15 for 24 h increased the intracellular Ca2+ concentration ([Ca2+]i) in response to membrane depolarization, as determined by Ca2+ imaging. Whole-cell current recordings indicated that GDF-15 increased the inward Ca2+ current (ICa) without altering steady-state activation of Ca2+ channels. Treatment with nifedipine, an inhibitor of L-type Ca2+ channels, abrogated GDF-15-induced increases in [Ca2+]i and ICa. The GDF-15-induced increase in ICa was mediated via up-regulation of the Cav1.3 α subunit, which was attenuated by inhibiting Akt/mTOR and ERK (extracellular-signal-regulated kinase) pathways and by pharmacological inhibition of Src-mediated TβRII phosphorylation. Given that Cav1.3 is not only a channel for Ca2+ influx, but also a transcriptional regulator, our data confirm that GDF-15 induces protein expression via TβRII and activation of a non-Smad pathway, and provide novel insight into the mechanism of GDF-15 function in neurons. PMID:27114559

  2. 大鼠小脑颗粒神经元体外原代培养%Primary culture of rat cerebellar granule neurons in vitro

    Institute of Scientific and Technical Information of China (English)

    姚洪菊; 周令望; 裴俊瑞; 刘晓娜; 王静

    2013-01-01

    目的 体外原代培养大鼠小脑颗粒神经元,为研究慢性砷暴露对小脑神经元的毒性作用提供实验方法.方法 取生后5~7天Wistar仔鼠,体式显微镜下分离小脑皮层,0.25%胰蛋白酶消化、DNA Ⅰ酶洗涤制成单细胞悬液,两次差速贴壁后接种在多聚赖氨酸包被的培养板内,相差镜下观察大鼠小脑颗粒神经元成长、发育变化及突触形成.采用神经元特异性烯醇化酶(NSE)免疫荧光技术鉴定神经元.结果 培养后第24小时,相差显微镜下可见大鼠小脑颗粒神经元贴壁,呈网状排列;第2~3天,神经元胞体由椭圆形变成圆形,轮廓逐渐清晰,细胞伸出突起,突起逐渐延长,细胞间通过突起连接,形成了稀疏的神经元突触网络;第4~6天,细胞体积进一步增大,细胞间通过广泛的突触联系,神经元清晰饱满,形成了复杂的神经元网络.共聚焦显微镜下,可见大量含NSE的神经元.结论 成功地进行了大鼠小脑颗粒神经元的原代培养,该方法可为今后研究慢性砷暴露对小脑细胞的毒性作用提供实验依据.%Objective To establish a stable primary culture of rat cerebellar granule neurons in vitro for further study the toxic effects of chronic arsenic exposure on cerebellar cells.Methods Cerebellar cortices were taken from brain of Wistar rat 5-7 day old after born under stereoscopic microscope.Single cell suspension was acquired after digestion and washing with trypsin (0.25%) and DNase Ⅰ solution,respectively.Granule cells were purified from other cells by differential velocity adherence method for two times.Rat cerebellar granule neurons were seeded in culture plate pre-coated with poly-L-lysine.Neurons growth,development and synaptic connections were observed daily.The neurons were identified by neuron specific enolase (NSE) immunofluorescence technique.Results The neurons were affixed to the culture plate in 24 hours,in reticular arrangement observed under

  3. Characterization of two novel nuclear BTB/POZ domain zinc finger isoforms. Association with differentiation of hippocampal neurons, cerebellar granule cells, and macroglia

    DEFF Research Database (Denmark)

    Mitchelmore, Cathy; Kjaerulff, Karen M; Pedersen, Hans C;

    2002-01-01

    BTB/POZ (broad complex tramtrack bric-a-brac/poxvirus and zinc finger) zinc finger factors are a class of nuclear DNA-binding proteins involved in development, chromatin remodeling, and cancer. However, BTB/POZ domain zinc finger factors linked to development of the mammalian cerebral cortex......, cerebellum, and macroglia have not been described previously. We report here the isolation and characterization of two novel nuclear BTB/POZ domain zinc finger isoforms, designated HOF(L) and HOF(S), that are specifically expressed in early hippocampal neurons, cerebellar granule cells, and gliogenic...

  4. Cr (VI) induced oxidative stress and toxicity in cultured cerebellar granule neurons at different stages of development and protective effect of Rosmarinic acid.

    Science.gov (United States)

    Dashti, Abolfazl; Soodi, Maliheh; Amani, Nahid

    2016-03-01

    Chromium (Cr) is a widespread metal ion in the workplace, industrial effluent, and water. The toxicity of chromium (VI) on various organs including the liver, kidneys, and lung were studied, but little is known about neurotoxicity. In this study, neurotoxic effects of Cr (VI) have been investigated by cultured cerebellar granule neurons (CGNs). Immature and mature neurons were exposed to different concentrations of potassium dichromate for 24 h and cytotoxicity was measured by MTT assay. In addition, immature neurons were exposed for 5 days as regards cytotoxic effect in development stages. The reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and the protective effect of Rosmarinic acid on mature and immature neurons exposed to potassium dichromate, were measured. Furthermore, lipid peroxidation, glutathione peroxidase (GPx), and acetylcholinesterase activity in mature neurons were assessed following exposure to potassium dichromate. The results indicate that toxicity of Cr (VI) dependent on maturation steps. Cr (VI) was less toxic for immature neurons. Also, Cr (VI) induced MMP reduction and ROS production in both immature and mature neurons. In Cr (VI) treated neurons, increased lipid peroxidation and GPx activity but not acetylcholinesterase activity was observed. Interestingly, Rosmarinic acid, as a natural antioxidant, could protect mature but not immature neurons against Cr (VI) induced toxicity. Our findings revealed vulnerability of mature neurons to Cr (VI) induced toxicity and oxidative stress. PMID:25213303

  5. GABA agonist induced changes in ultrastructure and GABA receptor expression in cerebellar granule cells is linked to hyperpolarization of the neurons

    DEFF Research Database (Denmark)

    Belhage, B; Hansen, G H; Schousboe, A

    1990-01-01

    GABA has been shown to exert a neurotrophic like activity by enhancing the morphological and functional maturation of neurons. Mechanisms involved in this effect of GABA are largely unknown but since GABA has been shown to mediate a hyperpolarizing action on neurons it can be assumed...... that this action might be important. In order to investigate this possibility, the ability to mimic the trophic actions of GABA of different agents known to influence the membrane potential or the GABA gated chloride channels was studied. Hence, GABA receptor expression as well as the ultrastructure of cerebellar...... granule cells were monitored after exposure of the cells in culture to either bromide, valinomycin or picrotoxin. It was found that cells which at early developmental stages (4 days in culture) were exposed to bromide or valinomycin expressed low affinity GABA receptors similar to cells treated...

  6. GABA agonist induced changes in ultrastructure and GABA receptor expression in cerebellar granule cells is linked to hyperpolarization of the neurons

    DEFF Research Database (Denmark)

    Belhage, B; Hansen, Gert Helge; Schousboe, A

    1990-01-01

    GABA has been shown to exert a neurotrophic like activity by enhancing the morphological and functional maturation of neurons. Mechanisms involved in this effect of GABA are largely unknown but since GABA has been shown to mediate a hyperpolarizing action on neurons it can be assumed that this...... action might be important. In order to investigate this possibility, the ability to mimic the trophic actions of GABA of different agents known to influence the membrane potential or the GABA gated chloride channels was studied. Hence, GABA receptor expression as well as the ultrastructure of cerebellar...... granule cells were monitored after exposure of the cells in culture to either bromide, valinomycin or picrotoxin. It was found that cells which at early developmental stages (4 days in culture) were exposed to bromide or valinomycin expressed low affinity GABA receptors similar to cells treated with the...

  7. Activation of c—Jun and suppression of phospho—p44/42 were involved in diphenylhydantoin—induced apoptosis of cultured rat cerebellar granule neurons

    Institute of Scientific and Technical Information of China (English)

    ZHAOLing-Zhi; SUXing-Wen; HUANGYi-Jun; QIUPeng-Xin; YANGGuang-Mei

    2003-01-01

    AIM:To investigate possible intracellular signal molecules involved in diphenylhydantoin (DPH)-mediated apoptosis of cerebellar granule neurons (CGN) and explore possible nolecular mechanisms of neurotoxicity of DPH.METHODS: Fluorescein diacetate (FDA) stain, hochest 33258 stain, and agar gel electrophoresis were used to test morphological and biological characters of primary CGN and cortical neurons (CN) in the presence or absence of 100μmol/L DPH; Western blot and RT-PCR were employed to further investigate apoptotic/survival signal moleculars involved in the neuronal apoptotic signal transdution. RESULTS:DPH 100μmol/L induced a typical apoptosis of CGN but had no toxicity on CN. Cerebellar granule neural apoptosis induced by 100μmol/L DPH was significantly inhibited by pre-treatment with SB203580(10μmol/L) or CEP-11004(1μmol/L) for 1h. DPH markedly upregulated the levels of phospho-c-Jun (active c-Jun), total c-Jun protein and c-jun mRNA in CGN. The levels of phospho-c-Jun dramatically elevated by DPH at 8 h were significantly inhibited by SB203580(10μmol/L) or CEP-11004 (1μmol/L). Moreover, the activities of p44/42 (ERK1/ERK2), other members of MAP kinases and generally believed to be important survival effetors in CGN, were markedly suppressed. However, the activities of both JNK and p38 were little affected in the process of apoptosis of CGN induced by 100μmol/L DPH. CONCLUSION: The selective toxicity of DPH on CGN is likely due to its ability to induce apoptosis of CGN, it is a process involved activation of c-Jun and suppression of the activity of p44/42.

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

    Science.gov (United States)

    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. PMID:26725322

  9. Neuroprotective Effect of Total and Sequential Extract of Scrophularia striata Boiss. in Rat Cerebellar Granule Neurons Following Glutamate- Induced Neurotoxicity: An In-vitro Study

    Science.gov (United States)

    Salavati, Parvin; Ramezani, Mina; Monsef-Esfahani, Hamid R; Hajiagha, Reza; Parsa, Maliheh; Tavajohi, Shoreh; Ostad, Seyed Nasser

    2013-01-01

    Neuroprotective effect of the extract from aerial parts of Scrophularia striata Boiss (Scrophulariaceae) was investigated against glutamate-induced neurotoxicity on cultured rat pups Cerebellar Granule Neurons (CGNs). CGNs from 8 days old Sprague-Dawley rat were prepared and cultured. The experiments were performed after 8 days in culture. The plant was collected from the northeastern part (Ruin region) of Iran and air-dried at room temperature. The total extract was prepared with maceration of prepared powder in ethanol 80% for three times. Sequential extracts were obtained using dried and powdered aerial parts with increasingly polar solvents: petroleum ether, chloroform, ethyl acetate and methanol 80% solution. Cultured cells were exposed to 125 μM of glutamate for 12 h following a 24 h of incubation with test fractions at concentration of 10 mcg/mL. Morphological assay was performed using invert light microscope after fixation and staining with haematoxylin. Neuronal viability was measured using MTT assay. Statistical analysis was done using SPSS software. One way analysis of variance (ANOVA) was performed by Tukey post-hoc test. Values were considered statistically significant when p-value ≤ 0.05. Results of this study showed a significant neuroprotective activity of high polarity methanolic fraction of aerial parts of Scrophularia striata against glutamate-induced neurotoxicity in a dosedependent manner. Treatment with 10 mcg/mL of the fractions showed the best result. PMID:24250613

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

    Science.gov (United States)

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

  11. Increased excitability and altered action potential waveform in cerebellar granule neurons of the Ts65Dn mouse model of Down syndrome.

    Science.gov (United States)

    Usowicz, Maria M; Garden, Claire L P

    2012-07-17

    Down syndrome (DS) is characterized by intellectual disability and impaired motor control. Lack of coordinated movement, poor balance, and unclear speech imply dysfunction of the cerebellum, which is known to be reduced in volume in DS. The principal cause of the smaller cerebellum is a diminished number of granule cells (GCs). These neurons form the 'input layer' of the cerebellar cortex, where sensorimotor information carried by incoming mossy fibers is transformed before it is conveyed to Purkinje cells and inhibitory interneurons. However, it is not known how processing of this information is affected in the hypogranular cerebellum that characterizes DS. Here we explore the possibility that the electrical properties of the surviving GCs are changed. We find that in the Ts65Dn mouse model of DS, GCs have a higher input resistance at voltages approaching the threshold for firing, which causes them to be more excitable. In addition, they fire narrower and larger amplitude action potentials. These subtly modified electrical properties may result in atypical transfer of information at the input layer of the cerebellum.

  12. Neuritin activates insulin receptor pathway to up-regulate Kv4.2-mediated transient outward K+ current in rat cerebellar granule neurons.

    Science.gov (United States)

    Yao, Jin-Jing; Gao, Xiao-Fei; Chow, Chi-Wing; Zhan, Xiao-Qin; Hu, Chang-Long; Mei, Yan-Ai

    2012-11-30

    Neuritin is a new neurotrophic factor discovered in a screen to identify genes involved in activity-dependent synaptic plasticity. Neuritin also plays multiple roles in the process of neural development and synaptic plasticity. The receptors for binding neuritin and its downstream signaling effectors, however, remain unclear. Here, we report that neuritin specifically increases the densities of transient outward K(+) currents (I(A)) in rat cerebellar granule neurons (CGNs) in a time- and concentration-dependent manner. Neuritin-induced amplification of I(A) is mediated by increased mRNA and protein expression of Kv4.2, the main α-subunit of I(A). Exposure of CGNs to neuritin markedly induces phosphorylation of ERK (pERK), Akt (pAkt), and mammalian target of rapamycin (pmTOR). Neuritin-induced I(A) and increased expression of Kv4.2 are attenuated by ERK, Akt, or mTOR inhibitors. Unexpectedly, pharmacological blockade of insulin receptor, but not the insulin-like growth factor 1 receptor, abrogates the effect of neuritin on I(A) amplification and Kv4.2 induction. Indeed, neuritin activates downstream signaling effectors of the insulin receptor in CGNs and HeLa. Our data reveal, for the first time, an unanticipated role of the insulin receptor in previously unrecognized neuritin-mediated signaling. PMID:23066017

  13. Primary culture and identification of cerebellar granule neurons from newborn rats%新生大鼠小脑颗粒神经元原代培养与鉴定

    Institute of Scientific and Technical Information of China (English)

    周礼华; 徐淑秀; 江城梅

    2011-01-01

    目的:建立一种较为理想的小脑颗粒神经元原代培养方法.方法:取新生5~7天SD大鼠,分离小脑皮质,胰酶消化后差速贴壁,种植在预先涂有左旋多聚赖氨酸的培养板内,第3天加入阿糖胞苷纯化神经元;采用神经元特异性烯醇化酶免疫细胞荧光技术鉴定神经元.结果:细胞存活率达(98±1.07)%;24 h内基本贴壁;第3天细胞突起增多、变长;培养6~8天,细胞突起交织成网,形成典型的神经细胞网络;神经元特异性烯醇化酶鉴定神经元细胞占90%左右.结论:实验获取神经元纯度较高,是小脑颗粒神经元体外培养的一种较理想的方法.%Objective: To establish a suitable primary culture method of rat cerebellar granule neurons. Methods: Rat cerebellar granule neurons were prepared from 5 -7 day old Sprague-Dawley rat pups, the cerebella was freed of meninges, minced, trypsinized,then the cell suspension was preplated for 30 min for remove any glial cells, dissociated cells were seeded at plates which had been pre-coated with Poly-L-Lysine, arabinosylcytosine was added to the culture medium on day 3 after seeding for inhibition of non-neuronal cell division. Neurons were identified by neuron-specific enolase immunofluorescence technic. Results:The survival rate of the cells was (98 ± 1.07)% ;the neurons were affixed to the culture plate after 24 hours,neurite growth was apparently on day 3,integrated neural network was formed on day 6 - 8. Cerebellar granule neurons was about 90% by neuron-specific enolase identifying. Conclusions:Neuron purity was higher in the experiment;it is a perfect technique for primary culture of rat cerebellar granule neurons.

  14. EFFECT OF GENISTEIN ON RAT CEREBELLAR GRANULE NEURON APOPTOSIS INDUCED BY ACRYLAMIDE%三羟异黄酮对丙烯酰胺致大鼠小脑颗粒神经元凋亡的影响

    Institute of Scientific and Technical Information of China (English)

    周礼华; 徐淑秀; 江城梅

    2011-01-01

    目的 探讨不同浓度三羟异黄酮(GEN)对丙烯酰胺(ACR)诱导大鼠小脑颗粒神经元(CGNs)凋亡的影响.方法 取新生5-7 d SD大鼠小脑皮质细胞培养,采用神经元特异性烯醉化酶免疫细胞荧光技术鉴定神经元,将培养8d的神经元进行随机分组,正常对照组、ACR染毒组(浓度为10 mmol/L)、GEN预处理组Ⅰ、Ⅱ,Ⅲ,Ⅳ(浓度为10、25、50、100 μmol/L的GEN预先处理细胞12h,再予ACR作用 24 h).甲基噻唑基四唑(MTT)法检测神经元活性;相差显微镜及Hoechst33342染色分别观察细胞及其核形态学变化;原位细胞凋亡检测法(TUNEL)观察神经元凋亡细胞数.结果 10 μmol/L组及25 μmol/L组GEN可拮杭ACR所致的大鼠CGNs凋亡,提高神经元活性,降低TUNEL阳性细胞数,减少ACR所致的神经元胞体皱缩、细胞核固缩等特征;而50 μmol/L组及100 μmol/L组对ACR引起的神经元凋亡没有保护作用.给论一定浓度范围的三羟异黄酮可以保护丙烯酰胺所致的大鼠CGNs凋亡.%Objective To investigate the effects of genistein (GEN) on apoptosis of rat cerebellar granule neurons induced by acrylamide (ACR) . Method Rat cerebellar granule neurons were prepared from the cerebellar cortex cells of 5-7 d -old Spragule-Dawley rat pups. The neurons were identified by neuron-specific enolase immunofluorescence technic.The 8 d cultured cells were divided randomly into control group. ACR model group. GEN pretreatment group Ⅰ ,Ⅱ ,Ⅲ,Ⅳ in which the cerebellar granule neurons were pretreated with 10. 25. 50. 100 μmol/L GEN for 12 h; and the culture medium was cleared, then changed to fresh DMEM/F-12 solution with the above mentioned GEN and 10 mmol/L ACR added for 24 h.The neuronal viability was measured by metylthiazdyltetrazolium (MTT); and their nuclei were observed by phase-contrast and Hochest33342 staining separately. Neuronal apoptosis was observed by TdT-mediated dUTP nick end labeling (TUNEL).Results GEN at the dose of 10, 25

  15. Segmental identity and cerebellar granule cell induction in rhombomere 1

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    Bell Esther

    2004-06-01

    Full Text Available Abstract Background Cerebellar granule cell precursors are specifically generated within the hindbrain segment, rhombomere 1, which is bounded rostrally by the midbrain/hindbrain isthmus and caudally by the boundary of the Hoxa2 expression domain. While graded signals from the isthmus have a demonstrable patterning role within this region, the significance of segmental identity for neuronal specification within rhombomere 1 is unexplored. We examined the response of granule cell precursors to the overexpression of Hoxa2, which normally determines patterns of development specific to the hindbrain. How much does the development of the cerebellum, a midbrain/hindbrain structure, reflect its neuromeric origin as a hindbrain segment? Results We show that a Gbx2-positive, Otx2-/Hoxa2-negative territory corresponding to rhombomere 1 forms prior to an identifiable isthmic organiser. Early global overexpression of Hoxa2 at embryonic day 0 has no effect on the expression of isthmic signalling molecules or the allocation of rhombomere 1 territory, but selectively results in the loss of granule cell markers at embryonic day 6 and the depletion of cell bodies from the external granule cell layer. By comparison the trochlear nucleus and locus coeruleus form normally in ventral rhombomere 1 under these conditions. Microsurgery, coupled with electroporation, to target Hoxa2 overexpression to rhombic lip precursors, reveals a profound, autonomous respecification of migration. Rhombic lip derivatives, normally destined to occupy the external granule cell layer, violate the cerebellar boundary to form a ventrolateral nucleus in a position comparable to that occupied by rhombic lip derived neurons in rhombomere 2. Conclusions Different overexpression strategies reveal that the recognition of migration cues by granule cell precursors is dependent on their identity as rhombomere 1 derivatives. Segmental patterning cues operate autonomously within the rhombic lip

  16. Neuroglobin Plays a Protective Role in Arsenite-Induced Cytotoxicity by Inhibition of Cdc42 and Rac1GTPases in Rat Cerebellar Granule Neurons

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    Xiaona Liu

    2015-07-01

    Full Text Available Background and Aims: We have previously shown that neuroglobin (Ngb expression can be regulated by sodium arsenite (NaAsO2 exposure in rat cerebellar granule neurons (CGNs. However, the precise molecular mechanisms of Ngb action are largely unknown. Ras homolog (Rho guanosine triphosphatases (Rho GTPases are involved in the regulation of a number of cellular processes, including cell cytotoxicity. It has been reported that Ngb can act as a guanine nucleotide dissociation inhibitior (GDI role to inactivate Rho GTPases. Therefore, we investigated Rho GTPases activation induced by NaAsO2 exposure in rat CGNs and effects of Rho GTPases activation on the cells. We also investigated the role of Ngb in this process. Methods: Primary cultures of CGNs were prepared from 7-day-old Wistar rat pups. The cytotoxic effects of NaAsO2 on CGNs were evaluated using the Cell Counting Kit-8 assay and TUNEL staining. RNA interference technology was used to silence Ngb, and the subsequent effects were evaluated by quantitative RT-PCR and Western blot. Cdc42 and Rac1 activation were measured by pull-down assay and Western blot. Results: NaAsO2 induced cytotoxicity in rat CGNs, increased GTP-bound form of Cdc42 and Rac1 GTPases in the cells. Furthermore, inhibition of Cdc42 or Rac1 activity using the inhibitor ZCL278 or NSC23766 decreased apoptosis and increased cell viability in the cells exposed to NaAsO2. Using siRNA-mediated knockdown, we show that NaAsO2-induced cytotoxicity was exacerbated, activation of Cdc42 (GTP-Cdc42 and Rac1 (GTP-Rac1 was increased in Ngb RNA silencing cells. Conclusions: cytotoxic effects of NaAsO2 on rat CGNs is induced at least partly by Cdc42 and Rac1 activation, and Ngb can inhibit Cdc42 and Rac1 activation to play protective role in rat CGNs exposed to NaAsO2.

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

    Science.gov (United States)

    Morales, Daniver; Hatten, Mary E

    2006-11-22

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

  18. Properties of bilateral spinocerebellar activation of cerebellar cortical neurons

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    Pontus eGeborek

    2014-10-01

    Full Text Available We aimed to explore the cerebellar cortical inputs from two spinocerebellar pathways, the spinal border cell-component of the ventral spinocerebellar tract (SBC-VSCT and the dorsal spinocerebellar tract (DSCT, respectively, in the sublobule C1 of the cerebellar posterior lobe. The two pathways were activated by electrical stimulation of the contralateral lateral funiculus (coLF and the ipsilateral LF (iLF at lower thoracic levels. Most granule cells in sublobule C1 did not respond at all but part of the granule cell population displayed high-intensity responses to either coLF or iLF stimulation. As a rule, Golgi cells and Purkinje cell simple spikes responded to input from both LFs, although Golgi cells could be more selective. In addition, a small population of granule cells responded to input from both the coLF and the iLF. However, in these cases, similarities in the temporal topography and magnitude of the responses suggested that the same axons were stimulated from the two LFs, i.e. that the axons of individual spinocerebellar neurons could be present in both funiculi. This was also confirmed for a population of spinal neurons located within known locations of SBC-VSCT neurons and dorsal horn DSCT neurons. We conclude that bilateral spinocerebellar responses can occur in cerebellar granule cells, but the VSCT and DSCT systems that provide the input can also be organized bilaterally. The implications for the traditional functional separation of VSCT and DSCT systems and the issue whether granule cells primarily integrate functionally similar information or not are discussed.

  19. 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.

    Science.gov (United States)

    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.

  20. Acute ethanol exposure inhibits silencing of cerebellar Golgi cell firing induced by granule cell axon input

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    Paolo eBotta

    2014-02-01

    Full Text Available Golgi cells (GoCs are specialized interneurons that provide inhibitory input to granule cells in the cerebellar cortex. GoCs are pacemaker neurons that spontaneously fire action potentials, triggering spontaneous inhibitory postsynaptic currents in granule cells and also contributing to the generation tonic GABAA receptor-mediated currents in granule cells. In turn, granule cell axons provide feedback glutamatergic input to GoCs. It has been shown that high frequency stimulation of granule cell axons induces a transient pause in GoC firing in a type 2-metabotropic glutamate receptor (mGluR2-dependent manner. Here, we investigated the effect ethanol on the pause of GoC firing induced by high frequency stimulation of granule cell axons. GoC electrophysiological recordings were performed in parasagittal cerebellar vermis slices from postnatal day 23 to 26 rats. Loose-patch cell-attached recordings revealed that ethanol (40 mM reversibly decreases the pause duration. An antagonist of mGluR2 reduced the pause duration but did not affect the effect of ethanol. Whole-cell voltage-clamp recordings showed that currents evoked by an mGluR2 agonist were not significantly affected by ethanol. Perforated-patch experiments in which hyperpolarizing and depolarizing currents were injected into GoCs demonstrated that there is an inverse relationship between spontaneous firing and pause duration. Slight inhibition of the Na+/K+ pump mimicked the effect of ethanol on pause duration. In conclusion, ethanol reduces the granule cell axon-mediated feedback mechanism by reducing the input responsiveness of GoCs. This would result in a transient increase of GABAA receptor-mediated inhibition of granule cells, limiting information flow at the input stage of the cerebellar cortex.

  1. The critical role of lipid rafts nanodomains in the cross-talk between calcium and reactive oxygen and nitrogen species in cerebellar granule neurons apoptosis by extracellular potassium deprivation

    Directory of Open Access Journals (Sweden)

    Carlos Gutierrez-Merino

    2016-01-01

    Full Text Available The apoptosis of cerebellar granule neurons (CGN induced by low-potassium in serum free medium in vitro has become a widely used model for neuronal apoptosis during in vivo brain development. In this review we shall summarize first the basic features of this model for neuronal apoptosis. Next, we shall focus on the L-type calcium channels (LTCC inactivation as the primary pro-apoptotic signal in low K+-induced CGN death. This apoptotic process can be split into two major and sequential cellular signaling phases: one reversible phase that offers a temporal window for therapeutic interventions to prevent neuronal death, and an irreversible later phase. Therefore, we shall comment next the critical role of reactive oxygen species (ROS production and major ROS sources triggering the entry of CGN in the irreversible stages of low K+-induced apoptosis. Then, we shall present the experimental evidences showing clustering of LTCC and ROS producing enzymes in plasma membrane lipid rafts of CGN matured in vitro, which have opened new perspectives for cell signaling in the early and reversible phase of this apoptosis. The role of lipid rafts nanodomains as fast response calcium/nitric oxide transducers of the switch of CGN to low K+ medium will be discussed next. The two major conclusions drawn from this review are: (1 deregulation of the pool of cytochrome b5 reductase associated to plasma membrane-lipid rafts, at least in part due to overexpression of cytochrome b5, can account for the critical superoxide anion overshot which triggers the entry in the irreversible phase of low K+ apoptosis of CGN, and (2 LTCC inactivation is rapidly transduced by lipid rafts nanodomains into a large drop of cytosolic calcium, a switch-off of nitric oxide production and subsequent inactivation of survival signaling pathways dependent on the activity of CaMKII, PKA and Akt/PKB kinases.

  2. Stimulation of the N-methyl-D-aspartate receptor has a trophic effect on differentiating cerebellar granule cells

    DEFF Research Database (Denmark)

    Balázs, R; Hack, N; Jørgensen, Ole Steen

    1988-01-01

    N-methyl-D-aspartate (NMDA) supplementation of cerebellar cultures enriched in granule neurones (about 90%) prevented the extensive cell loss which occurs when cultivation takes place, in serum containing media, in the presence of 'low' K+ (5-15 mM). Estimation of tetanus toxin receptors and N...

  3. GABA agonist promoted formation of low affinity GABA receptors on cerebellar granule cells is restricted to early development

    DEFF Research Database (Denmark)

    Belhage, B; Hansen, G H; Schousboe, A;

    1988-01-01

    The ability of the GABA receptor agonist 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP) to promote formation of low affinity GABA receptors on cerebellar granule cells was tested using primary cultures of these neurons. Granule cells were exposed to THIP (150 microM) for 6 hr after......, respectively, 4, 7, 10 and 14 days in culture. It was found that THIP treatment of 4- and 7-day-old cultures led to formation of low affinity GABA receptors, whereas such receptors could not be detected after THIP treatment in the older cultures (10 and 14 days) in spite of the fact that these cultured granule...... cells expressed a high density of high affinity GABA receptors. It is concluded that the ability of THIP to promote formation of low affinity GABA receptors on cerebellar granule cells is restricted to an early developmental period....

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

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    Christian eRössert

    2014-10-01

    Full Text Available 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 modelling 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-fibre 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-fibre 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.

  5. GlyT2+ Neurons in the Lateral Cerebellar Nucleus

    OpenAIRE

    Uusisaari, Marylka; Knöpfel, Thomas

    2009-01-01

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

  6. Effect of orphan nuclear receptor NR4A1 expression on oxygen-glucose deprivation-induced apoptosis in cultured rots cerebellar granule neurons%孤儿核受体NR4A1表达对氧-葡萄糖剥夺诱导培养大鼠小脑颗粒神经元凋亡的影响

    Institute of Scientific and Technical Information of China (English)

    肖国栋; 成松明; 孙涛; 曹勇军

    2013-01-01

    Objective To investigate the effect of orphan nuclear receptor NR4A1 expression on oxygenglucose deprivation (OGD)-induced apoptosis in cultured rat cerebellar granule neurons and its possible mechanisms.Methods Primary rat cerebellar granule neurons were cultured for 7 to 8 days,and then treated with OGD.The activity of cultured rat cerebellar granule neurons was assessed by methyl thiazolyl tetrazolium (MTT) assay,apoptosis was detected with flow cytometry,the expressions of NR4A1,caspase-3 and cytochrome c were determined by Western blot analysis,NR4A1 mRNA expression was detected with real-time polymerase chain reaction.The rat cerebellar granule neurons were transfected with lentiviral vector-encoding rat NR4A1.The apoptotic rates and expressions of caspase-3 and cytochrome c in rat cerebellar granule neurons transfected with NR4A1 were detected after OGD.Results The activity of rat cerebellar granule neurons decreased significantly,the apoptotic rate increased significantly,the expressions of NR4A1 mRNA and protein as well as caspase-3 and cytochrome c incrased significantly along with the OGD time.NR4A1 was overexpressed,apoptosis rate was significantly reduced in rat cerebellar granule neurons transfected with NR4A1.The expressions of caspase-3 and cytochrome c were significantly reduced in the rat cerebellar granule neurons transfected with NR4A1 after OGD.Conclusions NR4A1 overexpression may reduce OGD-induced apoptosis in rat cerebellar granule neurons by downregulating the expressions of caspase-3 and cytochrome c.%目的 探讨孤儿核受体NR4A1表达对氧-葡萄糖剥夺(oxy gen-glucose deprivation,OGD)诱导培养大鼠小脑颗粒神经元凋亡的影响及其可能机制.方法 大鼠小脑颗粒细胞原代培养7~8 d后给予OGD处理.应用四甲基偶氮唑蓝法检测细胞活性,流式细胞术检测细胞凋亡率,蛋白质印迹法检测NR4A1、胱天蛋白酶-3和细胞色素c蛋白表达,实时定量聚合酶链反应检测NR4A1m

  7. Protective effects of genistein against apoptosis induced by acrylamide in cultured rat cerebellar granule neurons%三羟异黄酮对丙烯酰胺诱导大鼠小脑颗粒神经元凋亡的保护作用

    Institute of Scientific and Technical Information of China (English)

    周礼华; 徐淑秀; 江城梅

    2011-01-01

    OBJECTIVE: To investigate the protective effects of genistein on apoptosis of rat cerebellar granule neurons induced by acrylamide. METHODS: Rat cerebellar granule neurons were prepared from the cerebellar cortex cells of 5-7day-old SD rats pups. The neurons were identified by Nissl staining method.The 8-day cultured cells passage were divided randomly into control group, acrylamide model group, genistein pretreatment group Ⅰ ,Ⅱ , Ⅲ (cerebellar granule neurons were pretreated with 10,25,50 μ mol/L genistein for 12 hours,the culture medium discarded and fresh DMEM/F12 solution added with the above mentioned concentration of genistein with 10 mmol/L acrylamide tocultured neurons for 24 hours). The neuronal viability was measured by MTT. Morphology of neurons and their nuclei were examined by phase-contrast and Hochest33342 staining,respectively. The ratio of apoptotic cells was detected by TUNEL.RESULTS: The cell survival rates of genistein pretreatment group Ⅱ and Ⅲ were not significantly higher than acrylamide model group. Genistein pretreatment group Ⅰ significantly prolonged the cell survival rate. The effects of diminished neuronal body, chromatin concentration and the ratio of apoptotic cells induced by acrylamide were markedly weakened.CONCLUSION: Genistein did not show a dose-dependent effect on protection. The appropriate concentration of 10 μ mol/L was found to protect against apoptosis induced by acrylamide in primary culture of cerebellar granule neurons.%目的:探讨三羟异黄酮(genistein,GEN)对丙烯酰胺(acrylamide,ACR)诱导的大鼠小脑颗粒神经元凋亡的保护作用.方法:取新生5~7 d的SD大鼠小脑皮质细胞进行培养,采用尼氏染色法鉴定神经元,将培养8 d的神经元随机分成5组:正常对照组、ACR染毒组(浓度为10mmol/L)以及CEN不同浓度保护组(染毒前分别用浓度为10、25、50μmol/L的GEN预先处理细胞12h,再给予ACR染毒24 h).MTT法检测细胞

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

    International Nuclear Information System (INIS)

    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, differentiation 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

  9. Expression of NR2B in cerebellar granule cells specifically facilitates effect of motor training on motor learning.

    Directory of Open Access Journals (Sweden)

    Jianwei Jiao

    Full Text Available It is believed that gene/environment interaction (GEI plays a pivotal role in the development of motor skills, which are acquired via practicing or motor training. However, the underlying molecular/neuronal mechanisms are still unclear. Here, we reported that the expression of NR2B, a subunit of NMDA receptors, in cerebellar granule cells specifically enhanced the effect of voluntary motor training on motor learning in the mouse. Moreover, this effect was characterized as motor learning-specific and developmental stage-dependent, because neither emotional/spatial memory was affected nor was the enhanced motor learning observed when the motor training was conducted starting at the age of 3 months old in these transgenic mice. These results indicate that changes in the expression of gene(s that are involved in regulating synaptic plasticity in cerebellar granule cells may constitute a molecular basis for the cerebellum to be involved in the GEI by facilitating motor skill learning.

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

    Directory of Open Access Journals (Sweden)

    Bob eJacobs

    2014-04-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

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

    OpenAIRE

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

    2015-01-01

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

  13. Weaver mutant mouse cerebellar granule cells respond normally to chronic depolarization

    DEFF Research Database (Denmark)

    Bjerregaard, Annette; Mogensen, Helle Smidt; Hack, N;

    1997-01-01

    We studied the effects of chronic K(+)-induced membrane depolarization and treatment with N-methyl-D-aspartate (NMDA) on cerebellar granule cells (CGCs) from weaver mutant mice and non-weaver litter-mates. The weaver mutation is a Gly-to-Ser substitution in a conserved region of the Girk2 G prote...

  14. N-methyl-D-aspartate promotes the survival of cerebellar granule cells: pharmacological characterization

    DEFF Research Database (Denmark)

    Balázs, R; Hack, N; Jørgensen, Ole Steen;

    1989-01-01

    The survival of cerebellar granule cells in culture is promoted by chronic exposure to N-methyl-D-aspartate (NMDA). The effect is due to the stimulation of 'conventional' NMDA receptor-ionophore complex: it is concentration dependent, voltage dependent and blocked by the selective antagonists D-2...

  15. Requirement for zebrafish ataxin-7 in differentiation of photoreceptors and cerebellar neurons.

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    Constantin Yanicostas

    Full Text Available The expansion of a polyglutamine (polyQ tract in the N-terminal region of ataxin-7 (atxn7 is the causative event in spinocerebellar ataxia type 7 (SCA7, an autosomal dominant neurodegenerative disorder mainly characterized by progressive, selective loss of rod-cone photoreceptors and cerebellar Purkinje and granule cells. The molecular and cellular processes underlying this restricted neuronal vulnerability, which contrasts with the broad expression pattern of atxn7, remains one of the most enigmatic features of SCA7, and more generally of all polyQ disorders. To gain insight into this specific neuronal vulnerability and achieve a better understanding of atxn7 function, we carried out a functional analysis of this protein in the teleost fish Danio rerio. We characterized the zebrafish atxn7 gene and its transcription pattern, and by making use of morpholino-oligonucleotide-mediated gene inactivation, we analysed the phenotypes induced following mild or severe zebrafish atxn7 depletion. Severe or nearly complete zebrafish atxn7 loss-of-function markedly impaired embryonic development, leading to both early embryonic lethality and severely deformed embryos. More importantly, in relation to SCA7, moderate depletion of the protein specifically, albeit partially, prevented the differentiation of both retina photoreceptors and cerebellar Purkinje and granule cells. In addition, [1-232] human atxn7 fragment rescued these phenotypes showing strong function conservation of this protein through evolution. The specific requirement for zebrafish atxn7 in the proper differentiation of cerebellar neurons provides, to our knowledge, the first in vivo evidence of a direct functional relationship between atxn7 and the differentiation of Purkinje and granule cells, the most crucial neurons affected in SCA7 and most other polyQ-mediated SCAs. These findings further suggest that altered protein function may play a role in the pathophysiology of the disease, an

  16. Does cerebellar neuronal integrity relate to cognitive ability?

    International Nuclear Information System (INIS)

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

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

    DEFF Research Database (Denmark)

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

    1991-01-01

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

  18. [EXPRESSION OF DOUBLECORTIN AND NeuN IN THE DEVELOPING CEREBELLAR NEURONS IN RAT].

    Science.gov (United States)

    Zimatkin, S M; Karniushko, O A

    2016-01-01

    This work was performed on the offspring of 5 outbred female albino rats to give a comparative immunohistochemical evaluation of doublecortin (DCX) and NeuN expression in the neurons of the cerebellar cortex and nucleus interpositus in the early postnatal ontogenesis (postnatal days 2-15). DCX expression was detected in postmitotic neurons of the external granular layer and migrating neurons of the cerebellar cortex. At postnatal days 2 and 7 DCX expression in neocerebellum was higher than in paleocerebellum. NeuN expression was found to appear in migrating granule neurons, and reach the maximum in mature neurons of internal granular layer. DCX expression was not detected in Purkinje cells and in the nucleus interpositus of the cerebellum. In neurons of the nucleus interpositus the expression of NeuN progressively increased from postnatal days 2 to 15. Thus, a comparative immunohistochemical study of the dynamics of the expression of the pair of molecular markers studied proved to be an effective way of the assessment of the development of granular neurons of the cerebellum in early postnatal ontogenesis. PMID:27487661

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

    Directory of Open Access Journals (Sweden)

    Elisa Galliano

    2013-04-01

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

  20. Mitotic Events in Cerebellar Granule Progenitor Cells that Expand Cerebellar Surface Area Are Critical for Normal Cerebellar Cortical Lamination in Mice

    Science.gov (United States)

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

    2015-01-01

    Late embryonic and postnatal cerebellar folial surface area expansion promotes cerebellar cortical cytoarchitectural lamination. We developed a streamlined sampling scheme to generate unbiased estimates of murine cerebellar surface area and volume using stereological principles. We demonstrate that during the proliferative phase of the external granule layer (EGL) and folial surface area expansion, EGL thickness does not change and thus is a topological proxy for progenitor self-renewal. The topological constraints indicate that during proliferative phases, migration out of the EGL is balanced by self-renewal. Progenitor self-renewal must, therefore, include mitotic events yielding either 2 cells in the same layer to increase surface area (β-events) and mitotic events yielding 2 cells, with 1 cell in a superficial layer and 1 cell in a deeper layer (α-events). As the cerebellum grows, therefore, β-events lie upstream of α-events. Using a mathematical model constrained by the measurements of volume and surface area, we could quantify inter-mitotic times for β-events on a per-cell basis in post-natal mouse cerebellum. Furthermore, we found that loss of CCNA2, which decreases EGL proliferation and secondarily induces cerebellar cortical dyslamination, shows preserved α-type events. Thus, CCNA2-null cerebellar granule progenitor cells are capable of self-renewal of the EGL stem cell niche; this is concordant with prior findings of extensive apoptosis in CCNA2-null mice. Similar methodologies may provide another layer of depth to the interpretation of results from stereological studies. PMID:25668568

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

    Science.gov (United States)

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

    2016-01-01

    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 (p75NTR) 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 p75NTR 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 p75NTR, GCPs continue to proliferate beyond their normal period, resulting in a larger cerebellum that persists into adulthood, with consequent motor deficits. DOI: http://dx.doi.org/10.7554/eLife.16654.001 PMID:27434667

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

    Science.gov (United States)

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

    2015-12-01

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

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

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Hösli, E; Belhage, B;

    1991-01-01

    . At the light microscope level specific staining of GABAA-receptors was localized in various types of neurones in explant cultures of rat cerebellum using the indirect peroxidase-antiperoxidase (PAP) technique, whereas no specific staining was found in astrocytes. At the electron microscope level labeling...... of GABAA-receptors was observed in the plasma membrane of both the cell bodies and processes in dissociated primary cultures of cerebellar granule cells using an indirect preembedding immunogold staining technique which in contrast to the classical PAP technique allows quantitative estimations...... to be performed. Quantification of the labeling intensity revealed a higher concentration of GABAA-receptors per microns plasma membrane in the cell bodies than in the processes. In discrete areas an extremely high density of the GABAA-receptors was observed. No specific labeling of GABAA-receptors was observed...

  4. Spontaneous calcium waves in granule cells in cerebellar slice cultures

    DEFF Research Database (Denmark)

    Apuschkin, Mia; Ougaard, Maria; Rekling, Jens C

    2013-01-01

    Multiple regions in the CNS display propagating correlated activity during embryonic and postnatal development. This activity can be recorded as waves of increased calcium concentrations in spiking neurons or glia cells, and have been suggested to be involved in patterning, axonal guidance...

  5. Mitochondria and calcium flux as targets of neuroprotection caused by minocycline in cerebellar granule cells

    OpenAIRE

    Garcia-Martinez, Eva Maria; Sanz-Blasco, Sara; Karachitos, Andonis; Bandez, Miguel J.; Fernandez-Gomez, Francisco J.; Perez-Alvarez, Sergio; Mera, Raquel Maria Melero Fernandez De; Jordan, Maria J.; Aguirre, Norberto; Galindo, Maria F.; Villalobos, Carlos; Navarro, Ana; Kmita, Hanna; Jordán, Joaquín

    2009-01-01

    Abstract Minocycline, an antibiotic of the tetracycline family, has attracted considerable interest for its theoretical therapeutic applications in neurodegenerative diseases. However, the mechanism of action underlying its effect remains elusive. Here we have studied the effect of minocycline under excitotoxic conditions. Fluorescence and bioluminescence imaging studies in rat cerebellar granular neuron cultures using fura-2/AM and mitochondria-targeted aequorin revealed that mino...

  6. Coordinated scaling of cortical and cerebellar numbers of neurons

    Directory of Open Access Journals (Sweden)

    Suzana Herculano-Houzel

    2010-03-01

    Full Text Available While larger brains possess concertedly larger cerebral cortices and cerebella, the relative size of the cerebral cortex increases with brain size, but relative cerebellar size does not. In the absence of data on numbers of neurons in these structures, this discrepancy has been used to dispute the hypothesis that the cerebral cortex and cerebellum function and have evolved in concert and to support a trend towards neocorticalization in evolution. However, the rationale for interpreting changes in absolute and relative size of the cerebral cortex and cerebellum relies on the assumption that they reflect absolute and relative numbers of neurons in these structures across all species – an assumption that our recent studies have shown to be flawed. Here I show for the first time that the numbers of neurons in the cerebral cortex and cerebellum are directly correlated across 19 mammalian species of 4 different orders, including humans, and increase concertedly in a similar fashion both within and across the orders Eulipotyphla (Insectivora, Rodentia, Scandentia and Primata, such that on average a ratio of 3.6 neurons in the cerebellum to every neuron in the cerebral cortex is maintained across species. This coordinated scaling of cortical and cerebellar numbers of neurons provides direct evidence in favor of concerted function, scaling and evolution of these brain structures, and suggests that the common notion that equates cognitive advancement with neocortical expansion should be revisited to consider in its stead the coordinated scaling of neocortex and cerebellum as a functional ensemble.

  7. Probabilistic identification of cerebellar cortical neurones across species.

    Directory of Open Access Journals (Sweden)

    Gert Van Dijck

    Full Text Available Despite our fine-grain anatomical knowledge of the cerebellar cortex, electrophysiological studies of circuit information processing over the last fifty years have been hampered by the difficulty of reliably assigning signals to identified cell types. We approached this problem by assessing the spontaneous activity signatures of identified cerebellar cortical neurones. A range of statistics describing firing frequency and irregularity were then used, individually and in combination, to build Gaussian Process Classifiers (GPC leading to a probabilistic classification of each neurone type and the computation of equi-probable decision boundaries between cell classes. Firing frequency statistics were useful for separating Purkinje cells from granular layer units, whilst firing irregularity measures proved most useful for distinguishing cells within granular layer cell classes. Considered as single statistics, we achieved classification accuracies of 72.5% and 92.7% for granular layer and molecular layer units respectively. Combining statistics to form twin-variate GPC models substantially improved classification accuracies with the combination of mean spike frequency and log-interval entropy offering classification accuracies of 92.7% and 99.2% for our molecular and granular layer models, respectively. A cross-species comparison was performed, using data drawn from anaesthetised mice and decerebrate cats, where our models offered 80% and 100% classification accuracy. We then used our models to assess non-identified data from awake monkeys and rabbits in order to highlight subsets of neurones with the greatest degree of similarity to identified cell classes. In this way, our GPC-based approach for tentatively identifying neurones from their spontaneous activity signatures, in the absence of an established ground-truth, nonetheless affords the experimenter a statistically robust means of grouping cells with properties matching known cell classes. Our

  8. Temporal development of GABA agonist induced alterations in ultrastructure and GABA receptor expression in cultured cerebellar granule cells

    DEFF Research Database (Denmark)

    Hansen, G H; Belhage, B; Schousboe, A;

    1987-01-01

    The temporal development of the effect of THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) on the ultrastructure composition and GABA receptor expression in cerebellar granule cells was investigated by quantitative electron microscopy (morphometric analysis) and GABA binding assays...... exposed to THIP (150 microM) for 3 hr low affinity GABA receptors were induced. These findings show that the effect of THIP on the ultrastructure composition and GABA receptor expression in cultured cerebellar granule cells may be interrelated and moreover it is likely that the turn-over of GABA receptors...

  9. Temporal development of GABA agonist induced alterations in ultrastructure and GABA receptor expression in cultured cerebellar granule cells

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Belhage, B; Schousboe, A;

    1987-01-01

    The temporal development of the effect of THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) on the ultrastructure composition and GABA receptor expression in cerebellar granule cells was investigated by quantitative electron microscopy (morphometric analysis) and GABA binding assays. It was...... exposed to THIP (150 microM) for 3 hr low affinity GABA receptors were induced. These findings show that the effect of THIP on the ultrastructure composition and GABA receptor expression in cultured cerebellar granule cells may be interrelated and moreover it is likely that the turn-over of GABA receptors...

  10. Glutamate-induced protein phosphorylation in cerebellar granule cells: role of protein kinase C.

    Science.gov (United States)

    Eboli, M L; Mercanti, D; Ciotti, M T; Aquino, A; Castellani, L

    1994-10-01

    Protein phosphorylation in response to toxic doses of glutamate has been investigated in cerebellar granule cells. 32P-labelled cells have been stimulated with 100 microM glutamate for up to 20 min and analysed by one and two dimensional gel electrophoresis. A progressive incorporation of label is observed in two molecular species of about 80 and 43 kDa (PP80 and PP43) and acidic isoelectric point. Glutamate-stimulated phosphorylation is greatly reduced by antagonists of NMDA and non-NMDA glutamate receptors. The effect of glutamate is mimicked by phorbol esters and is markedly reduced by inhibitors of protein kinase C (PKC) such as staurosporine and calphostin C. PP80 has been identified by Western blot analysis as the PKC substrate MARCKS (myristoylated alanine-rich C kinase substrate), while antibody to GAP-43 (growth associated protein-43), the nervous tissue-specific substrate of PKC, failed to recognize PP43. Our results suggest that PKC is responsible for the early phosphorylative events induced by toxic doses of glutamate in cerebellar granule cells. PMID:7891841

  11. Effects of inhibitors of protein synthesis and intracellular transport on the gamma-aminobutyric acid agonist-induced functional differentiation of cultured cerebellar granule cells

    DEFF Research Database (Denmark)

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

    1990-01-01

    differentiation and GABA receptor expression was investigated in cultured cerebellar granule cells. After 4 days in culture the neurons were exposed to the inhibitors for 6 h in the simultaneous presence of THIP. Subsequently, cultures were either fixed for electron microscopic examination or used for preparation...... of membranes for [3H]GABA binding assays. In some experiments the functional activity of the newly induced low-affinity GABA receptors was assessed by investigation of the ability of GABA to inhibit neurotransmitter release from the neurons. These experiments were performed to differentiate between...... an intracellular and a plasma membrane localization of the receptors. In all experiments cultures treated with THIP alone served as controls. The inhibitors of protein synthesis totally abolished the ability of THIP to induce low-affinity GABA receptors. In contrast, the inhibitors of intracellular transport...

  12. Perinatal exposure to low-dose methylmercury induces dysfunction of motor coordination with decreases in synaptophysin expression in the cerebellar granule cells of rats.

    Science.gov (United States)

    Fujimura, Masatake; Cheng, Jinping; Zhao, Wenchang

    2012-06-29

    Methylmercury (MeHg) is an environmental pollutant that is toxic to the developing central nervous system (CNS) in children, even at low exposure levels. Perinatal exposure to MeHg is known to induce neurological symptoms with neuropathological changes in the CNS. However, the relationship between the neurological symptoms and neuropathological changes induced in offspring as a result of exposure to low-dose MeHg is not well defined. In the present study, neurobehavioral analyses revealed that exposure to a low level of MeHg (5 ppm in drinking water) during developmental caused a significant deficit in the motor coordination of rats in the rotating rod test. In contrast, general neuropathological findings, including neuronal cell death and the subsequent nerve inflammation, were not observed in the region of the cerebellum responsible for regulating motor coordination. Surprisingly, the expression of synaptophysin (SPP), a marker protein for synaptic formation, significantly decreased in cerebellar granule cells. These results showed that perinatal exposure to low-dose MeHg causes neurobehavioral impairment without general neuropathological changes in rats. We demonstrated for the first time that exposure to low-dose MeHg during development induces the dysfunction of motor coordination due to changes of synaptic homeostasis in cerebellar granule cells.

  13. Depletion of polyamines prevents the neurotrophic activity of the GABA-agonist THIP in cultured rat cerebellar granule cells

    DEFF Research Database (Denmark)

    Abraham, J H; Hansen, Gert Helge; Seiler, N;

    1993-01-01

    Effects of polyamine depletion by alpha-difluoromethylornithine (DFMO) were studied on the GABA-agonist mediated enhancement of the morphological development of cultured rat cerebellar granule cells. An increase in the number of neurite extending cells and in the cytoplasmic density of organelles...... morphological development of the granule cell cultures. Thus, the number of neurite extending cells was reduced to 50% of the number in the control cultures upon culturing in the presence of DFMO alone or in combination with THIP. Moreover, the THIP mediated increase in the cytoplasmic density of rough...

  14. Conditional knockout of tumor overexpressed gene in mouse neurons affects RNA granule assembly, granule translation, LTP and short term habituation.

    Directory of Open Access Journals (Sweden)

    Elisa Barbarese

    Full Text Available In neurons, specific RNAs are assembled into granules, which are translated in dendrites, however the functional consequences of granule assembly are not known. Tumor overexpressed gene (TOG is a granule-associated protein containing multiple binding sites for heterogeneous nuclear ribonucleoprotein (hnRNP A2, another granule component that recognizes cis-acting sequences called hnRNP A2 response elements (A2REs present in several granule RNAs. Translation in granules is sporadic, which is believed to reflect monosomal translation, with occasional bursts, which are believed to reflect polysomal translation. In this study, TOG expression was conditionally knocked out (TOG cKO in mouse hippocampal neurons using cre/lox technology. In TOG cKO cultured neurons granule assembly and bursty translation of activity-regulated cytoskeletal associated (ARC mRNA, an A2RE RNA, are disrupted. In TOG cKO brain slices synaptic sensitivity and long term potentiation (LTP are reduced. TOG cKO mice exhibit hyperactivity, perseveration and impaired short term habituation. These results suggest that in hippocampal neurons TOG is required for granule assembly, granule translation and synaptic plasticity, and affects behavior.

  15. Gamma-aminobutyric acid agonist-induced alterations in the ultrastructure of cultured cerebellar granule cells is restricted to early development

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Belhage, B; Schousboe, A;

    1988-01-01

    The effect of 4,5,6,7-tetrahydroisoxazolo[5,4-c]-pyridin-3-ol (THIP) on the ultrastructural composition of cultured cerebellar granule cells was investigated during development by quantitative electron microscopy (morphometric analysis). Granule cells were exposed to THIP (150 microM) for 6 h aft...... of these organelles was observed in 14-day-old cultures exposed to THIP for 6 h. These findings show that the effect of THIP on the ultrastructural composition of cultured cerebellar granule cells is restricted to early development.......The effect of 4,5,6,7-tetrahydroisoxazolo[5,4-c]-pyridin-3-ol (THIP) on the ultrastructural composition of cultured cerebellar granule cells was investigated during development by quantitative electron microscopy (morphometric analysis). Granule cells were exposed to THIP (150 microM) for 6 h after...

  16. Effects of long-term hypothyroidism in the morphology and synaptic organization of cerebellar ectopic granule cells

    OpenAIRE

    Madeira, M. D.; Azevedo, F.P.; Paula-Barbosa, M M

    1988-01-01

    Abundant ectopic granule cells scattered in the cerebellar molecular layer have been observed in 30- day-old hypothyroid rats. Their morphological features indicate that they must be regarded as mature heterotopic cells arrested during their migration towards the granular layer. As their impoverished dendritic trees are identical to those seen in controls, it is unlikely that the lack of thyroid hormones played a major role in the deficient dendritic outgrowth....

  17. Somatostatin receptors are expressed by immature cerebellar granule cells: evidence for a direct inhibitory effect of somatostatin on neuroblast activity.

    OpenAIRE

    Gonzalez, B; Leroux, P.; Lamacz, M; Bodenant, C; Balazs, R.; Vaudry, H.

    1992-01-01

    Somatostatin and somatostatin receptors are transiently expressed in the immature rat cerebellar cortex but virtually undetectable in the cerebellum of adults. Although somatostatin binding sites have been visualized during the postnatal period in the external granule cell layer, the type of cell that expresses somatostatin receptors has never been identified; thus, the potential function of somatostatin in the developing cerebellum remains unknown. In the present study, we have taken advanta...

  18. Dynamic changes of [Ca2+]i in cerebellar granule cells exposed to pulsed electric fields

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Intracellular free Ca2+ concentration ([Ca2+]i) in embryonic chick cerebellar granule cells loaded with fluo-3/AM and exposed to a single pulsed electric field was investigated using a confocal laser scanning microscope and fluorescent microscope equipped with CCD video imaging system.The results showed that [Ca2+]i increased immediately and rose to the peak rapidly as the cells exposed to a single pulsed electric field.The amplitude and rate of the increases of [Ca2+]i depend on the intensity of external electric field.In the presence of Ca2+ chelant EGTA or Ca2+ channels blocker La3+ in the pulsation solutions,the increase of [Ca2+]i was still observable.It was also observed that [Ca2+]i of different intracellular areas in the cell elevated simultaneously while the peak of the increase of [Ca2+]i in the poles of the cell preceded to the peak in its somata and recovered to a plateau within a short time.

  19. Dynamic changes of [Ca2+]i in cerebellar granule cells exposed to pulsed electric fields

    Institute of Scientific and Technical Information of China (English)

    陈雅; 王彦; 孙彤; 张锦珠; 景向红; 李瑞午

    2000-01-01

    Intracellular free Ca2+ concentration ([Ca2+]i) in embryonic chick cerebellar granule cells loaded with fluo-3/AM and exposed to a single pulsed electric field was investigated using a confocal laser scanning microscope and fluorescent microscope equipped with CCD video imaging system. The results showed that [Ca2+]i increased immediately and rose to the peak rapidly as the cells exposed to a single pulsed electric field. The amplitude and rate of the increases of [Ca2+]i depend on the intensity of external electric field. In the presence of Ca2+ chelant EGTA or Ca2+ channels blocker La3+ in the pulsation solutions, the increase of [Ca2+]i was still observable. It was also observed that [Ca2+]i of different intracellular areas in the cell elevated simultaneously while the peak of the increase of [Ca2+]i in the poles of the cell preceded to the peak in its somata and recovered to a plateau within a short time.

  20. Sonic hedgehog-induced histone deacetylase activation is required for cerebellar granule precursor hyperplasia in medulloblastoma.

    Directory of Open Access Journals (Sweden)

    Seung Joon Lee

    Full Text Available Medulloblastoma, the most common pediatric brain tumor, is thought to arise from deregulated proliferation of cerebellar granule precursor (CGP cells. Sonic hedgehog (Shh is the primary mitogen that regulates proliferation of CGP cells during the early stages of postnatal cerebellum development. Aberrant activation of Shh signaling during this time has been associated with hyperplasia of CGP cells and eventually may lead to the development of medulloblastoma. The molecular targets of Shh signaling involved in medulloblastoma formation are still not well-understood. Here, we show that Shh regulates sustained activation of histone deacetylases (HDACs and that this activity is required for continued proliferation of CGP cells. Suppression of HDAC activity not only blocked the Shh-induced CGP proliferation in primary cell cultures, but also ameliorated aberrant CGP proliferation at the external germinal layer (EGL in a medulloblastoma mouse model. Increased levels of mRNA and protein of several HDAC family members were found in medulloblastoma compared to wild type cerebellum suggesting that HDAC activity is required for the survival/progression of tumor cells. The identification of a role of HDACs in the early steps of medulloblastoma formation suggests there may be a therapeutic potential for HDAC inhibitors in this disease.

  1. Developmental expression and differentiation-related neuron-specific splicing of metastasis suppressor 1 (Mtss1 in normal and transformed cerebellar cells

    Directory of Open Access Journals (Sweden)

    Baader Stephan L

    2007-10-01

    Full Text Available Abstract Background Mtss1 encodes an actin-binding protein, dysregulated in a variety of tumors, that interacts with sonic hedgehog/Gli signaling in epidermal cells. Given the prime importance of this pathway for cerebellar development and tumorigenesis, we assessed expression of Mtss1 in the developing murine cerebellum and human medulloblastoma specimens. Results During development, Mtss1 is transiently expressed in granule cells, from the time point they cease to proliferate to their synaptic integration. It is also expressed by granule cell precursor-derived medulloblastomas. In the adult CNS, Mtss1 is found exclusively in cerebellar Purkinje cells. Neuronal differentiation is accompanied by a switch in Mtss1 splicing. Whereas immature granule cells express a Mtss1 variant observed also in peripheral tissues and comprising exon 12, this exon is replaced by a CNS-specific exon, 12a, in more mature granule cells and in adult Purkinje cells. Bioinformatic analysis of Mtss1 suggests that differential exon usage may affect interaction with Fyn and Src, two tyrosine kinases previously recognized as critical for cerebellar cell migration and histogenesis. Further, this approach led to the identification of two evolutionary conserved nuclear localization sequences. These overlap with the actin filament binding site of Mtss1, and one also harbors a potential PKA and PKC phosphorylation site. Conclusion Both the pattern of expression and splicing of Mtss1 is developmentally regulated in the murine cerebellum. These findings are discussed with a view on the potential role of Mtss1 for cytoskeletal dynamics in developing and mature cerebellar neurons.

  2. Methylmercury disrupts the balance between phosphorylated and non-phosphorylated cofilin in primary cultures of mice cerebellar granule cells A proteomic study

    International Nuclear Information System (INIS)

    Methylmercury is an environmental contaminant that is particularly toxic to the developing central nervous system; cerebellar granule neurons are especially vulnerable. Here, primary cultures of cerebellar granule cells (CGCs) were continuously exposed to methylmercury for up to 16 days in vitro (div). LC50 values were 508 ± 199, 345 ± 47, and 243 ± 45 nM after exposure for 6, 11, and 16 div, respectively. Proteins from cultured mouse CGCs were separated by 2DE. Seventy-one protein spots were identified by MALDI-TOF PMF and MALDI-TOF/TOF sequencing. Prolonged exposure to a subcytotoxic concentration of methylmercury significantly increased non-phosphorylated cofilin both in cell protein extracts (1.4-fold; p < 0.01) and in mitochondrial-enriched fractions (1.7-fold; p < 0.01). The decrease in P-cofilin induced by methylmercury was concentration-dependent and occurred after different exposure times. The percentage of P-cofilin relative to total cofilin significantly decreased to 49 ± 13% vs. control cells after exposure to 300 nM methylmercury for 5 div. The balance between the phosphorylated and non-phosphorylated form of cofilin regulates actin dynamics and facilitates actin filament turnover. Filamentous actin dynamics and reorganization are responsible of neuron shape change, migration, polarity formation, regulation of synaptic structures and function, and cell apoptosis. An alteration of the complex regulation of the cofilin phosphorylation/dephosphorylation pathway could be envisaged as an underlying mechanism compatible with reported signs of methylmercury-induced neurotoxicity.

  3. Specification of spatial identities of cerebellar neuron progenitors by ptf1a and atoh1 for proper production of GABAergic and glutamatergic neurons.

    Science.gov (United States)

    Yamada, Mayumi; Seto, Yusuke; Taya, Shinichiro; Owa, Tomoo; Inoue, Yukiko U; Inoue, Takayoshi; Kawaguchi, Yoshiya; Nabeshima, Yo-Ichi; Hoshino, Mikio

    2014-04-01

    In the cerebellum, the bHLH transcription factors Ptf1a and Atoh1 are expressed in distinct neuroepithelial regions, the ventricular zone (VZ) and the rhombic lip (RL), and are required for producing GABAergic and glutamatergic neurons, respectively. However, it is unclear whether Ptf1a or Atoh1 is sufficient for specifying GABAergic or glutamatergic neuronal fates. To test this, we generated two novel knock-in mouse lines, Ptf1a(Atoh1) and Atoh1(Ptf1a), that are designed to express Atoh1 and Ptf1a ectopically in the VZ and RL, respectively. In Ptf1a(Atoh1) embryos, ectopically Atoh1-expressing VZ cells produced glutamatergic neurons, including granule cells and deep cerebellar nuclei neurons. Correspondingly, in Atoh1(Ptf1a) animals, ectopically Ptf1a-expressing RL cells produced GABAergic populations, such as Purkinje cells and GABAergic interneurons. Consistent results were also obtained from in utero electroporation of Ptf1a or Atoh1 into embryonic cerebella, suggesting that Ptf1a and Atoh1 are essential and sufficient for GABAergic versus glutamatergic specification in the neuroepithelium. Furthermore, birthdating analyses with BrdU in the knock-in mice or with electroporation studies showed that ectopically produced fate-changed neuronal types were generated at temporal schedules closely simulating those of the wild-type RL and VZ, suggesting that the VZ and RL share common temporal information. Observations of knock-in brains as well as electroporated brains revealed that Ptf1a and Atoh1 mutually negatively regulate their expression, probably contributing to formation of non-overlapping neuroepithelial domains. These findings suggest that Ptf1a and Atoh1 specify spatial identities of cerebellar neuron progenitors in the neuroepithelium, leading to appropriate production of GABAergic and glutamatergic neurons, respectively.

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

    Directory of Open Access Journals (Sweden)

    Hourinaz Behesti

    2013-01-01

    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.

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

    Science.gov (United States)

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

    2010-01-01

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

  6. SMAD4 is essential for generating subtypes of neurons during cerebellar development

    OpenAIRE

    Fernandes, Marie; Antoine, Michelle; Hébert, Jean M.

    2012-01-01

    Cerebellum development involves the coordinated production of multiple neuronal cell types. The cerebellar primordium contains two germinative zones, the rhombic lip (RL) and the ventricular zone (VZ), which generate the different types of glutamatergic and GABAergic neurons, respectively. What regulates the specification and production of glutamatergic and GABAergic neurons as well as the subtypes for each of these two broad classes remains largely unknown. Here we demonstrate with condition...

  7. Serotonergic modulation and its influence on signal processing at cellular level in deep cerebellar nuclei neurons

    OpenAIRE

    Lee, Meng-Larn

    2007-01-01

    Deep cerebellar nuclei (DCN) neurons generate the final output of cerebellum and receive abundant modulatory serotonergic inputs from brainstem neurons. The aim of this present study was to elucidate the influence of serotonin on signal processing performed by DCN neurons. Since signal processing is determined by the interplay between intrinsic and synaptic properties, the impact of serotonin on intrinsic as well as synaptic properties was investigated. To this end whole-cell patch clamp reco...

  8. The effect of hydroxylated PCBs on DCF-fluorescence and cell death in cultured rat cerebellar granule cells

    Energy Technology Data Exchange (ETDEWEB)

    Fonnum, F.; Dreiem, A.; Rykken, S. [Norwegian Defence Research Establishment (Norway); Lehmler, H.Y.; Robertson, L. [Univ. of Iowa (United States); Mariussen, E. [Norwegian Inst. for Air Research (Norway)

    2004-09-15

    We have previously investigated the effects of polychlorinated biphenyls (PCBs) on free radical formation and cell death in cerebellar granule cells. PCBs may be metabolised to hydroxylated polychlorinated biphenyls (HO-PCBs) in the body. Therefore, we wanted to expand our study to include also the HO-PCBs. After hydroxylation, many of the PCBs are conjugated to either glucoronic acid or sulphate, which facilitates their excretion. Nevertheless, some of the HO-PCBs are retained in the body. The structures of some of the HO-PCBs show a certain similarity to the structure of the cathecholamines, and PCBs have been shown to affect the level of cathecholamines in the brain. Therefore, we compared the effect of some HO-PCBs with the effects of PCBs on some important physiological parameters in the brain. In the present communication we have compared the effects of PCB and HO-PCB on formation of DCF-fluorescence, which is used as a measure of reactive oxygen species (ROS) formation, and cell death in cultured rat cerebellar granule cells.

  9. Exposure to extremely low-frequency electromagnetic fields modulates Na+ currents in rat cerebellar granule cells through increase of AA/PGE2 and EP receptor-mediated cAMP/PKA pathway.

    Directory of Open Access Journals (Sweden)

    Yan-Lin He

    Full Text Available Although the modulation of Ca(2+ channel activity by extremely low-frequency electromagnetic fields (ELF-EMF has been studied previously, few reports have addressed the effects of such fields on the activity of voltage-activated Na(+ channels (Na(v. Here, we investigated the effects of ELF-EMF on Na(v activity in rat cerebellar granule cells (GCs. Our results reveal that exposing cerebellar GCs to ELF-EMF for 10-60 min significantly increased Na(v currents (I(Na by 30-125% in a time- and intensity-dependent manner. The Na(v channel steady-state activation curve, but not the steady-state inactivation curve, was significantly shifted (by 5.2 mV towards hyperpolarization by ELF-EMF stimulation. This phenomenon is similar to the effect of intracellular application of arachidonic acid (AA and prostaglandin E(2 (PGE(2 on I(Na in cerebellar GCs. Increases in intracellular AA, PGE(2 and phosphorylated PKA levels in cerebellar GCs were observed following ELF-EMF exposure. Western blottings indicated that the Na(V 1.2 protein on the cerebellar GCs membrane was increased, the total expression levels of Na(V 1.2 protein were not affected after exposure to ELF-EMF. Cyclooxygenase inhibitors and PGE(2 receptor (EP antagonists were able to eliminate this ELF-EMF-induced increase in phosphorylated PKA and I(Na. In addition, ELF-EMF exposure significantly enhanced the activity of PLA(2 in cerebellar GCs but did not affect COX-1 or COX-2 activity. Together, these data demonstrate for the first time that neuronal I(Na is significantly increased by ELF-EMF exposure via a cPLA2 AA PGE(2 EP receptors PKA signaling pathway.

  10. Two forms of cerebellar glial cells interact differently with neurons in vitro

    OpenAIRE

    1984-01-01

    Specific interactions between neurons and glia dissociated from early postnatal mouse cerebellar tissue were studied in vitro by indirect immunocytochemical staining with antisera raised against purified glial filament protein, galactocerebroside, and the NILE glycoprotein. Two forms of cells were stained with antisera raised against purified glial filament protein. The first, characterized by a cell body 9 microns diam and processes 130-150 microns long, usually had two to three neurons asso...

  11. Importance of genetics in fetal alcohol effects: null mutation of the nNOS gene worsens alcohol-induced cerebellar neuronal losses and behavioral deficits.

    Science.gov (United States)

    Bonthius, Daniel J; Winters, Zachary; Karacay, Bahri; Bousquet, Samantha Larimer; Bonthius, Daniel J

    2015-01-01

    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 4.4mg/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 in wild type. Thus, homozygous

  12. Effect of a GABA agonist on the expression and distribution of GABAA receptors in the plasma membrane of cultured cerebellar granule cells: an immunocytochemical study

    DEFF Research Database (Denmark)

    Hansen, G H; Belhage, B; Schousboe, A

    1991-01-01

    The effect of the gamma-aminobutyric acid (GABA) agonist 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP, 150 microM) on the localization and density of GABAA receptors in the plasma membrane of rat cerebellar granule cells in primary cultures was studied at the electron microscope (EM) level...

  13. Glutamate receptor activation in cultured cerebellar granule cells increases cytosolic free Ca2+ by mobilization of cellular Ca2+ and activation of Ca2+ influx

    DEFF Research Database (Denmark)

    Bouchelouche, P; Belhage, B; Frandsen, A;

    1989-01-01

    The Ca2+ sensitive fluorescent probe, fura-2 has been used to monitor cytosolic free calcium levels in mature primary cultures of cerebellar granule cells during exposure to L-glutamate and other excitatory amino acids: quisqualate (QA) kainate (KA) and N-methyl-D-aspartate (NMDA). Glutamate...

  14. Selective stimulation of excitatory amino acid receptor subtypes and the survival of cerebellar granule cells in culture: effect of kainic acid

    DEFF Research Database (Denmark)

    Balázs, R; Hack, N; Jørgensen, Ole Steen

    1990-01-01

    Our previous studies showed that the survival of cerebellar granule cells in culture is promoted by treatment with N-methyl-D-aspartate. Here we report on the influence of another glutamate analogue, kainic acid, which, in contrast to N-methyl-D-aspartate, is believed to stimulate transmitter rec...

  15. Interactome of Two Diverse RNA Granules Links mRNA Localization to Translational Repression in Neurons

    Directory of Open Access Journals (Sweden)

    Renate Fritzsche

    2013-12-01

    Full Text Available Transport of RNAs to dendrites occurs in neuronal RNA granules, which allows local synthesis of specific proteins at active synapses on demand, thereby contributing to learning and memory. To gain insight into the machinery controlling dendritic mRNA localization and translation, we established a stringent protocol to biochemically purify RNA granules from rat brain. Here, we identified a specific set of interactors for two RNA-binding proteins that are known components of neuronal RNA granules, Barentsz and Staufen2. First, neuronal RNA granules are much more heterogeneous than previously anticipated, sharing only a third of the identified proteins. Second, dendritically localized mRNAs, e.g., Arc and CaMKIIα, associate selectively with distinct RNA granules. Third, our work identifies a series of factors with known roles in RNA localization, translational control, and RNA quality control that are likely to keep localized transcripts in a translationally repressed state, often in distinct types of RNPs.

  16. Neuronal RNA granules: a link between RNA localization and stimulation-dependent translation

    Science.gov (United States)

    Krichevsky, A. M.; Kosik, K. S.

    2001-01-01

    RNA granules are a macromolecular structure observed in neurons, where they serve as motile units that translocate mRNAs. Isolated RNA granules are highly enriched in Staufen protein and ultrastructurally contain densely packed clusters of ribosomes. With depolarization, many mRNAs, including those involved in plasticity, rapidly shift from the RNA granule fraction to polysomes. Depolarization reorganizes granules and induces a less compact organization of their ribosomes. RNA granules are not translationally competent, as indicated by the failure to incorporate radioactive amino acids and the absence of eIF4E, 4G, and tRNAs. We concluded that RNA granules are a local storage compartment for mRNAs under translational arrest but are poised for release to actively translated pools. Local release of mRNAs and ribosomes from granules may serve as a macromolecular mechanism linking RNA localization to translation and synaptic plasticity.

  17. Cerebellar stem cells do not produce neurons and astrocytes in adult mouse

    Energy Technology Data Exchange (ETDEWEB)

    Su, Xin; Guan, Wuqiang; Yu, Yong-Chun; Fu, Yinghui, E-mail: fuyh@fudan.edu.cn

    2014-07-18

    Highlights: • No new neurons and astrocytes are generated in adult mouse cerebellum. • Very few mash1{sup +} or nestin{sup +} stem cells exist, and most of them are quiescent. • Cell proliferation rate is diversified among cerebellar regions and decreases over time. - Abstract: Although previous studies implied that cerebellar stem cells exist in some adult mammals, little is known about whether these stem cells can produce new neurons and astrocytes. In this study by bromodeoxyuridine (BrdU) intraperitoneal (i.p.) injection, we found that there are abundant BrdU{sup +} cells in adult mouse cerebellum, and their quantity and density decreases significantly over time. We also found cell proliferation rate is diversified in different cerebellar regions. Among these BrdU{sup +} cells, very few are mash1{sup +} or nestin{sup +} stem cells, and the vast majority of cerebellar stem cells are quiescent. Data obtained by in vivo retrovirus injection indicate that stem cells do not produce neurons and astrocytes in adult mouse cerebellum. Instead, some cells labeled by retrovirus are Iba1{sup +} microglia. These results indicate that very few stem cells exist in adult mouse cerebellum, and none of these stem cells contribute to neurogenesis and astrogenesis under physiological condition.

  18. Cerebellar stem cells do not produce neurons and astrocytes in adult mouse

    International Nuclear Information System (INIS)

    Highlights: • No new neurons and astrocytes are generated in adult mouse cerebellum. • Very few mash1+ or nestin+ stem cells exist, and most of them are quiescent. • Cell proliferation rate is diversified among cerebellar regions and decreases over time. - Abstract: Although previous studies implied that cerebellar stem cells exist in some adult mammals, little is known about whether these stem cells can produce new neurons and astrocytes. In this study by bromodeoxyuridine (BrdU) intraperitoneal (i.p.) injection, we found that there are abundant BrdU+ cells in adult mouse cerebellum, and their quantity and density decreases significantly over time. We also found cell proliferation rate is diversified in different cerebellar regions. Among these BrdU+ cells, very few are mash1+ or nestin+ stem cells, and the vast majority of cerebellar stem cells are quiescent. Data obtained by in vivo retrovirus injection indicate that stem cells do not produce neurons and astrocytes in adult mouse cerebellum. Instead, some cells labeled by retrovirus are Iba1+ microglia. These results indicate that very few stem cells exist in adult mouse cerebellum, and none of these stem cells contribute to neurogenesis and astrogenesis under physiological condition

  19. Multiple types of cerebellar target neurons and their circuitry in the vestibulo-ocular reflex.

    Science.gov (United States)

    Shin, Minyoung; Moghadam, Setareh H; Sekirnjak, Chris; Bagnall, Martha W; Kolkman, Kristine E; Jacobs, Richard; Faulstich, Michael; du Lac, Sascha

    2011-07-27

    The cerebellum influences behavior and cognition exclusively via Purkinje cell synapses onto neurons in the deep cerebellar and vestibular nuclei. In contrast with the rich information available about the organization of the cerebellar cortex and its synaptic inputs, relatively little is known about microcircuitry postsynaptic to Purkinje cells. Here we examined the cell types and microcircuits through which Purkinje cells influence an oculomotor behavior controlled by the cerebellum, the horizontal vestibulo-ocular reflex, which involves only two eye muscles. Using a combination of anatomical tracing and electrophysiological recordings in transgenic mouse lines, we identified several classes of neurons in the medial vestibular nucleus that receive Purkinje cell synapses from the cerebellar flocculus. Glycinergic and glutamatergic flocculus target neurons (FTNs) with somata densely surrounded by Purkinje cell terminals projected axons to the ipsilateral abducens and oculomotor nuclei, respectively. Of three additional types of FTNs that were sparsely innervated by Purkinje cells, glutamatergic and glycinergic neurons projected to the contralateral and ipsilateral abducens, respectively, and GABAergic neurons projected to contralateral vestibular nuclei. Densely innervated FTNs had high spontaneous firing rates and pronounced postinhibitory rebound firing, and were physiologically homogeneous, whereas the intrinsic excitability of sparsely innervated FTNs varied widely. Heterogeneity in the molecular expression, physiological properties, and postsynaptic targets of FTNs implies that Purkinje cell activity influences the neural control of eye movements in several distinct ways. These results indicate that the cerebellum regulates a simple reflex behavior via at least five different cell types that are postsynaptic to Purkinje cells.

  20. Casein Kinase 1δ Is an APC/CCdh1 Substrate that Regulates Cerebellar Granule Cell Neurogenesis

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    Clara Penas

    2015-04-01

    Full Text Available Although casein kinase 1δ (CK1δ is at the center of multiple signaling pathways, its role in the expansion of CNS progenitor cells is unknown. Using mouse cerebellar granule cell progenitors (GCPs as a model for brain neurogenesis, we demonstrate that the loss of CK1δ or treatment of GCPs with a highly selective small molecule inhibits GCP expansion. In contrast, CK1δ overexpression increases GCP proliferation. Thus, CK1δ appears to regulate GCP neurogenesis. CK1δ is targeted for proteolysis via the anaphase-promoting complex/cyclosome (APC/CCdh1 ubiquitin ligase, and conditional deletion of the APC/CCdh1 activator Cdh1 in cerebellar GCPs results in higher levels of CK1δ. APC/CCdh1 also downregulates CK1δ during cell-cycle exit. Therefore, we conclude that APC/CCdh1 controls CK1δ levels to balance proliferation and cell-cycle exit in the developing CNS. Similar studies in medulloblastoma cells showed that CK1δ holds promise as a therapeutic target.

  1. Long-Term Spatiotemporal Reconfiguration of Neuronal Activity Revealed by Voltage-Sensitive Dye Imaging in the Cerebellar Granular Layer.

    Science.gov (United States)

    Gandolfi, Daniela; Mapelli, Jonathan; D'Angelo, Egidio

    2015-01-01

    Understanding the spatiotemporal organization of long-term synaptic plasticity in neuronal networks demands techniques capable of monitoring changes in synaptic responsiveness over extended multineuronal structures. Among these techniques, voltage-sensitive dye imaging (VSD imaging) is of particular interest due to its good spatial resolution. However, improvements of the technique are needed in order to overcome limits imposed by its low signal-to-noise ratio. Here, we show that VSD imaging can detect long-term potentiation (LTP) and long-term depression (LTD) in acute cerebellar slices. Combined VSD imaging and patch-clamp recordings revealed that the most excited regions were predominantly associated with granule cells (GrCs) generating EPSP-spike complexes, while poorly responding regions were associated with GrCs generating EPSPs only. The correspondence with cellular changes occurring during LTP and LTD was highlighted by a vector representation obtained by combining amplitude with time-to-peak of VSD signals. This showed that LTP occurred in the most excited regions lying in the core of activated areas and increased the number of EPSP-spike complexes, while LTD occurred in the less excited regions lying in the surround. VSD imaging appears to be an efficient tool for investigating how synaptic plasticity contributes to the reorganization of multineuronal activity in neuronal circuits. PMID:26294979

  2. Long-Term Spatiotemporal Reconfiguration of Neuronal Activity Revealed by Voltage-Sensitive Dye Imaging in the Cerebellar Granular Layer

    Directory of Open Access Journals (Sweden)

    Daniela Gandolfi

    2015-01-01

    Full Text Available Understanding the spatiotemporal organization of long-term synaptic plasticity in neuronal networks demands techniques capable of monitoring changes in synaptic responsiveness over extended multineuronal structures. Among these techniques, voltage-sensitive dye imaging (VSD imaging is of particular interest due to its good spatial resolution. However, improvements of the technique are needed in order to overcome limits imposed by its low signal-to-noise ratio. Here, we show that VSD imaging can detect long-term potentiation (LTP and long-term depression (LTD in acute cerebellar slices. Combined VSD imaging and patch-clamp recordings revealed that the most excited regions were predominantly associated with granule cells (GrCs generating EPSP-spike complexes, while poorly responding regions were associated with GrCs generating EPSPs only. The correspondence with cellular changes occurring during LTP and LTD was highlighted by a vector representation obtained by combining amplitude with time-to-peak of VSD signals. This showed that LTP occurred in the most excited regions lying in the core of activated areas and increased the number of EPSP-spike complexes, while LTD occurred in the less excited regions lying in the surround. VSD imaging appears to be an efficient tool for investigating how synaptic plasticity contributes to the reorganization of multineuronal activity in neuronal circuits.

  3. 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

    Directory of Open Access Journals (Sweden)

    Carducci Claudia

    2012-04-01

    Full Text Available Abstract 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

  4. Role of astrocytes in depolarization-coupled release of glutamate in cerebellar cultures

    DEFF Research Database (Denmark)

    Bak, Lasse K; Waagepetersen, Helle S; Schousboe, Arne

    2004-01-01

    Release of preloaded D-[3H]aspartate in response to depolarization induced by high potassium, N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) or the endogenous agonist glutamate was studied using cultured glutamatergic cerebellar granule neurons, cerebellar...

  5. Poly (ADP-ribose polymerase plays an important role in intermittent hypoxia-induced cell death in rat cerebellar granule cells

    Directory of Open Access Journals (Sweden)

    Chiu Sheng-Chun

    2012-03-01

    Full Text Available Abstract Background Episodic cessation of airflow during sleep in patients with sleep apnea syndrome results in intermittent hypoxia (IH. Our aim was to investigate the effects of IH on cerebellar granule cells and to identify the mechanism of IH-induced cell death. Methods Cerebellar granule cells were freshly prepared from neonatal Sprague-Dawley rats. IH was created by culturing the cerebellar granule cells in the incubators with oscillating O2 concentration at 20% and 5% every 30 min for 1-4 days. The results of this study are based on image analysis using a confocal microscope and associated software. Cellular oxidative stress increased with increase in IH. In addition, the occurrence of cell death (apoptosis and necrosis increased as the duration of IH increased, but decreased in the presence of an iron chelator (phenanthroline or poly (ADP-ribose polymerase (PARP inhibitors [3-aminobenzamide (3-AB and DPQ]. The fluorescence of caspase-3 remained the same regardless of the duration of IH, and Western blots did not detect activation of caspase-3. However, IH increased the ratio of apoptosis-inducing factor (AIF translocation to the nucleus, while PARP inhibitors (3-AB reduced this ratio. Results According to our findings, IH increased oxidative stress and subsequently leading to cell death. This effect was at least partially mediated by PARP activation, resulting in ATP depletion, calpain activation leading to AIF translocation to the nucleus. Conclusions We suggest that IH induces cell death in rat primary cerebellar granule cells by stimulating oxidative stress PARP-mediated calpain and AIF activation.

  6. Adolescent development of neuron structure in dentate gyrus granule cells of male Syrian hamsters

    OpenAIRE

    Zehr, Julia L.; Nichols, Liana R.; Schulz, Kalynn M.; Sisk, Cheryl L.

    2008-01-01

    Hippocampal function, including spatial cognition and stress responses, matures during adolescence. In addition, hippocampal neuron structure is modified by gonadal steroid hormones, which increase dramatically at this time. This study investigated pubertal changes in dendritic complexity of dentate gyrus neurons. Dendrites, spines, and cell bodies of Golgiimpregnated neurons from the granule cell layer were traced in pre-, mid-, and late pubertal male Syrian hamsters (21, 35, and 49 days of ...

  7. Cultured neurons as model systems for biochemical and pharmacological studies on receptors for neurotransmitter amino acids

    DEFF Research Database (Denmark)

    Schousboe, A; Drejer, J; Hansen, Gert Helge;

    1985-01-01

    By the use of primary cultures of neurons consisting of cerebral cortex interneurons or cerebellar granule cells it is possible to study biochemical and pharmacological aspects of receptors for GABA and glutamate. Cerebellar granule cells have been shown to express both high- and low-affinity GAB...

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

    OpenAIRE

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

    2006-01-01

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

  9. Primate Cerebellar Granule Cells Exhibit a Tonic GABAAR Conductance that is not Affected by Alcohol: A Possible Cellular Substrate of the Low Level of Response Phenotype.

    Directory of Open Access Journals (Sweden)

    Claudia eMohr

    2013-11-01

    Full Text Available In many rodent brain regions, alcohol increases vesicular release of GABA, resulting in an increase in the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs and the magnitude of tonic GABAA receptor (GABAAR currents. A neglected issue in translating the rodent literature to humans is the possibility that phylogenetic differences alter the actions of alcohol. To address this issue we made voltage-clamp recordings from granule cells (GCs in cerebellar slices from the non-human primate, Macaca fascicularis. We found that similar to Sprague Dawley rats (SDRs, non-human primate (NHP GCs exhibit a tonic conductance generated by 6 subunit containing GABAARs, as evidenced by its blockade by the broad spectrum GABAAR antagonist, GABAzine (10M, inhibition by 6 selective antagonist, furosemide (100M, and enhancement by THDOC (10-20nM and THIP (500nM. In contrast to SDR GCs, in most NHP GCs (~60%, application of EtOH (25-105mM did not increase sIPSC frequency or the tonic GABAAR current. In a minority of cells (~40%, EtOH did increase sIPSC frequency and the tonic current. The relative lack of response to EtOH was associated with reduced expression of neuronal nitric oxide synthase (nNOS, which we recently reported mediates EtOH-induced enhancement of vesicular GABA release in rats. The EtOH-induced increase in tonic GABAAR current was significantly smaller in NHPs than in SDRs, presumably due to less GABA release, because there were no obvious differences in the density of GABAARs or GABA transporters between SDR and NHP GCs. Thus, EtOH does not directly modulate 6 subunit GABAARs in NHPs. Instead, EtOH enhanced GABAergic transmission is mediated by enhanced GABA release. Further, SDR GC responses to alcohol are only representative of a subpopulation of NHP GCs. This suggests that the impact of EtOH on NHP cerebellar physiology will be reduced compared to SDRs, and will likely have different computational and behavioral

  10. N-methyl-D-aspartate promotes the survival of cerebellar granule cells in culture

    DEFF Research Database (Denmark)

    Balázs, R; Jørgensen, Ole Steen; Hack, N

    1988-01-01

    and of reduction rate of a tetrazolium salt). Furthermore, proteins which are relatively enriched in either nerve cells (neuronal cell adhesion molecule, D3-protein and synaptin) or in glia (glutamine synthetase) were also measured. The findings showed that the rescue of cells by N-methyl-D-aspartate involved...

  11. In vivo analysis of inhibitory synaptic inputs and rebounds in deep cerebellar nuclear neurons.

    Directory of Open Access Journals (Sweden)

    Fredrik Bengtsson

    Full Text Available Neuronal function depends on the properties of the synaptic inputs the neuron receive and on its intrinsic responsive properties. However, the conditions for synaptic integration and activation of intrinsic responses may to a large extent depend on the level of background synaptic input. In this respect, the deep cerebellar nuclear (DCN neurons are of particular interest: they feature a massive background synaptic input and an intrinsic, postinhibitory rebound depolarization with profound effects on the synaptic integration. Using in vivo whole cell patch clamp recordings from DCN cells in the cat, we find that the background of Purkinje cell input provides a tonic inhibitory synaptic noise in the DCN cell. Under these conditions, individual Purkinje cells appear to have a near negligible influence on the DCN cell and clear-cut rebounds are difficult to induce. Peripheral input that drives the simple spike output of the afferent PCs to the DCN cell generates a relatively strong DCN cell inhibition, but do not induce rebounds. In contrast, synchronized climbing fiber activation, which leads to a synchronized input from a large number of Purkinje cells, can induce profound rebound responses. In light of what is known about climbing fiber activation under behaviour, the present findings suggest that DCN cell rebound responses may be an unusual event. Our results also suggest that cortical modulation of DCN cell output require a substantial co-modulation of a large proportion of the PCs that innervate the cell, which is a possible rationale for the existence of the cerebellar microcomplex.

  12. BarTeL, a Genetically Versatile, Bioluminescent and Granule Neuron Precursor-Targeted Mouse Model for Medulloblastoma

    Science.gov (United States)

    Mahdi, Min Y.; Gonzalez-Gomez, Ignacio; Asgharzadeh, Shahab; D’Apuzzo, Massimo; Erdreich-Epstein, Anat; Moats, Rex A.

    2016-01-01

    Medulloblastomas are the most common malignant pediatric brain tumor and have been divided into four major molecular subgroups. Animal models that mimic the principal molecular aberrations of these subgroups will be important tools for preclinical studies and allow greater understanding of medulloblastoma biology. We report a new transgenic model of medulloblastoma that possesses a unique combination of desirable characteristics including, among others, the ability to incorporate multiple and variable genes of choice and to produce bioluminescent tumors from a limited number of somatic cells within a normal cellular environment. This model, termed BarTeL, utilizes a Barhl1 homeobox gene promoter to target expression of a bicistronic transgene encoding both the avian retroviral receptor TVA and an eGFP-Luciferase fusion protein to neonatal cerebellar granule neuron precursor (cGNP) cells, which are cells of origin for the sonic hedgehog (SHH) subgroup of human medulloblastomas. The Barhl1 promoter-driven transgene is expressed strongly in mammalian cGNPs and weakly or not at all in mature granule neurons. We efficiently induced bioluminescent medulloblastomas expressing eGFP-luciferase in BarTeL mice by infection of a limited number of somatic cGNPs with avian retroviral vectors encoding the active N-terminal fragment of SHH and a stabilized MYCN mutant. Detection and quantification of the increasing bioluminescence of growing tumors in young BarTeL mice was facilitated by the declining bioluminescence of their uninfected maturing cGNPs. Inclusion of eGFP in the transgene allowed enriched sorting of cGNPs from neonatal cerebella. Use of a single bicistronic avian vector simultaneously expressing both Shh and Mycn oncogenes increased the medulloblastoma incidence and aggressiveness compared to mixed virus infections. Bioluminescent tumors could also be produced by ex vivo transduction of neonatal BarTeL cerebellar cells by avian retroviruses and subsequent

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

    Science.gov (United States)

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

    2001-12-01

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

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

    International Nuclear Information System (INIS)

    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, 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.

  15. Neurogenin2 directs granule neuroblast production and amplification while NeuroD1 specifies neuronal fate during hippocampal neurogenesis.

    Directory of Open Access Journals (Sweden)

    Laurent Roybon

    Full Text Available The specification and differentiation of dentate gyrus granule neurons in the hippocampus require temporally and spatially coordinated actions of both intrinsic and extrinsic molecules. The basic helix-loop-helix transcription factor Neurogenin2 (Ngn2 and NeuroD1 are key regulators in these processes. Based on existing classification, we analyzed the molecular events occurring during hippocampal neurogenesis, primarily focusing on juvenile animals. We found that Ngn2 is transiently expressed by late type-2a amplifying progenitors. The Ngn2 progenies mature into hippocampal granule neurons. Interestingly, the loss of Ngn2 at early stages of development leads to a robust reduction in neurogenesis, but does not disturb granule neuron maturation per se. We found that the role of Ngn2 is to maintain progenitors in an undifferentiated state, allowing them to amplify prior to their maturation into granule neurons upon NeuroD1 induction. When we overexpressed Ngn2 and NeuroD1 in vivo, we found NeuroD1 to exhibit a more pronounced neuron-inductive effect, leading to granule neuron commitment, than that displayed by Ngn2. Finally, we observed that all markers expressed during the transcriptional control of hippocampal neurogenesis in rodents are also present in the human hippocampus. Taken together, we demonstrate a critical role of for Ngn2 and NeuroD1 in controlling neuronal commitment and hippocampal granule neuroblast formation, both during embryonic development and in post-natal hippocampal granule neurogenesis.

  16. Molecular mechanisms of benzodiazepine-induced down-regulation of GABAA receptor alpha 1 subunit protein in rat cerebellar granule cells.

    OpenAIRE

    Brown, M. J.; Bristow, D. R.

    1996-01-01

    1. Chronic benzodiazepine treatment of rat cerebellar granule cells induced a transient down-regulation of the gamma-aminobutyric acidA (GABAA) receptor alpha 1 subunit protein, that was dose-dependent (1 nM-1 microM) and prevented by the benzodiazepine antagonist flumazenil (1 microM). After 2 days of treatment with 1 microM flunitrazepam the alpha 1 subunit protein was reduced by 41% compared to untreated cells, which returned to, and remained at, control cell levels from 4-12 days of treat...

  17. Expression of the GABA(A) receptor alpha6 subunit in cultured cerebellar granule cells is developmentally regulated by activation of GABA(A) receptors

    DEFF Research Database (Denmark)

    Carlson, B X; Belhage, B; Hansen, G H;

    1997-01-01

    Primary cultures of cerebellar granule cells, prepared from cerebella of 7-day-old rats and cultured for 4 or 8 days, were used to study the neurodifferentiative effect of a GABA(A) receptor agonist, 4,5,6,7-tetrahydroisoxazol[5,4-c]pyridin-3-ol (THIP), on the expression of the alpha6 GABA...... suggest that THIP has a trophic effect on alpha6 subunit expression, and this effect occurs only at an early developmental stage. Moreover, this study presents further evidence for the role of GABA(A) agonists, and thus the neurotransmitter, GABA, in regulating the expression of GABA(A) receptor subunits...

  18. Glutamate receptor activation in cultured cerebellar granule cells increases cytosolic free Ca2+ by mobilization of cellular Ca2+ and activation of Ca2+ influx

    DEFF Research Database (Denmark)

    Bouchelouche, P; Belhage, B; Frandsen, A;

    1989-01-01

    The Ca2+ sensitive fluorescent probe, fura-2 has been used to monitor cytosolic free calcium levels in mature primary cultures of cerebellar granule cells during exposure to L-glutamate and other excitatory amino acids: quisqualate (QA) kainate (KA) and N-methyl-D-aspartate (NMDA). Glutamate...... at micromolar concentrations produced a prompt and dose-related increase in the intracellular concentration of free Ca2+, ([Ca2+]i), whereas QA, KA and NMDA had no effect. This increase was also seen in the absence of extracellular Ca2+, suggesting that L-glutamate promotes mobilization of Ca2+ from...

  19. Serum and depolarizing agents cause acute neurotoxicity in cultured cerebellar granule cells: role of the glutamate receptor responsive to N-methyl-D-aspartate.

    OpenAIRE

    Schramm, M.; Eimerl, S; Costa, E

    1990-01-01

    The life span of neonatal rat cerebellar granule cells, grown in basal minimal Eagle's medium containing 10% (vol/vol) fetal calf serum, was extended to 21-30 days by weekly supplementation with glucose. Addition of 1% fetal calf serum to the culture at 14 days killed 85% of the cells within 1 hr. This lethal effect could be prevented by the N-methyl-D-aspartate (NMDA) receptor antagonists dibenzocyclohepteneimine (MK-801) and 3-(2-carboxypiperazin-4-yl)propyl-1-phosphonate (CPP). These findi...

  20. l-Serine and glycine serve as major astroglia-derived trophic factors for cerebellar Purkinje neurons

    OpenAIRE

    Furuya, Shigeki; Tabata, Toshihide; Mitoma, Junya; Yamada, Keiko; Yamasaki, Miwako; Makino, Asami; Yamamoto, Toshifumi; Watanabe, Masahiko; Kano, Masanobu; Hirabayashi, Yoshio

    2000-01-01

    Glial cells support the survival and development of central neurons through the supply of trophic factors. Here we demonstrate that l-serine (l-Ser) and glycine (Gly) also are glia-derived trophic factors. These amino acids are released by astroglial cells and promote the survival, dendritogenesis, and electrophysiological development of cultured cerebellar Purkinje neurons. Although l-Ser and Gly are generally classified as nonessential amino acids, 3-phosphoglyce...

  1. STD-dependent and independent encoding of input irregularity as spike rate in a computational model of a cerebellar nucleus neuron

    NARCIS (Netherlands)

    J. Luthman (Johannes); F.E. Hoebeek (Freek); R. Maex (Reinoud); N. Davey (Neil); R. Adams (Rod); C.I. de Zeeuw (Chris); V. Steuber (Volker)

    2011-01-01

    textabstractNeurons in the cerebellar nuclei (CN) receive inhibitory inputs from Purkinje cells in the cerebellar cortex and provide the major output from the cerebellum, but their computational function is not well understood. It has recently been shown that the spike activity of Purkinje cells is

  2. Expression of the GABA(A) receptor alpha6 subunit in cultured cerebellar granule cells is developmentally regulated by activation of GABA(A) receptors

    DEFF Research Database (Denmark)

    Carlson, B X; Belhage, B; Hansen, Gert Helge;

    1997-01-01

    Primary cultures of cerebellar granule cells, prepared from cerebella of 7-day-old rats and cultured for 4 or 8 days, were used to study the neurodifferentiative effect of a GABA(A) receptor agonist, 4,5,6,7-tetrahydroisoxazol[5,4-c]pyridin-3-ol (THIP), on the expression of the alpha6 GABA......Da (alpha6 subunit) radioactive peaks in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). In contrast, THIP-treated granule cells at 8 DIV demonstrated a small but significant decrease from control cultures in the photoincorporation of [3H]Ro15-4513 in the 51-kDa peak; however......, no significant change in [3H]Ro15-4513 binding was observed for the 56-kDa polypeptide. Immunolabeling of the alpha6 subunit using silver-enhanced, immuno-gold staining of granule cells showed a significant effect with THIP treatment only at 4 DIV and not at 8 DIV. Examination by light microscopy demonstrated...

  3. GABA-agonists induce the formation of low-affinity GABA-receptors on cultured cerebellar granule cells via preexisting high affinity GABA receptors

    DEFF Research Database (Denmark)

    Belhage, B; Meier, E; Schousboe, A

    1986-01-01

    The kinetics of specific GABA-binding to membranes isolated from cerebellar granule cells, cultured for 12 days from dissociated cerebella of 7-day-old rats was studied using [3H]GABA as the ligand. The granule cells were cultured in the presence of the specific GABA receptor agonist 4, 5, 6, 7......-tetrahydroisoxazolo [5,4-c]pyridin-3-ol (THIP, 150 microM) or THIP plus the antagonist bicuculline methobromide (150 microM of each) or in the absence of the agonist or antagonist. Membranes isolated from granule cells cultured in a medium without the GABA agonist revealed a single binding site for GABA with a...... binding constant (KD) of 7.9 +/- 0.4 nM and a Bmax of 3.42 +/- 0.08 pmol X mg-1 protein. Membranes from cells cultured in the presence of THIP had two binding sites for GABA with KD-values of 6.8 +/- 0.9 nM and 476 +/- 311 nM, respectively. The corresponding Bmax values were 4.41 +/- 0.42 pmol X mg-1 and...

  4. Lipid raft localization of GABA A receptor and Na+, K+-ATPase in discrete microdomain clusters in rat cerebellar granule cells

    DEFF Research Database (Denmark)

    Dalskov, Stine-Mathilde; Immerdal, Lissi; Niels-Christiansen, Lise-Lotte W;

    2005-01-01

    The microdomain localization of the GABA(A) receptor in rat cerebellar granule cells was studied by subcellular fractionation and fluorescence- and immunogold electron microscopy. The receptor resided in lipid rafts, prepared at 37 degrees C by extraction with the nonionic detergent Brij 98......, reflecting clustering of the two proteins in separate membrane microdomains. Both proteins were observed in patchy "hot spots" at the cell surface as well as in isolated lipid rafts. Their insolubility in Brij 98 was only marginally affected by methyl-beta-cyclodextrin. In contrast, both the GABA(A) receptor...... and Na(+), K(+)-ATPase were largely soluble in ice cold Triton X-100. This indicates that Brij 98 extraction defines an unusual type of cholesterol-independent lipid rafts that harbour membrane proteins also associated with underlying scaffolding/cytoskeletal proteins such as gephyrin (GABA(A) receptor...

  5. Effect of a GABA agonist on the expression and distribution of GABAA receptors in the plasma membrane of cultured cerebellar granule cells: an immunocytochemical study

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Belhage, B; Schousboe, A

    1991-01-01

    The effect of the gamma-aminobutyric acid (GABA) agonist 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP, 150 microM) on the localization and density of GABAA receptors in the plasma membrane of rat cerebellar granule cells in primary cultures was studied at the electron microscope (EM) level......, the density of the GABAA receptors was significantly increased in the THIP-treated cultures as compared to the control cultures and this effect of THIP was particularly pronounced in the processes. GABAA receptors were occasionally observed to form 'hot spots' in process-like structures and again...... at the EM level using the preembedding immunogold technique. It is likely that low-affinity GABAA receptors are preferentially located in the cell processes and to a considerable extent in the form of 'hot spots'. However, these 'hot spots' also contain high-affinity receptors....

  6. Progressive multifocal leukoencephalopathy with bilateral middle cerebellar peduncle lesions confirmed by repeated CSF-JC virus tests and coexistence of JC virus granule cell neuronopathy. Report of a case.

    Science.gov (United States)

    Ito, Daisuke; Yasui, Keizo; Hasegawa, Yasuhiro; Nakamichi, Kazuo; Katsuno, Masahisa; Takahashi, Akira

    2016-07-28

    A 65 year-old woman with small lymphocytic leukemia presented with subacute cerebellar ataxia. Six months after rituximab chemotherapy, a cranial MRI revealed lesions in the bilateral middle cerebellar peduncles. Both cerebrospinal fluid (CSF) JC virus (JCV)-DNA PCR test on three occasions and brain biopsy were negative. CSF tests were repeated. The fourth test performed 6 months after the onset showed positive JCV-DNA, and a definite diagnosis of progressive multifocal leukoencephalopathy (PML) was made. Neuroimaging of cerebellar atrophy was considered to be coexistence of granule cell neuronopathy. Medication with mirtazapine and mefloquine was temporarily effective for several months. Little are known solitary bilateral MRI lesions of the middle cerebellar peduncle in PML. JCV-PCR test of CSF may be negative at an earlier stage of PML. Repeated CSF tests should be essential to confirming the diagnosis in such cases. PMID:27356732

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

    Science.gov (United States)

    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...

  8. The survival of cultured mouse cerebellar granule cells is not dependent on elevated potassium-ion concentration

    DEFF Research Database (Denmark)

    Mogensen, Helle Smidt; Hack, N; Balázs, R;

    1994-01-01

    degenerated cells was removed by prior DNAase treatment. These DNA estimates of cell numbers were comparable with values obtained by direct counting of fluorescein diacetate-stained viable cells. In agreement with previous studies, the survival of rat granule cells was promoted by increasing the concentration...

  9. Interactive effects involving different classes of excitatory amino acid receptors and the survival of cerebellar granule cells in culture

    DEFF Research Database (Denmark)

    Balázs, R; Hack, N; Jørgensen, Ole Steen

    1990-01-01

    Differentiating granule cells develop survival requirements in culture which can be met by treatment with high K+ or N-methyl-D-aspartate (NMDA) and, according to our recent findings, also with low concentrations of kainic acid (KA, 50 microM). We have now attempted to elucidate the mechanism(s) ...

  10. An NCAM-derived FGF-receptor agonist, the FGL-peptide, induces neurite outgrowth and neuronal survival in primary rat neurons

    DEFF Research Database (Denmark)

    Neiiendam, Johanne Louise; Køhler, Lene Boding; Christensen, Claus;

    2004-01-01

    interaction with FGFR in primary cultures of three different neuronal cell types all expressing FGFR subtype 1: dopaminergic, hippocampal and cerebellar granule neurons. Moreover, we show that the FGL peptide promotes neuronal survival upon induction of cell death in the same three cell types. The effects...

  11. Defects in the CAPN1 Gene Result in Alterations in Cerebellar Development and Cerebellar Ataxia in Mice and Humans

    Directory of Open Access Journals (Sweden)

    Yubin Wang

    2016-06-01

    Full Text Available A CAPN1 missense mutation in Parson Russell Terrier dogs is associated with spinocerebellar ataxia. We now report that homozygous or heterozygous CAPN1-null mutations in humans result in cerebellar ataxia and limb spasticity in four independent pedigrees. Calpain-1 knockout (KO mice also exhibit a mild form of ataxia due to abnormal cerebellar development, including enhanced neuronal apoptosis, decreased number of cerebellar granule cells, and altered synaptic transmission. Enhanced apoptosis is due to absence of calpain-1-mediated cleavage of PH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1, which results in inhibition of the Akt pro-survival pathway in developing granule cells. Injection of neonatal mice with the indirect Akt activator, bisperoxovanadium, or crossing calpain-1 KO mice with PHLPP1 KO mice prevented increased postnatal cerebellar granule cell apoptosis and restored granule cell density and motor coordination in adult mice. Thus, mutations in CAPN1 are an additional cause of ataxia in mammals, including humans.

  12. Defects in the CAPN1 gene result in alterations in cerebellar development and in cerebellar ataxia in mice and humans

    Science.gov (United States)

    Wang, Yubin; Hersheson, Joshua; Lopez, Dulce; Hamad, Monia Ben; Liu, Yan; Lee, Ka-Hung; Pinto, Vanessa; Seinfeld, Jeff; Wiethoff, Sarah; Sun, Jiandong; Amouri, Rim; Hentati, Faycal; Baudry, Neema; Tran, Jennifer; Singleton, Andrew B; Coutelier, Marie; Brice, Alexis; Stevanin, Giovanni; Durr, Alexandra; Bi, Xiaoning; Houlden, Henry; Baudry, Michel

    2016-01-01

    SUMMARY A CAPN1 missense mutation in Parson Russell Terrier dogs is associated with spinocerebellar ataxia. We now report that homozygous CAPN1 null mutations in humans result in cerebellar ataxia and limb spasticity in four independent pedigrees. Calpain-1 knock-out (KO) mice also exhibit a mild form of ataxia due to abnormal cerebellar development, including enhanced neuronal apoptosis, decreased number of cerebellar granule cells, and altered synaptic transmission. Enhanced apoptosis is due to absence of calpain-1 mediated cleavage of PH domain and Leucine rich repeat Protein Phosphatase 1 (PHLPP1), which results in inhibition of the Akt pro-survival pathway in developing granule cells. Injection of neonatal mice with the indirect Akt activator, bisperoxovanadium, or crossing calpain-1 KO mice with PHLPP1 KO mice prevented increased postnatal cerebellar granule cell apoptosis, and restored granule cell density and motor coordination in adult mice. Thus, mutations in CAPN1 are an additional cause of ataxia in mammals, including humans. PMID:27320912

  13. Characterization of NCAM diversity in cultured neurons

    DEFF Research Database (Denmark)

    Gegelashvili, George; Andersson, A M; Schousboe, Arne;

    1993-01-01

    A single transcript of the NCAM gene undergoes differential processing resulting in a multiplicity of mRNAs and their translation products. In this study, the diversity of NCAM in rat primary neuronal cultures was investigated utilizing immuno- and Northern blot analyses. NCAM polypeptides of 190 k......Da (NCAM-A) and 135 kDa (NCAM-B) were shown to be associated with the neuronal phenotype. These data were confirmed by Northern blotting, which in both neocortical neurons and cerebellar granule neurons revealed mRNA classes of 7.4 kb and 6.7 kb encoding for NCAM-A and -B, respectively. However......, oligonucleotide probes, specific for selected exons or exon combinations, revealed special features of cerebellar granule neurons as compared to neocortical neurons: expression of 4.3 kb NCAM mRNA, a relatively low amount of VASE-containing variants, and an apparent lack of mRNA species containing exons alpha...

  14. Ethanol-Induced Cerebellar Ataxia: Cellular and Molecular Mechanisms.

    Science.gov (United States)

    Dar, M Saeed

    2015-08-01

    The cerebellum is an important target of ethanol toxicity given that cerebellar ataxia is the most consistent physical manifestation of acute ethanol consumption. Despite the significance of the cerebellum in ethanol-induced cerebellar ataxia (EICA), the cellular and molecular mechanisms underlying EICA are incompletely understood. However, two important findings have shed greater light on this phenomenon. First, ethanol-induced blockade of cerebellar adenosine uptake in rodent models points to a role for adenosinergic A1 modulation of EICA. Second, the consistent observation that intracerebellar administration of nicotine in mice leads to antagonism of EICA provides evidence for a critical role of cerebellar nitric oxide (NO) in EICA reversal. Based on these two important findings, this review discusses the potential molecular events at two key synaptic sites (mossy fiber-granule cell-Golgi cell (MGG synaptic site) and granule cell parallel fiber-Purkinje cell (GPP synaptic site) that lead to EICA. Specifically, ethanol-induced neuronal NOS inhibition at the MGG synaptic site acts as a critical trigger for Golgi cell activation which leads to granule cell deafferentation. Concurrently, ethanol-induced inhibition of adenosine uptake at the GPP synaptic site produces adenosine accumulation which decreases glutamate release and leads to the profound activation of Purkinje cells (PCs). These molecular events at the MGG and GPP synaptic sites are mutually reinforcing and lead to cerebellar dysfunction, decreased excitatory output of deep cerebellar nuclei, and EICA. The critical importance of PCs as the sole output of the cerebellar cortex suggests normalization of PC function could have important therapeutic implications.

  15. Label-free distinguishing between neurons and glial cells based on two-photon excited fluorescence signal of neuron perinuclear granules

    Science.gov (United States)

    Du, Huiping; Jiang, Liwei; Wang, Xingfu; Liu, Gaoqiang; Wang, Shu; Zheng, Liqin; Li, Lianhuang; Zhuo, Shuangmu; Zhu, Xiaoqin; Chen, Jianxin

    2016-08-01

    Neurons and glial cells are two critical cell types of brain tissue. Their accurate identification is important for the diagnosis of psychiatric disorders such as depression and schizophrenia. In this paper, distinguishing between neurons and glial cells by using the two-photon excited fluorescence (TPEF) signals of intracellular intrinsic sources was performed. TPEF microscopy combined with TUJ-1 and GFAP immunostaining and quantitative image analysis demonstrated that the perinuclear granules of neurons in the TPEF images of brain tissue and the primary cultured cortical cells were a unique characteristic of neurons compared to glial cells which can become a quantitative feature to distinguish neurons from glial cells. With the development of miniaturized TPEF microscope (‘two-photon fiberscopes’) imaging devices, TPEF microscopy can be developed into an effective diagnostic and monitoring tool for psychiatric disorders such as depression and schizophrenia.

  16. Nicotine-like effects of the neonicotinoid insecticides acetamiprid and imidacloprid on cerebellar neurons from neonatal rats.

    Directory of Open Access Journals (Sweden)

    Junko Kimura-Kuroda

    Full Text Available BACKGROUND: Acetamiprid (ACE and imidacloprid (IMI belong to a new, widely used class of pesticide, the neonicotinoids. With similar chemical structures to nicotine, neonicotinoids also share agonist activity at nicotinic acetylcholine receptors (nAChRs. Although their toxicities against insects are well established, their precise effects on mammalian nAChRs remain to be elucidated. Because of the importance of nAChRs for mammalian brain function, especially brain development, detailed investigation of the neonicotinoids is needed to protect the health of human children. We aimed to determine the effects of neonicotinoids on the nAChRs of developing mammalian neurons and compare their effects with nicotine, a neurotoxin of brain development. METHODOLOGY/PRINCIPAL FINDINGS: Primary cultures of cerebellar neurons from neonatal rats allow for examinations of the developmental neurotoxicity of chemicals because the various stages of neurodevelopment-including proliferation, migration, differentiation, and morphological and functional maturation-can be observed in vitro. Using these cultures, an excitatory Ca(2+-influx assay was employed as an indicator of neural physiological activity. Significant excitatory Ca(2+ influxes were evoked by ACE, IMI, and nicotine at concentrations greater than 1 µM in small neurons in cerebellar cultures that expressed the mRNA of the α3, α4, and α7 nAChR subunits. The firing patterns, proportion of excited neurons, and peak excitatory Ca(2+ influxes induced by ACE and IMI showed differences from those induced by nicotine. However, ACE and IMI had greater effects on mammalian neurons than those previously reported in binding assay studies. Furthermore, the effects of the neonicotinoids were significantly inhibited by the nAChR antagonists mecamylamine, α-bungarotoxin, and dihydro-β-erythroidine. CONCLUSIONS/SIGNIFICANCE: This study is the first to show that ACE, IMI, and nicotine exert similar excitatory effects

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

    Directory of Open Access Journals (Sweden)

    Lisa eMapelli

    2015-05-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  19. Tracking the Fragile X Mental Retardation Protein in a Highly Ordered Neuronal RiboNucleoParticles Population: A Link between Stalled Polyribosomes and RNA Granules.

    Directory of Open Access Journals (Sweden)

    Rachid El Fatimy

    2016-07-01

    Full Text Available Local translation at the synapse plays key roles in neuron development and activity-dependent synaptic plasticity. mRNAs are translocated from the neuronal soma to the distant synapses as compacted ribonucleoparticles referred to as RNA granules. These contain many RNA-binding proteins, including the Fragile X Mental Retardation Protein (FMRP, the absence of which results in Fragile X Syndrome, the most common inherited form of intellectual disability and the leading genetic cause of autism. Using FMRP as a tracer, we purified a specific population of RNA granules from mouse brain homogenates. Protein composition analyses revealed a strong relationship between polyribosomes and RNA granules. However, the latter have distinct architectural and structural properties, since they are detected as close compact structures as observed by electron microscopy, and converging evidence point to the possibility that these structures emerge from stalled polyribosomes. Time-lapse video microscopy indicated that single granules merge to form cargoes that are transported from the soma to distal locations. Transcriptomic analyses showed that a subset of mRNAs involved in cytoskeleton remodelling and neural development is selectively enriched in RNA granules. One third of the putative mRNA targets described for FMRP appear to be transported in granules and FMRP is more abundant in granules than in polyribosomes. This observation supports a primary role for FMRP in granules biology. Our findings open new avenues for the study of RNA granule dysfunctions in animal models of nervous system disorders, such as Fragile X syndrome.

  20. Tracking the Fragile X Mental Retardation Protein in a Highly Ordered Neuronal RiboNucleoParticles Population: A Link between Stalled Polyribosomes and RNA Granules

    Science.gov (United States)

    Tremblay, Sandra; Jaglin, Xavier; Dury, Alain; Robert, Claude; De Koninck, Paul; Khandjian, Edouard W.

    2016-01-01

    Local translation at the synapse plays key roles in neuron development and activity-dependent synaptic plasticity. mRNAs are translocated from the neuronal soma to the distant synapses as compacted ribonucleoparticles referred to as RNA granules. These contain many RNA-binding proteins, including the Fragile X Mental Retardation Protein (FMRP), the absence of which results in Fragile X Syndrome, the most common inherited form of intellectual disability and the leading genetic cause of autism. Using FMRP as a tracer, we purified a specific population of RNA granules from mouse brain homogenates. Protein composition analyses revealed a strong relationship between polyribosomes and RNA granules. However, the latter have distinct architectural and structural properties, since they are detected as close compact structures as observed by electron microscopy, and converging evidence point to the possibility that these structures emerge from stalled polyribosomes. Time-lapse video microscopy indicated that single granules merge to form cargoes that are transported from the soma to distal locations. Transcriptomic analyses showed that a subset of mRNAs involved in cytoskeleton remodelling and neural development is selectively enriched in RNA granules. One third of the putative mRNA targets described for FMRP appear to be transported in granules and FMRP is more abundant in granules than in polyribosomes. This observation supports a primary role for FMRP in granules biology. Our findings open new avenues for the study of RNA granule dysfunctions in animal models of nervous system disorders, such as Fragile X syndrome. PMID:27462983

  1. Valine but not leucine or isoleucine supports neurotransmitter glutamate synthesis during synaptic activity in cultured cerebellar neurons.

    Science.gov (United States)

    Bak, Lasse K; Johansen, Maja L; Schousboe, Arne; Waagepetersen, Helle S

    2012-09-01

    Synthesis of neuronal glutamate from α-ketoglutarate for neurotransmission necessitates an amino group nitrogen donor; however, it is not clear which amino acid(s) serves this role. Thus, the ability of the three branched-chain amino acids (BCAAs), leucine, isoleucine, and valine, to act as amino group nitrogen donors for synthesis of vesicular neurotransmitter glutamate was investigated in cultured mouse cerebellar (primarily glutamatergic) neurons. The cultures were superfused in the presence of (15) N-labeled BCAAs, and synaptic activity was induced by pulses of N-methyl-D-aspartate (300 μM), which results in release of vesicular glutamate. At the end of the superfusion experiment, the vesicular pool of glutamate was released by treatment with α-latrotoxin (3 nM, 5 min). This experimental paradigm allows a separate analysis of the cytoplasmic and vesicular pools of glutamate. Amount and extent of (15) N labeling of intracellular amino acids plus vesicular glutamate were analyzed employing HPLC and LC-MS analysis. Only when [(15) N]valine served as precursor did the labeling of both cytoplasmic and vesicular glutamate increase after synaptic activity. In addition, only [(15) N]valine was able to maintain the amount of vesicular glutamate during synaptic activity. This indicates that, among the BCAAs, only valine supports the increased need for synthesis of vesicular glutamate.

  2. Neuronal classification and marker gene identification via single-cell expression profiling of brainstem vestibular neurons subserving cerebellar learning

    OpenAIRE

    Kodama, Takashi; Guerrero, Shiloh; Shin, Minyoung; Moghadam, Seti; Faulstich, Michael; du Lac, Sascha

    2012-01-01

    Identification of marker genes expressed in specific cell types is essential for the genetic dissection of neural circuits. Here we report a new strategy for classifying heterogeneous populations of neurons into functionally distinct types and for identifying associated marker genes. Quantitative single-cell expression profiling of genes related to neurotransmitters and ion channels enables functional classification of neurons; transcript profiles for marker gene candidates identify molecular...

  3. Long-term potentiation of inhibitory synaptic transmission onto cerebellar Purkinje neurons contributes to adaptation of vestibulo-ocular reflex.

    Science.gov (United States)

    Tanaka, Shinsuke; Kawaguchi, Shin-Ya; Shioi, Go; Hirano, Tomoo

    2013-10-23

    Synaptic plasticity in the cerebellum is thought to contribute to motor learning. In particular, long-term depression (LTD) at parallel fiber (PF) to Purkinje neuron (PN) excitatory synapses has attracted much attention of neuroscientists as a primary cellular mechanism for motor learning. In contrast, roles of plasticity at cerebellar inhibitory synapses in vivo remain unknown. Here, we have investigated the roles of long-lasting enhancement of transmission at GABAergic synapses on a PN that is known as rebound potentiation (RP). Previous studies demonstrated that binding of GABAA receptor with GABAA receptor-associated protein (GABARAP) is required for RP, and that a peptide that blocks this binding suppresses RP induction. To address the functional roles of RP, we generated transgenic mice that express this peptide fused to a fluorescent protein selectively in PNs using the PN-specific L7 promoter. These mice failed to show RP, although they showed no changes in the basal amplitude or frequency of miniature IPSCs. The transgenic mice also showed no abnormality in gross cerebellar morphology, LTD, or other excitatory synaptic properties, or intrinsic excitability of PNs. Next, we attempted to evaluate their motor control and learning ability by examining reflex eye movements. The basal dynamic properties of the vestibulo-ocular reflex and optokinetic response, and adaptation of the latter, were normal in the transgenic mice. In contrast, the transgenic mice showed defects in the adaptation of vestibulo-ocular reflex, a model paradigm of cerebellum-dependent motor learning. These results together suggest that RP contributes to a certain type of motor learning.

  4. Neuronal inhibition of astroglial cell proliferation is membrane mediated

    OpenAIRE

    1987-01-01

    Previously we have used a microwell tissue culture assay to show that early postnatal mouse cerebellar astroglia have a flattened morphology and proliferate rapidly when they are cultured in the absence of neurons, but develop specific cell-cell contacts and undergo morphological differentiation when they are co-cultured with purified granule neurons (Hatten, M. E., 1985, J. Cell Biol., 100:384-396). In these studies of cell binding between neurons and astroglia, measurement with light and fl...

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

    Directory of Open Access Journals (Sweden)

    William Wisden

    2009-12-01

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

  6. Interaction and colocalization of HERMES/RBPMS with NonO, PSF, and G3BP1 in neuronal cytoplasmic RNP granules in mouse retinal line cells.

    Science.gov (United States)

    Furukawa, Mari T; Sakamoto, Hiroshi; Inoue, Kunio

    2015-04-01

    HERMES, also called RBPMS, is a conserved RNA binding protein with a single RNA recognition motif (RRM) that is abundantly expressed in retinal ganglion cells (RGCs) and in the heart in vertebrates. Here, we identified NonO and PSF as the interacting proteins of HERMES only when the neuronal differentiation of the retinal cell line RGC-5 was induced. Although NonO and PSF are nuclear paraspeckle components, these proteins formed cytoplasmic granules with HERMES in the neurites. G3BP1, a component of stress granules, was also colocalized to the granules, interacting with NonO and HERMES even in the absence of cellular stress. Consistent with a previous report that KIF5 interacts with neuronal granules, the localization of KIF5A overlapped with the cytoplasmic granules in differentiated RGC-5 cells. Thus, our study strongly suggests that the cytoplasmic granule containing HERMES, NonO, PSF, and G3BP1 is a neuronal RNA-protein granule that is transported in neurites during retinal differentiation. PMID:25651939

  7. Cell-autonomous death of cerebellar purkinje neurons with autophagy in niemann-pick type C disease.

    Directory of Open Access Journals (Sweden)

    2005-07-01

    Full Text Available Niemann-Pick type C is a neurodegenerative lysosomal storage disorder caused by mutations in either of two genes, npc1 and npc2. Cells lacking Npc1, which is a transmembrane protein related to the Hedgehog receptor Patched, or Npc2, which is a secreted cholesterol-binding protein, have aberrant organelle trafficking and accumulate large quantities of cholesterol and other lipids. Though the Npc proteins are produced by all cells, cerebellar Purkinje neurons are especially sensitive to loss of Npc function. Since Niemann-Pick type C disease involves circulating molecules such as sterols and steroids and a robust inflammatory response within the brain parenchyma, it is crucial to determine whether external factors affect the survival of Purkinje cells (PCs. We investigated the basis of neurodegeneration in chimeric mice that have functional npc1 in only some cells. Death of mutant npc1 cells was not prevented by neighboring wild-type cells, and wild-type PCs were not poisoned by surrounding mutant npc1 cells. PCs undergoing cell-autonomous degeneration have features consistent with autophagic cell death. Chimeric mice exhibited a remarkable delay and reduction of wasting and ataxia despite their substantial amount of mutant tissue and dying cells, revealing a robust mechanism that partially compensates for massive PC death.

  8. Cell-autonomous death of cerebellar purkinje neurons with autophagy in Niemann-Pick type C disease.

    Directory of Open Access Journals (Sweden)

    Dennis C Ko

    2005-07-01

    Full Text Available Niemann-Pick type C is a neurodegenerative lysosomal storage disorder caused by mutations in either of two genes, npc1 and npc2. Cells lacking Npc1, which is a transmembrane protein related to the Hedgehog receptor Patched, or Npc2, which is a secreted cholesterol-binding protein, have aberrant organelle trafficking and accumulate large quantities of cholesterol and other lipids. Though the Npc proteins are produced by all cells, cerebellar Purkinje neurons are especially sensitive to loss of Npc function. Since Niemann-Pick type C disease involves circulating molecules such as sterols and steroids and a robust inflammatory response within the brain parenchyma, it is crucial to determine whether external factors affect the survival of Purkinje cells (PCs. We investigated the basis of neurodegeneration in chimeric mice that have functional npc1 in only some cells. Death of mutant npc1 cells was not prevented by neighboring wild-type cells, and wild-type PCs were not poisoned by surrounding mutant npc1 cells. PCs undergoing cell-autonomous degeneration have features consistent with autophagic cell death. Chimeric mice exhibited a remarkable delay and reduction of wasting and ataxia despite their substantial amount of mutant tissue and dying cells, revealing a robust mechanism that partially compensates for massive PC death.

  9. STD-dependent and independent encoding of input irregularity as spike rate in a computational model of a cerebellar nucleus neuron.

    Science.gov (United States)

    Luthman, Johannes; Hoebeek, Freek E; Maex, Reinoud; Davey, Neil; Adams, Rod; De Zeeuw, Chris I; Steuber, Volker

    2011-12-01

    Neurons in the cerebellar nuclei (CN) receive inhibitory inputs from Purkinje cells in the cerebellar cortex and provide the major output from the cerebellum, but their computational function is not well understood. It has recently been shown that the spike activity of Purkinje cells is more regular than previously assumed and that this regularity can affect motor behaviour. We use a conductance-based model of a CN neuron to study the effect of the regularity of Purkinje cell spiking on CN neuron activity. We find that increasing the irregularity of Purkinje cell activity accelerates the CN neuron spike rate and that the mechanism of this recoding of input irregularity as output spike rate depends on the number of Purkinje cells converging onto a CN neuron. For high convergence ratios, the irregularity induced spike rate acceleration depends on short-term depression (STD) at the Purkinje cell synapses. At low convergence ratios, or for synchronised Purkinje cell input, the firing rate increase is independent of STD. The transformation of input irregularity into output spike rate occurs in response to artificial input spike trains as well as to spike trains recorded from Purkinje cells in tottering mice, which show highly irregular spiking patterns. Our results suggest that STD may contribute to the accelerated CN spike rate in tottering mice and they raise the possibility that the deficits in motor control in these mutants partly result as a pathological consequence of this natural form of plasticity.

  10. Low in situ expression of antioxidative enzymes in rat cerebellar granular cells susceptible to methylmercury.

    Science.gov (United States)

    Fujimura, M; Usuki, F

    2014-01-01

    Methylmercury (MeHg), an environmental neurotoxicant, induces site-specific toxicity in the brain. Although oxidative stress has been demonstrated with MeHg toxicity, the site-specific toxicity is not completely understood. Among the cerebellar neurons, cerebellar granule cells (CGCs) appear vulnerable to MeHg, whereas Purkinje cells and molecular layer neurons are resistant. Here, we use a MeHg-intoxicated rat model to investigate these cerebellar neurons for the different causes of susceptibility to MeHg. Rats were exposed to 20 ppm MeHg for 4 weeks and subsequently exhibited neuropathological changes in the cerebellum that were similar to those observed in humans. We first isolated the three cerebellar neuron types using a microdissection system and then performed real-time PCR analyses for antioxidative enzymes. We observed that expression of manganese-superoxide dismutase (Mn-SOD), glutathione peroxidase 1 (GPx1), and thioredoxin reductase 1 (TRxR1) was significantly higher in Purkinje cells and molecular layer neurons than in CGCs. Finally, we performed immunohistochemical analyses on the cerebellum. Immunohistochemistry showed increased expression of Mn-SOD, GPx1, and TRxR1 in Purkinje cells and molecular layer neurons, which was coincident with the mRNA expression patterns. Considering Mn-SOD, GPx1, and TRxR1 are critical for protecting cells against MeHg intoxication, the results indicate that low expression of these antioxidative enzymes increases CGCs vulnerability to MeHg toxicity.

  11. Forkhead transcription factor FoxM1 regulates mitotic entry and prevents spindle defects in cerebellar granule neuron precursors

    NARCIS (Netherlands)

    Schueller, Ulrich; Zhao, Qing; Godinho, Susana A.; Heine, Vivi M.; Medema, Rene H.; Pellman, David; Rowitch, David H.

    2007-01-01

    The forkhead transcription factor FoxM1 has been reported to regulate, variously, proliferation and/or spindle formation during the G(2)/M transition of the cell cycle. Here we define specific functions of FoxM1 during brain development by the investigation of FoxM1 loss-of-function mutations in the

  12. Peptides modeled after the alpha-domain of metallothionein induce neurite outgrowth and promote survival of cerebellar granule neurons

    DEFF Research Database (Denmark)

    Asmussen, Johanne Wirenfeldt; Ambjørn, Malene; Bock, Elisabeth;

    2009-01-01

    Metallothionein (MT) is a metal-binding protein capable of preventing oxidative stress and apoptotic cell death in the central nervous system of mammals, and hence is of putative therapeutic value in the treatment of neurodegenerative disorders. Recently, we demonstrated that a peptide modeled...

  13. 3H-D-aspartate release from cerebellar granule neurons is differentially regulated by glutamate- and K(+)-stimulation

    DEFF Research Database (Denmark)

    Belhage, B; Rehder, V; Hansen, Gert Helge;

    1992-01-01

    transmitter release was dependent on an intact cytoskeleton or not, the colchicine-like drug Nocodazole, which also blocks transport of vesicles, was used. K(+)-stimulated transmitter release consisted for the major part (around 70%) of a Ca(2+)-dependent, Nocodazole sensitive release component and this K...

  14. Metastasis suppressor 1 regulates neurite outgrowth in primary neuron cultures.

    Science.gov (United States)

    Yu, Juan; Lin, Shuyun; Wang, Mei; Liang, Lijun; Zou, Zijiao; Zhou, Xinfeng; Wang, Meichi; Chen, Ping; Wang, Ying

    2016-10-01

    Metastasis suppressor 1 (MTSS1) or missing in metastasis (MIM) is an actin- and membrane-binding protein with tumor suppressor functions. MTSS1 is important for cell morphology, motility, metastasis. The role of MTSS1 in cell morphology has been widely investigated in non-neuronal tissues; however the role of MTSS1 in neurite outgrowth remains unclear. Here we investigated the effect of MTSS1 on neurite outgrowth in primary cerebellar granule and hippocampal neurons of mouse. We found that overexpression of MTSS1 in cerebellar granule neurons significantly enhanced dendrite elaboration but inhibited axon elongation. This phenotype was significantly reduced by deletion of the Wiskott-Aldrich homology 2 (WH2) motif and point mutation in the insulin receptor substrate p53 (IRSp53) and MIM/MTSS1 homology (IMD) domain. Furthermore, inhibition of Rac1 activity or blocking of phosphatidyl inositol phosphates (PIPs) signaling decreased the effect of MTSS1 markedly. In accordance with the over-expression data, knockdown of MTSS1 in cerebellar granule neurons could increase the axon length but decrease the dendrite length and the number of dendrites. In addition, MTSS1 knock down in embryonic hippocampal neurons suppressed neurite branching and reduced dendrite length. Our findings have demonstrated that MTSS1 modulates neuronal morphology, possibly through a Rac1-PIPs signaling pathway. PMID:27401056

  15. Cerebellar nuclei neurons show only small excitatory responses to optogenetic olivary stimulation in transgenic mice: in vivo and in vitro studies

    Directory of Open Access Journals (Sweden)

    Huo eLu

    2016-03-01

    Full Text Available To study the olivary input to the cerebellar nuclei (CN we used optogenetic stimulation in transgenic mice expressing channelrhodopsin-2 (ChR2 in olivary neurons. We obtained in vivo extracellular Purkinje cell (PC and CN recordings in anesthetized mice while stimulating the contralateral inferior olive (IO with a blue laser (single pulse, 10 - 50 ms duration. Peri-stimulus histograms were constructed to show the spike rate changes after optical stimulation. Among 29 CN neurons recorded, 15 showed a decrease in spike rate of variable strength and duration, and only 1 showed a transient spiking response. These results suggest that direct olivary input to CN neurons is usually overridden by stronger Purkinje cell inhibition triggered by climbing fiber responses. To further investigate the direct input from the climbing fiber collaterals we also conducted whole cell recordings in brain slices, where we used local stimulation with blue light. Due to the expression of ChR2 in Purkinje cell axons as well as the IO in our transgenic line, strong inhibitory responses could be readily triggered with optical stimulation (13 of 15 neurons. After blocking this inhibition with GABAzine, only in 5 of 13 CN neurons weak excitatory responses were revealed. Therefore our in vitro results support the in vivo findings that the excitatory input to CN neurons from climbing fiber collaterals in adult mice is masked by the inhibition under normal conditions.

  16. Nitric oxide damages neuronal mitochondria and induces apoptosis in neurons

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The cytotoxic effect of nitric oxide on primarily cultured rat cerebellar granule cells was studied,and the mechanisms were discussed.The results showed that nitric oxide donor S-nitroso-N-acetyl-penicillamine (SNAP; 500 μmol/L) could induce apoptosis in immature cultures of cerebellar granule cells.Flow cytometry and HPLC analyses revealed that after treatment with SNAP,the mitochondrial transmembrane potential and the cellular ATP content decreased significantly.Nitric oxide scavenger hemoglobin could effectively prevent the neuronal mitochondria from dysfunction and attenuate apoptosis.The results suggested that nitric oxide activated the apoptotic program by inhibiting the activity of mitochondrial respiratory chain and thus decreasing the cellular ATP content.

  17. The Nuclear Transcription Factor RAR Associates with Neuronal RNA Granules and Suppresses Translation

    Science.gov (United States)

    All-trans-retinoic acid stimulates dendritic growth in hippocampal neurons within minutes by activating mitogen-activated protein kinase and mTOR and increasing dendritic translation of calcium calmodulin-dependent protein kinase II alpha and the alpha-amino-3-hydroxyl-5-methyl-4-isoxazole propionat...

  18. Running rewires the neuronal network of adult-born dentate granule cells.

    Science.gov (United States)

    Vivar, Carmen; Peterson, Benjamin D; van Praag, Henriette

    2016-05-01

    Exercise improves cognition in humans and animals. Running increases neurogenesis in the dentate gyrus of the hippocampus, a brain area important for learning and memory. It is unclear how running modifies the circuitry of new dentate gyrus neurons to support their role in memory function. Here we combine retroviral labeling with rabies virus mediated trans-synaptic retrograde tracing to define and quantify new neuron afferent inputs in young adult male C57Bl/6 mice, housed with or without a running wheel for one month. Exercise resulted in a shift in new neuron networks that may promote sparse encoding and pattern separation. Neurogenesis increased in the dorsal, but not the ventral, dentate gyrus by three-fold, whereas afferent traced cell labeling doubled in number. Regional analysis indicated that running differentially affected specific inputs. Within the hippocampus the ratio of innervation from inhibitory interneurons and glutamatergic mossy cells to new neurons was reduced. Distal traced cells were located in sub-cortical and cortical regions, including perirhinal, entorhinal and sensory cortices. Innervation from entorhinal cortex (EC) was augmented, in proportion to the running-induced enhancement of adult neurogenesis. Within EC afferent input and short-term synaptic plasticity from lateral entorhinal cortex, considered to convey contextual information to the hippocampus was increased. Furthermore, running upregulated innervation from regions important for spatial memory and theta rhythm generation, including caudo-medial entorhinal cortex and subcortical medial septum, supra- and medial mammillary nuclei. Altogether, running may facilitate contextual, spatial and temporal information encoding by increasing adult hippocampal neurogenesis and by reorganization of new neuron circuitry. PMID:26589333

  19. Potentiation of Methylmercury-Induced Death in Rat Cerebellar Granular Neurons Occurs by Further Decrease of Total Intracellular GSH with BDNF via TrkB in Vitro.

    Science.gov (United States)

    Sakaue, Motoharu; Maki, Takehiro; Kaneko, Takuya; Hemmi, Natsuko; Sekiguchi, Hitomi; Horio, Tomoyo; Kadowaki, Erina; Ozawa, Aisa; Yamamoto, Masako

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) is a principal factor for neurogenesis, neurodevelopment and neural survival through a BDNF receptor, tropomyosin-related kinase (Trk) B, while BDNF can also cause a decrease in the intracellular glutathione (GSH) level. We investigated the exacerbation of methylmercury-induced death of rat cerebellar granular neurons (CGNs) by BDNF in vitro. Since methylmercury can decrease intracellular GSH levels, we hypothesized that a further decrease of the intracellular GSH level is involved in the process of the exacerbation of neuronal cell death. In the present study, we established that in CGN culture, a decrease of the intracellular GSH level was further potentiated with BDNF in the process of the methylmercury-induced neuronal death and also in GSH reducer-induced neuronal death. BDNF treatment promoted the decrease in GSH levels induced by methylmercury and also by L-buthionine sulfoximine (BSO) and diethyl maleate (DEM). The promoting effect of BDNF was observed in a TrkB-vector transformant of the rat neuroblastoma B35 cell line but not in the mock-vector transformant. These results indicate that the exacerbating effect of BDNF on methylmercury-induced neuronal death in cultures of CGNs includes a further decrease of intracellular GSH levels, for which TrkB is essential. PMID:27251509

  20. Differential distribution of GABAA receptor subunits in soma and processes of cerebellar granule cells: effects of maturation and a GABA agonist

    DEFF Research Database (Denmark)

    Elster, L; Hansen, Gert Helge; Belhage, B;

    1995-01-01

    of receptors resulting in a single population of the latter neurons, a process enhanced by exposure to THIP. This may indicate that receptor development is a discontinuous process with individual neurons following different temporal patterns. In double-labeling experiments, a spatially close association...

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

    Directory of Open Access Journals (Sweden)

    Egidio eD‘Angelo

    2013-05-01

    Full Text Available 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 double 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 the neuron. 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 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 extension 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.

  2. Differential sensitivity of cerebellar purkinje neurons to ethanol in selectively outbred lines of mice: maintenance in vitro independent of synaptic transmission.

    Science.gov (United States)

    Basile, A; Hoffer, B; Dunwiddie, T

    1983-03-28

    The effects of ethanol on spontaneous firing of cerebellar Purkinje neurons were examined in outbred lines of mice (short-sleep, SS; and long-sleep, LS) which exhibit differential behavioral sensitivity to ethanol. In order to determine whether the differences in Purkinje cell ethanol sensitivity which are observed in situ reflect differences in intrinsic properties of Purkinje neurons, we developed an isolated in vitro preparation of mouse cerebellum. Even when synaptic transmission was largely inhibited by elevating Mg2+ and decreasing Ca2+ concentrations, Purkinje cells demonstrated stable long-term firing rates quite similar to those observed in vivo. Purkinje cells responded to superfusion of ethanol with both increases and decreases in firing rate. Inhibition of rate was more commonly observed, and was the only response which was demonstrably dose-dependent. The differential sensitivity to ethanol which we have previously reported in vivo was maintained even under under these conditions, with the LS mice being approximately 5 times more sensitive to the depressant effects of ethanol. In addition, it was shown that ethanol, at the concentrations used in these experiments, decreased the amplitude and increased the duration of single action potentials. Thus, taken together, these results suggest that the differential sensitivity of outbred lines to the soporific effects of ethanol are paralleled by differences in the sensitivity of Purkinje neurons in vitro to superfusion with ethanol. Because these differences can be observed even when synaptic transmission is largely suppressed, it would appear that these differences are intrinsic to the purkinje neurons themselves.

  3. Cerebellar microfolia and other abnormalities of neuronal growth, migration, and lamination in the Pit1dw-J homozygote mutant mouse

    Science.gov (United States)

    Sekiguchi, M.; Abe, H.; Moriya, M.; Tanaka, O.; Nowakowski, R. S.

    1998-01-01

    The Snell dwarf mouse (Pit1dw-J homozygote) has a mutation in the Pit1 gene that prevents the normal formation of the anterior pituitary. In neonates and adults there is almost complete absence of growth hormone (GH), prolactin (PRL), thyroxin (T4), and thyroid-stimulating hormone (TSH). Since these hormones have been suggested to play a role in normal development of the central nervous system (CNS), we have investigated the effects of the Pit1dw-J mutation on the cerebellum and hippocampal formation. In the cerebellum, there were abnormalities of both foliation and lamination. The major foliation anomalies were 1) changes in the relative size of specific folia and also the proportional sizes of the anterior vs posterior cerebellum; and 2) the presence of between one and three microfolia per half cerebellum. The microfolia were all in the medial portion of the hemisphere in the caudal part of the cerebellum. Each microfolium was just rostral to a normal fissure and interposed between the fissure and a normal gyrus. Lamination abnormalities included an increase in the number of single ectopic granule cells in the molecular layer in both cerebellar vermis (86%) and hemisphere (40%) in comparison with the wild-type mouse. In the hippocampus of the Pit1dw-J homozygote mouse, the number of pyramidal cells was decreased, although the width of the pyramidal cell layer throughout areas CA1-CA3 appeared to be normal, but less densely populated than in the wild-type mouse. Moreover, the number of granule cells that form the granule cell layer was decreased from the wild-type mouse and some ectopic granule cells (occurring both as single cells and as small clusters) were observed in the innermost portion of the molecular layer. The abnormalities observed in the Pit1dw-J homozygote mouse seem to be caused by both direct and indirect effects of the deficiency of TSH (or T4), PRL, or GH rather than by a direct effect of the deletion of Pit1.

  4. The damage of alcohol to cerebellar cells from primary cultured rats%酒精对原代培养大鼠小脑细胞的损害

    Institute of Scientific and Technical Information of China (English)

    许小林; 薛强

    2001-01-01

    原代培养的新生大鼠小脑颗粒神经元及小脑细胞经不同浓度的酒精进行处理,用倒置显微镜及四甲基偶氮唑蓝(MTT)法测定细胞存活率。结果酒精浓度在5~40 mmol/L时,细胞存活率呈剂量依赖性降低。酒精浓度增至160mmol/L时,颗粒神经元的存活率回升。提示酒精对原代培养大鼠小脑细胞有细胞毒性作用。在高浓度(160mmol/L)时,其对颗粒神经元毒性减小。%The cerebellar granule neurons and cerebellar cells from newborn primary cultured rats were treated with alcohol of different concentration. The cytotoxicity of alcohol on rats was observed. The survival rate of cells was detected by using an inverted microscope and MTT assay. Results showed that the survival rate of the rat cerebellar cells presented a dosage-dependent decrease when the concentration of the alcohol was from 5~40mmol/L, when the concentration reached 160mmol/L, the survival rate of rat cerebellar granule neurons rose again. This study suggests that alcohol has a cytotoxity to primary cultured rat cerebellar cells but at a high concentration its toxicity to cerebellar granule neurons of primary cultured rats is reduced.

  5. Bypassing hazard of housekeeping genes: Their evaluation in rat granule neurons treated with cerebrospinal fluid of Multiple Sclerosis subjects

    Directory of Open Access Journals (Sweden)

    Deepali eMathur

    2015-09-01

    Full Text Available Gene expression studies employing real-time PCR has become an intrinsic part of biomedical research. Appropriate normalization of target gene transcript(s based on stably expressed housekeeping genes is crucial in individual experimental conditions to obtain accurate results. In multiple sclerosis (MS, several gene expression studies have been undertaken, however, the suitability of housekeeping genes to express stably in this disease is not yet explored. Recent research suggests that their expression level may vary under different experimental conditions. Hence it is indispensible to evaluate their expression stability to accurately normalize target gene transcripts. The present study aims to evaluate the expression stability of seven housekeeping genes in rat granule neurons treated with cerebrospinal fluid of MS patients. The selected reference genes were quantified by real time PCR and their expression stability was assessed using GeNorm and NormFinder algorithms. Both methods reported transferrin receptor (Tfrc and microglobulin beta-2 (B2m the most stable genes whereas beta-actin (ActB and glyceraldehyde-3-phosphate-dehydrogenase (Gapdh the most fluctuated ones. Altogether our data demonstrate the significance of pre-validation of housekeeping genes for accurate normalization and indicates Tfrc and B2m as best endogenous controls in MS. ActB and Gapdh are not recommended in gene expression studies related to the current one.

  6. Cerebellar Degeneration

    Science.gov (United States)

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

  7. Exclusion of the neuronal nitric oxide synthase gene and the human achaete-scute homologue 1 gene as candidate loci for spinal cerebellar ataxia 2 (SCA2)

    Energy Technology Data Exchange (ETDEWEB)

    Twells, R.; Xu, W. [Imperial College, London (United Kingdom)]|[Institute of Animal Physiology and Genetics Research, Babraham, Cambridge (United Kingdom); Ball, D. [Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States)] [and others

    1994-09-01

    The autosomal dominant ataxias are a heterogeneous group of disorders, characterized by progressive degeneration of the cerebellum, pons and inferior olives, as well as the spinal cord. We previously mapped the spinal cerebellar ataxia 2 locus (SCA2) to chromosome 12q23-24.1 in a large Cuban founder population, flanked by the markers D12S58 and PLA2. Anticipation is a common feature of this disorder and therefore we have examined genes in this region which contain trinucleotide repeat motifs as candidate loci for SCA2. The neuronal nitric oxide synthase gene (NOS) has recently been assigned to chromosome 12q24.2-24.3 by fluorescent in situ hybridization. Neuronal NOS is responsible for the production of nitric oxide, a neurotransmitter expressed in high levels in the cerebellum as well as other regions of the nervous system. We report here the identification and analysis of an (AAT){sub n} repeat motif in an intronic region of the neuronal NOS gene, genetic mapping data and its exclusion from being involved in SCA2. We also report the exclusion of the human achaete-scute homologue 1 gene (HASH1), instrumental in neurosensory development in mouse, from being involved in SCA2 by the analysis of a proximal (CAG){sub n} repeat motif in the Cuban pedigrees, and its genetic location on chromosome 12q.

  8. NMDAR1 mRNA expression and glutamate receptor stimulated increase in cytosolic calcium concentration in rat and mouse cerebellar granule cells

    DEFF Research Database (Denmark)

    Mogensen, H S; Jørgensen, Ole Steen

    1996-01-01

    concentration of mRNA for the obligatory NMDA receptor subunit, NMDAR1, and (b) the glutamate/NMDA stimulated increase in cytosolic Ca(2+)-ion concentration in cultures at physiological or elevated K(+)-ion concentration. The expression of NMDAR1 mRNA was measured by competitive PCR of reversely transcribed m......RNA and was normalized to that of the constitutively expressed H3.3 histone mRNA. The glutamate and NMDA stimulated increase in cytosolic Ca(2+)-ion concentration was measured using the fluorescent Ca(2+)-chelator Fluo3. In contrast to the hypothesis, we found NMDAR1 mRNA expression to be lower in mouse...... than in rat granule cells cultured for 4 days at physiological K(+)-ion concentration. However, the NMDA stimulated increase in cytosolic Ca(2+)-ion concentration did not differ in 4-day rat and mouse cultures. Although the glutamate-stimulated increase in cytosolic Ca(2+)-ion concentration in 2-day...

  9. C-terminal Binding Proteins are Essential Pro-survival Factors that Undergo Caspase-dependent Downregulation during Neuronal Apoptosis

    OpenAIRE

    Stankiewicz, Trisha R.; Schroeder, Emily K.; Kelsey, Natalie A.; Bouchard, Ron J.; Linseman, Daniel A.

    2013-01-01

    C-terminal binding proteins (CtBPs) are transcriptional co-repressors that are subject to proteasome-dependent downregulation during apoptosis. Alternative mechanisms that regulate CtBP expression are currently under investigation and the role of CtBPs in neuronal survival is largely unexplored. Here, we show that CtBPs are downregulated in cerebellar granule neurons (CGNs) induced to undergo apoptosis by a variety of stressors. Moreover, antisense-mediated downregulation of CtBP1 is sufficie...

  10. Effects of inhibitors of protein synthesis and intracellular transport on the gamma-aminobutyric acid agonist-induced functional differentiation of cultured cerebellar granule cells

    DEFF Research Database (Denmark)

    Belhage, B; Hansen, Gert Helge; Meier, E;

    1990-01-01

    The effect of inhibitors of protein synthesis (actinomycin D, cycloheximide), proteases (leupeptin), and intracellular transport (colchicine, monensin) on the gamma-aminobutyric acid (GABA) agonist [4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP)]-induced changes in morphological differenti......The effect of inhibitors of protein synthesis (actinomycin D, cycloheximide), proteases (leupeptin), and intracellular transport (colchicine, monensin) on the gamma-aminobutyric acid (GABA) agonist [4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP)]-induced changes in morphological...... of membranes for [3H]GABA binding assays. In some experiments the functional activity of the newly induced low-affinity GABA receptors was assessed by investigation of the ability of GABA to inhibit neurotransmitter release from the neurons. These experiments were performed to differentiate between...

  11. A role for mixed lineage kinases in granule cell apoptosis induced by cytoskeletal disruption

    DEFF Research Database (Denmark)

    Müller, Georg Johannes; Geist, Marie Aavang; Veng, Lone Merete;

    2006-01-01

    Microtubule disruption by colchicine induces apoptosis in selected neuronal populations. However, little is known about the upstream death signalling events mediating the neurotoxicity. We investigated first whether colchicine-induced granule cell apoptosis activates the c-Jun N-terminal kinase...... (JNK) pathway. Cultured murine cerebellar granule cells were exposed to 1 microm colchicine for 24 h. Activation of the JNK pathway was detected by western blotting as well as immunocytochemistry using antibodies against phospho-c-Jun (p-c-Jun). Next, adult male rats were injected...... intracerebroventricularly with colchicine (10 microg), and JNK pathway activation in dentate granule cells (DGCs) was detected by antibodies against p-c-Jun. The second part of the study tested the involvement of mixed lineage kinases (MLK) as upstream activators of the JNK pathway in colchicine toxicity, using CEP-1347, a...

  12. Cerebellar Hypoplasia

    Science.gov (United States)

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

  13. Sonic hedgehog patterning during cerebellar development.

    Science.gov (United States)

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

    2016-01-01

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

  14. Acute cerebellar ataxia

    Science.gov (United States)

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

  15. Cytoplasmic TERT Associates to RNA Granules in Fully Mature Neurons: Role in the Translational Control of the Cell Cycle Inhibitor p15INK4B.

    Directory of Open Access Journals (Sweden)

    Francesca Iannilli

    Full Text Available The main role of Telomerase Reverse Transcriptase (TERT is to protect telomere length from shortening during cell division. However, recent works have revealed the existence of a pool of TERT associated to mitochondria, where it plays a role in survival. We here show that in fully differentiated neurons the largest pool of cytoplasmic TERT associates to TIA1 positive RNA granules, where it binds the messenger RNA of the cyclin kinase inhibitor p15INK4B. Upon stress, p15INK4B and TERT dissociate and p15INK4B undergoes efficient translation, allowing its pro-survival function. These results unveil another mechanism implicated in the survival of fully differentiated neurons.

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

    Directory of Open Access Journals (Sweden)

    Ruben Dario Pinzon Morales

    2015-05-01

    Full Text Available 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 textcolor{red}{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.

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

    Science.gov (United States)

    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). PMID:25983678

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

    Science.gov (United States)

    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.

  19. A marked paucity of granule cells in the developing cerebellum of the Npc1−/− mouse is corrected by a single injection of hydroxypropyl-β-cyclodextrin

    Science.gov (United States)

    Nusca, S.; Canterini, S.; Palladino, G.; Bruno, F.; Mangia, F.; Erickson, R.P.; Fiorenza, M.T.

    2014-01-01

    In this study we show that postnatal development of cerebellar granule neurons (GNs) is defective in Npc1−/− mice. Compared to age-matched wild-type littermates, there is an accelerated disappearance of the external granule layer (EGL) in these mice. This is due to a premature exit from the cell cycle of GN precursors residing at the level of the EGL. As a consequence, the size of cerebellar lobules of these mice displays a 20%–25% reduction compared to that of age-matched wild-type mice. This size reduction is detectable at post-natal day 28 (PN28), when cerebellar GN development is completed while signs of neuronal atrophy are not yet apparent. Based on the analysis of EGL thickness and the determination of proliferating GN fractions at increasing developmental times (PN8–PN14), we trace the onset of this GN developmental defect during the second postnatal week. We also show that during this developmental time Shh transcripts undergo a significant reduction in Npc1−/− mice compared to age-matched wild-type mice. In light of the mitogenic activity of Shh on GNs, this observation further supports the presence of defective GN proliferation in Npc1−/− mice. A single injection of hydroxypropyl-β-cyclodextrin at PN7 rescues this defect, restoring the normal patterns of granule neuron proliferation and cerebellar lobule size. To our knowledge, these findings identify a novel developmental defect that was underappreciated in previous studies. This defect was probably overlooked because Npc1 loss-of-function does not affect cerebellar foliation and causes the internal granule layer and molecular layer to decrease proportionally, giving rise to a normally appearing, yet harmoniously smaller, cerebellum. PMID:24969023

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

    Science.gov (United States)

    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.

  1. Isolation Rearing Reduces Neuronal Excitability in Dentate Gyrus Granule Cells of Adolescent C57BL/6J Mice: Role of GABAergic Tonic Currents and Neurosteroids.

    Science.gov (United States)

    Talani, Giuseppe; Biggio, Francesca; Licheri, Valentina; Locci, Valentina; Biggio, Giovanni; Sanna, Enrico

    2016-01-01

    Early-life exposure to stress, by impacting on a brain still under development, is considered a critical factor for the increased vulnerability to psychiatric disorders and abuse of psychotropic substances during adulthood. As previously reported, rearing C57BL/6J weanling mice in social isolation (SI) from their peers for several weeks, a model of prolonged stress, is associated with a decreased plasma and brain levels of neuroactive steroids such as 3α,5α-THP, with a parallel up-regulation of extrasynaptic GABAA receptors (GABAAR) in dentate gyrus (DG) granule cells compared to group-housed (GH) mice. In the present study, together with the SI-induced decrease in plasma concentration of both progesterone and 3α,5α-THP, and an increase in THIP-stimulated GABAergic tonic currents, patch-clamp analysis of DG granule cells revealed a significant decrease in membrane input resistance and action potential (AP) firing rate, in SI compared to GH mice, suggesting that SI exerts an inhibitory action on neuronal excitability of these neurons. Voltage-clamp recordings of glutamatergic spontaneous excitatory postsynaptic currents (sEPSCs) revealed a SI-associated decrease in frequency as well as a shift from paired-pulse (PP) depression to PP facilitation (PPF) of evoked EPSCs, indicative of a reduced probability of glutamate release. Daily administration of progesterone during isolation reverted the changes in plasma 3α,5α-THP as well as in GABAergic tonic currents and neuronal excitability caused by SI, but it had only a limited effect on the changes in the probability of presynaptic glutamate release. Overall, the results obtained in this work, together with those previously published, indicate that exposure of mice to SI during adolescence reduces neuronal excitability of DG granule cells, an effect that may be linked to the increased GABAergic tonic currents as a consequence of the sustained decrease in plasma and hippocampal levels of neurosteroids. All these

  2. Long-Term Spatiotemporal Reconfiguration of Neuronal Activity Revealed by Voltage-Sensitive Dye Imaging in the Cerebellar Granular Layer

    OpenAIRE

    Gandolfi, Daniela; Mapelli, Jonathan; D’Angelo, Egidio

    2015-01-01

    Understanding the spatiotemporal organization of long-term synaptic plasticity in neuronal networks demands techniques capable of monitoring changes in synaptic responsiveness over extended multineuronal structures. Among these techniques, voltage-sensitive dye imaging (VSD imaging) is of particular interest due to its good spatial resolution. However, improvements of the technique are needed in order to overcome limits imposed by its low signal-to-noise ratio. Here, we show that VSD imaging ...

  3. [Cerebellar stroke].

    Science.gov (United States)

    Paradowski, Michał; Zimny, Anna; Paradowski, Bogusław

    2015-01-01

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

  4. Cellular and molecular basis of cerebellar development

    Science.gov (United States)

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

    2013-01-01

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

  5. Cellular and Molecular Basis of Cerebellar Development

    Directory of Open Access Journals (Sweden)

    Salvador eMartinez

    2013-06-01

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

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

    Science.gov (United States)

    Fujita, Masahiko

    2013-06-01

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

  7. Characterization of isolated mouse cerebellar cell populations in vitro.

    Science.gov (United States)

    Schnitzer, J; Schachner, M

    1981-12-01

    Cells from early postnatal mouse cerebellar cortex were isolated by discontinuous BSA gradient centrifugation. Three cellular fractions were obtained and called A (interface at 0-10% BSA), B ( 10-15%) and C (15-25%). These fractions were characterized after maintenance in vitro for 3 days by indirect immunofluorescence labeling with several cell type-specific probes: Tetanus toxin was used as a neuronal marker.Under the described culture conditions Thy-1.2 antibodies served as additional markers for mature neurons and NS-4 antiserum for neurons and oligodendroglial cells. Glial fibrillary acidic (GFA) protein was used as a marker for differentiated astroglia, and fibronectin as a marker for fibroblasts. Monoclonal antibodies to 04 antigen and antiserum to corpus callosum served to distinguish oligodendroglia. Fraction C contains most of the cellular debris and cells with large cell bodies (about 20 micrometers in diameter) which are positive for Thy-1, NS-4, and tetanus toxin. By birthdate labeling with [3H]thymidine these cells can be identified as Purkinje cells and/or Golgi type II cells. Fraction B is relatively heterogeneous. It contains predominantly GFA protien-positive astroglial cells (about 50% of all cells) which can be classified into 3 morphologically distinct cell types, flat epithelioid cells and star-shaped cells with thick or very thin cellular processes. Fraction B is enriched also in 04 antigen-positive oligodendrocytes, fibronectin-positive fibroblasts and Thy-1 negative, but NS-4 and tetanus toxin positive cells with small cell bodies and many fine processes. These small neurons, putative stellate and basket cells, have many fine processes and are morphologically different from th bipolar putative granule cells, some of which are also present in this fraction. Fraction C contains predominantly small neurons, mostly putative granule cell (more than 0% of all cells) which are positive for NS-4 and tetanus toxin, but negative for Thy-1.

  8. Metallothionein and a peptide modeled after metallothionein, EmtinB, induce neuronal differentiation and survival through binding to receptors of the low-density lipoprotein receptor family

    DEFF Research Database (Denmark)

    Ambjørn, Malene; Asmussen, Johanne W; Lindstam, Mats;

    2007-01-01

    Accumulating evidence suggests that metallothionein (MT)-I and -II promote neuronal survival and regeneration in vivo. The present study investigated the molecular mechanisms underlying the differentiation and survival-promoting effects of MT and a peptide modeled after MT, EmtinB. Both MT...... and EmtinB directly stimulated neurite outgrowth and promoted survival in vitro using primary cultures of cerebellar granule neurons. In addition, expression and surface localization of megalin, a known MT receptor, and the related lipoprotein receptor-related protein-1 (LRP) are demonstrated in cerebellar...... granule neurons. By means of surface plasmon resonance MT and EmtinB were found to bind to both megalin and LRP. The bindings were abrogated in the presence of receptor-associated protein-1, an antagonist of the low-density lipoprotein receptor family, which also inhibited MT- and EmtinB-induced neurite...

  9. Valine but not leucine or isoleucine supports neurotransmitter glutamate synthesis during synaptic activity in cultured cerebellar neurons

    DEFF Research Database (Denmark)

    Bak, Lasse Kristoffer; Johansen, Maja L.; Schousboe, Arne;

    2012-01-01

    Synthesis of neuronal glutamate from a-ketoglutarate for neurotransmission necessitates an amino group nitrogen donor; however, it is not clear which amino acid(s) serves this role. Thus, the ability of the three branched-chain amino acids (BCAAs), leucine, isoleucine, and valine, to act as amino...... and extent of (15) N labeling of intracellular amino acids plus vesicular glutamate were analyzed employing HPLC and LC-MS analysis. Only when [(15) N]valine served as precursor did the labeling of both cytoplasmic and vesicular glutamate increase after synaptic activity. In addition, only [(15) N]valine...... was able to maintain the amount of vesicular glutamate during synaptic activity. This indicates that, among the BCAAs, only valine supports the increased need for synthesis of vesicular glutamate. © 2012 Wiley Periodicals, Inc....

  10. Siah regulation of Pard3A controls neuronal cell adhesion during germinal zone exit.

    Science.gov (United States)

    Famulski, Jakub K; Trivedi, Niraj; Howell, Danielle; Yang, Yuan; Tong, Yiai; Gilbertson, Richard; Solecki, David J

    2010-12-24

    The brain's circuitry is established by directed migration and synaptogenesis of neurons during development. Although neurons mature and migrate in specific patterns, little is known about how neurons exit their germinal zone niche. We found that cerebellar granule neuron germinal zone exit is regulated by proteasomal degradation of Pard3A by the Seven in Absentia homolog (Siah) E3 ubiquitin ligase. Pard3A gain of function and Siah loss of function induce precocious radial migration. Time-lapse imaging using a probe to measure neuronal cell contact reveals that Pard3A promotes adhesive interactions needed for germinal zone exit by recruiting the epithelial tight junction adhesion molecule C to the neuronal cell surface. Our findings define a Siah-Pard3A signaling pathway that controls adhesion-dependent exit of neuronal progenitors or immature neurons from a germinal zone niche.

  11. Bipotential precursors of putative fibrous astrocytes and oligodendrocytes in rat cerebellar cultures express distinct surface features and neuron-like γ-aminobutyric acid transport

    International Nuclear Information System (INIS)

    When postnatal rat cerebellar cells were cultured in a chemically defined, serum-free medium, the only type of astrocyte present was unable to accumulate γ-[3H]aminobutyric acid (GABA), did not express surface antigens recognized by two monoclonal antibodies, A2B5 and LB1, and showed minimal proliferation. In these cultures, nonneuronal A2B5+, LB1+ stellate cells exhibiting neuron-like [3H]GABA uptake formed cell colonies of increasing size and were GFAP-. After about one week of culturing, the A2B5+, LB1+, GABA-uptake positive cell groups became galactocerebroside (GalCer) positive. Immunocytolysis of the A2B5+ cells at 3 and 4 days in vitro prevented the appearance of the A2B5+, LB1+, GABA-uptake positive cell colonies, and also of the GalCer+ cell groups. If 10% (vol/vol) fetal calf serum was added to 6-day cultures, the A2B5+, LB1+, GABA-uptake positive cell groups expressed GFAP and not GalCer. If the serum was added to the cultures 2 days after lysing the A2B5+ cells, only A2B5-, LB1-, GABA-uptake negative astrocytes proliferated. It is concluded that the putative fibrous astrocytes previously described in serum-containing cultures derive from bipotential precursors that differentiate into oligodendrocytes (GalCer+) in serum-free medium or into astrocytes (GFAP+) in the presence of serum, while the epithelioid A2B5-, LB1-, GABA-uptake negative astrocytes originate from a different precursor not yet identified

  12. Synchrony and neural coding in cerebellar circuits

    Directory of Open Access Journals (Sweden)

    Abigail L Person

    2012-12-01

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

  13. Developmental Neurotoxicity of 3,3',4,4'-Tetrachloroazobenzene with Thyroxine Deficit: Sensitivity of Glia and Dentate Granule Neurons in the Absence of Behavioral Changes

    Directory of Open Access Journals (Sweden)

    G. Jean Harry

    2014-09-01

    Full Text Available Thyroid hormones (TH regulate biological processes implicated in neurodevelopmental disorders and can be altered with environmental exposures. Developmental exposure to the dioxin-like compound, 3,3',4,4'-tetrachloroazobenzene (TCAB, induced a dose response deficit in serum T4 levels with no change in 3,5,3'-triiodothyronine or thyroid stimulating hormone. Female Sprague-Dawley rats were orally gavaged (corn oil, 0.1, 1.0, or 10 mg TCAB/kg/day two weeks prior to cohabitation until post-partum day 3 and male offspring from post-natal day (PND 4–21. At PND21, the high dose showed a deficit in body weight gain. Conventional neuropathology detected no neuronal death, myelin disruption, or gliosis. Astrocytes displayed thinner and less complex processes at 1.0 and 10 mg/kg/day. At 10 mg/kg/day, microglia showed less complex processes, unbiased stereology detected fewer hippocampal CA1 pyramidal neurons and dentate granule neurons (GC and Golgi staining of the cerebellum showed diminished Purkinje cell dendritic arbor. At PND150, normal maturation of GC number and Purkinje cell branching area was not observed in the 1.0 mg/kg/day dose group with a diminished number and branching suggestive of effects initiated during developmental exposure. No effects were observed on post-weaning behavioral assessments in control, 0.1 and 1.0 mg/kg/day dose groups. The demonstrated sensitivity of hippocampal neurons and glial cells to TCAB and T4 deficit raises support for considering additional anatomical features of brain development in future DNT evaluations.

  14. Light stimuli control neuronal migration by altering of insulin-like growth factor 1 (IGF-1) signaling.

    Science.gov (United States)

    Li, Ying; Komuro, Yutaro; Fahrion, Jennifer K; Hu, Taofang; Ohno, Nobuhiko; Fenner, Kathleen B; Wooton, Jessica; Raoult, Emilie; Galas, Ludovic; Vaudry, David; Komuro, Hitoshi

    2012-02-14

    The role of genetic inheritance in brain development has been well characterized, but little is known about the contributions of natural environmental stimuli, such as the effect of light-dark cycles, to brain development. In this study, we determined the role of light stimuli in neuronal cell migration to elucidate how environmental factors regulate brain development. We show that in early postnatal mouse cerebella, granule cell migration accelerates during light cycles and decelerates during dark cycles. Furthermore, cerebellar levels of insulin-like growth factor 1 (IGF-1) are high during light cycles and low during dark cycles. There are causal relationships between light-dark cycles, speed of granule cell migration, and cerebellar IGF-1 levels. First, changes in light-dark cycles result in corresponding changes in the fluctuations of both speed of granule cell migration and cerebellar IGF-1 levels. Second, in vitro studies indicate that exogenous IGF-1 accelerates the migration of isolated granule cells through the activation of IGF-1 receptors. Third, in vivo studies reveal that inhibiting the IGF-1 receptors decelerates granule cell migration during light cycles (high IGF-1 levels) but does not alter migration during dark cycles (low IGF-1 levels). In contrast, stimulating the IGF-1 receptors accelerates granule cell migration during dark cycles (low IGF-1 levels) but does not alter migration during light cycles (high IGF-1 levels). These results suggest that during early postnatal development light stimuli control granule cell migration by altering the activity of IGF-1 receptors through modification of cerebellar IGF-1 levels.

  15. The cellular state determines the effect of melatonin on the survival of mixed cerebellar cell culture.

    Directory of Open Access Journals (Sweden)

    Daiane Gil Franco

    Full Text Available 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.

  16. Cytotoxic CD8+ T cells and CD138+ plasma cells prevail in cerebrospinal fluid in non-paraneoplastic cerebellar ataxia with contactin-associated protein-2 antibodies

    Directory of Open Access Journals (Sweden)

    Melzer Nico

    2012-07-01

    Full Text Available Abstract Objective The purpose of this paper is to report a patient with otherwise unexplained cerebellar ataxia with serum antibodies against contactin-associated protein-2 (CASPR-2 and provide a detailed description of the composition of cellular infiltrates in the cerebrospinal fluid (CSF compared to the peripheral blood (PB. CASPR-2 antibodies strongly labeling axons of cerebellar granule neurons have recently been identified in sera from nine patients with otherwise unexplained progressive cerebellar ataxia with mild to severe cerebellar atrophy. Design This is a report of a single case. Methods The study methods used were neurologic examination, magnetic resonance imaging, fluorodeoxyglucose positron emisson tomography, lumbar puncture and multicolor flow-cytometry. Results A 23-year-old Caucasian male presented with a two-year history of a progressive cerebellar and brainstem syndrome. Magnetic resonance imaging (MRI showed pronounced cerebellar atrophy, especially of the medial parts of the hemispheres and the vermis. Cerebral fluorodeoxyglucose positron emission tomography (FDG-PET showed pronounced hypometabolism of the whole cerebellum. CASPR-2 antibodies were detected in the serum but not the CSF, and none of the staging and laboratory assessments revealed other causes of progressive cerebellar degeneration. Interestingly, flow-cytometry of the CSF as compared to the PB showed increased fractions of CD138+ plasma cells as well as human leukocyte antigen (HLA-DR+ CD8+ T cells suggesting that both B cells and CD8+ T cells were preferentially recruited to and activated within the CSF- (and putatively central nervous system (CNS- compartment. Conclusion We confirm the association of CASPR-2 serum antibodies with cerebellar ataxia and provide the first evidence for a combined humoral and cellular immune response in this novel antibody-associated inflammatory CNS disease.

  17. A possible role of the non-GAT1 GABA transporters in transfer of GABA from GABAergic to glutamatergic neurons in mouse cerebellar neuronal cultures

    DEFF Research Database (Denmark)

    Suñol, C; Babot, Z; Cristòfol, R;

    2010-01-01

    . The distribution of GAD, GABA and the vesicular glutamate transporter VGlut-1 was assessed using specific antibodies combined with immunofluorescence microscopy. Additionally, tiagabine, SKF 89976-A, betaine, beta-alanine, nipecotic acid and guvacine were used to inhibit the GAT1, betaine/GABA (BGT1), GAT2 and GAT...... neurons constituting the majority of the cells. GABA uptake exhibited the kinetics of high affinity transport and could be partly (20%) inhibited by betaine (IC(50) 142 microM), beta-alanine (30%) and almost fully (90%) inhibited by SKF 89976-A (IC(50) 0.8 microM) or nipecotic acid and guvacine at 1 m...... is not likely involved in this redistribution since addition of 15 microM tiagabine (GAT1 inhibitor) to the culture medium had no effect on the overall GABA content of the cells. Likewise the BGT1 transporter cannot alone account for the redistribution since inclusion of 3 mM betaine in the culture medium had...

  18. Rac1 regulates neuronal polarization through the WAVE complex

    DEFF Research Database (Denmark)

    Tahirovic, Sabina; Hellal, Farida; Neukirchen, Dorothee;

    2010-01-01

    physiological function of Rac1 in neuronal development, we have generated a conditional knock-out mouse, in which Rac1 is ablated in the whole brain. Rac1-deficient cerebellar granule neurons, which do not express other Rac isoforms, showed impaired neuronal migration and axon formation both in vivo and in...... vitro. In addition, Rac1 ablation disrupts lamellipodia formation in growth cones. The analysis of Rac1 effectors revealed the absence of the Wiskott-Aldrich syndrome protein (WASP) family verprolin-homologous protein (WAVE) complex from the plasma membrane of knock-out growth cones. Loss of WAVE...... function inhibited axon growth, whereas overexpression of a membrane-tethered WAVE mutant partially rescued axon growth in Rac1-knock-out neurons. In addition, pharmacological inhibition of the WAVE complex effector Arp2/3 also reduced axon growth. We propose that Rac1 recruits the WAVE complex to the...

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

    Energy Technology Data Exchange (ETDEWEB)

    Akane, Hirotoshi [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan); Saito, Fumiyo [Chemicals Evaluation and Research Institute, Japan, 1-4-25 Koraku, Bunkyo-ku, Tokyo 112-0004 (Japan); Shiraki, Ayako [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan); Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193 (Japan); Takeyoshi, Masahiro; Imatanaka, Nobuya [Chemicals Evaluation and Research Institute, Japan, 1-4-25 Koraku, Bunkyo-ku, Tokyo 112-0004 (Japan); Itahashi, Megu [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan); Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193 (Japan); Murakami, Tomoaki [Laboratory of Veterinary Toxicology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan); Shibutani, Makoto, E-mail: mshibuta@cc.tuat.ac.jp [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan)

    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 at 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 tissues

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

    International Nuclear Information System (INIS)

    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 at 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+ neurons at 1000 ppm and Fos+ 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 tissues decreased

  1. Efficient differentiation of human embryonic stem cells into functional cerebellar-like cells.

    Science.gov (United States)

    Erceg, Slaven; Ronaghi, Mohammad; Zipancic, Ivan; Lainez, Sergio; Roselló, Mireia Gárcia; Xiong, Chen; Moreno-Manzano, Victoria; Rodríguez-Jiménez, Fernando Javier; Planells, Rosa; Alvarez-Dolado, Manuel; Bhattacharya, Shom Shanker; Stojkovic, Miodrag

    2010-11-01

    The cerebellum has critical roles in motor and sensory learning and motor coordination. Many cerebellum-related disorders indicate cell therapy as a possible treatment of neural loss. Here we show that application of inductive signals involved in early patterning of the cerebellar region followed by application of different factors directs human embryonic stem cell differentiation into cerebellar-like cells such as granule neurons, Purkinje cells, interneuron, and glial cells. Neurons derived using our protocol showed a T-shaped polarity phenotype and express similar markers to the developed human cerebellum. Electrophysiological measurements confirmed functional electrical properties compatible with these cells. In vivo implantation of differentiated human embryonic stem cells transfected with MATH1-GFP construct into neonatal mice resulted in cell migration across the molecular and the Purkinje cell layers and settlement in the internal molecular layers. Our findings demonstrate that the universal mechanisms involved in the development of cerebellum can be efficiently recapitulated in vitro, which enables the design of new strategies for cell replacement therapy, to study early human development and pathogenesis of neurodegenerative diseases. PMID:20521974

  2. Activity of the lactate-alanine shuttle is independent of glutamate-glutamine cycle activity in cerebellar neuronal-astrocytic cultures

    DEFF Research Database (Denmark)

    Bak, Lasse K; Sickmann, Helle M; Schousboe, Arne;

    2004-01-01

    The glutamate-glutamine cycle describes the neuronal release of glutamate into the synaptic cleft, astrocytic uptake, and conversion into glutamine, followed by release for use as a neuronal glutamate precursor. This only explains the fate of the carbon atoms, however, and not that of the ammonia...

  3. Ectopic cerebellar cell migration causes maldevelopment of Purkinje cells and abnormal motor behaviour in Cxcr4 null mice.

    Directory of Open Access Journals (Sweden)

    Guo-Jen Huang

    Full Text Available SDF-1/CXCR4 signalling plays an important role in neuronal cell migration and brain development. However, the impact of CXCR4 deficiency in the postnatal mouse brain is still poorly understood. Here, we demonstrate the importance of CXCR4 on cerebellar development and motor behaviour by conditional inactivation of Cxcr4 in the central nervous system. We found CXCR4 plays a key role in cerebellar development. Its loss leads to defects in Purkinje cell dentritogenesis and axonal projection in vivo but not in cell culture. Transcriptome analysis revealed the most significantly affected pathways in the Cxcr4 deficient developing cerebellum are involved in extra cellular matrix receptor interactions and focal adhesion. Consistent with functional impairment of the cerebellum, Cxcr4 knockout mice have poor coordination and balance performance in skilled motor tests. Together, these results suggest ectopic the migration of granule cells impairs development of Purkinje cells, causes gross cerebellar anatomical disruption and leads to behavioural motor defects in Cxcr4 null mice.

  4. Foxc1 dependent mesenchymal signalling drives embryonic cerebellar growth

    Science.gov (United States)

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

    2014-01-01

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

  5. Studies with neuronal cells: From basic studies of mechanisms of neurotoxicity to the prediction of chemical toxicity.

    Science.gov (United States)

    Suñol, C; Babot, Z; Fonfría, E; Galofré, M; García, D; Herrera, N; Iraola, S; Vendrell, I

    2008-08-01

    Neurotoxicology considers that chemicals perturb neurological functions by interfering with the structure or function of neural pathways, circuits and systems. Using in vitro methods for neurotoxicity studies should include evaluation of specific targets for the functionalism of the nervous system and general cellular targets. In this review we present the neuronal characteristics of primary cultures of cortical neurons and of cerebellar granule cells and their use in neurotoxicity studies. Primary cultures of cortical neurons are constituted by around 40% of GABAergic neurons, whereas primary cultures of cerebellar granule cells are mainly constituted by glutamatergic neurons. Both cultures express functional GABAA and ionotropic glutamate receptors. We present neurotoxicity studies performed in these cell cultures, where specific neural targets related to GABA and glutamate neurotransmission are evaluated. The effects of convulsant polychlorocycloalkane pesticides on the GABAA, glycine and NMDA receptors points to the GABAA receptor as the neural target that accounts for their in vivo acute toxicity, whereas NMDA disturbance might be relevant for long-term toxicity. Several compounds from a list of reference compounds, whose severe human poisoning result in convulsions, inhibited the GABAA receptor. We also present cell proteomic studies showing that the neurotoxic contaminant methylmercury affect mitochondrial proteins. We conclude that the in vitro assays that have been developed can be useful for their inclusion in an in vitro test battery to predict human toxicity.

  6. C9orf72 Hexanucleotide Expansions Are Associated with Altered Endoplasmic Reticulum Calcium Homeostasis and Stress Granule Formation in Induced Pluripotent Stem Cell‐Derived Neurons from Patients with Amyotrophic Lateral Sclerosis and Frontotemporal Dementia

    Science.gov (United States)

    Dafinca, Ruxandra; Scaber, Jakub; Ababneh, Nida'a; Lalic, Tatjana; Weir, Gregory; Christian, Helen; Vowles, Jane; Douglas, Andrew G.L.; Fletcher‐Jones, Alexandra; Browne, Cathy; Nakanishi, Mahito; Turner, Martin R.; Wade‐Martins, Richard

    2016-01-01

    Abstract An expanded hexanucleotide repeat in a noncoding region of the C9orf72 gene is a major cause of amyotrophic lateral sclerosis (ALS), accounting for up to 40% of familial cases and 7% of sporadic ALS in European populations. We have generated induced pluripotent stem cells (iPSCs) from fibroblasts of patients carrying C9orf72 hexanucleotide expansions, differentiated these to functional motor and cortical neurons, and performed an extensive phenotypic characterization. In C9orf72 iPSC‐derived motor neurons, decreased cell survival is correlated with dysfunction in Ca2+ homeostasis, reduced levels of the antiapoptotic protein Bcl‐2, increased endoplasmic reticulum (ER) stress, and reduced mitochondrial membrane potential. Furthermore, C9orf72 motor neurons, and also cortical neurons, show evidence of abnormal protein aggregation and stress granule formation. This study is an extensive characterization of iPSC‐derived motor neurons as cellular models of ALS carrying C9orf72 hexanucleotide repeats, which describes a novel pathogenic link between C9orf72 mutations, dysregulation of calcium signaling, and altered proteostasis and provides a potential pharmacological target for the treatment of ALS and the related neurodegenerative disease frontotemporal dementia. Stem Cells 2016;34:2063–2078 PMID:27097283

  7. Neuroprotective effect of melatonin against ischemia/reperfusion-induced neuronal apoptosis in mouse cerebellum

    Institute of Scientific and Technical Information of China (English)

    Qiuhong Duan; Tao Lu; Yixiang Han; Zhiqiang Lu; Ximing Wang

    2007-01-01

    model group and control group. ③DNA level was analyzed and cell apoptosis was observed by agarose gel electrophoresis(AGE). ④Mitochondrial transmembrane potential of cells, and apoptotic way in each group were analyzed by confocal laser scanning microscopy.MAIN OUTCOME MEASURES: ①Mitochondrial cytochrome C level of cerebellar nerve cells. ②LDH activity of cerebellar nerve cells. ③DNA AGE results. ④Mitochondrial transmembrane potential change.RESULTS: ①Mitochondrial cytochrome C level of cerebellar nerve cells: cytochrome C was obviously released at 6 hours of OGD-reperfusion. Mel inhibited the release of cytochrome C in dose-dependent manner. ②LDH activity of cerebellar nerve cells: LDH activity (A value) was significantly lower in the high- and middle-concentration Mel groups than in the model group (P<0.05). LDH activity (A value) in the low-concentration Mel group was 0.415 0 + 0.012 9, indicating that Mel could decrease LDH activity of OGD-treated cell supernatant and promote membrane stablization in dose-dependent manner.③AGE results of DNA: 1×10-9 mol/L was considered as the best concentration of melatonin. Cell DNA was extracted for AGE. Results presented typical ladder shape, indicating apoptosis appeared, while apoptosis was lessened in the Mel treatment group and Mel prevention group.④Mitochondrial transmembrane potential change: Experimental results showed that green fluorescein was evenly distributed in cerebellar granule cells cultured normally, and the axons of neurons were very clear. The body of neurons was condensed and the axons disappeared after cerebellar granule cells undergoing OGD injury. Mel could compltetly reverse the effect of OGD.CONCLUSION:Mel can enhance crerbellar neuronal membrane stabilization of rats in dose-dependent manner,and suppress OGD-induced apoptosis of cerebellar granule cells by preventing against mitochondrial apoptosis.

  8. Inverse Stochastic Resonance in Cerebellar Purkinje Cells

    Science.gov (United States)

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

    2016-01-01

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

  9. Inverse Stochastic Resonance in Cerebellar Purkinje Cells.

    Science.gov (United States)

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

    2016-08-01

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

  10. Optimisation of a 96-well electroporation assay for postnatal rat CNS neurons suitable for cost-effective medium-throughput screening of genes that promote neurite outgrowth

    Directory of Open Access Journals (Sweden)

    Thomas eHutson

    2011-12-01

    Full Text Available Following an injury, central nervous system (CNS neurons show a very limited regenerative response which results in their failure to successfully form functional connections with their original target. This is due in part to the reduced intrinsic growth state of CNS neurons, which is characterised by their failure to express key regeneration-associated genes (RAGs and by the presence of growth inhibitory molecules in CNS environment that form a molecular and physical barrier to regeneration. Here we have optimised a 96-well electroporation and neurite outgrowth assay for postnatal rat cerebellar granule neurons cultured upon an inhibitory cellular substrate expressing myelin-associated glycoprotein or a mixture of growth-inhibitory chondroitin sulphate proteoglycans. Optimal electroporation parameters resulted in 25% transfection efficiency and 50% viability for postnatal rat cerebellar granule neurons (CGNs. The neurite outgrowth of transduced neurons was quantitatively measured using a semi-automated image capture and analysis system. The neurite outgrowth was significantly reduced by the inhibitory substrates which we demonstrated could be partially reversed using a Rho Kinase inhibitor. We are now using this assay to screen large sets of RAGs for their ability to increase neurite outgrowth on a variety of growth inhibitory and permissive substrates.

  11. Glucocorticoid treatment of MCMV infected newborn mice attenuates CNS inflammation and limits deficits in cerebellar development.

    Directory of Open Access Journals (Sweden)

    Kate Kosmac

    2013-03-01

    Full Text Available Infection of the developing fetus with human cytomegalovirus (HCMV is a major cause of central nervous system disease in infants and children; however, mechanism(s of disease associated with this intrauterine infection remain poorly understood. Utilizing a mouse model of HCMV infection of the developing CNS, we have shown that peripheral inoculation of newborn mice with murine CMV (MCMV results in CNS infection and developmental abnormalities that recapitulate key features of the human infection. In this model, animals exhibit decreased granule neuron precursor cell (GNPC proliferation and altered morphogenesis of the cerebellar cortex. Deficits in cerebellar cortical development are symmetric and global even though infection of the CNS results in a non-necrotizing encephalitis characterized by widely scattered foci of virus-infected cells with mononuclear cell infiltrates. These findings suggested that inflammation induced by MCMV infection could underlie deficits in CNS development. We investigated the contribution of host inflammatory responses to abnormal cerebellar development by modulating inflammatory responses in infected mice with glucocorticoids. Treatment of infected animals with glucocorticoids decreased activation of CNS mononuclear cells and expression of inflammatory cytokines (TNF-α, IFN-β and IFNγ in the CNS while minimally impacting CNS virus replication. Glucocorticoid treatment also limited morphogenic abnormalities and normalized the expression of developmentally regulated genes within the cerebellum. Importantly, GNPC proliferation deficits were normalized in MCMV infected mice following glucocorticoid treatment. Our findings argue that host inflammatory responses to MCMV infection contribute to deficits in CNS development in MCMV infected mice and suggest that similar mechanisms of disease could be responsible for the abnormal CNS development in human infants infected in-utero with HCMV.

  12. Oxidative injury in multiple sclerosis cerebellar grey matter.

    Science.gov (United States)

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

    2016-07-01

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

  13. Cerebellar liponeurocytoma: a case-report

    Directory of Open Access Journals (Sweden)

    K.V. Sreedhar Babu

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

  14. The Neuroprotective Effect of Lithium in cannabinoid Dependence is Mediated through Modulation of Cyclic AMP, ERK1/2 and GSK-3β Phosphorylation in Cerebellar Granular Neurons of Rat

    Science.gov (United States)

    Rahimi, Hamid Reza; Ghahremani, Mohammad Hossein; Dehpour, Ahmad Reza; Sharifzadeh, Mohammad; Ejtemaei-Mehr, Shahram; Razmi, Ali; Ostad, Seyed Nasser

    2015-01-01

    Lithium (Li), a glycogen synthase kinase-3β (GSK-3β) inhibitor, has used to attenuate the cannabinoid-induced dependence/withdrawal signs, but molecular mechanisms related to this are unclear. Recent studies indicate the involvement of upstream extracellular signal kinase1/2 (ERK1/2) and downstream GSK-3β pathways in the development of cannabinoid-induced dependence. This is mediated through cannabinoid receptor 1 (CB1) enriched in cerebellar granular neurons (CGNs). Accordingly, the present study aimed to investigate the mechanism of modulatory/neuroprotective effects of Li on a cannabinoid agonist (WIN 55,212-2 (WIN))-induced dependence, through quantitative analysis of some involved proteins such as ERK1/2, GSK-3β and related signaling pathways including their phosphorylated forms; and cAMP level as the other molecular mechanisms leading to dependence, in CGNs model. The CGNs were prepared from 7-day-old Wistar rat pup in a 12-well plate, pretreated with Li (1mM) and an ERK1/2 inhibitor SL327 (SL, 10 µM). The WIN (1 µM) was added 30 minutes prior to treatment and AM251 (AM, 1 µM), as a cannabinoid antagonist was co-treated with WIN. The cAMP level, as an indicator of cannabinoid-induced dependence, was measured by ELISA following forskolin (FSK) stimulation. Western blot analyses determined the phosphorylated forms of ERK1/2 (p-ERK1/2), GSK-3β (p-GSK-3β) as well as their total expressions in various treatment times and doses in CGNs. WIN alone could down regulate the cAMP/p-ERK1/2 cascade compared to AM treatment. However, P-GSK-3β was up-regulated with Li and WIN or with SL and Li pretreatment to AM-induced cellular response, which was the highest 60 minutes after CGNs exposure. Results further suggested the potential role of Li pretreatment to diminish the development of cannabinoid-induced dependence/neuronal injury through possible mechanisms of modulating the cAMP/p-ERK1/2 cascade independent of p-GSK-3β signaling pathway in-vitro. PMID:26664379

  15. Molecular composition of IMP1 ribonucleoprotein granules

    DEFF Research Database (Denmark)

    Jønson, Lars; Vikesaa, Jonas; Krogh, Anders;

    2007-01-01

    Localized mRNAs are transported to sites of local protein synthesis in large ribonucleoprotein (RNP) granules, but their molecular composition is incompletely understood. Insulin-like growth factor II mRNA-binding protein (IMP) zip code-binding proteins participate in mRNA localization, and in mo......Localized mRNAs are transported to sites of local protein synthesis in large ribonucleoprotein (RNP) granules, but their molecular composition is incompletely understood. Insulin-like growth factor II mRNA-binding protein (IMP) zip code-binding proteins participate in mRNA localization......, and in motile cells IMP-containing granules are dispersed around the nucleus and in cellular protrusions. We isolated the IMP1-containing RNP granules and found that they represent a unique RNP entity distinct from neuronal hStaufen and/or fragile X mental retardation protein granules, processing bodies......, and stress granules. Granules were 100-300 nm in diameter and consisted of IMPs, 40 S ribosomal subunits, shuttling heterologous nuclear RNPs, poly(A)-binding proteins, and mRNAs. Moreover granules contained CBP80 and factors belonging to the exon junction complex and lacked eIF4E, eIF4G, and 60 S ribosomal...

  16. Lissencephaly and cerebellar hypoplasia in a goat

    Directory of Open Access Journals (Sweden)

    José Rômulo Soares dos Santos

    2013-10-01

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

  17. The anti-epileptic drug levetiracetam reverses the inhibition by negative allosteric modulators of neuronal GABA- and glycine-gated currents

    OpenAIRE

    Rigo, J-M; Hans, G.; Nguyen, L.; Rocher, V; Belachew, S; Malgrange, B; Leprince, P.; Moonen, G.; Selak, I; Matagne, A; Klitgaard, H

    2002-01-01

    In this study in vitro and in vivo approaches were combined in order to investigate if the anti-epileptic mechanism(s) of action of levetiracetam (LEV; Keppra®) may involve modulation of inhibitory neurotransmission.GABA- and glycine-gated currents were studied in vitro using whole-cell patch-clamp techniques applied on cultured cerebellar granule, hippocampal and spinal neurons. Protection against clonic convulsions was assessed in vivo in sound-susceptible mice. The effect of LEV was compar...

  18. Optogenetics in the cerebellum: Purkinje cell-specific approaches for understanding local cerebellar functions.

    Science.gov (United States)

    Tsubota, Tadashi; Ohashi, Yohei; Tamura, Keita

    2013-10-15

    The cerebellum consists of the cerebellar cortex and the cerebellar nuclei. Although the basic neuronal circuitry of the cerebellar cortex is uniform everywhere, anatomical data demonstrate that the input and output relationships of the cortex are spatially segregated between different cortical areas, which suggests that there are functional distinctions between these different areas. Perturbation of cerebellar cortical functions in a spatially restricted fashion is thus essential for investigating the distinctions among different cortical areas. In the cerebellar cortex, Purkinje cells are the sole output neurons that send information to downstream cerebellar and vestibular nuclei. Therefore, selective manipulation of Purkinje cell activities, without disturbing other neuronal types and passing fibers within the cortex, is a direct approach to spatially restrict the effects of perturbations. Although this type of approach has for many years been technically difficult, recent advances in optogenetics now enable selective activation or inhibition of Purkinje cell activities, with high temporal resolution. Here we discuss the effectiveness of using Purkinje cell-specific optogenetic approaches to elucidate the functions of local cerebellar cortex regions. We also discuss what improvements to current methods are necessary for future investigations of cerebellar functions to provide further advances.

  19. The prion protein constitutively controls neuronal store-operated Ca2+ entry through Fyn kinase

    Directory of Open Access Journals (Sweden)

    Agnese eDe Mario

    2015-10-01

    Full Text Available The prion protein (PrPC is a cell surface glycoprotein mainly expressed in neurons, whose misfolded isoforms generate the prion responsible for incurable neurodegenerative disorders. Whereas PrPC involvement in prion propagation is well established, PrPC physiological function is still enigmatic despite suggestions that it could act in cell signal transduction by modulating phosphorylation cascades and Ca2+ homeostasis. Because PrPC binds neurotoxic protein aggregates with high-affinity, it has also been proposed that PrPC acts as receptor for amyloid-β (Aβ oligomers associated with Alzheimer’s disease (AD, and that PrPC-Aβ binding mediates AD-related synaptic dysfunctions following activation of the tyrosine kinase Fyn.Here, use of gene-encoded Ca2+ probes targeting different cell domains in primary cerebellar granule neurons expressing, or not, PrPC allowed us to investigate whether PrPC regulates store-operated Ca2+ entry (SOCE and the implication of Fyn in this control. Our findings show that PrPC attenuates SOCE, and Ca2+ accumulation in the cytosol and mitochondria, by constitutively restraining Fyn activation and tyrosine phosphorylation of STIM1, a key molecular component of SOCE. This data establishes the existence of a PrPC-Fyn-SOCE triad in neurons.We also demonstrate that treating cerebellar granule and cortical neurons with soluble Aβ(1-42 oligomers abrogates the control of PrPC over Fyn and SOCE, suggesting a PrPC-dependent mechanism for Aβ-induced neuronal Ca2+ dyshomeostasis.

  20. Cerebellar anatomy as applied to cerebellar microsurgical resections

    Directory of Open Access Journals (Sweden)

    Alejandro Ramos

    2012-06-01

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

  1. The forced swimming-induced behavioural immobility response involves histone H3 phospho-acetylation and c-Fos induction in dentate gyrus granule neurons via activation of the N-methyl-D-aspartate/extracellular signal-regulated kinase/mitogen- and stress-activated kinase signalling pathway.

    Science.gov (United States)

    Chandramohan, Yalini; Droste, Susanne K; Arthur, J Simon C; Reul, Johannes M H M

    2008-05-01

    The hippocampus is involved in learning and memory. Previously, we have shown that the acquisition of the behavioural immobility response after a forced swim experience is associated with chromatin modifications and transcriptional induction in dentate gyrus granule neurons. Given that both N-methyl-D-aspartate (NMDA) receptors and the extracellular signal-regulated kinases (ERK) 1/2 signalling pathway are involved in neuroplasticity processes underlying learning and memory, we investigated in rats and mice whether these signalling pathways regulate chromatin modifications and transcriptional events participating in the acquisition of the immobility response. We found that: (i) forced swimming evoked a transient increase in the number of phospho-acetylated histone H3-positive [P(Ser10)-Ac(Lys14)-H3(+)] neurons specifically in the middle and superficial aspects of the dentate gyrus granule cell layer; (ii) antagonism of NMDA receptors and inhibition of ERK1/2 signalling blocked forced swimming-induced histone H3 phospho-acetylation and the acquisition of the behavioural immobility response; (iii) double knockout (DKO) of the histone H3 kinase mitogen- and stress-activated kinases (MSK) 1/2 in mice completely abolished the forced swimming-induced increases in histone H3 phospho-acetylation and c-Fos induction in dentate granule neurons and the behavioural immobility response; (iv) blocking mineralocorticoid receptors, known not to be involved in behavioural immobility in the forced swim test, did not affect forced swimming-evoked histone H3 phospho-acetylation in dentate neurons; and (v) the pharmacological manipulations and gene deletions did not affect behaviour in the initial forced swim test. We conclude that the forced swimming-induced behavioural immobility response requires histone H3 phospho-acetylation and c-Fos induction in distinct dentate granule neurons through recruitment of the NMDA/ERK/MSK 1/2 pathway.

  2. Developmental delay in motor skill acquisition in Niemann-Pick C1 mice reveals abnormal cerebellar morphogenesis.

    Science.gov (United States)

    Caporali, Paola; Bruno, Francesco; Palladino, Giampiero; Dragotto, Jessica; Petrosini, Laura; Mangia, Franco; Erickson, Robert P; Canterini, Sonia; Fiorenza, Maria Teresa

    2016-01-01

    Niemann-Pick type C1 (NPC1) disease is a lysosomal storage disorder caused by defective intracellular trafficking of exogenous cholesterol. Purkinje cell (PC) degeneration is the main sign of cerebellar dysfunction in both NPC1 patients and animal models. It has been recently shown that a significant decrease in Sonic hedgehog (Shh) expression reduces the proliferative potential of granule neuron precursors in the developing cerebellum of Npc1 (-/-) mice. Pursuing the hypothesis that this developmental defect translates into functional impairments, we have assayed Npc1-deficient pups belonging to the milder mutant mouse strain Npc1 (nmf164) for sensorimotor development from postnatal day (PN) 3 to PN21. Npc1 (nmf164) / Npc1 (nmf164) pups displayed a 2.5-day delay in the acquisition of complex motor abilities compared to wild-type (wt) littermates, in agreement with the significant disorganization of cerebellar cortex cytoarchitecture observed between PN11 and PN15. Compared to wt, Npc1 (nmf164) homozygous mice exhibited a poorer morphological differentiation of Bergmann glia (BG), as indicated by thicker radial shafts and less elaborate reticular pattern of lateral processes. Also BG functional development was defective, as indicated by the significant reduction in GLAST and Glutamine synthetase expression. A reduced VGluT2 and GAD65 expression also indicated an overall derangement of the glutamatergic/GABAergic stimulation that PCs receive by climbing/parallel fibers and basket/stellate cells, respectively. Lastly, Npc1-deficiency also affected oligodendrocyte differentiation as indicated by the strong reduction of myelin basic protein. Two sequential 2-hydroxypropyl-β-cyclodextrin administrations at PN4 and PN7 counteract these defects, partially preventing functional impairment of BG and fully restoring the normal patterns of glutamatergic/GABAergic stimulation to PCs.These findings indicate that in Npc1 (nmf164) homozygous mice the derangement of synaptic

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

    NARCIS (Netherlands)

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

    2015-01-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  6. Alzheimer's Proteins, Oxidative Stress, and Mitochondrial Dysfunction Interplay in a Neuronal Model of Alzheimer's Disease

    Science.gov (United States)

    Bobba, Antonella; Petragallo, Vito A.; Marra, Ersilia; Atlante, Anna

    2010-01-01

    In this paper, we discuss the interplay between beta-amyloid (Aβ) peptide, Tau fragments, oxidative stress, and mitochondria in the neuronal model of cerebellar granule neurons (CGNs) in which the molecular events reminiscent of AD are activated. The identification of the death route and the cause/effect relationships between the events leading to death could be helpful to manage the progression of apoptosis in neurodegeneration and to define antiapoptotic treatments acting on precocious steps of the death process. Mitochondrial dysfunction is among the earliest events linked to AD and might play a causative role in disease onset and progression. Recent studies on CGNs have shown that adenine nucleotide translocator (ANT) impairment, due to interaction with toxic N-ter Tau fragment, contributes in a significant manner to bioenergetic failure and mitochondrial dysfunction. These findings open a window for new therapeutic strategies aimed at preserving and/or improving mitochondrial function. PMID:20862336

  7. Alzheimer's Proteins, Oxidative Stress, and Mitochondrial Dysfunction Interplay in a Neuronal Model of Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Antonella Bobba

    2010-01-01

    Full Text Available In this paper, we discuss the interplay between beta-amyloid (A peptide, Tau fragments, oxidative stress, and mitochondria in the neuronal model of cerebellar granule neurons (CGNs in which the molecular events reminiscent of AD are activated. The identification of the death route and the cause/effect relationships between the events leading to death could be helpful to manage the progression of apoptosis in neurodegeneration and to define antiapoptotic treatments acting on precocious steps of the death process. Mitochondrial dysfunction is among the earliest events linked to AD and might play a causative role in disease onset and progression. Recent studies on CGNs have shown that adenine nucleotide translocator (ANT impairment, due to interaction with toxic N-ter Tau fragment, contributes in a significant manner to bioenergetic failure and mitochondrial dysfunction. These findings open a window for new therapeutic strategies aimed at preserving and/or improving mitochondrial function.

  8. Granulation of fine powder

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ching-Fong

    2016-08-09

    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 form a dense compact with a higher density and more uniform pore size distribution.

  9. Memory consolidation in the cerebellar cortex.

    Directory of Open Access Journals (Sweden)

    Daniel O Kellett

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

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

    Science.gov (United States)

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

    2015-11-01

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

  11. Consensus Paper: Neuroimmune Mechanisms of Cerebellar Ataxias

    OpenAIRE

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

    2015-01-01

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

  12. Neuronal regulation of astroglial morphology and proliferation in vitro

    OpenAIRE

    1985-01-01

    To analyze the interdependence of neurons and astroglia during central nervous system development, a rapid method for purifying early postnatal cerebellar neurons and astroglia, and recombining them in vitro, has been developed. The influence of neurons on astroglial shape and proliferation has been evaluated with an in vitro model system previously used to describe the role of cerebellar astroglia in neuronal migration and positioning (Hatten, M. E., and R. K. H. Liem, 1981, J. Cell Biol., 9...

  13. A cerebellar neuroprosthetic system: computational architecture and in vivo experiments

    Directory of Open Access Journals (Sweden)

    Ivan eHerreros Alonso

    2014-05-01

    Full Text Available Emulating the input-output functions performed by a brain structure opens the possibility for developing neuro-prosthetic systems that replace damaged neuronal circuits. Here, we demonstrate the feasibility of this approach by replacing the cerebellar circuit responsible for the acquisition and extinction of motor memories. Specifically, we show that a rat can undergo acquisition, retention and extinction of the eye-blink reflex even though the biological circuit responsible for this task has been chemically inactivated via anesthesia. This is achieved by first developing a computational model of the cerebellar microcircuit involved in the acquisition of conditioned reflexes and training it with synthetic data generated based on physiological recordings. Secondly, the cerebellar model is interfaced with the brain of an anesthetized rat, connecting the model's inputs and outputs to afferent and efferent cerebellar structures. As a result, we show that the anesthetized rat, equipped with our neuro-prosthetic system, can be classically conditioned to the acquisition of an eye-blink response. However, non-stationarities in the recorded biological signals limit the performance of the cerebellar model. Thus, we introduce an updated cerebellar model and validate it with physiological recordings showing that learning becomes stable and reliable. The resulting system represents an important step towards replacing lost functions of the central nervous system via neuro-prosthetics, obtained by integrating a synthetic circuit with the afferent and efferent pathways of a damaged brain region. These results also embody an early example of science-based medicine, where on the one hand the neuro-prosthetic system directly validates a theory of cerebellar learning that informed the design of the system, and on the other one it takes a step towards the development of neuro-prostheses that could recover lost learning functions in animals and, in the longer term

  14. Cerebellar development in the absence of Gbx function in zebrafish.

    Science.gov (United States)

    Su, Chen-Ying; Kemp, Hilary A; Moens, Cecilia B

    2014-02-01

    The midbrain-hindbrain boundary (MHB) is a well-known organizing center during vertebrate brain development. The MHB forms at the expression boundary of Otx2 and Gbx2, mutually repressive homeodomain transcription factors expressed in the midbrain/forebrain and anterior hindbrain, respectively. The genetic hierarchy of gene expression at the MHB is complex, involving multiple positive and negative feedback loops that result in the establishment of non-overlapping domains of Wnt1 and Fgf8 on either side of the boundary and the consequent specification of the cerebellum. The cerebellum derives from the dorsal part of the anterior-most hindbrain segment, rhombomere 1 (r1), which undergoes a distinctive morphogenesis to give rise to the cerebellar primordium within which the various cerebellar neuron types are specified. Previous studies in the mouse have shown that Gbx2 is essential for cerebellar development. Using zebrafish mutants we show here that in the zebrafish gbx1 and gbx2 are required redundantly for morphogenesis of the cerebellar primordium and subsequent cerebellar differentiation, but that this requirement is alleviated by knocking down Otx. Expression of fgf8, wnt1 and the entire MHB genetic program is progressively lost in gbx1-;gbx2- double mutants but is rescued by Otx knock-down. This rescue of the MHB genetic program depends on rescued Fgf signaling, however the rescue of cerebellar primordium morphogenesis is independent of both Gbx and Fgf. Based on our findings we propose a revised model for the role of Gbx in cerebellar development.

  15. Development of the cerebellar cortex in the mouse

    Institute of Scientific and Technical Information of China (English)

    Xiangshu Cheng; Jin Du; Dongming Yu; Qiying Jiang; Yanqiu Hu; Lei Wang; Mingshan Li; Jinbo Deng

    2011-01-01

    The cerebellum is a highly conserved structure in the central nervous system of vertebrates, and is involved in the coordination of voluntary motor behavior. Supporting this function, the cerebellar cortex presents a layered structure which requires precise spatial and temporal coordination of proliferation, migration, differentiation, and apoptosis events. The formation of the layered structure in the developing cerebellum remains unclear. The present study investigated the development of the cerebellar cortex. The results demonstrate that the primordium of the cerebellum comprises the ependymal, mantle, and marginal layers at embryonic day 12 (E12). Subsequently, the laminated cerebellar cortex undergoes cell proliferation, differentiation, and migration, and at about postnatal day 0 (P0), the cerebellar cortex presents an external granular layer, a molecular layer, a Purkinje layer, and an internal granular layer. The external granular layer is thickest at P6/7 and disappears at P20. From P0 to P30, the internal granular cells and the Purkinje cells gradually differentiate and develop until maturity. Apoptotic neurons are evident in the layered structure in the developing cerebellar cortex. The external granular layer disappears gradually because of cell migration and apoptosis. The cells of the other layers primarily undergo differentiation, development, and apoptosis.

  16. Neuron-microglia crosstalk up-regulates neuronal FGF-2 expression which mediates neuroprotection against excitotoxicity via JNK1/2.

    Science.gov (United States)

    Figueiredo, Catarina; Pais, Teresa F; Gomes, João R; Chatterjee, Sukalyan

    2008-10-01

    Glial cells and neurons are in constant reciprocal signalling both under physiological and neuropathological conditions. Microglial activation is often associated with neuronal death during inflammation of the CNS, although microglial cells are also known to exert a neuroprotective role. In this work, we investigated the interplay between cerebellar granule neurons (CGN) and microglia in the perspective of CGN survival to an excitotoxic stimulus, quinolinic acid (QA), a catabolite of the tryptophan degradation pathway. We observed that CGN succumb to QA challenge via extracellular signal regulated kinase 1 and 2 (ERK) activation. Our data with transgenic mice expressing the natural inhibitor of calpains, calpastatin, indicate that together with cathepsins they mediate QA-induced toxicity acting downstream of the mitogen-activated protein kinase kinase-ERK pathway. Microglial cells are not only resistant to QA but can rescue neurons from QA-mediated toxicity when they are mixed in culture with neurons or by using mixed culture-conditioned medium (MCCM). This effect is mediated via fibroblast growth factor-2 (FGF-2) present in MCCM. FGF-2 is transcriptionally up-regulated in neurons and secreted in the MCCM as a result of neuron-microglia crosstalk. The neuroprotection is associated with the retention of cathepsins in the lysosomes and with transactivation of inducible heat-shock protein 70 downstream of FGF-2. Furthermore, FGF-2 upon release by neurons activates c-jun N-terminal kinase 1 and 2 pathway which also contributes to neuronal survival. We suggest that FGF-2 plays a pivotal role in neuroprotection against QA as an outcome of neuron-microglia interaction.

  17. Cerebellar degeneration in neuroleptic malignant syndrome: neuropathologic findings and review of the literature concerning heat-related nervous system injury.

    OpenAIRE

    Lee, S.; Merriam, A; Kim, T. S.; Liebling, M; Dickson, D. W.; Moore, G. R.

    1989-01-01

    A selective subtotal cerebellar neuronal degeneration was found in a patient who died 4 1/2 months after suffering neuroleptic malignant syndrome (NMS), a rare, potentially fatal disorder associated with neuroleptic medications. It is suggested that the cerebellar neuronal degeneration in this case was due to hyperpyrexia, a cardinal clinical feature of NMS. Similar pathologic findings appear not to have been previously reported in NMS but have been described in heat-induced central nervous s...

  18. Microglia in Glia-Neuron Co-cultures Exhibit Robust Phagocytic Activity Without Concomitant Inflammation or Cytotoxicity.

    Science.gov (United States)

    Adams, Alexandra C; Kyle, Michele; Beaman-Hall, Carol M; Monaco, Edward A; Cullen, Matthew; Vallano, Mary Lou

    2015-10-01

    A simple method to co-culture granule neurons and glia from a single brain region is described, and microglia activation profiles are assessed in response to naturally occurring neuronal apoptosis, excitotoxin-induced neuronal death, and lipopolysaccharide (LPS) addition. Using neonatal rat cerebellar cortex as a tissue source, glial proliferation is regulated by omission or addition of the mitotic inhibitor cytosine arabinoside (AraC). After 7-8 days in vitro, microglia in AraC(-) cultures are abundant and activated based on their amoeboid morphology, expressions of ED1 and Iba1, and ability to phagocytose polystyrene beads and the majority of neurons undergoing spontaneous apoptosis. Microglia and phagocytic activities are sparse in AraC(+) cultures. Following exposure to excitotoxic kainate concentrations, microglia in AraC(-) cultures phagocytose most dead neurons within 24 h without exacerbating neuronal loss or mounting a strong or sustained inflammatory response. LPS addition induces a robust inflammatory response, based on microglial expressions of TNF-α, COX-2 and iNOS proteins, and mRNAs, whereas these markers are essentially undetectable in control cultures. Thus, the functional effector state of microglia is primed for phagocytosis but not inflammation or cytotoxicity even after kainate exposure that triggers death in the majority of neurons. This model should prove useful in studying the progressive activation states of microglia and factors that promote their conversion to inflammatory and cytotoxic phenotypes.

  19. Cerebellar abnormalities typical of methylmercury poisoning in a fledged saltmarsh sparrow, Ammodramus caudacutus.

    Science.gov (United States)

    Scoville, Sheila A; Lane, Oksana P

    2013-05-01

    A fledged, 12-15 day-old saltmarsh sparrow, Ammodramus caudacutus, was collected from an accidental kill on Cinder Island, Long Island, NY, USA. The sparrow was assessed for feather mercury levels and the brain analyzed for cerebellar abnormalities by microscopic examination. In humans, fetal Minamata disease is caused by maternal ingestion of mercury. It is characterized by disrupted and disordered cerebellar neuronal migration in the fetus or infant. Results from this sparrow show cerebellar abnormalities typical of Minamata disease. It is the first known avian or mammalian specimen taken from the wild to show the abnormalities typical of the human fetal syndrome.

  20. Anaerobic sludge granulation

    NARCIS (Netherlands)

    Hulshoff Pol, L.W.; Castro Lopes, de S.I.; Lettinga, G.; Lens, P.N.L.

    2004-01-01

    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades
    This paper reviews different theories on anaerobic sludge granulation in UASB-reactors that have been proposed during the past two decades. The initial stage

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

    Science.gov (United States)

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

    2016-06-01

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

  2. Effect of benzene on the cerebellar structure and behavioral characteristics in rats

    Institute of Scientific and Technical Information of China (English)

    Ali Rafati; Mahboobeh Erfanizadeh; Ali Noorafshan; Saied Karbalay-Doust

    2015-01-01

    Objective:To investigate the effects of benzene on rat’s cerebellum structure and behavioral characteristics, including anxiety and motor impairment. Methods:Twenty rats were randomly allocated into two groups orally receiving distilled water and benzene (200 mg/kg/day). A total of 10 rats were used at the beginning of benzene exposure. Two rats died during benzene treatment and 8 rats remained for evaluation of the behavioral test and finally 6 rats underwent histological assessment. At the end of the 4th week, motor function and anxiety were evaluated in rotarod test and elevated plus maze, respectively. Besides, the cerebellum was dissected for structural assessment using stereological methods. Results:Performance of the benzene-treated rats in fixed and accelerating speed rotarod was impaired and their riding time (endurance) was lower compared to the control group (P=0.02). The benzene-treated rats also spent less time in the open arms and had fewer entrances to the open arms in comparison to the control group, indicating anxiety (P=0.01). The total volume of the cerebellar hemisphere, its cortex, intracerebellar nuclei, total number of the Purkinje, Bergmann, Golgi, granule, neurons and glial cells of the molecular layer, and neurons and glial cells of the intracerebellar nuclei were reduced by 34%-76%in the benzene-treated rats in comparison to the distilled water group (P=0.003). The most cell loss was seen in Bergmann glia. Conclusions:The structure of cerebellum altered after benzene treatment. In addition, motor impairment and anxiety could be seen in benzene-treated rats.

  3. Effect of benzene on the cerebellar structure and behavioral characteristics in rats

    Institute of Scientific and Technical Information of China (English)

    Ali; Rafati; Mahboobeh; Erfanizadeh; Ali; Noorafshan; Saied; Karbalay-Doust

    2015-01-01

    Objective: To investigate the effects of benzene on rat’s cerebellum structure and behavioral characteristics, including anxiety and motor impairment.Methods: Twenty rats were randomly allocated into two groups orally receiving distilled water and benzene(200 mg/kg/day). A total of 10 rats were used at the beginning of benzene exposure. Two rats died during benzene treatment and 8 rats remained for evaluation of the behavioral test and finally 6 rats underwent histological assessment. At the end of the 4th week, motor function and anxiety were evaluated in rotarod test and elevated plus maze, respectively. Besides, the cerebellum was dissected for structural assessment using stereological methods.Results: Performance of the benzene-treated rats in fixed and accelerating speed rotarod was impaired and their riding time(endurance) was lower compared to the control group(P = 0.02). The benzene-treated rats also spent less time in the open arms and had fewer entrances to the open arms in comparison to the control group, indicating anxiety(P = 0.01). The total volume of the cerebellar hemisphere, its cortex, intracerebellar nuclei, total number of the Purkinje, Bergmann, Golgi, granule, neurons and glial cells of the molecular layer, and neurons and glial cells of the intracerebellar nuclei were reduced by 34%-76% in the benzene-treated rats in comparison to the distilled water group(P = 0.003). The most cell loss was seen in Bergmann glia. Conclusions: The structure of cerebellum altered after benzene treatment. In addition, motor impairment and anxiety could be seen in benzene-treated rats.

  4. Sleep disorders in cerebellar ataxias

    Directory of Open Access Journals (Sweden)

    José L. Pedroso

    2011-04-01

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

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

    OpenAIRE

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-02-15

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

  7. Autosomal recessive cerebellar ataxias

    Directory of Open Access Journals (Sweden)

    Palau Francesc

    2006-11-01

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

  8. The effects of undernutrition on connectivity in the cerebellar cortex of adult rats.

    OpenAIRE

    Yucel, F; Warren, M. A.; Gumusburun, E

    1994-01-01

    The effects of a 30 d period of undernutrition, followed in some animals by nutritional rehabilitation, on neuronal connectivity in adult rat cerebellum were investigated using the disector method. There was no significant difference between well fed (719 +/- 74, mean +/- S.E.) and undernourished (709 +/- 53) synapse-to-neuron ratios in 134-d-old rat cerebellar cortex, nor was there a significant difference in synapse-to-neuron ratios between control animals (941 +/- 71) and previously undern...

  9. Cerebellum and motor learning, motor memory and motor integration: morphology and distribution of neuropeptide Y neurons in rat cerebellar cortex%大鼠小脑皮质内神经肽Y能神经元的形态与分布小脑的运动学习、记忆及整合功能

    Institute of Scientific and Technical Information of China (English)

    王省; 孙银平; 蔡新华

    2005-01-01

    BACKGROUND: Neuropeptide Y (NPY) neurons are extensively located in various brain regions such as cerebral cortex, caudate-putamen nucleus, syslimbic system, thalamus and brain stem. They are also involved in various brain activities such as motor learning, motor memory and motor integration. Considering the fact that cerebellum can reorganize through motor learning, we tried to identify the morphology and distribution of NPY neurons in rat's cerebellar cortex to obtain the morphologic knowledge that is related to its cerebellar-cortex-based motor learning.OBJECTIVE: To investigate the morphology and distribution of NPY -immunoreactive neurons in rat's cerebellar cortex, and discuss the relationship between NPY neurons and cerebellum motor learning and motor memory.DESIGN: A single-sample-study based on animal samples.SETTING: Anatomy Department, Pathophysiology Department and Morphology Center in Xinxiang Medical College.MATERIALS: From July to December 2001, the experiment was performed at the Morphology Center in Xinxiang Medical College. Ten Sprague-Dawley (SD) rats, clean grade, regardless of their gender and weighing 100-200 g,were selected.METHODS: After intraperitoneal injection anesthesia and ascending aorta infusion fixation, the cerebellum was taken out by craniosurgery. The cerebellum was immersed in the same fixative fluid for duration of 48 hours, and then was embedded in paraffin. The next step was to make continuous sagittal sections. NPY neurons were identified by SP immunohistochemical staining, using rats cerebral section as the positive control. In the negative control, the first antibody replaced by Bovine Calf Serum(BCS), and the second antibody replaced by 0.01 mol/L PBS. Sequentially the light-microscopic observation and micrography were recorded.MAIN OUTCOME MEASUREMENTS: The Morphology and distribution of NPY neurons in rat's cerebellar cortex were taken as main outcome measurements.RESULTS: NPY-immunoreactive neurons were distributed in

  10. Effect of Twin Screw Granulator Process Parameters on Granule Attributes

    OpenAIRE

    Xu, Haosheng; Sayin, Ridade; Litster, James

    2014-01-01

    Twin screw wet granulation has been considered as an efficient and effective technique of manufacturing granules (agglomerates made up of small particles) and has been widely applied in pharmaceutical industry. However, narrow granule size distributions are difficult to achieve. This study aims to elucidate the effect of process parameters such as liquid feed rate and screw configuration on the granule attributes through granule characterization. The methods used are sieve analysis (for size ...

  11. Cerebellar Malformations and Cognitive Disdorders

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2007-10-01

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

  12. Mining the granule proteome

    DEFF Research Database (Denmark)

    Albrethsen, Jakob; Goetze, Jens P; Johnsen, Anders H

    2015-01-01

    Proteomics of secretory granules is an emerging strategy for identifying secreted proteins, including potentially novel candidate biomarkers and peptide hormones. In addition, proteomics can provide information about the abundance, localization and structure (post-translational modification) of g...

  13. Age-related changes of structures in cerebellar cortex of cat

    Indian Academy of Sciences (India)

    Changzheng Zhang; Tianmiao Hua; Zaiman Zhu; Xun Luo

    2006-03-01

    We studied the structures of the cerebellar cortex of young adult and old cats for age-related changes, which were statistically analysed. Nissl staining was used to visualize the cortical neurons. The immunohistochemical method was used to display glial fibrillary acidic protein (GFAP)-immunoreactive (IR) astrocytes and neurofilament-immunoreactive (NF-IR) neurons. Under the microscope, the thickness of the cerebellar cortex was measured; and the density of neurons in all the layers as well as that of GFAP-IR cells in the granular layer was analysed. Compared with young adult cats, the thickness of the molecular layer and total cerebellar cortex was significantly decreased in old cats, and that of the granular layer increased. The density of neurons in each layer was significantly lower in old cats than in young adult ones. Astrocytes in old cats were significantly denser than in young adult ones, and accompanied by evident hypertrophy of the cell bodies and enhanced immunoreaction of GFAP substance. Purkinje cells (PCs) in old cats showed much fewer NF-IR dendrites than those in young adults. The above findings indicate a loss of neurons and decrease in the number of dendrites of the PCs in the aged cerebellar cortex, which might underlie the functional decline of afferent efficacy and information integration in the senescent cerebellum. An age-dependent enhancement of activity of the astrocytes may exert a protective effect on neurons in the aged cerebellum.

  14. Complex partial seizures: cerebellar metabolism

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-07-01

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

  15. Timing tasks synchronize cerebellar and frontal ramping activity and theta oscillations: Implications for cerebellar stimulation in diseases of impaired cognition

    Directory of Open Access Journals (Sweden)

    Krystal Lynn Parker

    2016-01-01

    Full Text Available Timing is a fundamental and highly conserved mammalian capability yet the underlying neural mechanisms are widely debated. Ramping activity of single neurons that gradually increase or decrease activity to encode the passage of time, has been speculated to predict a behaviorally relevant temporal event. Cue-evoked low-frequency activity has also been implicated in temporal processing. Ramping activity and low-frequency oscillations occur throughout the brain and could indicate a network-based approach to timing. Temporal processing requires cognitive mechanisms of working memory, attention, and reasoning which are dysfunctional in neuropsychiatric disease. Therefore, timing tasks could be used to probe cognition in animals with disease phenotypes. The medial frontal cortex and cerebellum are involved in cognition. Cerebellar stimulation has been shown to influence medial frontal activity and improve cognition in schizophrenia. However, the mechanism underlying the efficacy of cerebellar stimulation is unknown. Here we discuss how timing tasks can be used to probe cerebellar interactions with the frontal cortex and the therapeutic potential of cerebellar stimulation. The goal of this theory and hypothesis manuscript is threefold. First, we will summarize evidence indicating that in addition to motor learning, timing tasks involve cognitive processes that are present within both the cerebellum and medial frontal cortex. Second, we propose methodologies to investigate the connections between these areas in patients with Parkinson’s disease, autism, and schizophrenia. We hypothesis that cerebellar transcranial stimulation may rescue medial frontal ramping activity, theta oscillations, and timing abnormalities, thereby restoring executive function in diseases of impaired cognition. These hypotheses could inspire the use of timing tasks as biomarkers for neuronal and cognitive abnormalities in neuropsychiatric disease and promote the therapeutic

  16. The relation between granule size, granule stickiness, and torque in the high-shear granulation process

    NARCIS (Netherlands)

    Bouwman, A.M.; Henstra, M.J.; Hegge, J.J.M.E.; Zhang, Z.; Ingram, A.; Seville, J.P.K.; Frijlink, H.W.

    2005-01-01

    Purpose. To investigate the background of the observed relationship between measured torque and granule size in high-shear granulation processes. Methods. Torque was measured during the granulation process; the behavior of individual wet granules during compaction was investigated using micromanipul

  17. Expression of classical cadherins in the cerebellar anlage: quantitative and functional aspects.

    Science.gov (United States)

    Gliem, Michael; Weisheit, Gunnar; Mertz, Kirsten D; Endl, Elmar; Oberdick, John; Schilling, Karl

    2006-12-01

    During central nervous system (CNS) development, cell migration precedes and is key to the integration of diverse sets of cells. Mechanistically, CNS histogenesis is realized through a balanced interplay of cell-cell and cell-matrix adhesion molecules. Here, we summarize experiments that probe the developmental expression and potential significance of a set of cadherins, including M-, N- and R-cadherin, for patterning of the cerebellar cortex. We established a transgenic marker that allows cerebellar granule cells to be followed from the neuroblast stage to their final, postmitotic settlement. In conjunction with flow cytometry, this allowed us to derive a quantitative view of cadherin expression in differentiating granule cells and relate it to the expression of the same cadherins in cerebellar inhibitory interneuronal precursors. In vitro reaggregation analysis supports a role for cadherins in cell sorting and migration within the nascent cerebellar cortex that may be rationalized within the context of the differential adhesion hypothesis (Foty, R.A. and Steinberg, M.S., 2005. The differential adhesion hypothesis: a direct evaluation. Dev. Biol. 278, 255-263.).

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

    Science.gov (United States)

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

    2015-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Juan eJiang

    2015-07-01

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

  20. At the Edge of Chaos: How Cerebellar Granular Layer Network Dynamics Can Provide the Basis for Temporal Filters.

    Directory of Open Access Journals (Sweden)

    Christian Rössert

    2015-10-01

    Full Text Available Models of the cerebellar microcircuit often assume that input signals from the mossy-fibers are expanded and recoded to provide a foundation from which the Purkinje cells can synthesize output filters to implement specific input-signal transformations. Details of this process are however unclear. While previous work has shown that recurrent granule cell inhibition could in principle generate a wide variety of random outputs suitable for coding signal onsets, the more general application for temporally varying signals has yet to be demonstrated. Here we show for the first time that using a mechanism very similar to reservoir computing enables random neuronal networks in the granule cell layer to provide the necessary signal separation and extension from which Purkinje cells could construct basis filters of various time-constants. The main requirement for this is that the network operates in a state of criticality close to the edge of random chaotic behavior. We further show that the lack of recurrent excitation in the granular layer as commonly required in traditional reservoir networks can be circumvented by considering other inherent granular layer features such as inverted input signals or mGluR2 inhibition of Golgi cells. Other properties that facilitate filter construction are direct mossy fiber excitation of Golgi cells, variability of synaptic weights or input signals and output-feedback via the nucleocortical pathway. Our findings are well supported by previous experimental and theoretical work and will help to bridge the gap between system-level models and detailed models of the granular layer network.

  1. Spectral components of cytosolic [Ca2+] spiking in neurons

    DEFF Research Database (Denmark)

    Kardos, J; Szilágyi, N; Juhász, G;

    1998-01-01

    We show here, by means of evolutionary spectral analysis and synthesis of cytosolic Ca2+ ([Ca2+]c) spiking observed at the single cell level using digital imaging fluorescence microscopy of fura-2-loaded mouse cerebellar granule cells in culture, that [Ca2+]c spiking can be resolved into evolutio......We show here, by means of evolutionary spectral analysis and synthesis of cytosolic Ca2+ ([Ca2+]c) spiking observed at the single cell level using digital imaging fluorescence microscopy of fura-2-loaded mouse cerebellar granule cells in culture, that [Ca2+]c spiking can be resolved into...

  2. Lithium protects ethanol-induced neuronal apoptosis

    International Nuclear Information System (INIS)

    Lithium is widely used for the treatment of bipolar disorder. Recent studies have demonstrated its neuroprotective effect. Ethanol is a potent neurotoxin that is particularly harmful to the developing nervous system. In this study, we evaluated lithium's neuroprotection against ethanol-induced apoptosis. Transient exposure of infant mice to ethanol caused apoptotic cell death in brain, which was prevented significantly by administering a low dose of lithium 15 min later. In cultured cerebellar granule neurons, ethanol-induced apoptosis and activation of caspase-3/9, both of which were prevented by lithium. However, lithium's protection is not mediated by its commonly known inhibition of glycogen synthase3β, because neither ethanol nor lithium has significant effects on the phosphorylation of Akt (ser473) or GSK3β (ser9). In addition, the selective GSK-3β inhibitor SB-415286 was unable to prevent ethanol-induced apoptosis. These data suggest lithium may be used as a potential preventive measure for ethanol-induced neurological deficits

  3. Cognition and Emotion in Cerebellar Disorders

    Science.gov (United States)

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

  4. Familial cerebellar ataxia and diabetes insipidus.

    OpenAIRE

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

    1988-01-01

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

  5. CaMKII inhibition promotes neuronal apoptosis by transcriptionally upregulating Bim expression.

    Science.gov (United States)

    Zhao, Yiwei; Zhu, Lin; Yu, Shaojun; Zhu, Jing; Wang, Chong

    2016-09-28

    The effects of Ca/calmodulin-dependent protein kinase II (CaMKII) on neuronal apoptosis are complex and contradictory, and the underlying mechanisms remain unclear. Bcl-2-interacting mediator of cell death (Bim) is an important proapoptotic protein under many physiological and pathophysiological conditions. However, there is no evidence that CaMKII and Bim are mechanistically linked in neuronal apoptosis. In this study, we showed that CaMKII inhibition by the inhibitors KN-62 and myristoylated autocamtide-2-related inhibitory peptide promoted apoptosis in cerebellar granule neurons in a dose-dependent manner. CaMKII inhibition increased Bim protein and messenger RNA levels. The expression of early growth response factor-1, a transcription factor of Bim, was also induced by CaMKII inhibitors. These data suggested that CaMKII repressed the transcriptional expression of Bim. Moreover, knockdown of Bim using small interfering RNAs attenuated the proapoptotic effects of CaMKII inhibition. Taken together, this is the first report to show that CaMKII inhibition transcriptionally upregulates Bim expression to promote neuronal apoptosis, providing new insights into the proapoptotic mechanism of CaMKII inhibition. PMID:27483389

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

    Science.gov (United States)

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

    2015-07-01

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

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

    Science.gov (United States)

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

    2015-07-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Raudel eSánchez-Campusano

    2012-03-01

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

  10. Language Impairment in Cerebellar Ataxia

    NARCIS (Netherlands)

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

    2014-01-01

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

  11. Speech Prosody in Cerebellar Ataxia

    Science.gov (United States)

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

    2007-01-01

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

  12. Acid phosphatase localization in neurons of Bulla gouldiana (Gastropoda: Opisthobranchia.

    Science.gov (United States)

    Robles, L J; Fisher, S K

    1975-01-01

    The organization of the ganglia and the ultrastructure of the neurons of Bulla gouldiana are similar to those described for other molluscs. Acid phosphatase positive reactions were found in the large pigmented granules, small dense bodies, multivesicular bodies, and Golgi lamellae and associated vesicles. The small dense bodies and multivesicular bodies may be stages in the formation of the larger pigmented granules which are interpreted as lysosomes. Comparison is made between the pigmented granules in Bulla and the lipofuscin bodies of vertebrate neurons. The possible involvement of these pigmented granules in the hyperpolarization of Bulla and Aplysia neurons to light is discussed. PMID:1122539

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

    Science.gov (United States)

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

    2016-06-01

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

  14. Mice lacking the transcription factor SHOX2 display impaired cerebellar development and deficits in motor coordination.

    Science.gov (United States)

    Rosin, Jessica M; McAllister, Brendan B; Dyck, Richard H; Percival, Christopher J; Kurrasch, Deborah M; Cobb, John

    2015-03-01

    Purkinje cells of the developing cerebellum secrete the morphogen sonic hedgehog (SHH), which is required to maintain the proliferative state of granule cell precursors (GCPs) prior to their differentiation and migration to form the internal granule layer (IGL). Despite a wealth of knowledge regarding the function of SHH during cerebellar development, the upstream regulators of Shh expression during this process remain largely unknown. Here we report that the murine short stature homeobox 2 (Shox2) gene is required for normal Shh expression in dorsal-residing Purkinje cells. Using two different Cre drivers, we show that elimination of Shox2 in the brain results in developmental defects in the inferior colliculus and cerebellum. Specifically, loss of Shox2 in the cerebellum results in precocious differentiation and migration of GCPs from the external granule layer (EGL) to the IGL. This correlates with premature bone morphogenetic protein 4 (Bmp4) expression in granule cells of the dorsal cerebellum. The size of the neonatal cerebellum is reduced in Shox2-mutant animals, which is consistent with a reduction in the number of GCPs present in the EGL, and could account for the smaller vermis and thinner IGL present in adult Shox2mutants. Shox2-mutant mice also display reduced exploratory activity, altered gait and impaired motor coordination. Our findings are the first to show a role for Shox2 in brain development. We provide evidence that Shox2 plays an important role during cerebellar development, perhaps to maintain the proper balance of Shh and Bmp expression levels in the dorsal vermis, and demonstrate that in the absence of Shox2, mice display both cerebellar impairments and deficits in motor coordination, ultimately highlighting the importance of Shox2 in the cerebellum.

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

    Institute of Scientific and Technical Information of China (English)

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

    2010-01-01

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

  16. Global dysrhythmia of cerebro-basal ganglia-cerebellar networks underlies motor tics following striatal disinhibition.

    Science.gov (United States)

    McCairn, Kevin W; Iriki, Atsushi; Isoda, Masaki

    2013-01-01

    Motor tics, a cardinal symptom of Tourette syndrome (TS), are hypothesized to arise from abnormalities within cerebro-basal ganglia circuits. Yet noninvasive neuroimaging of TS has previously identified robust activation in the cerebellum. To date, electrophysiological properties of cerebellar activation and its role in basal ganglia-mediated tic expression remain unknown. We performed multisite, multielectrode recordings of single-unit activity and local field potentials from the cerebellum, basal ganglia, and primary motor cortex using a pharmacologic monkey model of motor tics/TS. Following microinjections of bicuculline into the sensorimotor putamen, periodic tics occurred predominantly in the orofacial region, and a sizable number of cerebellar neurons showed phasic changes in activity associated with tic episodes. Specifically, 64% of the recorded cerebellar cortex neurons exhibited increases in activity, and 85% of the dentate nucleus neurons displayed excitatory, inhibitory, or multiphasic responses. Critically, abnormal discharges of cerebellar cortex neurons and excitatory-type dentate neurons mostly preceded behavioral tic onset, indicating their central origins. Latencies of pathological activity in the cerebellum and primary motor cortex substantially overlapped, suggesting that aberrant signals may be traveling along divergent pathways to these structures from the basal ganglia. Furthermore, the occurrence of tic movement was most closely associated with local field potential spikes in the cerebellum and primary motor cortex, implying that these structures may function as a gate to release overt tic movements. These findings indicate that tic-generating networks in basal ganglia mediated tic disorders extend beyond classical cerebro-basal ganglia circuits, leading to global network dysrhythmia including cerebellar circuits.

  17. Stellar granulation and interferometry

    CERN Document Server

    Chiavassa, A

    2015-01-01

    Stars are not smooth. Their photosphere is covered by a granulation pattern associated with the heat transport by convection. The convection-related surface structures have different size, depth, and temporal variations with respect to the stellar type. The related activity (in addition to other phenomena such as magnetic spots, rotation, dust, etc.) potentially causes bias in stellar parameters determination, radial velocity, chemical abundances determinations, and exoplanet transit detections. The role of long-baseline interferometric observations in this astrophysical context is crucial to characterize the stellar surface dynamics and correct the potential biases. In this Chapter, we present how the granulation pattern is expected for different kind of stellar types ranging from main sequence to extremely evolved stars of different masses and how interferometric techniques help to study their photospheric dynamics.

  18. Reduced neuronal size and mTOR pathway activity in the Mecp2 A140V Rett syndrome mouse model [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Sampathkumar Rangasamy

    2016-09-01

    Full Text Available Rett syndrome (RTT is a neurodevelopmental disorder caused by mutation in the X-linked MECP2 gene, encoding methyl-CpG-binding protein 2. We have created a mouse model (Mecp2 A140V “knock-in” mutant expressing the recurrent human MECP2 A140V mutation linked to an X-linked mental retardation/Rett syndrome phenotype. Morphological analyses focused on quantifying soma and nucleus size were performed on primary hippocampus and cerebellum granule neuron (CGN cultures from mutant (Mecp2A140V/y and wild type (Mecp2+/y male mice. Cultured hippocampus and cerebellar granule neurons from mutant animals were significantly smaller than neurons from wild type animals. We also examined soma size in hippocampus neurons from individual female transgenic mice that express both a mutant  (maternal allele and a wild type Mecp2 gene linked to an eGFP transgene (paternal allele. In cultures from such doubly heterozygous female mice, the size of neurons expressing the mutant (A140V allele also showed a significant reduction compared to neurons expressing wild type MeCP2, supporting a cell-autonomous role for MeCP2 in neuronal development. IGF-1 (insulin growth factor-1 treatment of neuronal cells from Mecp2 mutant mice rescued the soma size phenotype. We also found that Mecp2  mutation leads to down-regulation of the mTOR signaling pathway, known to be involved in neuronal size regulation. Our results suggest that i reduced neuronal size is an important in vitro cellular phenotype of Mecp2 mutation in mice, and ii MeCP2 might play a critical role in the maintenance of neuronal structure by modulation of the mTOR pathway. The definition of a quantifiable cellular phenotype supports using neuronal size as a biomarker in the development of a high-throughput, in vitro assay to screen for compounds that rescue small neuronal phenotype (“phenotypic assay”.

  19. Presynaptic calcium signalling in cerebellar mossy fibres

    Directory of Open Access Journals (Sweden)

    Louiza B Thomsen

    2010-02-01

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

  20. Dioxin modulates expression of receptor for activated C kinase (RACK-1) in developing neurons

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.H.; Kim, S.Y.; Lee, H.G.; Kim, M.Y.; Lee, J.H.; Chae, W.G. [Catholic Univ. of Daegu, Dept. of Pharmacology/Toxicology, Daegu (Korea)

    2004-09-15

    TCDD is sensitive to the central nerve system of the developing brain. The TCDD-induced neurodevelopmental deficits include the cognitive disability and motor dysfunction. While TCDD may lead to neurodevelopmental and neurobehavioral deficit, it is not known which molecular substances are intracellular targets for TCDD. Since TCDD accumulates in brain and the brain contains the Ah receptor, it is possible that TCDD may act at the target site such as cerebellum, which is responsible for cognitive abilities and motor function. A recent in vitro studies using cerebellar granule cells demonstrated a translocation of PKC-{alpha} and {epsilon} following the TCDD or PCB exposure. One of the most pivotal second messenger molecules involved in neuronal function and development is protein kinase C (PKC). PKC signaling pathways have been implicated as an important factor in learning and memory processes. PKC signaling events are optimized by the adaptor proteins, which organize PKCs near their selective substrates and away from others. RACK-1(receptor for activated C-kinase) is one of adaptor proteins that anchor the activated PKC at the site of translocation 6. RACKs bind PKC only in the presence of PKC activators. RACKs are 30- and 36-kDa proteins located in cytoskeletal compartment and play a key role in PKC activation and in membrane amchoring. Since different PKC isoforms translocate to distinct subcellular sites on activation, it is suggested that isoform-specific RACK may be present. Activation of certain PKC isoforms (PKC-a and {beta}II) is preferentially associated with RACK-1. While TCDD modulates PKC signaling pathway, role of RACK-1 on TCDD-mediated signaling pathway is not known. To identify the intracellular target for TCDD and understand a mechanism of signaling pathway in the developing brain, the present study attempted to analyze effects of RACK-1 in the cerebellar granule cells following TCDD exposure.

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

    Science.gov (United States)

    Venkatraman, Anand; Opal, Puneet

    2016-08-01

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

  2. Sustained Reduction of Cerebellar Activity in Experimental Epilepsy

    Directory of Open Access Journals (Sweden)

    Kim Rijkers

    2015-01-01

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

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

    Science.gov (United States)

    Venkatraman, Anand; Opal, Puneet

    2016-08-01

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

  4. Preventive effects of imperatorin on perfluorohexanesulfonate-induced neuronal apoptosis via inhibition of intracellular calcium-mediated ERK pathway.

    Science.gov (United States)

    Lee, Eunkyung; Choi, So-Young; Yang, Jae-Ho; Lee, Youn Ju

    2016-07-01

    Early life neuronal exposure to environmental toxicants has been suggested to be an important etiology of neurodegenerative disease development. Perfluorohexanesulfonate (PFHxS), one of the major perfluoroalkyl compounds, is widely distributed environmental contaminants. We have reported that PFHxS induces neuronal apoptosis via ERK-mediated pathway. Imperatorin is a furanocoumarin found in various edible plants and has a wide range of pharmacological effects including neuroprotection. In this study, the effects of imperatorin on PFHxS-induced neuronal apoptosis and the underlying mechanisms are examined using cerebellar granule cells (CGC). CGC were isolated from seven-day old rats and were grown in culture for seven days. Caspase-3 activity and TUNEL staining were used to determine neuronal apoptosis. PFHxS-induced apoptosis of CGC was significantly reduced by imperatorin and PD98059, an ERK pathway inhibitor. PFHxS induced a persistent increase in intracellular calcium, which was significantly blocked by imperatorin, NMDA receptor antagonist, MK801 and the L-type voltage-dependent calcium channel blockers, diltiazem and nifedipine. The activation of caspase-3 by PFHxS was also inhibited by MK801, diltiazem and nifedipine. PFHxS-increased ERK activation was inhibited by imperatorin, MK801, diltiazem and nifedipine. Taken together, imperatorin protects CGC against PFHxS-induced apoptosis via inhibition of NMDA receptor/intracellular calcium-mediated ERK pathway. PMID:27382356

  5. Molecular components required for resting and stimulated endocytosis of botulinum neurotoxins by glutamatergic and peptidergic neurons.

    Science.gov (United States)

    Meng, Jianghui; Wang, Jiafu; Lawrence, Gary W; Dolly, J Oliver

    2013-08-01

    Proteins responsible for basal and stimulated endocytosis in nerves containing small clear synaptic vesicles (SCSVs) or large dense-core vesicles (LDCVs) are revealed herein, using probes that exploit surface-exposed vesicle proteins as acceptors for internalization. Basal uptake of botulinum neurotoxins (BoNTs) by both SCSV-releasing cerebellar granule neurons (CGNs) and LDCV-enriched trigeminal ganglionic neurons (TGNs) was found to require protein acceptors and acidic compartments. In addition, dynamin, clathrin, adaptor protein complex-2 (AP2), and amphiphysin contribute to the depolarization-evoked entry. For fast recycling of SCSVs, knockdown and knockout strategies demonstrated that CGNs use predominantly dynamin 1, whereas isoform 2 and, to a smaller extent, isoform 3 support a less rapid mode of stimulated endocytosis. Accordingly, proximity ligation assay confirmed that dynamin 1 and 2 colocalize with amphiphysin 1 in CGNs, and the latter copurified with both dynamins from cell extracts. In contrast, LDCV-releasing TGNs preferentially employ dynamins 2 and 3 and amphiphysin 1 for evoked endocytosis and lack the fast phase. Hence, stimulation recruits dynamin, clathrin, AP2, and amphiphysin to augment BoNT internalization, and neurons match endocytosis mediators to the different demands for locally recycling SCSVs or replenishing distally synthesized LDCVs. PMID:23640057

  6. Mutations in DNMT1 cause autosomal dominant cerebellar ataxia, deafness and narcolepsy

    DEFF Research Database (Denmark)

    Winkelmann, Juliane; Lin, Ling; Schormair, Barbara;

    2012-01-01

    Autosomal dominant cerebellar ataxia, deafness and narcolepsy (ADCA-DN) is characterized by late onset (30-40 years old) cerebellar ataxia, sensory neuronal deafness, narcolepsy-cataplexy and dementia. We performed exome sequencing in five individuals from three ADCA-DN kindreds and identified DNMT.......GLY605Ala mutation was subsequently identified. Narcolepsy and deafness were the first symptoms to appear in all pedigrees, followed by ataxia. DNMT1 is a widely expressed DNA methyltransferase maintaining methylation patterns in development, and mediating transcriptional repression by direct binding...

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

    NARCIS (Netherlands)

    Smeets, C J L M; Verbeek, D S

    2014-01-01

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

  8. Visualizing the distribution of synapses from individual neurons in the mouse brain.

    Directory of Open Access Journals (Sweden)

    Ling Li

    Full Text Available BACKGROUND: Proper function of the mammalian brain relies on the establishment of highly specific synaptic connections among billions of neurons. To understand how complex neural circuits function, it is crucial to precisely describe neuronal connectivity and the distributions of synapses to and from individual neurons. METHODS AND FINDINGS: In this study, we present a new genetic synaptic labeling method that relies on expression of a presynaptic marker, synaptophysin-GFP (Syp-GFP in individual neurons in vivo. We assess the reliability of this method and use it to analyze the spatial patterning of synapses in developing and mature cerebellar granule cells (GCs. In immature GCs, Syp-GFP is distributed in both axonal and dendritic regions. Upon maturation, it becomes strongly enriched in axons. In mature GCs, we analyzed synapses along their ascending segments and parallel fibers. We observe no differences in presynaptic distribution between GCs born at different developmental time points and thus having varied depths of projections in the molecular layer. We found that the mean densities of synapses along the parallel fiber and the ascending segment above the Purkinje cell (PC layer are statistically indistinguishable, and higher than previous estimates. Interestingly, presynaptic terminals were also found in the ascending segments of GCs below and within the PC layer, with the mean densities two-fold lower than that above the PC layer. The difference in the density of synapses in these parts of the ascending segment likely reflects the regional differences in postsynaptic target cells of GCs. CONCLUSIONS: The ability to visualize synapses of single neurons in vivo is valuable for studying synaptogenesis and synaptic plasticity within individual neurons as well as information flow in neural circuits.

  9. Cerebellar medulloblastoma presenting with skeletal metastasis

    OpenAIRE

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

    2004-01-01

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

  10. Crossed cerebral - cerebellar diaschisis : MRI evaluation.

    Directory of Open Access Journals (Sweden)

    Chakravarty A

    2002-07-01

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

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  12. Crossed cerebellar hyperperfusion in brain perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-10-01

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

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

    Science.gov (United States)

    Anheim, M; Tranchant, C

    2011-01-01

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

  14. Long-term NR2B expression in the cerebellum alters granule cell development and leads to NR2A down-regulation and motor deficits

    NARCIS (Netherlands)

    Schlett, K; Pieri, [No Value; Metzger, F; Marchetti, L; Dere, E; Kirilly, D; Tarnok, K; Barabas, B; Varga, AK; Gerspach, J; Huston, JP; Pfizenmaier, K; Kohr, G; Eisel, ULM; Pieri, Isabelle; Steigerwald, Frank; Kis Varga, Ágnes; Huston, Joseph P.; Köhr, Georg

    2004-01-01

    N-methyl-D-aspartate receptor (NMDAR) composition in granule cells changes characteristically during cerebellar development. To analyze the importance of NR2B replacement by NR2C and NR2A subunits until the end of the first month of age, we generated mice with lasting NR2B expression but deficiency

  15. Fetal MRI and antenatal diagnosis of unilateral cerebellar hypoplasia

    OpenAIRE

    Houda El Mhabrech; Ahmed Zrig; Chiraz Hafsa

    2015-01-01

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

  16. Isolation of RNP granules

    DEFF Research Database (Denmark)

    Jønson, Lars; Nielsen, Finn Cilius; Christiansen, Jan

    2011-01-01

    be regarded as a supramolecular assembly of RNA and protein, probably representing several overlapping post-transcriptional operons. The present protocol describes how RNP granules may be isolated by the transgenic expression of a 3X FLAG version of an RNA-binding protein under tetracycline control...... via the tetracycline receptor/operator complex. In this way, inclusion of an appropriate tetracycline concentration ensures expression of the tagged version at the endogenous level, and the 3X FLAG tag is a convenient "handle" for the subsequent immunoprecipitation by immobilized anti-FLAG antibody....

  17. Influence on Glycolipid Metabolism, Neuron and Microvascular by Chinese Medicine Dai-Xie-An Granules among Aging Rats of Metabolic Syndrome%代谢安颗粒对老龄代谢综合征大鼠糖脂代谢、神经元及微血管的影响

    Institute of Scientific and Technical Information of China (English)

    余海滨; 赵敏; 李建生

    2014-01-01

    This article was aimed to study the therapeutic effect of Chinese medicine Dai-Xie-A n (DXA) granules a-mong aging rats of metabolic syndrome (MS) in order to evaluate relative indicators and the pathophysiological role in neurons and microvascular injury among aging MS rats. Aging MS rat model was established by feeding high-fat diet and the established model was evaluated. Under the guidance of traditional Chinese medicine (TCM) theory, metabol-ic indexes, such as general state of health, glycolipid metabolism, insulin sensitivity, were explored in order to ob-serve effects on brain neurons and microvascular injury among aging MS rats. The results showed that DXA granules can improve glycolipid metabolism among aging MS rats, decrease TC, TG, TC/HDL, decrease the level of blood sug-ar and serum insulin, improve insulin resistance, decrease abdominal fat accumulation, reduce neuronal apoptosis, and increase microvascular angiogenesis. These effects are similar to rosiglitazone. It was concluded that DXA gran-ules can ameliorate glycolipid disorders, protect brain neurons and microvascular injury of aging MS rats.%目的:使用中药代谢安颗粒对老龄代谢综合征(MS)大鼠进行干预治疗,研究其对老龄大鼠MS相关指标及对老年MS大鼠神经元和微血管损伤的病理生理作用。方法:对老龄大鼠给予高脂饲料建立MS动物模型,并对模型进行评价,在中医理论指导下,探索代谢安对老年 MS大鼠一般情况、糖脂代谢、胰岛素敏感性等一系列指标的影响,观察其对大鼠脑神经元和微血管损伤的作用。结果:代谢安能改善老年MS大鼠糖脂代谢紊乱状态,降低血清总胆固醇(TC)、甘油三酯(TG)、TC/高密度脂蛋白(HDL)比值,降低血糖、血清胰岛素水平,改善胰岛素抵抗状态,减少腹腔脂肪蓄积;代谢安能减少大鼠脑神经元细胞的凋亡,增加微血管新生。其作用均和罗格列酮相

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

    Directory of Open Access Journals (Sweden)

    Mikiko eKayakabe

    2014-01-01

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

  19. The clinical presentation of preterm cerebellar haemorrhage

    NARCIS (Netherlands)

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

    2010-01-01

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

  20. Altered cerebellar feedback projections in Asperger syndrome.

    Science.gov (United States)

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

    2008-07-15

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

  1. Cerebellar stroke-manifesting as mania

    Directory of Open Access Journals (Sweden)

    Venkatesan Jagadesan

    2014-01-01

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

  2. Cerebellar Ataxia and Glutamic Acid Decarboxylase Antibodies

    Science.gov (United States)

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

    2016-01-01

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

  3. Moluo Yangping Granule (

    Institute of Scientific and Technical Information of China (English)

    LI; En-fu

    2001-01-01

    Peptic ulcer is a common and frequently encountered disease. H2 receptor blocker and several other drugs have been used in treating peptic ulcer (PU) since many years ago, but there still remain a rather large number of intractable ulcer and recurrent ulcer. Recently the discovery of Helicobacter pylori (HP), as well as the relationship between HP and PU relapse was confirmed, but there still lacks of perfect therapeutic program for anti-HP infection(1). From June 1993 to August 1996, we used a pure TCM preparation Moluo Yangping granule (摩罗疡平冲剂, MYG) in treating 64 PU patients, and satisfactory results have been obtained. The report is as follows.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  6. A cerebellar learning model of vestibulo-ocular reflex adaptation in wild-type and mutant mice.

    Science.gov (United States)

    Clopath, Claudia; Badura, Aleksandra; De Zeeuw, Chris I; Brunel, Nicolas

    2014-05-21

    Mechanisms of cerebellar motor learning are still poorly understood. The standard Marr-Albus-Ito theory posits that learning involves plasticity at the parallel fiber to Purkinje cell synapses under control of the climbing fiber input, which provides an error signal as in classical supervised learning paradigms. However, a growing body of evidence challenges this theory, in that additional sites of plasticity appear to contribute to motor adaptation. Here, we consider phase-reversal training of the vestibulo-ocular reflex (VOR), a simple form of motor learning for which a large body of experimental data is available in wild-type and mutant mice, in which the excitability of granule cells or inhibition of Purkinje cells was affected in a cell-specific fashion. We present novel electrophysiological recordings of Purkinje cell activity measured in naive wild-type mice subjected to this VOR adaptation task. We then introduce a minimal model that consists of learning at the parallel fibers to Purkinje cells with the help of the climbing fibers. Although the minimal model reproduces the behavior of the wild-type animals and is analytically tractable, it fails at reproducing the behavior of mutant mice and the electrophysiology data. Therefore, we build a detailed model involving plasticity at the parallel fibers to Purkinje cells' synapse guided by climbing fibers, feedforward inhibition of Purkinje cells, and plasticity at the mossy fiber to vestibular nuclei neuron synapse. The detailed model reproduces both the behavioral and electrophysiological data of both the wild-type and mutant mice and allows for experimentally testable predictions.

  7. HDAC2 selectively regulates FOXO3a-mediated gene transcription during oxidative stress-induced neuronal cell death.

    Science.gov (United States)

    Peng, Shengyi; Zhao, Siqi; Yan, Feng; Cheng, Jinbo; Huang, Li; Chen, Hong; Liu, Qingsong; Ji, Xunming; Yuan, Zengqiang

    2015-01-21

    All neurodegenerative diseases are associated with oxidative stress-induced neuronal death. Forkhead box O3a (FOXO3a) is a key transcription factor involved in neuronal apoptosis. However, how FOXO3a forms complexes and functions in oxidative stress processing remains largely unknown. In the present study, we show that histone deacetylase 2 (HDAC2) forms a physical complex with FOXO3a, which plays an important role in FOXO3a-dependent gene transcription and oxidative stress-induced mouse cerebellar granule neuron (CGN) apoptosis. Interestingly, we also found that HDAC2 became selectively enriched in the promoter region of the p21 gene, but not those of other target genes, and inhibited FOXO3a-mediated p21 transcription. Furthermore, we found that oxidative stress reduced the interaction between FOXO3a and HDAC2, leading to an increased histone H4K16 acetylation level in the p21 promoter region and upregulated p21 expression in a manner independent of p53 or E2F1. Phosphorylation of HDAC2 at Ser 394 is important for the HDAC2-FOXO3a interaction, and we found that cerebral ischemia/reperfusion reduced phosphorylation of HDAC2 at Ser 394 and mitigated the HDAC2-FOXO3a interaction in mouse brain tissue. Our study reveals the novel regulation of FOXO3a-mediated selective gene transcription via epigenetic modification in the process of oxidative stress-induced cell death, which could be exploited therapeutically.

  8. Delayed translocation of NGFI-B/RXR in glutamate stimulated neurons allows late protection by 9-cis retinoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Mathisen, Gro H.; Fallgren, Asa B.; Strom, Bjorn O.; Boldingh Debernard, Karen A.; Mohebi, Beata U. [Department of Pharmaceutical Biosciences, University of Oslo, P.O. Box 1068, Blindern, N-0316 Oslo (Norway); Paulsen, Ragnhild E., E-mail: r.e.paulsen@farmasi.uio.no [Department of Pharmaceutical Biosciences, University of Oslo, P.O. Box 1068, Blindern, N-0316 Oslo (Norway)

    2011-10-14

    Highlights: {yields} NGFI-B and RXR translocate out of the nucleus after glutamate treatment. {yields} Arresting NGFI-B/RXR in the nucleus protects neurons from excitotoxicity. {yields} Late protection by 9-cis RA is possible due to a delayed translocation of NGFI-B/RXR. -- Abstract: Nuclear receptor and apoptosis inducer NGFI-B translocates out of the nucleus as a heterodimer with RXR in response to different apoptosis stimuli, and therefore represents a potential pharmacological target. We found that the cytosolic levels of NGFI-B and RXR{alpha} were increased in cultures of cerebellar granule neurons 2 h after treatment with glutamate (excitatory neurotransmitter in the brain, involved in stroke). To find a time-window for potential intervention the neurons were transfected with gfp-tagged expressor plasmids for NGFI-B and RXR. The default localization of NGFI-Bgfp and RXRgfp was nuclear, however, translocation out of the nucleus was observed 2-3 h after glutamate treatment. We therefore hypothesized that the time-window between treatment and translocation would allow late protection against neuronal death. The RXR ligand 9-cis retinoic acid was used to arrest NGFI-B and RXR in the nucleus. Addition of 9-cis retinoic acid 1 h after treatment with glutamate reduced the cytosolic translocation of NGFI-B and RXR{alpha}, the cytosolic translocation of NGFI-Bgfp observed in live neurons, as well as the neuronal death. However, the reduced translocation and the reduced cell death were not observed when 9-cis retinoic acid was added after 3 h. Thus, late protection from glutamate induced death by addition of 9-cis retinoic acid is possible in a time-window after apoptosis induction.

  9. Plasticity within non-cerebellar pathways rapidly shapes motor performance in vivo.

    Science.gov (United States)

    Mitchell, Diana E; Della Santina, Charles C; Cullen, Kathleen E

    2016-01-01

    Although cerebellar mechanisms are vital to maintain accuracy during complex movements and to calibrate simple reflexes, recent in vitro studies have called into question the widely held view that synaptic changes within cerebellar pathways exclusively guide alterations in motor performance. Here we investigate the vestibulo-ocular reflex (VOR) circuitry by applying temporally precise activation of vestibular afferents in awake-behaving monkeys to link plasticity at different neural sites with changes in motor performance. Behaviourally relevant activation patterns produce rapid attenuation of direct pathway VOR neurons, but not their nerve input. Changes in the strength of this pathway are sufficient to induce a lasting decrease in the evoked VOR. In addition, indirect brainstem pathways display complementary nearly instantaneous changes, contributing to compensating for the reduced sensitivity of primary VOR neurons. Taken together, our data provide evidence that multiple sites of plasticity within VOR pathways can rapidly shape motor performance in vivo. PMID:27157829

  10. Plasticity within non-cerebellar pathways rapidly shapes motor performance in vivo

    Science.gov (United States)

    Mitchell, Diana E.; Della Santina, Charles C.; Cullen, Kathleen E.

    2016-01-01

    Although cerebellar mechanisms are vital to maintain accuracy during complex movements and to calibrate simple reflexes, recent in vitro studies have called into question the widely held view that synaptic changes within cerebellar pathways exclusively guide alterations in motor performance. Here we investigate the vestibulo-ocular reflex (VOR) circuitry by applying temporally precise activation of vestibular afferents in awake-behaving monkeys to link plasticity at different neural sites with changes in motor performance. Behaviourally relevant activation patterns produce rapid attenuation of direct pathway VOR neurons, but not their nerve input. Changes in the strength of this pathway are sufficient to induce a lasting decrease in the evoked VOR. In addition, indirect brainstem pathways display complementary nearly instantaneous changes, contributing to compensating for the reduced sensitivity of primary VOR neurons. Taken together, our data provide evidence that multiple sites of plasticity within VOR pathways can rapidly shape motor performance in vivo. PMID:27157829

  11. Clinical characteristics and pathogenesis of cerebellar glioblastoma.

    Science.gov (United States)

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

    2014-11-01

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

  12. Pediatric Neurocutaneous Syndromes with Cerebellar Involvement.

    Science.gov (United States)

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

    2016-08-01

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

  13. Transplantation of cerebellar neural stem cells improves motor coordination and neuropathology in Machado-Joseph disease mice.

    Science.gov (United States)

    Mendonça, Liliana S; Nóbrega, Clévio; Hirai, Hirokazu; Kaspar, Brian K; Pereira de Almeida, Luís

    2015-02-01

    Machado-Joseph disease is a neurodegenerative disease without effective treatment. Patients with Machado-Joseph disease exhibit significant motor impairments such as gait ataxia, associated with multiple neuropathological changes including mutant ATXN3 inclusions, marked neuronal loss and atrophy of the cerebellum. Thus, an effective treatment of symptomatic patients with Machado-Joseph disease may require cell replacement, which we investigated in this study. For this purpose, we injected cerebellar neural stem cells into the cerebellum of adult Machado-Joseph disease transgenic mice and assessed the effect on the neuropathology, neuroinflammation mediators and neurotrophic factor levels and motor coordination. We found that upon transplantation into the cerebellum of adult Machado-Joseph disease mice, cerebellar neural stem cells differentiate into neurons, astrocytes and oligodendrocytes. Importantly, cerebellar neural stem cell transplantation mediated a significant and robust alleviation of the motor behaviour impairments, which correlated with preservation from Machado-Joseph disease-associated neuropathology, namely reduction of Purkinje cell loss, reduction of cellular layer shrinkage and mutant ATXN3 aggregates. Additionally, a significant reduction of neuroinflammation and an increase of neurotrophic factors levels was observed, indicating that transplantation of cerebellar neural stem cells also triggers important neuroprotective effects. Thus, cerebellar neural stem cells have the potential to be used as a cell replacement and neuroprotective approach for Machado-Joseph disease therapy.

  14. A computational study of synaptic mechanisms of partial memory transfer in cerebellar vestibulo-ocular-reflex learning.

    Science.gov (United States)

    Masuda, Naoki; Amari, Shun-ichi

    2008-04-01

    There is a debate regarding whether motor memory is stored in the cerebellar cortex, or the cerebellar nuclei, or both. Memory may be acquired in the cortex and then be transferred to the cerebellar nuclei. Based on a dynamical system modeling with a minimal set of variables, we theoretically investigated possible mechanisms of memory transfer and consolidation in the context of vestibulo-ocular reflex learning. We tested different plasticity rules for synapses in the cerebellar nuclei and took robustness of behavior against parameter variation as the criterion of plausibility of a model variant. In the most plausible scenarios, mossy-fiber nucleus-neuron synapses or Purkinje-cell nucleus-neuron synapses are plastic on a slow time scale and store permanent memory, whose content is passed from the cerebellar cortex storing transient memory. In these scenarios, synaptic strengths are potentiated when the mossy-fiber afferents to the nuclei are active during a pause in Purkinje-cell activities. Furthermore, assuming that mossy fibers create a limited variety of signals compared to parallel fibers, our model shows partial memory transfer from the cortex to the nuclei.

  15. Multidimensional modelling of anaerobic granules

    DEFF Research Database (Denmark)

    Picioreanu, C.; Batstone, Damien J.; van Loosdrecht, M.C.M.

    2005-01-01

    . The model uses individual-based representation of biomass particles within the granule (biofilm), and describes spreading by an iterative pushing technique. The overall computational domain consists of one granule, and is divided into a grid with Cartesian coordinates. The number of grid elements does...... not limit the number of biomass particles, and it is not necessary to use grid-spreading techniques, such as cellular automata, which result in Cartesian artefacts. The model represents both microscopic and macroscopic features in granule structure, previously observed using in-situ molecular techniques......A multispecies, two- and three-dimensional model was developed, based on a previously published planar biofilm model, and the biochemical structure of the ADM1. Several soluble substrates diffuse and react in the granule. Local pH is calculated from acid-base equilibria and charge balance...

  16. Cerebellar cortical degeneration in adult American Staffordshire Terriers.

    Science.gov (United States)

    Olby, Natasha; Blot, Stephane; Thibaud, Jean-Laurent; Phillips, Jeff; O'Brien, Dennis P; Burr, Jeanne; Berg, Jason; Brown, Talmage; Breen, Matthew

    2004-01-01

    Adult-onset cerebellar cortical degeneration recently has been reported in American Staffordshire Terriers. We describe the clinical and histopathologic features of this disease and examine its mode of inheritance in 63 affected dogs. The age at which neurologic deficits 1st were recognized varied from 18 months to 9 years, with the majority of dogs presented to veterinarians between 4 and 6 years of age. Time from onset of clinical signs to euthanasia varied from 6 months to 6.5 years, with the majority of affected dogs surviving from 2 to 4 years. Initial neurologic findings included stumbling, truncal sway, and ataxia exacerbated by lifting the head up and negotiating stairs. Signs progressed to obvious ataxia characterized by dysmetria, nystagmus, coarse intention tremor, variable loss of menace reaction, marked truncal sway, and falling with transient opisthotonus. With continued progression, dogs became unable to walk without falling repeatedly. Cerebellar atrophy was visible on magnetic resonance images and on gross pathology. Histopathologic findings included marked loss of Purkinje neurons with thinning of the molecular and granular layers and increased cellularity of the cerebellar nuclei. The closest common ancestor of the dogs was born in the 1950s and inheritance was most consistent with an autosomal recessive mode of transmission with a prevalence estimated at 1 in 400 dogs. This inherited disease is comparable to the group of diseases known as spinocerebellar ataxias in humans. Many spinocerebellar ataxias in humans are caused by nucleotide repeats, and this genetic aberration merits investigation as a potential cause of the disease in American Staffordshire Terriers. PMID:15058771

  17. CT findings in cerebellar hemangioblastomas

    Energy Technology Data Exchange (ETDEWEB)

    Heiss, E.; Albert, F.

    1982-02-01

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

  18. Granulopoiesis and granules of human neutrophils.

    Science.gov (United States)

    Cowland, Jack B; Borregaard, Niels

    2016-09-01

    Granules are essential for the ability of neutrophils to fulfill their role in innate immunity. Granule membranes contain proteins that react to environmental cues directing neutrophils to sites of infection and initiate generation of bactericidal oxygen species. Granules are densely packed with proteins that contribute to microbial killing when liberated to the phagosome or extracellularly. Granules are, however, highly heterogeneous and are traditionally subdivided into azurophil granules, specific granules, and gelatinase granules in addition to secretory vesicles. This review will address issues pertinent to formation of granules, which is a process intimately connected to maturation of neutrophils from their precursors in the bone marrow. We further discuss possible mechanisms by which decisions are made regarding sorting of proteins to constitutive secretion or storage in granules and how degranulation of granule subsets is regulated. PMID:27558325

  19. Linking granulation performance with residence time and granulation liquid distributions in twin-screw granulation: An experimental investigation.

    Science.gov (United States)

    Kumar, Ashish; Alakarjula, Maija; Vanhoorne, Valérie; Toiviainen, Maunu; De Leersnyder, Fien; Vercruysse, Jurgen; Juuti, Mikko; Ketolainen, Jarkko; Vervaet, Chris; Remon, Jean Paul; Gernaey, Krist V; De Beer, Thomas; Nopens, Ingmar

    2016-07-30

    Twin-screw granulation is a promising wet granulation technique for the continuous manufacturing of pharmaceutical solid dosage forms. A twin screw granulator displays a short residence time. Thus, the solid-liquid mixing must be achieved quickly by appropriate arrangement of transport and kneading elements in the granulator screw allowing the production of granules with a size distribution appropriate for tableting. The distribution of residence time and granulation liquid is governed by the field conditions (such as location and length of mixing zones) in the twin-screw granulator, thus contain interesting information on granulation time, mixing and resulting sub-processes such as wetting, aggregation and breakage. In this study, the impact of process (feed rate, screw speed and liquid-to-solid ratio) and equipment parameters (number of kneading discs and stagger angle) on the residence time (distribution), the granulation liquid-powder mixing and the resulting granule size distributions during twin-screw granulation were investigated. Residence time and axial mixing data was extracted from tracer maps and the solid-liquid mixing was quantified from moisture maps, obtained by monitoring the granules at the granulator outlet using near infra-red chemical imaging (NIR-CI). The granule size distribution was measured using the sieving method. An increasing screw speed dominantly reduced the mean residence time. Interaction of material throughput with the screw speed and with the number of kneading discs led to most variation in the studied responses including residence time and mixing capacity. At a high screw speed, granulation yield improved due to high axial mixing. However, increasing material throughput quickly lowers the yield due to insufficient mixing of liquid and powder. Moreover, increasing liquid-to-solid ratio resulted in more oversized granules, and the fraction of oversized granules further increased at higher throughput. Although an increasing number

  20. Linking granulation performance with residence time and granulation liquid distributions in twin-screw granulation: An experimental investigation.

    Science.gov (United States)

    Kumar, Ashish; Alakarjula, Maija; Vanhoorne, Valérie; Toiviainen, Maunu; De Leersnyder, Fien; Vercruysse, Jurgen; Juuti, Mikko; Ketolainen, Jarkko; Vervaet, Chris; Remon, Jean Paul; Gernaey, Krist V; De Beer, Thomas; Nopens, Ingmar

    2016-07-30

    Twin-screw granulation is a promising wet granulation technique for the continuous manufacturing of pharmaceutical solid dosage forms. A twin screw granulator displays a short residence time. Thus, the solid-liquid mixing must be achieved quickly by appropriate arrangement of transport and kneading elements in the granulator screw allowing the production of granules with a size distribution appropriate for tableting. The distribution of residence time and granulation liquid is governed by the field conditions (such as location and length of mixing zones) in the twin-screw granulator, thus contain interesting information on granulation time, mixing and resulting sub-processes such as wetting, aggregation and breakage. In this study, the impact of process (feed rate, screw speed and liquid-to-solid ratio) and equipment parameters (number of kneading discs and stagger angle) on the residence time (distribution), the granulation liquid-powder mixing and the resulting granule size distributions during twin-screw granulation were investigated. Residence time and axial mixing data was extracted from tracer maps and the solid-liquid mixing was quantified from moisture maps, obtained by monitoring the granules at the granulator outlet using near infra-red chemical imaging (NIR-CI). The granule size distribution was measured using the sieving method. An increasing screw speed dominantly reduced the mean residence time. Interaction of material throughput with the screw speed and with the number of kneading discs led to most variation in the studied responses including residence time and mixing capacity. At a high screw speed, granulation yield improved due to high axial mixing. However, increasing material throughput quickly lowers the yield due to insufficient mixing of liquid and powder. Moreover, increasing liquid-to-solid ratio resulted in more oversized granules, and the fraction of oversized granules further increased at higher throughput. Although an increasing number

  1. Cerebellar mutism: review of the literature

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  2. Cerebellar Involvement in Ataxia and Generalized Epilepsy

    NARCIS (Netherlands)

    L. Kros (Lieke)

    2015-01-01

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

  3. Cerebellar mutism: review of the literature

    DEFF Research Database (Denmark)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2003-12-01

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

  5. Nerve growth factor enhances DNA synthesis in cultured cerebellar neuroblasts.

    Science.gov (United States)

    Confort, C; Charrasse, S; Clos, J

    1991-10-01

    The cerebellar neuroblasts in primary cultures from five-day-old rats bore NGF receptor immunoreactivity, suggesting a potential responsive to NGF. At low plating density, NGF was found to enhance DNA synthesis in these cells in a dose-dependent manner. As these cells synthesize NGF, one possibility to account for the lack of response of neuroblasts plated at high density is that the amount of endogenous trophic agent produced in this culture condition is sufficient to ensure an optimal effect. The results demonstrate that premitotic neuroblasts in the CNS, as well postmitotic neurons, are responsive to NGF. At the early stage of its development, the cerebellum therefore appears to be a very good autocrine model of NGF action. PMID:1661619

  6. Nerve growth factor enhances DNA synthesis in cultured cerebellar neuroblasts.

    Science.gov (United States)

    Confort, C; Charrasse, S; Clos, J

    1991-10-01

    The cerebellar neuroblasts in primary cultures from five-day-old rats bore NGF receptor immunoreactivity, suggesting a potential responsive to NGF. At low plating density, NGF was found to enhance DNA synthesis in these cells in a dose-dependent manner. As these cells synthesize NGF, one possibility to account for the lack of response of neuroblasts plated at high density is that the amount of endogenous trophic agent produced in this culture condition is sufficient to ensure an optimal effect. The results demonstrate that premitotic neuroblasts in the CNS, as well postmitotic neurons, are responsive to NGF. At the early stage of its development, the cerebellum therefore appears to be a very good autocrine model of NGF action.

  7. Sustained Arc expression in adult-generated granule cells.

    Science.gov (United States)

    Meconi, Alicia; Lui, Erika; Marrone, Diano F

    2015-08-31

    The dentate gyrus (DG) plays a critical role in memory formation and maintenance. Fitting this specialized role, the DG has many unique characteristics. In addition to being one of the few places in which new neurons are continually added in adulthood, the region also shows a unique long-term sustained transcriptional response of the immediate-early gene Arc to sensory input. Although we know that adult-generated granule cells are reliably recruited into behaviorally-driven neuronal network, it remains unknown whether they display robust late-phase sustained transcription in response to activity like their developmentally-generated counterparts. Since this late-phase of transcription is required for enduring plasticity, knowing if sustained transcription appears as soon as these cells are incorporated provides information on their potential for plasticity. To address this question, adult F344 rats were injected with BrdU (50mg/kg/day for 5 days) and 4 weeks later explored a novel environment. Arc expression in both BrdU- and BrdU+ neurons was determined 0.5h, 1h, 2h, 6h, 8h, 12h, or 24h following this behavior. Recently-generated granule cells showed a robust sustained Arc expression following a discrete behavioral experience. These data provide information on a potential mechanism to sculpt the representations of events occurring within hours of each other to create uncorrelated representations of episodes despite a highly excitable population of neurons. PMID:26219984

  8. Organophosphorus insecticides chlorpyrifos and diazinon and oxidative stress in neuronal cells in a genetic model of glutathione deficiency.

    Science.gov (United States)

    Giordano, Gennaro; Afsharinejad, Zhara; Guizzetti, Marina; Vitalone, Annabella; Kavanagh, Terrance J; Costa, Lucio G

    2007-03-01

    Over the past several years evidence has been accumulating from in vivo animal studies, observations in humans, and in vitro studies, that organophosphorus (OP) insecticides may induce oxidative stress. Such effects may contribute to some of the toxic manifestations of OPs, particularly upon chronic or developmental exposures. The aim of this study was to investigate the role of oxidative stress in the neurotoxicity of two commonly used OPs, chlorpyrifos (CPF) and diazinon (DZ), their oxygen analogs (CPO and DZO), and their "inactive" metabolites (TCP and IMP), in neuronal cells from a genetic model of glutathione deficiency. Cerebellar granule neurons from wild type mice (Gclm +/+) and mice lacking the modifier subunit of glutamate cysteine ligase (Gclm -/-), the first and limiting step in the synthesis of glutathione (GSH), were utilized. The latter display very low levels of GSH and are more susceptible to the toxicity of agents that increase oxidative stress. CPO and DZO were the most cytotoxic compounds, followed by CPF and DZ, while TCP and IMP displayed lower toxicity. Toxicity was significantly higher (10- to 25-fold) in neurons from Gclm (-/-) mice, and was antagonized by various antioxidants. Depletion of GSH from Gclm (+/+) neurons significantly increased their sensitivity to OP toxicity. OPs increased intracellular levels of reactive oxygen species and lipid peroxidation and in both cases the effects were greater in neurons from Gclm (-/-) mice. OPs did not alter intracellular levels of GSH, but significantly increased those of oxidized glutathione (GSSG). Cytotoxicity was not antagonized by cholinergic antagonists, but was decreased by the calcium chelator BAPTA-AM. These studies indicate that cytotoxicity of OPs involves generation of reactive oxygen species and is modulated by intracellular GSH, and suggest that it may involve disturbances in intracellular homeostasis of calcium.

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

    Directory of Open Access Journals (Sweden)

    Takeru Honda

    2011-07-01

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

  10. Fetal MRI and antenatal diagnosis of unilateral cerebellar hypoplasia

    Directory of Open Access Journals (Sweden)

    Houda El Mhabrech

    2015-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

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

  12. A spiking network model of cerebellar Purkinje cells and molecular layer interneurons exhibiting irregular firing

    Directory of Open Access Journals (Sweden)

    William eLennon

    2014-12-01

    Full Text Available While the anatomy of the cerebellar microcircuit is well studied, how it implements cerebellar function is not understood. A number of models have been proposed to describe this mechanism but few emphasize the role of the vast network Purkinje cells (PKJs form with the molecular layer interneurons (MLIs – the stellate and basket cells. We propose a model of the MLI-PKJ network composed of simple spiking neurons incorporating the major anatomical and physiological features. In computer simulations, the model reproduces the irregular firing patterns observed in PKJs and MLIs in vitro and a shift toward faster, more regular firing patterns when inhibitory synaptic currents are blocked. In the model, the time between PKJ spikes is shown to be proportional to the amount of feedforward inhibition from an MLI on average. The two key elements of the model are: (1 spontaneously active PKJs and MLIs due to an endogenous depolarizing current, and (2 adherence to known anatomical connectivity along a parasagittal strip of cerebellar cortex. We propose this model to extend previous spiking network models of the cerebellum and for further computational investigation into the role of irregular firing and MLIs in cerebellar learning and function.

  13. Cerebellar Nicotinic Cholinergic Receptors are Intrinsic to the Cerebellum: Implications for Diverse Functional Roles

    Science.gov (United States)

    Turner, Jill R.; Ortinski, Pavel I.; Sherrard, Rachel M.

    2016-01-01

    Although recent studies have delineated the specific nicotinic subtypes present in the mammalian cerebellum, very little is known about their location or function within the cerebellum. This is of increased interest since nicotinic receptors (nAChRs) in the cerebellum have recently been implicated in the pathology of autism spectrum disorders. To begin to better understand the roles of these heteromeric nAChRs in the cerebellar circuitry and their therapeutic potential as targets for drug development, we used various chemical and stereotaxic lesion models in conjunction with slice electrophysiology to examine how specific heteromeric nAChR subtypes may influence the surrounding cerebellar circuitry. Using subunit-specific immunoprecipitation of radiolabeled nAChRs in the cerebella following N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride, p-chloroamphetamine, and pendunculotomy lesions, we show that most, if not all, cerebellar nicotinic receptors are present in cells within the cerebellum itself and not in extracerebellar afferents. Furthermore, we demonstrate that the β4-containing, but not the β2-containing, nAChRs intrinsic to the cerebellum can regulate inhibitory synaptic efficacy at two major classes of cerebellar neurons. These tandem findings suggest that nAChRs may present a potential drug target for disorders involving the cerebellum. PMID:21562921

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

    Science.gov (United States)

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

    2006-01-01

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

  15. Target cell-specific modulation of neuronal activity by astrocytes

    OpenAIRE

    Kozlov, A. S.; Angulo, M. C.; Audinat, E.; Charpak, S

    2006-01-01

    Interaction between astrocytes and neurons enriches the behavior of brain circuits. By releasing glutamate and ATP, astrocytes can directly excite neurons and modulate synaptic transmission. In the rat olfactory bulb, we demonstrate that the release of GABA by astrocytes causes long-lasting and synchronous inhibition of mitral and granule cells. In addition, astrocytes release glutamate, leading to a selective activation of granule-cell NMDA receptors. Thus, by releasing excitatory and inhibi...

  16. Expression of tryptophan 2,3-dioxygenase in mature granule cells of the adult mouse dentate gyrus

    Directory of Open Access Journals (Sweden)

    Ohira, Koji

    2010-09-01

    Full Text Available Abstract New granule cells are continuously generated in the dentate gyrus of the adult hippocampus. During granule cell maturation, the mechanisms that differentiate new cells not only describe the degree of cell differentiation, but also crucially regulate the progression of cell differentiation. Here, we describe a gene, tryptophan 2,3-dioxygenase (TDO, whose expression distinguishes stem cells from more differentiated cells among the granule cells of the adult mouse dentate gyrus. The use of markers for proliferation, neural progenitors, and immature and mature granule cells indicated that TDO was expressed in mature cells and in some immature cells. In mice heterozygous for the alpha-isoform of calcium/calmodulin-dependent protein kinase II, in which dentate gyrus granule cells fail to mature normally, TDO immunoreactivity was substantially downregulated in the dentate gyrus granule cells. Moreover, a 5-bromo-2'-deoxyuridine labeling experiment revealed that new neurons began to express TDO between 2 and 4 wk after the neurons were generated, when the axons and dendrites of the granule cells developed and synaptogenesis occurred. These findings indicate that TDO might be required at a late-stage of granule cell development, such as during axonal and dendritic growth, synaptogenesis and its maturation.

  17. Metabolic anatomy of paraneoplastic cerebellar degeneration

    International Nuclear Information System (INIS)

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

  18. Oculomotor studies of cerebellar function in autism.

    Science.gov (United States)

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

    2005-11-15

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Tal Dotan Ben-Soussan

    2014-05-01

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

  2. CaMKIIalpha 3' untranslated region-directed mRNA translocation in living neurons: visualization by GFP linkage

    Science.gov (United States)

    Rook, M. S.; Lu, M.; Kosik, K. S.

    2000-01-01

    The CaMKIIalpha mRNA extends into distal hippocampal dendrites, and the 3' untranslated region (3'UTR) is sufficient to mediate this localization. We labeled the 3'UTR of the CaMKIIalpha mRNA in hippocampal cultures by using a green fluorescent protein (GFP)/MS2 bacteriophage tagging system. The CaMKIIalpha 3'UTR formed discrete granules throughout the dendrites of transfected cells. The identity of the fluorescent granules was verified by in situ hybridization. Over 30 min time periods these granules redistributed without a net increase in granule number; with depolarization there is a tendency toward increased numbers of granules in the dendrites. These observations suggest that finer time resolution of granule motility might reveal changes in the motility characteristics of granules after depolarization. So that motile granules could be tracked, shorter periods of observation were required. The movements of motile granules can be categorized as oscillatory, unidirectional anterograde, or unidirectional retrograde. Colocalization of CaMKIIalpha 3'UTR granules and synapses suggested that oscillatory movements allowed the granules to sample several local synapses. Neuronal depolarization increased the number of granules in the anterograde motile pool. Based on the time frame over which the granule number increased, the translocation of granules may serve to prepare the dendrite for mounting an adequate local translation response to future stimuli. Although the resident pool of granules can respond to signals that induce local translation, the number of granules in a dendrite might reflect its activation history.

  3. Serglycin proteoglycan is not implicated in localizing exocrine pancreas enzymes to zymogen granules

    DEFF Research Database (Denmark)

    Niemann, Carsten U; Cowland, Jack B; Ralfkiaer, Elisabeth;

    2009-01-01

    Storage and release of proteins from granules forms the basis of cellular functions as diverse as cell mediated cytotoxicity, neuronal communication, activation of muscle fibres, and release of hormones or digestive enzymes from endocrine and exocrine glands, such as the pancreas. Serglycin...... is the major intracellular proteoglycan of haematopoietic cells. Serglycin is important for localization of proteins in granules of different haematopoietic cell types. Previous reports have indicated a role for serglycin in granule formation and localization of zymogens in granules of the exocrine pancreas...... in rat. We here present data showing that serglycin is not present at the protein level in human or murine pancreas. Furthermore, the amount and localization of three exocrine pancreas zymogens (amylase, trypsinogen, and carboxypeptidase A) is not affected by the absence of serglycin in a serglycin knock...

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

    Science.gov (United States)

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

    2012-04-01

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

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

    Science.gov (United States)

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

    2016-03-01

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

  6. Anomalous Cerebellar Anatomy in Chinese Children with Dyslexia

    OpenAIRE

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

    2016-01-01

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

  7. UPDATED INSIGHT ON FOAM BINDER GRANULATION

    OpenAIRE

    Saikh Mahammed Athar Alli

    2013-01-01

    To have updated handy reference as source of outstanding knowledge on foam binder granulation process in granulating the material(s). Granulation considered being important unit operation for producing pharmaceutical oral dosage forms. Revolutionising binder application methodology as advancement of wet granulation process best owed said process. It is a modified version of atomised spraying method and gaining wide acceptance. Product and process development calls for method of optimisation i...

  8. Ultrastructure of Maize Starch Granules. A Review

    OpenAIRE

    Gallant, Daniel J.; Bouchet, Brigitte

    1986-01-01

    History of starch granule ultrastructure and the principal data obtained on maize starch granules are analyzed. New results are developed: i) growth and development of the maize starch granules during maturation depend on the maize varieties and the tissue site in the kernel, especially the horny and flloury endosperms; ii) cytochemical studies of the starch granules differing from their amylose/amylopectin ratio show important differences in the distribution of their crystalline and amorph...

  9. GSK3 inhibitors stabilize Wee1 and reduce cerebellar granule cell progenitor proliferation

    OpenAIRE

    Penas, Clara; Mishra, Jitendra K; Wood, Spencer D; Schürer, Stephan C.; Roush, William R.; Ayad, Nagi G

    2015-01-01

    Ubiquitin mediated proteolysis is required for transition from one cell cycle phase to another. For instance, the mitosis inhibitor Wee1 is targeted for degradation during S phase and G2 to allow mitotic entry. Wee1 is an essential tyrosine kinase required for the G2/M transition and S-phase progression. Although several studies have concentrated on Wee1 regulation during mitosis, few have elucidated its degradation during interphase. Our prior studies have demonstrated that Wee1 is degraded ...

  10. A role for Bicaudal-D2 in radial cerebellar granule cell migration

    NARCIS (Netherlands)

    Jaarsma, Dick; van den Berg, Robert; Wulf, Phebe S.; van Erp, Susan; Keijzer, Nanda; Schlager, Max A; de Graaff, Esther; De Zeeuw, Chris I; Pasterkamp, R. Jeroen; Akhmanova, Anna; Hoogenraad, Casper C

    2014-01-01

    Bicaudal-D (BICD) belongs to an evolutionary conserved family of dynein adaptor proteins. It was first described in Drosophila as an essential factor in fly oogenesis and embryogenesis. Missense mutations in a human BICD homologue, BICD2, have been linked to a dominant mild early onset form of spina

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

    Science.gov (United States)

    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...

  12. Variation of granule mass fraction with coordination number in wet granulation process

    Institute of Scientific and Technical Information of China (English)

    Papiya Roy; Manish Vashishtha; Rajesh Khanna; Duwuri Subbarao

    2009-01-01

    In granulation, fine particles combine to form a coarse granule in the form of a particle matrix partially or fully saturated with a binder liquid. The final product of granulation possesses a wide variety of granule size distributions with surface mean diameters which differ with operating conditions. The final granule size depends on the operating conditions, e.g. operating gas velocity, inlet air temperature, initial feed particle size, and viscosity of the binder. The objective of this paper is to find out the uniformity in the relation between the granule mass fraction in the final granule size distribution and the number of feed particles present in the granules. The total number of granules obtained depends on the experimental conditions but the granule mass fraction and the number of feed particles forming a single granule are independent of operating variables, feed material and method of granulation. The paper purports further to compare the uniform nature of mass fraction of the granules in final granule size distribution and the primary particles required to form that particular granule size irrespective of experimental conditions of granulation.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Luciana eD’Alessio

    2016-02-01

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

  15. Seizure-Induced Motility of Differentiated Dentate Granule Cells Is Prevented by the Central Reelin Fragment

    Science.gov (United States)

    Orcinha, Catarina; Münzner, Gert; Gerlach, Johannes; Kilias, Antje; Follo, Marie; Egert, Ulrich; Haas, Carola A.

    2016-01-01

    Granule cell dispersion (GCD) represents a pathological widening of the granule cell layer in the dentate gyrus and it is frequently observed in patients with mesial temporal lobe epilepsy (MTLE). Recent studies in human MTLE specimens and in animal epilepsy models have shown that a decreased expression and functional inactivation of the extracellular matrix protein Reelin correlates with GCD formation, but causal evidence is still lacking. Here, we used unilateral kainate (KA) injection into the mouse hippocampus, an established MTLE animal model, to precisely map the loss of reelin mRNA-synthesizing neurons in relation to GCD along the septotemporal axis of the epileptic hippocampus. We show that reelin mRNA-producing neurons are mainly lost in the hilus and that this loss precisely correlates with the occurrence of GCD. To monitor GCD formation in real time, we used organotypic hippocampal slice cultures (OHSCs) prepared from mice which express enhanced green fluorescent protein (eGFP) primarily in differentiated dentate granule cells. Using life cell microscopy we observed that increasing doses of KA resulted in an enhanced motility of eGFP-positive granule cells. Moreover, KA treatment of OHSC resulted in a rapid loss of Reelin-producing interneurons mainly in the hilus, as observed in vivo. A detailed analysis of the migration behavior of individual eGFP-positive granule cells revealed that the majority of these neurons actively migrate toward the hilar region, where Reelin-producing neurons are lost. Treatment with KA and subsequent addition of the recombinant R3–6 Reelin fragment significantly prevented the movement of eGFP-positive granule cells. Together, these findings suggest that GCD formation is indeed triggered by a loss of Reelin in hilar interneurons. PMID:27516734

  16. Seizure-induced motility of differentiated dentate granule cells is prevented by the central Reelin fragment

    Directory of Open Access Journals (Sweden)

    Catarina Orcinha

    2016-07-01

    Full Text Available Granule cell dispersion (GCD represents a pathological widening of the granule cell layer (GCL in the dentate gyrus and it is frequently observed in patients with mesial temporal lobe epilepsy (MTLE. Recent studies in human MTLE specimens and in animal epilepsy models have shown that a decreased expression and functional inactivation of the extracellular matrix protein Reelin correlates with GCD formation, but causal evidence is still lacking. Here, we used unilateral kainate (KA injection into the mouse hippocampus, an established MTLE animal model, to precisely map the loss of reelin mRNA-synthesizing neurons in relation to GCD along the septotemporal axis of the epileptic hippocampus. We show that reelin mRNA-producing neurons are mainly lost in the hilus and that this loss precisely correlates with the occurrence of GCD. To monitor GCD formation in real time, we used organotypic hippocampal slice cultures (OHSC prepared from mice which express enhanced green fluorescent protein (eGFP primarily in differentiated dentate granule cells. Using life cell microscopy we observed that increasing doses of KA resulted in an enhanced motility of eGFP-positive granule cells. Moreover, KA treatment of OHSC resulted in a rapid loss of Reelin-producing interneurons mainly in the hilus as observed in vivo. A detailed analysis of the migration behavior of individual eGFP-positive granule cells revealed that the majority of these neurons actively migrate towards the hilar region where Reelin-producing neurons are lost. Treatment with KA and subsequent addition of the recombinant R3-6 Reelin fragment significantly prevented the movement of eGFP-positive granule cells. Together these findings suggest that GCD formation is indeed triggered by a loss of Reelin in hilar interneurons.

  17. Seizure-Induced Motility of Differentiated Dentate Granule Cells Is Prevented by the Central Reelin Fragment.

    Science.gov (United States)

    Orcinha, Catarina; Münzner, Gert; Gerlach, Johannes; Kilias, Antje; Follo, Marie; Egert, Ulrich; Haas, Carola A

    2016-01-01

    Granule cell dispersion (GCD) represents a pathological widening of the granule cell layer in the dentate gyrus and it is frequently observed in patients with mesial temporal lobe epilepsy (MTLE). Recent studies in human MTLE specimens and in animal epilepsy models have shown that a decreased expression and functional inactivation of the extracellular matrix protein Reelin correlates with GCD formation, but causal evidence is still lacking. Here, we used unilateral kainate (KA) injection into the mouse hippocampus, an established MTLE animal model, to precisely map the loss of reelin mRNA-synthesizing neurons in relation to GCD along the septotemporal axis of the epileptic hippocampus. We show that reelin mRNA-producing neurons are mainly lost in the hilus and that this loss precisely correlates with the occurrence of GCD. To monitor GCD formation in real time, we used organotypic hippocampal slice cultures (OHSCs) prepared from mice which express enhanced green fluorescent protein (eGFP) primarily in differentiated dentate granule cells. Using life cell microscopy we observed that increasing doses of KA resulted in an enhanced motility of eGFP-positive granule cells. Moreover, KA treatment of OHSC resulted in a rapid loss of Reelin-producing interneurons mainly in the hilus, as observed in vivo. A detailed analysis of the migration behavior of individual eGFP-positive granule cells revealed that the majority of these neurons actively migrate toward the hilar region, where Reelin-producing neurons are lost. Treatment with KA and subsequent addition of the recombinant R3-6 Reelin fragment significantly prevented the movement of eGFP-positive granule cells. Together, these findings suggest that GCD formation is indeed triggered by a loss of Reelin in hilar interneurons. PMID:27516734

  18. Seizure-Induced Motility of Differentiated Dentate Granule Cells Is Prevented by the Central Reelin Fragment.

    Science.gov (United States)

    Orcinha, Catarina; Münzner, Gert; Gerlach, Johannes; Kilias, Antje; Follo, Marie; Egert, Ulrich; Haas, Carola A

    2016-01-01

    Granule cell dispersion (GCD) represents a pathological widening of the granule cell layer in the dentate gyrus and it is frequently observed in patients with mesial temporal lobe epilepsy (MTLE). Recent studies in human MTLE specimens and in animal epilepsy models have shown that a decreased expression and functional inactivation of the extracellular matrix protein Reelin correlates with GCD formation, but causal evidence is still lacking. Here, we used unilateral kainate (KA) injection into the mouse hippocampus, an established MTLE animal model, to precisely map the loss of reelin mRNA-synthesizing neurons in relation to GCD along the septotemporal axis of the epileptic hippocampus. We show that reelin mRNA-producing neurons are mainly lost in the hilus and that this loss precisely correlates with the occurrence of GCD. To monitor GCD formation in real time, we used organotypic hippocampal slice cultures (OHSCs) prepared from mice which express enhanced green fluorescent protein (eGFP) primarily in differentiated dentate granule cells. Using life cell microscopy we observed that increasing doses of KA resulted in an enhanced motility of eGFP-positive granule cells. Moreover, KA treatment of OHSC resulted in a rapid loss of Reelin-producing interneurons mainly in the hilus, as observed in vivo. A detailed analysis of the migration behavior of individual eGFP-positive granule cells revealed that the majority of these neurons actively migrate toward the hilar region, where Reelin-producing neurons are lost. Treatment with KA and subsequent addition of the recombinant R3-6 Reelin fragment significantly prevented the movement of eGFP-positive granule cells. Together, these findings suggest that GCD formation is indeed triggered by a loss of Reelin in hilar interneurons.

  19. Behavioral experience induces zif268 expression in mature granule cells but suppresses its expression in immature granule cells

    Directory of Open Access Journals (Sweden)

    Kylie A. Huckleberry

    2015-08-01

    Full Text Available Thousands of neurons are born each day in the dentate gyrus (DG, but many of these cells die before reaching maturity. Both death and survival of adult-born neurons are regulated by neuronal activity in DG. The immediate-early gene (IEG zif268 is an important mediator of these effects, as its expression is induced by neural activity and knockout of zif268 impairs survival of adult-born neurons (Veyrac et al., 2013. Despite the apparent importance of zif268 for adult neurogenesis, its behavior-induced expression has not been fully characterized in adult-born neurons. Here we characterize behavior-evoked expression of zif268 in mature and newborn dentate granule cells (DGCs. In the general granule cell population, zif268 expression peaked 1 hour after novel environment exposure and returned to baseline by 8 hours post-exposure. However, in the doublecortin-positive (DCX+ immature neurons, zif268 expression was suppressed relative to home cage for at least 8 hours post-exposure. We next determined that exposure to water maze training, an enriched environment, or a novel environment caused approximately equal suppression of zif268 expression in DCX+ cells and approximately equal activation of zif268 in the general DGC population and in 6-week-old adult-born neurons. Finally, we asked whether zif268 suppression varied as a function of age within the DCX+ population, which ranges in age from 0 to approximately 4 weeks. Novel environment exposure had no significant effect on zif268 expression in 2- or 4-week-old BrdU-labeled neurons, but it significantly suppressed zif268 expression in 3-week-old neurons. In summary, behavioral experience transiently activated expression of zif268 in mature DGCs but caused a more long-lasting suppression of zif268 expression in immature, adult-born DGCs. We hypothesize that zif268 suppression inhibits memory-related synaptic plasticity in immature DGCs or mediates learning-induced apoptosis of immature adult

  20. Protective effect of melatonin on neurons after oxidative-stress injury

    Institute of Scientific and Technical Information of China (English)

    Ximing Wang; Zhiqiang Lu; Qiuhong Duan; Tao Lu; Shanshu He

    2006-01-01

    BACKGROUND: It has been suggested that melatonin(MT) can protect secondary neuronal injury.However,the protective effect of MT on neuronal injury in ischemia/reperfusion models in vitro still has not been proved.OBJECTIVE:To investigate the protective effect of MT on central ischemic injury of nerve cells and analyze its possible mechanism.DESIGN: Contrast observational study.SETTING: Department of Biochemistry and Molecular Biology,Tongji Medical College,Huazhong University of Science and Technology.MATERIALS: Rats aged 7-8 days and weighing 10-12g were provided by Medical Experimental Animal Center,Tongji Medical College,Huazhong University of Science and Technology,MT was provided by Sigma Company,USA.METHODS:The experiment was carried out in the Laboratory of Biochemistry and Molecular Biology,Tongji Hospital,Huazhong University of Science and Technology from October 2002 to March 2004.The effects of MT on the neurodegeneration induced by oxygen-glucose-deprivation (OGD) were tested in cultured rat cerebellar granule cells.Neuron damage was quantitatively assessed by Typan Blue exclusion and MTT assay at different time points after oxygen-glucose-deprivation(90 minutes).DNA gel electrophoresis and acridine orange stain were performed to determine the nature of cell damage.And fluorescence spectrophotometer was used for quantification of intracellular malondialdehyde(MDA)at various time intervals.MAIN OUTCOME MEASURES: Correlation between degrees of neuronal injury and reperfusion times,apoptosis,and production of MDA in cells.RESULTS:①The neuron injury was aggravated with reperfusion time.②The protective effect of MT was time-and dose-dependent when its concentration was not higher than 10 μmol/L.⑧When neurons were exposed to OGD for 90 minutes.part of the cells exhibited typical features of apoptosis:internucleosomal DNA condensation and DNA ladder on agarose gel electrophoresis.MT added to cells recovering from OGD exerted neuroprotective action

  1. Crossed cerebellar diaschisis in ischemic stroke

    DEFF Research Database (Denmark)

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

    1984-01-01

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

  2. Paraneoplastic cerebellar dysfunction in Hodgkin's lymphoma

    Directory of Open Access Journals (Sweden)

    Kazi Sazzad Manir

    2015-01-01

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

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

    Science.gov (United States)

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

    2008-01-01

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

  4. Drying and recovery of aerobic granules.

    Science.gov (United States)

    Hu, Jianjun; Zhang, Quanguo; Chen, Yu-You; Lee, Duu-Jong

    2016-10-01

    To dehydrate aerobic granules to bone-dry form was proposed as a promising option for long-term storage of aerobic granules. This study cultivated aerobic granules with high proteins/polysaccharide ratio and then dried these granules using seven protocols: drying at 37°C, 60°C, 4°C, under sunlight, in dark, in a flowing air stream or in concentrated acetone solutions. All dried granules experienced volume shrinkage of over 80% without major structural breakdown. After three recovery batches, although with loss of part of the volatile suspended solids, all dried granules were restored most of their original size and organic matter degradation capabilities. The strains that can survive over the drying and storage periods were also identified. Once the granules were dried, they can be stored over long period of time, with minimal impact yielded by the applied drying protocols. PMID:27392096

  5. Mapping of the SCA23 locus involved in autosomal dominant cerebellar ataxia to chromosome region 20p13-12.3

    NARCIS (Netherlands)

    Verbeek, D S; van de Warrenburg, B P; Wesseling, P; Pearson, P L; Kremer, H P; Sinke, R J

    2004-01-01

    We report upon a Dutch autosomal dominant cerebellar ataxia (ADCA) family, clinically characterized by a late-onset (>40 years), slowly progressive, isolated spinocerebellar ataxia (SCA). Neuropathological examination in one affected subject showed neuronal loss in the Purkinje cell layer, dentate n

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

    Directory of Open Access Journals (Sweden)

    Jessica A Bernard

    2014-11-01

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

  7. Ultrasonically detectable cerebellar haemorrhage in preterm infants.

    LENUS (Irish Health Repository)

    McCarthy, Lisa Kenyon

    2011-07-01

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

  8. Cerebellar cortical inhibition and classical eyeblink conditioning.

    Science.gov (United States)

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

    2002-02-01

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

  9. Improving cerebellar segmentation with statistical fusion

    Science.gov (United States)

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

    2016-03-01

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

  10. Accumulation and identification of lipofuscin-like pigment in the neurons of Bulla gouldiana (Gastropoda: Opisthobranchia).

    Science.gov (United States)

    Robles, L J

    1978-01-01

    A few reports suggest that pigmented granules found in molluscan neurons accumulate with age as do lipofuscin granules in vertebrate cells; however, no reports on molluscan neurons include detailed descriptions of granule accumulation or histochemical tests to identify the pigment as lipofuscin-like. In this study light microscope observations of living ganglia from 1.7, 2.7, and 3.0 cm and larger (shell length) sized Bulla gouldiana showed an increasing accumulation of orange-red pigment in the perikaryon corresponding to increasing shell size (i.e. age). With the electron microscope similar results were obtained, and lipofuscin-like granules were seen in the nerve cell cytoplasm of veliger larvae and in all adult sized Bulla. Staining with Sudan black B, Nile blue, chrome alum hematoxylin, PAS reagents, and exposure of the neurons to u.v. light to observe subsequent autofluorescence, yielded positive results in the areas of pigmented granule accumulation. Thus, the brillant orange-red granules that accumulate with age in the peripheral cytoplasm of adult Bulla neurons, and which are probably also present in larval stages, chemically resemble the lipofuscin granules of vertebrates. Similarities and differences between molluscan pigmented granules and vertebrate lipofuscin granules, in relation to structure and mechanisms of development and accumulation, are discussed. PMID:625150

  11. Anti-Yo and anti-glutamic acid decarboxylase antibodies presenting in carcinoma of the uterus with paraneoplastic cerebellar degeneration: a case report

    Directory of Open Access Journals (Sweden)

    Panegyres Peter K

    2012-06-01

    Full Text Available Abstract Introduction Paraneoplastic cerebellar degeneration is a rare non-metastatic manifestation of malignancy. In this report, to the best of our knowledge we describe for the first time a diagnosis of paraneoplastic cerebellar degeneration several months prior to the diagnosis of clear carcinoma of the uterus. Case presentation A 75-year-old Caucasian woman manifested a rapidly progressive cerebellar syndrome with nystagmus, past-pointing, dysdiadochokinesis, dysarthria, truncal ataxia and titubation. The paraneoplastic cerebellar degeneration was associated with anti-Yo and anti-glutamic acid decarboxylase antibodies. 14-3-3 protein was detected in the cerebrospinal fluid. She was treated with intravenous immunoglobulin prior to laparotomy, hysterectomy and bilateral salpingoophorectomy. Our patient has survived for three years following diagnosis and treatment. Conclusions To the best of our knowledge this is the first report of an association of clear cell carcinoma of the uterus and paraneoplastic cerebellar degeneration with both anti-Yo and anti-glutamic acid decarboxylase antibodies. The findings imply that both antibodies contributed to the fulminating paraneoplastic cerebellar degeneration observed in our patient, and this was of such severity it resulted in the release of 14-3-3 protein in the cerebrospinal fluid, a marker of neuronal death.

  12. Characterization of the hyperpolarization-activated chloride current in dissociated rat sympathetic neurons.

    Science.gov (United States)

    Clark, S; Jordt, S E; Jentsch, T J; Mathie, A

    1998-02-01

    1. Dissociated rat superior cervical ganglion (SCG) neurons have been shown to possess a hyperpolarization-activated inwardly rectifying chloride current. The current was not altered by changes in external potassium concentration, replacing external cations with NMDG (N-methyl-D-glucamine) or by addition of 10 mM caesium or barium ions. 2. The reversal potential of the current was altered by changing external anions. The anion selectivity of the current was Cl- > Br- > I- > cyclamate. All substituted permeant anions also blocked the current. 3. The current was blocked by DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid), 9AC (anthracene-9-carboxylic acid) and NPPB (5-nitro-2-(3-phenylpropylamino)benzoic acid) but was unaffected by SITS (4-acetamido-4'-isothiocyanatostilbene- 2,2'-disulphonic acid) and niflumic acid. The effective blockers were voltage dependent; DIDS and NPPB were more effective at depolarized potentials while 9AC was more effective at hyperpolarized potentials. 4. The current was enhanced by extracellular acidification and reduced by extracellular alkalinization. Reducing external osmolarity was without effect in conventional whole-cell recording but enhanced current amplitude in those perforated-patch recordings where little current was evident in control external solution. 5. The current in SCG neurons was blocked by external cadmium and zinc. ClC-2 chloride currents expressed in Xenopus oocytes were also sensitive to block by these divalent ions and by DIDS but the sensitivity of ClC-2 to block by cadmium ions was lower than that of the current in SCG neurons. 6. Reverse transcriptase-polymerase chain reaction (RT-PCR) experiments showed the presence of mRNA for ClC-2 in SCG neurons but not in rat cerebellar granule cells which do not possess a hyperpolarization-activated Cl- current. 7. The data suggest that ClC-2 may be functionally expressed in rat SCG neurons. This current may play a role in regulating the internal chloride

  13. Do brainstem omnipause neurons terminate saccades?

    Science.gov (United States)

    Rucker, Janet C; Ying, Sarah H; Moore, Willa; Optican, Lance M; Büttner-Ennever, Jean; Keller, Edward L; Shapiro, Barbara E; Leigh, R John

    2011-09-01

    Saccade-generating burst neurons (BN) are inhibited by omnipause neurons (OPN), except during saccades. OPN activity pauses before saccade onset and resumes at the saccade end. Microstimulation of OPN stops saccades in mid-flight, which shows that OPN can end saccades. However, OPN pause duration does not correlate well with saccade duration, and saccades are normometric after OPN lesions. We tested whether OPN were responsible for stopping saccades both in late-onset Tay-Sachs, which causes premature saccadic termination, and in individuals with cerebellar hypermetria. We studied gaze shifts between two targets at different distances aligned on one eye, which consist of a disjunctive saccade followed by vergence. High-frequency conjugate oscillations during the vergence movements that followed saccades were present in all subjects studied, indicating OPN silence. Thus, mechanisms other than OPN discharge (e.g., cerebellar caudal fastigial nucleus-promoting inhibitory BN discharge) must contribute to saccade termination. PMID:21950975

  14. Early maternal deprivation in rats induces gender-dependent effects on developing hippocampal and cerebellar cells.

    Science.gov (United States)

    Llorente, Ricardo; Gallardo, Meritxell López; Berzal, Alvaro Llorente; Prada, Carmen; Garcia-Segura, Luis Miguel; Viveros, María-Paz

    2009-05-01

    Adult animals submitted to a single prolonged episode of maternal deprivation [24h, postnatal day 9-10] show behavioral alterations that resemble specific symptoms of schizophrenia. According to the neurodevelopmental theory, these behavioral deficits might be mediated by detrimental neurodevelopmental processes that might be associated, at least partially, with stress-induced corticosterone responses. In order to address this hypothesis, we have focused on the hippocampus and cerebellar cortex, two brain regions that show high density of glucocorticoid receptors, and analyzed possible neuronal and glial alterations by immunohistochemical techniques. To evaluate the presence of degenerated neurons we used Fluoro-Jade-C (FJ-C) staining and for the study of astrocytes we employed glial fibrillary acidic protein (GFAP). Within control animals, females showed significantly more GFAP positive cells than males and a trend towards more FJ-C positive cells. Maternal deprivation induced neuronal degeneration and astroglial changes in the hippocampus and cerebellar cortex of neonatal rats that, in general, were more marked in males. This differential effect may be attributable to a greater vulnerability of males to this kind of early environmental insult and/or to sex-dependent differences in the onset and/or progression of the effects. The present experimental procedure may be instrumental in elucidating sex-dependent mechanisms of neurodevelopmental psychiatric disorders with a basis in early environmental insults.

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

    Science.gov (United States)

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

    2012-03-01

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

  16. Vestibular efferent neurons project to the flocculus

    Science.gov (United States)

    Shinder, M. E.; Purcell, I. M.; Kaufman, G. D.; Perachio, A. A.

    2001-01-01

    A bilateral projection from the vestibular efferent neurons, located dorsal to the genu of the facial nerve, to the cerebellar flocculus and ventral paraflocculus was demonstrated. Efferent neurons were double-labeled by the unilateral injections of separate retrograde tracers into the labyrinth and into the floccular and ventral parafloccular lobules. Efferent neurons were found with double retrograde tracer labeling both ipsilateral and contralateral to the sites of injection. No double labeling was found when using a fluorescent tracer with non-fluorescent tracers such as horseradish peroxidase (HRP) or biotinylated dextran amine (BDA), but large percentages of efferent neurons were found to be double labeled when using two fluorescent substances including: fluorogold, microruby dextran amine, or rhodamine labeled latex beads. These data suggest a potential role for vestibular efferent neurons in modulating the dynamics of the vestibulo-ocular reflex (VOR) during normal and adaptive conditions.

  17. Effect of methotrexate on cerebellar development in infant rats.

    Science.gov (United States)

    Sugiyama, Akihiko; Sun, Jing; Ueda, Kota; Furukawa, Satoshi; Takeuchi, Takashi

    2015-07-01

    Six-day-old rats were treated intraperitoneal injections with methotrexate 1 mg/kg, and the cerebellum was examined. Both the length and width of the vermis decreased in the methotrexate-treated group instead of the control from 4 day after treatment (DAT) onward. A significant reduction in the width of the external granular layer was detected on 2 and 3 DAT in the methotrexate group. By 4 DAT, the width of the external granular layer of the methotrexate group was indistinguishable from the control, and by 8 DAT, it was greater than that of the control. The molecular layer of methotrexate group on 8 and 15 DAT was thinner than that of the control. On 1 DAT, in the methotrexate group, there were many TUNEL and cleaved caspase-3-positive granular cells throughout the external granular layer, and they decreased time-dependently. On 1 DAT, in the methotrexate group, phospho-histone H3-positive cells in the external granular layer were fewer than in the control and tended to increase on 2-4 DAT. The p21-positive-rate of the external granule cells in the MTX group was higher than in the control on 1-4 DAT. These results suggested that methotrexate exposure on postnatal day 6 induces a delay, slowing in the migration of external granular cells to the inner granular layer, attributed to decrease or inhibition in the production of external granular cells that had arisen from apoptosis and the decrease in cell proliferative activity, resulting in cerebellar hypoplasia.

  18. The Effect of the Chopper on Granules from Wet High-Shear Granulation Using a PMA-1 Granulator

    OpenAIRE

    Briens, Lauren; Logan, Ryan

    2011-01-01

    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 perime...

  19. Linking granulation performance with residence time and granulation liquid distributions in twin-screw granulation: An experimental investigation

    DEFF Research Database (Denmark)

    Kumar, Ashish; Alakarjula, Maija; Vanhoorne, Valérie;

    2016-01-01

    interesting information on granulation time, mixing and resulting sub-processes such as wetting, aggregation and breakage. In this study, the impact of process (feed rate, screw speed and liquid-to-solid ratio) and equipment parameters (number of kneading discs and stagger angle) on the residence time...... the granules at the granulator outlet using near infra-red chemical imaging (NIR-CI). The granule size distribution was measured using the sieving method. An increasing screw speed dominantly reduced the mean residence time. Interaction of material throughput with the screw speed and with the number...

  20. Coupling internal cerebellar models enhances online adaptation and supports offline consolidation in sensorimotor tasks

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste ePassot

    2013-07-01

    Full Text Available The cerebellum is thought to mediate sensorimotor adaptation through the acquisition of internal models of the body–environment interaction. These representations can be of two types, identified as forward and inverse models. The first predicts the sensory consequences of actions, while the second provides the correct commands to achieve desired state transitions. In this paper, we propose a composite architecture consisting of multiple cerebellar internal models to account for the adaptation performance of humans during sensorimotor learning. The proposed model takes inspiration from the cerebellar microcomplex circuit, and employs spiking neurons to process information. We investigate the intrinsic properties of the cerebellar circuitry subserving efficient adaptation properties, and we assess the complementary contributions of internal representations by simulating our model in a procedural adaptation task. Our simulation results suggest that the coupling of internal models enhances learning performance significantly (compared with independent forward and inverse models, and it allows for the reproduction of human adaptation capabilities. Furthermore, we provide a computational explanation for the performance improvement observed after one night of sleep in a wide range of sensorimotor tasks. We predict that internal model coupling is a necessary condition for the offline consolidation of procedural memories.

  1. Preferential Transport and Metabolism of Glucose in Bergmann Glia over Purkinje Cells: A Multiphoton Study of Cerebellar Slices

    Institute of Scientific and Technical Information of China (English)

    L.F.BARROS; R.COURJARET; P.JAKOBY; A.LOAIZA; C.LOHR; J.W.DEITMER

    2009-01-01

    了解不同类型的细胞如何处理葡萄糖有助于解释能量供应是如何是如何根据大脑能量需求来进行调整的.荧光追踪结合共聚焦显微镜技术已用于研究培养的脑细胞摄取葡萄糖的实时动态过程.本文采用这种技术利用多光子显微镜观察急性制备的大鼠小脑脑片.带荧光的葡萄糖类似物2NBDG和6NBDG在小脑皮质的分子层中的转运速度比其在蒲肯野细胞胞体和颗粒细胞中快若干倍.洗脱游离示踪剂后,可见大部分磷酸化示踪剂都位于Bergmann胶质细胞,用胶质细胞标记物sulforhodamine 101免疫染色后进一步确认这一结果.有效回收荧光光漂白后显示,2NBDG-P可通过Bergmann胶质细胞之间的缝隙连接沿着分子层水平扩散.本文的结果表明在急性小脑切片中,Bergmann胶质细胞对葡萄糖的转运能力和糖酵解率高于蒲肯野细胞若干倍.由于小脑主要由葡萄糖提供能量,蒲肯野神经元被认为比Bergmann胶质细胞更耗能量,这些结果表明,在胶质细胞和神经元之间存在类似乳酸的能量代谢物介导的环路.%Knowing how different cell types handle glucose should help to decipher how energy supply is adjusted to energy demand in the brain. Previously, the uptake of glucose by cultured brain cells was studied in real-time using fluorescent tracers and confocal microscopy. Here, we have adapted this technique to acute slices prepared from the rat cerebellum by means of multiphoton microscopy. The transport of the fluorescent glucose analogs 2NBDG and 6NBDG was several-fold faster in the molecular layer of the cerebellar cortex than in Purkinje cell somata and granule cells. After washout of free tracer, it became apparent that most phosphorylated tracer was located in Bergmann glia, which was confirmed by counterstaining with the glial marker sulforhodamine 101. The effective recovery of fluorescence after photobleaching showed that 2NBDG-P can diffuse

  2. 2', 3'-cyclic nucleotide 3'-phosphodiesterase is expressed in dissociated rat cerebellar cells and included in the postsynaptic density fraction.

    Science.gov (United States)

    Cho, Sun-Jung; Jung, Jae Seob; Jin, IngNyol; Moon, Il Soo

    2003-08-31

    We have shown by protein sequencing that the phosphotyrosine-containing 48 kDa protein band of the rat cerebellar postsynaptic density fraction (CBL-PSD) is 2', 3'-cyclic nucleotide 3'-phosphodiesterase 2 (CNP2). Immunoblot analysis indicated that both CNP1 and CNP2 isoforms are present in the CBL-PSD fraction, whereas there is little CNP2 in the forebrain (FB)-PSD fraction. Both isoforms in the CBL-PSD fraction were tyrosine-phosphorylated to a basal extent. They were efficiently dissociated from the complexes in the PSD fraction by salt, but not by non-ionic detergents such as n-octyl glucoside (OG) and Triton X-100. Immunocytochemistry of dissociated cerebellar cultures revealed patchy CNP staining in oligodendrocytes (OLs), Purkinje cells (PCs), and unidentified PSD95-positive cells, but no staining in granule cells (GCs). Our results indicate that both CNP1 and CNP2 are expressed in cerian populations of cerebellar cells in addition to OL, and that they are associated with complexes that are co-isolated with the PSD. PMID:14503857

  3. Stress granules, P-bodies and cancer

    OpenAIRE

    Anderson, Paul; Kedersha, Nancy; Ivanov, Pavel

    2014-01-01

    Cancer cells are exposed to adverse conditions in the tumor microenvironment, and utilize post-transcriptional control mechanisms to re-program gene expression in ways that enhance cell survival. Stress granules and processing bodies are RNA-containing granules that contribute to this process by modulating cellular signaling pathways, metabolic machinery, and stress response programs. This review examines evidence implicating RNA granules in the pathogenesis of cancer and discusses their pote...

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

    Science.gov (United States)

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

    2016-03-01

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

  5. Medical image of the week: granulation tissue

    Directory of Open Access Journals (Sweden)

    Ganesh A

    2014-03-01

    Full Text Available A 57 year old woman presented with a tickling sensation in the back of throat and intermittent bleeding from the healing stoma one month after decannulation of her tracheostomy tube. On bronchoscopy a granuloma with surrounding granulation tissue was present in the subglottic space (Figure 1. Argon plasma coagulation (APC was performed to cauterize the granulation tissue (Figure 2. Formation of granulation tissue after tracheostomy is a common complication which can result in tracheal stenosis. APC and electrocautery using flexible bronchoscopy has been shown to safely and effectively remove the granulation tissue.

  6. Supplementary motor area and presupplementary motor area: targets of basal ganglia and cerebellar output.

    Science.gov (United States)

    Akkal, Dalila; Dum, Richard P; Strick, Peter L

    2007-10-01

    We used retrograde transneuronal transport of neurotropic viruses in Cebus monkeys to examine the organization of basal ganglia and cerebellar projections to two cortical areas on the medial wall of the hemisphere, the supplementary motor area (SMA) and the pre-SMA. We found that both of these cortical areas are the targets of disynaptic projections from the dentate nucleus of the cerebellum and from the internal segment of the globus pallidus (GPi). On average, the number of pallidal neurons that project to the SMA and pre-SMA is approximately three to four times greater than the number of dentate neurons that project to these cortical areas. GPi neurons that project to the pre-SMA are located in a rostral, "associative" territory of the nucleus, whereas GPi neurons that project to the SMA are located in a more caudal and ventral "sensorimotor" territory. Similarly, dentate neurons that project to the pre-SMA are located in a ventral, "nonmotor" domain of the nucleus, whereas dentate neurons that project to the SMA are located in a more dorsal, "motor" domain. The differential origin of subcortical projections to the SMA and pre-SMA suggests that these cortical areas are nodes in distinct neural systems. Although both systems are the target of outputs from the basal ganglia and the cerebellum, these two cortical areas seem to be dominated by basal ganglia input. PMID:17913900

  7. Isolated rhomboencephalosynapsis – a rare cerebellar anomaly

    International Nuclear Information System (INIS)

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

  8. Cerebellar ataxia as presenting feature of hypothyroidism.

    Science.gov (United States)

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

    2016-04-01

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

  9. Cerebellar and cerebral atrophy in trichothiodystrophy

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-10-01

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

  10. Hereditary spastic paraplegia with cerebellar ataxia

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  11. The paradox of high shear granulation : the formation of non-homogeneous granules

    NARCIS (Netherlands)

    Dries, Kaspar van den

    2004-01-01

    Wet granulation is a process used for the particle size enlargement of primary powders. The mixing of a liquid with the powder glues the primary particles together, which results in the formation of the granules. The mixing action can be performed in many ways, like tumbling (drum granulation), flui

  12. Granule exocytosis is required for platelet spreading: differential sorting of α-granules expressing VAMP-7.

    Science.gov (United States)

    Peters, Christian G; Michelson, Alan D; Flaumenhaft, Robert

    2012-07-01

    There has been recent controversy as to whether platelet α-granules represent a single granule population or are composed of different subpopulations that serve discrete functions. To address this question, we evaluated the localization of vesicle-associated membrane proteins (VAMPs) in spread platelets to determine whether platelets actively sort a specific subpopulation of α-granules to the periphery during spreading. Immunofluorescence microscopy demonstrated that granules expressing VAMP-3 and VAMP-8 localized to the central granulomere of spread platelets along with the granule cargos von Willebrand factor and serotonin. In contrast, α-granules expressing VAMP-7 translocated to the periphery of spread platelets along with the granule cargos TIMP2 and VEFG. Time-lapse microscopy demonstrated that α-granules expressing VAMP-7 actively moved from the granulomere to the periphery during spreading. Platelets from a patient with gray platelet syndrome lacked α-granules and demonstrated only minimal spreading. Similarly, spreading was impaired in platelets obtained from Unc13d(Jinx) mice, which are deficient in Munc13-4 and have an exocytosis defect. These studies identify a new α-granule subtype expressing VAMP-7 that moves to the periphery during spreading, supporting the premise that α-granules are heterogeneous and demonstrating that granule exocytosis is required for platelet spreading.

  13. Vestibular Neuronitis

    Science.gov (United States)

    ... Prevent Painful Swimmer's Ear Additional Content Medical News Vestibular Neuronitis By Lawrence R. Lustig, MD NOTE: This ... Drugs Herpes Zoster Oticus Meniere Disease Purulent Labyrinthitis Vestibular Neuronitis Vestibular neuronitis is a disorder characterized by ...

  14. Computed tomography in hypertensive cerebellar hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-11-01

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

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

    OpenAIRE

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

    1997-01-01

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

  16. Sensory mechanisms of balance control in cerebellar disease

    OpenAIRE

    Bunn, L. M.

    2011-01-01

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

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

    OpenAIRE

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

    1992-01-01

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

  18. Differential neuronal targeting of a new and two known calcium channel β4 subunit splice variants correlates with their regulation of gene expression.

    Science.gov (United States)

    Etemad, Solmaz; Obermair, Gerald J; Bindreither, Daniel; Benedetti, Ariane; Stanika, Ruslan; Di Biase, Valentina; Burtscher, Verena; Koschak, Alexandra; Kofler, Reinhard; Geley, Stephan; Wille, Alexandra; Lusser, Alexandra; Flockerzi, Veit; Flucher, Bernhard E

    2014-01-22

    The β subunits of voltage-gated calcium channels regulate surface expression and gating of CaV1 and CaV2 α1 subunits and thus contribute to neuronal excitability, neurotransmitter release, and calcium-induced gene regulation. In addition, certain β subunits are targeted into the nucleus, where they interact directly with the epigenetic machinery. Whereas their involvement in this multitude of functions is reflected by a great molecular heterogeneity of β isoforms derived from four genes and abundant alternative splicing, little is known about the roles of individual β variants in specific neuronal functions. In the present study, an alternatively spliced β4 subunit lacking the variable N terminus (β4e) is identified. It is highly expressed in mouse cerebellum and cultured cerebellar granule cells (CGCs) and modulates P/Q-type calcium currents in tsA201 cells and CaV2.1 surface expression in neurons. Compared with the other two known full-length β4 variants (β4a and β4b), β4e is most abundantly expressed in the distal axon, but lacks nuclear-targeting properties. To determine the importance of nuclear targeting of β4 subunits for transcriptional regulation, we performed whole-genome expression profiling of CGCs from lethargic (β4-null) mice individually reconstituted with β4a, β4b, and β4e. Notably, the number of genes regulated by each β4 splice variant correlated with the rank order of their nuclear-targeting properties (β4b > β4a > β4e). Together, these findings support isoform-specific functions of β4 splice variants in neurons, with β4b playing a dual role in channel modulation and gene regulation, whereas the newly detected β4e variant serves exclusively in calcium-channel-dependent functions. PMID:24453333

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

    Science.gov (United States)

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

    2002-04-01

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

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

    Science.gov (United States)

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

    1999-01-01

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

  1. Prion pathogenesis is faithfully reproduced in cerebellar organotypic slice cultures.

    Directory of Open Access Journals (Sweden)

    Jeppe Falsig

    Full Text Available Prions cause neurodegeneration in vivo, yet prion-infected cultured cells do not show cytotoxicity. This has hampered mechanistic studies of prion-induced neurodegeneration. Here we report that prion-infected cultured organotypic cerebellar slices (COCS experienced progressive spongiform neurodegeneration closely reproducing prion disease, with three different prion strains giving rise to three distinct patterns of prion protein deposition. Neurodegeneration did not occur when PrP was genetically removed from neurons, and a comprehensive pharmacological screen indicated that neurodegeneration was abrogated by compounds known to antagonize prion replication. Prion infection of COCS and mice led to enhanced fodrin cleavage, suggesting the involvement of calpains or caspases in pathogenesis. Accordingly, neurotoxicity and fodrin cleavage were prevented by calpain inhibitors but not by caspase inhibitors, whereas prion replication proceeded unimpeded. Hence calpain inhibition can uncouple prion replication from its neurotoxic sequelae. These data validate COCS as a powerful model system that faithfully reproduces most morphological hallmarks of prion infections. The exquisite accessibility of COCS to pharmacological manipulations was instrumental in recognizing the role of calpains in neurotoxicity, and significantly extends the collection of tools necessary for rigorously dissecting prion pathogenesis.

  2. Neuroprotection of microglial conditioned medium on 6-hydroxydopamine-induced neuronal death: role of transforming growth factor beta-2.

    Science.gov (United States)

    Polazzi, Elisabetta; Altamira, Luis Emiliano Peña; Eleuteri, Simona; Barbaro, Raffaella; Casadio, Chiara; Contestabile, Antonio; Monti, Barbara

    2009-07-01

    Microglia, the immune cells of the CNS, play essential roles in both physiological and pathological brain states. Here we have used an in vitro model to demonstrate neuroprotection of a 48 h-microglial conditioned medium (MCM) towards cerebellar granule neurons (CGNs) challenged with the neurotoxin 6-hydroxydopamine, which induces a Parkinson-like neurodegeneration, and to identify the protective factor(s). MCM nearly completely protects CGNs from 6-hydroxydopamine neurotoxicity and at least some of the protective factor(s) are peptidic in nature. While the fraction of the medium containing molecules 10 kDa are not neuroprotective. We further demonstrate that microglia release high amounts of transforming growth factor-beta2 (TGF-beta2) and that its exogenous addition to the fraction of the medium not containing it (< 10 kDa) fully restores the neuroprotective action. Moreover, MCM neuroprotection is significantly counteracted by an inhibitor of TGF-beta2 transduction pathway. Our results identify TGF-beta2 as an essential neuroprotective factor released by microglia in its culture medium that requires to be fully effective the concomitant presence of other factor(s) of low molecular weight. PMID:19457129

  3. Simultaneous monitoring of ionophore- and inhibitor-mediated plasma and mitochondrial membrane potential changes in cultured neurons.

    Science.gov (United States)

    Nicholls, David G

    2006-05-26

    Although natural and synthetic ionophores are widely exploited in cell studies, for example, to influence cytoplasmic free calcium concentrations and to depolarize in situ mitochondria, their inherent lack of membrane selectivity means that they affect the ion permeability of both plasma and mitochondrial membranes. A similar ambiguity affects the interpretation of signals from fluorescent membrane-permeant cations (usually termed "mitochondrial membrane potential indicators"), because the accumulation of these probes is influenced by both plasma and mitochondrial membrane potentials. To resolve some of these problems a technique is developed to allow simultaneous monitoring of plasma and mitochondrial membrane potentials at single-cell resolution using a cationic and anionic fluorescent probe. A computer program is described that transforms the fluorescence changes into dynamic estimates of changes in plasma and mitochondrial potentials. Exploiting this technique, primary cultures of rat cerebellar granule neurons display a concentration-dependent response to ionomycin: low concentrations mimic nigericin by hyperpolarizing the mitochondria while slowly depolarizing the plasma membrane and maintaining a stable elevated cytoplasmic calcium. Higher ionomycin concentrations induce a stochastic failure of calcium homeostasis that precedes both mitochondrial depolarization and an enhanced rate of plasma membrane depolarization. In addition, the protonophore carbonyl cyanide p-trifluoromethoxyphenylhydrazone only selectively depolarizes mitochondria at submicromolar concentrations. ATP synthase reversal following respiratory chain inhibition depolarizes the mitochondria by 26 mV. PMID:16551630

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

    DEFF Research Database (Denmark)

    Fonteyne, Margot; Fussell, Andrew Luke; Vercruysse, Jurgen;

    2014-01-01

    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...

  5. Mesenchymal stem cell transplantation ameliorates motor function deterioration of spinocerebellar ataxia by rescuing cerebellar Purkinje cells

    Directory of Open Access Journals (Sweden)

    Ma Wei-Hsien

    2011-08-01

    Full Text Available Abstract Background Spinocerebellar ataxia (SCA refers to a disease entity in which polyglutamine aggregates are over-produced in Purkinje cells (PCs of the cerebellum as well as other neurons in the central nervous system, and the formation of intracellular polyglutamine aggregates result in the loss of neurons as well as deterioration of motor functions. So far there is no effective neuroprotective treatment for this debilitating disease although numerous efforts have been made. Mesenchymal stem cells (MSCs possess multi-lineage differentiation potentials as well as immuno-modulatory properties, and are theoretically good candidates for SCA treatment. The purpose of this study is to investigate whether transplantation of human MSCs (hMSCs can rescue cerebellar PCs and ameliorate motor function deterioration in SCA in a pre-clinical animal model. Method Transgenic mice bearing poly-glutamine mutation in ataxin-2 gene (C57BL/6J SCA2 transgenic mice were serially transplanted with hMSCs intravenously or intracranially before and after the onset of motor function loss. Motor function of mice was evaluated by an accelerating protocol of rotarod test every 8 weeks. Immunohistochemical stain of whole brain sections was adopted to demonstrate the neuroprotective effect of hMSC transplantation on cerebellar PCs and engraftment of hMSCs into mice brain. Results Intravenous transplantation of hMSCs effectively improved rotarod performance of SCA2 transgenic mice and delayed the onset of motor function deterioration; while intracranial transplantation failed to achieve such neuroprotective effect. Immunohistochemistry revealed that intravenous transplantation was more effective in the preservation of the survival of cerebellar PCs and engraftment of hMSCs than intracranial injection, which was compatible to rotarod performance of transplanted mice. Conclusion Intravenous transplantation of hMSCs can indeed delay the onset as well as improve the motor

  6. Electrochemical performance of granulated titania nanoparticles

    Science.gov (United States)

    Wilhelm, O.; Pratsinis, S. E.; de Chambrier, E.; Crouzet, M.; Exnar, I.

    The electrochemical performance of Li-ion insertion into electrodes made of various sizes of anatase titania nanoparticles embedded in larger granulated entities (1-10 μm) is investigated. The granules are formed by spray drying of a suspension containing titania nanoparticles made by hydrolyzing titanium tetraisopropoxide (TTIP). Depending on the three process steps, i.e. hydrolysis-condensation, hydrothermal processing and spray drying, different properties for the electrode made from these granules can be achieved in terms of phase composition, specific surface area (SSA) and specific charge capacity. Hydrothermally processed (HP) particles are more resistant to calcination than sol-gel precipitated (SGP) ones and have a higher SSA which leads to a better performance with respect to specific charge capacity. Electrodes made from granulated nanoparticles have superior specific charge capacity than from non-granulated ones as the former have more inter-particle contacts.

  7. Differential Dendritic Integration of Synaptic Potentials and Calcium in Cerebellar Interneurons.

    Science.gov (United States)

    Tran-Van-Minh, Alexandra; Abrahamsson, Therése; Cathala, Laurence; DiGregorio, David A

    2016-08-17

    Dendritic voltage integration determines the transformation of synaptic inputs into output firing, while synaptic calcium integration drives plasticity mechanisms thought to underlie memory storage. Dendritic calcium integration has been shown to follow the same synaptic input-output relationship as dendritic voltage, but whether similar operations apply to neurons exhibiting sublinear voltage integration is unknown. We examined the properties and cellular mechanisms of these dendritic operations in cerebellar molecular layer interneurons using dendritic voltage and calcium imaging, in combination with synaptic stimulation or glutamate uncaging. We show that, while synaptic potentials summate sublinearly, concomitant dendritic calcium signals summate either linearly or supralinearly depending on the number of synapses activated. The supralinear dendritic calcium triggers a branch-specific, short-term suppression of neurotransmitter release that alters the pattern of synaptic activation. Thus, differential voltage and calcium integration permits dynamic regulation of neuronal input-output transformations without altering intrinsic nonlinear integration mechanisms.

  8. Differential Dendritic Integration of Synaptic Potentials and Calcium in Cerebellar Interneurons.

    Science.gov (United States)

    Tran-Van-Minh, Alexandra; Abrahamsson, Therése; Cathala, Laurence; DiGregorio, David A

    2016-08-17

    Dendritic voltage integration determines the transformation of synaptic inputs into output firing, while synaptic calcium integration drives plasticity mechanisms thought to underlie memory storage. Dendritic calcium integration has been shown to follow the same synaptic input-output relationship as dendritic voltage, but whether similar operations apply to neurons exhibiting sublinear voltage integration is unknown. We examined the properties and cellular mechanisms of these dendritic operations in cerebellar molecular layer interneurons using dendritic voltage and calcium imaging, in combination with synaptic stimulation or glutamate uncaging. We show that, while synaptic potentials summate sublinearly, concomitant dendritic calcium signals summate either linearly or supralinearly depending on the number of synapses activated. The supralinear dendritic calcium triggers a branch-specific, short-term suppression of neurotransmitter release that alters the pattern of synaptic activation. Thus, differential voltage and calcium integration permits dynamic regulation of neuronal input-output transformations without altering intrinsic nonlinear integration mechanisms. PMID:27537486

  9. Neuroprotective Effect of Carnosine on Primary Culture of Rat Cerebellar Cells under Oxidative Stress.

    Science.gov (United States)

    Lopachev, A V; Lopacheva, O M; Abaimov, D A; Koroleva, O V; Vladychenskaya, E A; Erukhimovich, A A; Fedorova, T N

    2016-05-01

    Dipeptide carnosine (β-alanyl-L-histidine) is a natural antioxidant, but its protective effect under oxidative stress induced by neurotoxins is studied insufficiently. In this work, we show the neuroprotective effect of carnosine in primary cultures of rat cerebellar cells under oxidative stress induced by 1 mM 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH), which directly generates free radicals both in the medium and in the cells, and 20 nM rotenone, which increases the amount of intracellular reactive oxygen species (ROS). In both models, adding 2 mM carnosine to the incubation medium decreased cell death calculated using fluorescence microscopy and enhanced cell viability estimated by the MTT assay. The antioxidant effect of carnosine inside cultured cells was demonstrated using the fluorescence probe dichlorofluorescein. Carnosine reduced by half the increase in the number of ROS in neurons induced by 20 nM rotenone. Using iron-induced chemiluminescence, we showed that preincubation of primary neuronal cultures with 2 mM carnosine prevents the decrease in endogenous antioxidant potential of cells induced by 1 mM AAPH and 20 nM rotenone. Using liquid chromatography-mass spectrometry, we showed that a 10-min incubation of neuronal cultures with 2 mM carnosine leads to a 14.5-fold increase in carnosine content in cell lysates. Thus, carnosine is able to penetrate neurons and exerts an antioxidant effect. Western blot analysis revealed the presence of the peptide transporter PEPT2 in rat cerebellar cells, which suggests the possibility of carnosine transport into the cells. At the same time, Western blot analysis showed no carnosine-induced changes in the level of apoptosis regulating proteins of the Bcl-2 family and in the phosphorylation of MAP kinases, which suggests that carnosine could have minimal or no side effects on proliferation and apoptosis control systems in normal cells. PMID:27297901

  10. Dry reprocessing MOX granules: DMOXG

    International Nuclear Information System (INIS)

    In DMOXG (Dry reprocessing of Mixed-OXide Granule), spent fuels are to be dissolved in molten salt (NaCl-2CsCl, 650degC) and to be electrolysed to eliminate and recover noble FP metals before the main process of fuel treatment. The U and Pu, after oxidized by chlorine and oxygen gas, will be recovered as oxides to fabricate MOX fuels. Compared to Purex process which has been adopted in Japan as a first generation of reprocessing plant, DMOXG process as a next generation will be simple and compact in design with an expected lower cost of construction. This will be favorable to Japan as a seismically active country. The paper pursues (1) compact facility, (2) reduction of low level wastes, (3) the same level of safety as Purex process and compares the relevant important techniques which appear in future development with already established techniques in Purex process. (S. Ohno)

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

    Science.gov (United States)

    Hirose, Genjiro

    2016-03-01

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

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

    Science.gov (United States)

    Manto, Mario; Habas, Christophe

    2016-01-01

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

  13. Acute cerebellar ataxia with human parvovirus B19 infection

    OpenAIRE

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

    1999-01-01

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



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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-10-01

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

  15. Cerebellar glioblastoma multiforme presenting as a cerebellopontine angle mass

    Directory of Open Access Journals (Sweden)

    Anupam Jindal

    2006-01-01

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

  16. Drug-induced cerebellar ataxia: a systematic review

    NARCIS (Netherlands)

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

    2014-01-01

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

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

    NARCIS (Netherlands)

    Beudel, Martijin; Galama, Sjoukje; Leenders, Klaus L.; de Jong, Bauke M.

    2008-01-01

    With functional MRI, we recently identified fronto-cerebellar activations in predicting time to reach a target and basal ganglia activation in velocity estimation, that is, small interval assessment. We now tested these functions in patients with Parkinson's disease (PD) and degenerative cerebellar

  18. Cerebellar glioblastoma multiforme in an adult

    OpenAIRE

    Mattos João Paulo; Marenco Horacio Armando; Campos José Maria; Faria Andréa Vasconcellos; Queiroz Luciano de Souza; Borges Guilherme; Oliveira Evandro de

    2006-01-01

    Cerebellar glioblastoma multiforme (GBM) is a rare tumor. This is the third case published in Brazilian literature and, the last one has been described more than 15 years ago. The aggressive behavior of GBM prompts for fast treatment, which can be hampered by the fact that the diagnosis of GBM requires a high degree of suspicion. We describe a case of GBM in a 46 years old man. In conjunction, we present a literature review including particular issues, clinical data, advances in imaging studi...

  19. Cerebellar glioblastoma multiforme in an adult

    Directory of Open Access Journals (Sweden)

    Mattos João Paulo

    2006-01-01

    Full Text Available Cerebellar glioblastoma multiforme (GBM is a rare tumor. This is the third case published in Brazilian literature and, the last one has been described more than 15 years ago. The aggressive behavior of GBM prompts for fast treatment, which can be hampered by the fact that the diagnosis of GBM requires a high degree of suspicion. We describe a case of GBM in a 46 years old man. In conjunction, we present a literature review including particular issues, clinical data, advances in imaging studies, pathological characteristics, treatment options and the behavior of such malignant tumor.

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

    Science.gov (United States)

    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. PMID:18379102

  1. A TECHNICAL NOTE ON GRANULATION TECHNOLOGY: A WAY TO OPTIMISE GRANULES

    Directory of Open Access Journals (Sweden)

    Mahammed Athar A. Saikh

    2013-01-01

    Full Text Available To provide an updated technical note on granulation technology (GT, mostly on novel GT, that will help researcher working/engaged in designing an efficient GT for getting granules with desired features. Granules were most widely used in the production of pharmaceutical oral dosage forms. Advancement in GT had revolutionized the sphere and resulted in development of several processes. Each and every process had advantages and disadvantages, and limitations. Depth knowledge in GT was a prerequisite to process product for obtaining targeted granulation with desired product parameters. In this regards updated literatures were collected from data bases, studied and was presented for easy reference of scientists engaged in granule production, so that they can adopt appropriate and suitable GT. Presented handy note will help researchers in designing a robust GT for getting optimised granule.

  2. Dipeptide Piracetam Analogue Noopept Improves Viability of Hippocampal HT-22 Neurons in the Glutamate Toxicity Model.

    Science.gov (United States)

    Antipova, T A; Nikolaev, S V; Ostrovskaya, P U; Gudasheva, T A; Seredenin, S B

    2016-05-01

    Effect of noopept (N-phenylacetyl-prolylglycine ethyl ester) on viability of neurons exposed to neurotoxic action of glutamic acid (5 mM) was studied in vitro in immortalized mouse hippocampal HT-22 neurons. Noopept added to the medium before or after glutamic acid improved neuronal survival in a concentration range of 10-11-10-5 M. Comparison of the effective noopept concentrations determined in previous studies on cultured cortical and cerebellar neurons showed that hippocampal neurons are more sensitive to the protective effect of noopept. PMID:27265136

  3. Computed tomographic features of cerebellar hemangioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Lan; Ko, Young Tae; Kim, Ho Kyun [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    1980-06-15

    Computed tomographic and angiographic findings of 6 proven cerebellar Hemangiotoma seen in this hospital during last 2 years were analyzed. The results were as follows: 1. Except one 14 years old female, all of them wee 37 to 48 years old males. 2. The operative findings of the tumors were 3 cystic tumors with mural nodules and 3 solid tumors. Computed tomographic findings were: 3. Of three cases of cystic cerebellar hemangiotomas, 2 cases revealed characteristic CT findings such as; a. In precontrast study, a well defined round lower density containing one isodense nodule in its periphery was seen in each case. The absorption coefficiency of each lower density was around 5 EMI unit. b. In post contrast study, the nodules were enhanced densely and homogeneously white the lower densities remain unchanged. 4. Of three cases of solid cerebella hemangiotoma, 2 cases revealed isodense mass suggested by mass effect such as displaced 4th ventricle and peripheral edema in precontrast study, while the remaining case revealed ill defined slightly high density with peripheral edema. In postcontrast study, the 2 isodense masses showed well circumscribed homogenous enhancement with central slight lower density in one of them, while high density mass revealed no enhancement at all. 5. The vertebral angiography performed in 5 cases revealed high vascular tumors with feeding arteries, draining veins and increased circulation time. 6. The tumor blushing seen in vertebral angiography was correlated to the postcontrast enhancement of solid tumors and mural nodules in cystic hemangioblastoma.

  4. Cerebellar ependymal cyst in a dog.

    Science.gov (United States)

    Wyss-Fluehmann, G; Konar, M; Jaggy, A; Vandevelde, M; Oevermann, A

    2008-11-01

    An 11-week-old, male, Staffordshire Bull Terrier had a history of generalized ataxia and falling since birth. The neurologic findings suggested a localization in the cerebellum. Magnetic resonance imaging of the brain was performed. In all sequences the area of the cerebellum was almost replaced by fluid isointense to cerebrospinal fluid. A complete necropsy was performed after euthanasia. Histologically, the lesion was characterized by extensive loss of cerebellar tissue in both hemispheres and vermis. Toward the surface of the cerebellar defect, the cavity was confined by ruptured and folded membranes consisting of a layer of glial fibrillary acidic (GFAP)-positive glial cells covered multifocally by epithelial cells. Some of these cells bore apical cilia and were cytokeratin and GFAP negative, supporting their ependymal origin. The histopathologic features of our case are consistent with the diagnosis of an ependymal cyst. Its glial and ependymal nature as demonstrated by histopathologic and immunohistochemical examination differs from arachnoid cysts, which have also been reported in dogs. The origin of these cysts remains controversial, but it has been suggested that they develop during embryogenesis subsequent to sequestration of developing neuroectoderm. We speculate that the cyst could have been the result of a pre- or perinatal, possibly traumatic, insult because hemorrhage, and tissue destruction had occurred. To our knowledge, this is the first description of an ependymal cyst in the veterinary literature.

  5. Remote cerebellar hemorrhage after lumbar spinal surgery

    Energy Technology Data Exchange (ETDEWEB)

    Cevik, Belma [Baskent University Faculty of Medicine, Department of Radiology, Fevzi Cakmak Cad. 10. sok. No: 45, Bahcelievler, Ankara 06490 (Turkey)], E-mail: belmac@baskent-ank.edu.tr; Kirbas, Ismail; Cakir, Banu; Akin, Kayihan; Teksam, Mehmet [Baskent University Faculty of Medicine, Department of Radiology, Fevzi Cakmak Cad. 10. sok. No: 45, Bahcelievler, Ankara 06490 (Turkey)

    2009-04-15

    Background: Postoperative remote cerebellar hemorrhage (RCH) as a complication of lumbar spinal surgery is an increasingly recognized clinical entity. The aim of this study was to determine the incidence of RCH after lumbar spinal surgery and to describe diagnostic imaging findings of RCH. Methods: Between October 1996 and March 2007, 2444 patients who had undergone lumbar spinal surgery were included in the study. Thirty-seven of 2444 patients were scanned by CT or MRI due to neurologic symptoms within the first 7 days of postoperative period. The data of all the patients were studied with regard to the following variables: incidence of RCH after lumbar spinal surgery, gender and age, coagulation parameters, history of previous arterial hypertension, and position of lumbar spinal surgery. Results: The retrospective study led to the identification of two patients who had RCH after lumbar spinal surgery. Of 37 patients who had neurologic symptoms, 29 patients were women and 8 patients were men. CT and MRI showed subarachnoid hemorrhage in the folia of bilateral cerebellar hemispheres in both patients with RCH. The incidence of RCH was 0.08% among patients who underwent lumbar spinal surgery. Conclusion: RCH is a rare complication of lumbar spinal surgery, self-limiting phenomenon that should not be mistaken for more ominous pathologic findings such as hemorrhagic infarction. This type of bleeding is thought to occur secondary to venous infarction, but the exact pathogenetic mechanism is unknown. CT or MRI allowed immediate diagnosis of this complication and guided conservative management.

  6. The evolution of granule fracture strength as a function of impeller tip speed and granule size for a novel reverse-phase wet granulation process.

    Science.gov (United States)

    Wade, J B; Martin, G P; Long, D F

    2015-07-01

    The feasibility of a novel reverse-phase wet granulation process has been established previously and several potential advantages over the conventional process have been highlighted (Wade et al., 2014a,b,b). Due to fundamental differences in the growth mechanism and granule consolidation behaviour between the two processes the reverse-phase approach generally formed granules with a greater mass mean diameter and a lower intragranular porosity than those formed by the conventional granulation process under the same liquid saturation and impeller tip speed conditions. The lower intragranular porosity was hypothesised to result in an increase in the granule strength and subsequent decrease in tablet tensile strength. Consequently, the aim of this study was to compare the effect of impeller tip speed and granule size on the strength and compaction properties of granules prepared using both the reverse-phase and conventional granulation processes. For the conventional granulation process an increase in the impeller tip speed from 1.57 to 4.71 ms(-1) (200-600 RPM) resulted in an increase in the mean granule strength (pimpeller tip speed had no effect (p>0.05) on mean granule strength whereas, like the conventional process, an increase in granule size fraction from 425-600 to 2000-3350 μm resulted in a decrease (p0.05) for either granulation approach. These data support the rejection of the original hypothesis which stated that an increase in granule strength may result in a decrease in the tablet tensile strength. The similar tablet tensile strength observed between the conventional and reverse-phase granulation processes indicated that while mechanistic differences exist in the formation of the granules, which resulted in significant granule-scale fracture strength differences, the granule compaction properties at pharmaceutically relevant tableting pressures were unaffected. PMID:25888799

  7. Measuring stellar granulation during planet transits

    CERN Document Server

    Chiavassa, A; Selsis, F; Leconte, J; Von Paris, P; Bordé, P; Magic, Z; Collet, R; Asplund, M

    2016-01-01

    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. We used realistic three-dimensional radiative hydrodynamical 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. We computed intensity maps from RHD simulations of the Sun and a K-dwarf star at different wavelength bands from optical to far-infrared. We modeled the transit using synthetic stellar-disk images and emulated the temporal variation of the granulation intensity. We identified two types of granulation noise that act simultaneously during the planet transit: (i) the intrinsic change in the granulation pattern with timescales smaller than the usual planet transit, and (ii) the fact that the transiting planet occults isolated regions of...

  8. (13)C metabolic flux analysis in neurons utilizing a model that accounts for hexose phosphate recycling within the pentose phosphate pathway.

    Science.gov (United States)

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

    2016-02-01

    Glycolysis, mitochondrial substrate oxidation, and the pentose phosphate pathway (PPP) are critical for neuronal bioenergetics and oxidation-reduction homeostasis, but quantitating their fluxes remains challenging, especially when processes such as hexose phosphate (i.e., glucose/fructose-6-phosphate) recycling in the PPP are considered. A hexose phosphate recycling model was developed which exploited the rates of glucose consumption, lactate production, and mitochondrial respiration to infer fluxes through the major glucose consuming pathways of adherent cerebellar granule neurons by replicating [(13)C]lactate labeling from metabolism of [1,2-(13)C2]glucose. Flux calculations were predicated on a steady-state system with reactions having known stoichiometries and carbon atom transitions. Non-oxidative PPP activity and consequent hexose phosphate recycling, as well as pyruvate production by cytoplasmic malic enzyme, were optimized by the model and found to account for 28 ± 2% and 7.7 ± 0.2% of hexose phosphate and pyruvate labeling, respectively. From the resulting fluxes, 52 ± 6% of glucose was metabolized by glycolysis, compared to 19 ± 2% by the combined oxidative/non-oxidative pentose cycle that allows for hexose phosphate recycling, and 29 ± 8% by the combined oxidative PPP/de novo nucleotide synthesis reactions. By extension, 62 ± 6% of glucose was converted to pyruvate, the metabolism of which resulted in 16 ± 1% of glucose oxidized by mitochondria and 46 ± 6% exported as lactate. The results indicate a surprisingly high proportion of glucose utilized by the pentose cycle and the reactions synthesizing nucleotides, and exported as lactate. While the in vitro conditions to which the neurons were exposed (high glucose, no lactate or other exogenous substrates) limit extrapolating these results to the in vivo state, the approach provides a means of assessing a number of metabolic fluxes within the context of hexose phosphate recycling in the PPP from a

  9. Actinomyces associated with persistent vaginal granulation tissue.

    OpenAIRE

    David L. Hemsell; Momin T Siddiqui; Chang, Joe S.; Drewes, Peter G.; Nihira, Mikio A; Clifford Y. Wai

    2005-01-01

    BACKGROUND: We report a case of symptomatic actinomycosis associated with vaginal suture erosion and granulation tissue refractory to conservative management, in an outpatient setting. CASE: Three months after total vaginal hysterectomy and uterosacral ligament vaginal vault suspension, a woman complained of painless, intermittent vaginal discharge and spotting. Despite cauterization of granulation tissue, vaginal spotting persisted for another month. On re-examination, braided polyester sutu...

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

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste Passot

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

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

    Science.gov (United States)

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

    2015-07-10

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

  12. Twin screw granulation - review of current progress.

    Science.gov (United States)

    Thompson, M R

    2015-01-01

    Twin screw granulation (TSG) is a new process of interest to the pharmaceutical community that can continuously wet granulate powders, doing so at lower liquid concentrations and with better product consistency than found by a high shear batch mixer. A considerable body of research has evolved over the short time since this process was introduced but generally with little comparison of results. A certain degree of confidence has been developed through these studies related to how process variables and many attributes of machinery configuration will affect granulation but some major challenges still lay ahead related to scalability, variations in the processing regimes related to degree of channel fill and the impact of wetting and granulation of complex powder formulations. This review examines the current literature for wet granulation processes studied in twin screw extrusion machinery, summarizing the influences of operational and system parameters affecting granule properties as well as strives to provide some practical observations to newly interested users of the technique. PMID:25402966

  13. Tetanus Toxin Hc Fragment Induces the Formation of Ceramide Platforms and Protects Neuronal Cells against Oxidative Stress.

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    Roger Cubí

    Full Text Available Tetanus toxin (TeTx is the protein, synthesized by the anaerobic bacteria Clostridium tetani, which causes tetanus disease. TeTx gains entry into target cells by means of its interaction with lipid rafts, which are membrane domains enriched in sphingomyelin and cholesterol. However, the exact mechanism of host membrane binding remains to be fully established. In the present study we used the recombinant carboxyl terminal fragment from TeTx (Hc-TeTx, the domain responsible for target neuron binding, showing that Hc-TeTx induces a moderate but rapid and sustained increase in the ceramide/sphingomyelin ratio in primary cultures of cerebellar granule neurons and in NGF-differentiated PC12 cells, as well as induces the formation of ceramide platforms in the plasma membrane. The mentioned increase is due to the promotion of neutral sphingomyelinase activity and not to the de novo synthesis, since GW4869, a specific neutral sphingomyelinase inhibitor, prevents neutral sphingomyelinase activity increase and formation of ceramide platforms. Moreover, neutral sphingomyelinase inhibition with GW4869 prevents Hc-TeTx-triggered signaling (Akt phosphorylation, as well as the protective effect of Hc-TeTx on PC12 cells subjected to oxidative stress, while siRNA directed against nSM2 prevents protection by Hc-TeTx of NSC-34 cells against oxidative insult. Finally, neutral sphingomyelinase activity seems not to be related with the internalization of Hc-TeTx into PC12 cells. Thus, the presented data shed light on the mechanisms triggered by TeTx after membrane binding, which could be related with the events leading to the neuroprotective action exerted by the Hc-TeTx fragment.

  14. Morphological changes among hippocampal dentate granule cells exposed to early kindling-epileptogenesis.

    Science.gov (United States)

    Singh, Shatrunjai P; He, Xiaoping; McNamara, James O; Danzer, Steve C

    2013-12-01

    Temporal lobe epilepsy is associated with changes in the morphology of hippocampal dentate granule cells. These changes are evident in numerous models that are associated with substantial neuron loss and spontaneous recurrent seizures. By contrast, previous studies have shown that in the kindling model, it is possible to administer a limited number of stimulations sufficient to produce a lifelong enhanced sensitivity to stimulus evoked seizures without associated spontaneous seizures and minimal neuronal loss. Here we examined whether stimulation of the amygdala sufficient to evoke five convulsive seizures (class IV or greater on Racine's scale) produce morphological changes similar to those observed in models of epilepsy associated with substantial cell loss. The morphology of GFP-expressing granule cells from Thy-1 GFP mice was examined either 1 day or 1 month after the last evoked seizure. Interestingly, significant reductions in dendritic spine density were evident 1 day after the last seizure, the magnitude of which had diminished by 1 month. Further, there was an increase in the thickness of the granule cell layer 1 day after the last evoked seizure, which was absent a month later. We also observed an increase in the area of the proximal axon, which again returned to control levels a month later. No differences in the number of basal dendrites were detected at either time point. These findings demonstrate that the early stages of kindling epileptogenesis produce transient changes in the granule cell body layer thickness, molecular layer spine density, and axon proximal area, but do not produce striking rearrangements of granule cell structure.

  15. Hyperosmolar sodium chloride is toxic to cultured neurons and causes reduction of glucose metabolism and ATP levels, an increase in glutamate uptake, and a reduction in cytosolic calcium.

    Science.gov (United States)

    Morland, Cecilie; Pettersen, Mi Nguyen; Hassel, Bjørnar

    2016-05-01

    Elevation of serum sodium, hypernatremia, which may occur during dehydration or treatment with sodium chloride, may cause brain dysfunction and damage, but toxic mechanisms are poorly understood. We found that exposure to excess NaCl, 10-100mmol/L, for 20h caused cell death in cultured cerebellar granule cells (neurons). Toxicity was due to Na(+), since substituting excess Na(+) with choline reduced cell death to control levels, whereas gluconate instead of excess Cl(-) did not. Prior to cell death from hyperosmolar NaCl, glucose consumption and lactate formation were reduced, and intracellular aspartate levels were elevated, consistent with reduced glycolysis or glucose uptake. Concomitantly, the level of ATP became reduced. Pyruvate, 10mmol/L, reduced NaCl-induced cell death. The extracellular levels of glutamate, taurine, and GABA were concentration-dependently reduced by excess NaCl; high-affinity glutamate uptake increased. High extracellular [Na(+)] caused reduction in intracellular free [Ca(2+)], but a similar effect was seen with mannitol, which was not neurotoxic. We suggest that inhibition of glucose metabolism with ensuing loss of ATP is a neurotoxic mechanism of hyperosmolar sodium, whereas increased uptake of extracellular neuroactive amino acids and reduced intracellular [Ca(2+)] may, if they occur in vivo, contribute to the cerebral dysfunction and delirium described in hypernatremia. PMID:26994581

  16. Hyperosmolar sodium chloride is toxic to cultured neurons and causes reduction of glucose metabolism and ATP levels, an increase in glutamate uptake, and a reduction in cytosolic calcium.

    Science.gov (United States)

    Morland, Cecilie; Pettersen, Mi Nguyen; Hassel, Bjørnar

    2016-05-01

    Elevation of serum sodium, hypernatremia, which may occur during dehydration or treatment with sodium chloride, may cause brain dysfunction and damage, but toxic mechanisms are poorly understood. We found that exposure to excess NaCl, 10-100mmol/L, for 20h caused cell death in cultured cerebellar granule cells (neurons). Toxicity was due to Na(+), since substituting excess Na(+) with choline reduced cell death to control levels, whereas gluconate instead of excess Cl(-) did not. Prior to cell death from hyperosmolar NaCl, glucose consumption and lactate formation were reduced, and intracellular aspartate levels were elevated, consistent with reduced glycolysis or glucose uptake. Concomitantly, the level of ATP became reduced. Pyruvate, 10mmol/L, reduced NaCl-induced cell death. The extracellular levels of glutamate, taurine, and GABA were concentration-dependently reduced by excess NaCl; high-affinity glutamate uptake increased. High extracellular [Na(+)] caused reduction in intracellular free [Ca(2+)], but a similar effect was seen with mannitol, which was not neurotoxic. We suggest that inhibition of glucose metabolism with ensuing loss of ATP is a neurotoxic mechanism of hyperosmolar sodium, whereas increased uptake of extracellular neuroactive amino acids and reduced intracellular [Ca(2+)] may, if they occur in vivo, contribute to the cerebral dysfunction and delirium described in hypernatremia.

  17. [A case of cerebral gigantism with cerebellar atrophy].

    Science.gov (United States)

    Kitazawa, K; Ikeda, M; Tsukagoshi, H

    1990-05-01

    A 37-year-old housewife, who had physical characteristics of cerebral gigantism, such as the tall stature, acromegaly, macrocephalia, high arched palate and antimongoloid slant, developed cerebellar ataxia and dysarthria. Her mother, uncle and grandmother were also reported to have slowly progressive gait disturbance. Her mother was also tall. Endocrinological studies failed to show any definite abnormality. CT and MRI revealed remarkable cerebellar atrophy. Though cerebral gigantism is often associated with clumsiness and incoordination, the etiology of the ataxia is poorly understood. This case indicates that the ataxia in cerebral gigantism may be, at least partly, caused by cerebellar atrophy. PMID:2401112

  18. Variant PTA Terminating in Cerebellar Artery, Associated with Multiple Aneurysms

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    Yeong Uk Hwang

    2016-01-01

    Full Text Available Persistent trigeminal artery (PTA is one of the remnant fetal anastomoses between the carotid artery and basilar artery. PTAs are classified according to angiographic appearance and various connection. Among them, those directly terminating in the cerebellar arteries are rare subtype. In addition, aneurysms of the PTA are unusual in the literature and have not previously accompanied this subtype of PTA connecting cerebellar artery. We present the first case of an aneurysm of the PTA which is directly terminating in the cerebellar arteries and combined with multiple aneurysms.

  19. Variant PTA Terminating in Cerebellar Artery, Associated with Multiple Aneurysms.

    Science.gov (United States)

    Hwang, Yeong Uk; Kim, Jin Woo

    2016-01-01

    Persistent trigeminal artery (PTA) is one of the remnant fetal anastomoses between the carotid artery and basilar artery. PTAs are classified according to angiographic appearance and various connection. Among them, those directly terminating in the cerebellar arteries are rare subtype. In addition, aneurysms of the PTA are unusual in the literature and have not previously accompanied this subtype of PTA connecting cerebellar artery. We present the first case of an aneurysm of the PTA which is directly terminating in the cerebellar arteries and combined with multiple aneurysms. PMID:27446623

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

    Science.gov (United States)

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

    2016-06-01

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

  1. Oral Administration of PF-01247324, a Subtype-Selective Nav1.8 Blocker, Reverses Cerebellar Deficits in a Mouse Model of Multiple Sclerosis

    OpenAIRE

    Shields, Shannon D.; Butt, Richard P.; Dib-Hajj, Sulayman D; WAXMAN, STEPHEN G.

    2015-01-01

    Cerebellar symptoms significantly diminish quality of life in patients with multiple sclerosis (MS). We previously showed that sodium channel Nav1.8, although normally restricted to peripheral somatosensory neurons, is upregulated in the cerebellum in MS, and that Nav1.8 expression is linked to ataxia and MS-like symptoms in mice. Furthermore, intracerebroventricular administration of the Nav1.8 blocker A-803467 temporarily reversed electrophysiological and behavioral manifestations of diseas...

  2. Hedgehog Signaling Modulates the Release of Gliotransmitters from Cultured Cerebellar Astrocytes.

    Science.gov (United States)

    Okuda, Hiroaki; Tatsumi, Kouko; Morita-Takemura, Shoko; Nakahara, Kazuki; Nochioka, Katsunori; Shinjo, Takeaki; Terada, Yuki; Wanaka, Akio

    2016-02-01

    Sonic hedgehog (Shh), a member of the Hedgehog (Hh) family, plays essential roles in the development of the central nervous system. Recent studies suggest that the Hh signaling pathway also functions in mature astrocytes under physiological conditions. We first examined the expression of genes encoding Hh signaling molecules in the adult mouse cerebellum by in situ hybridization histochemistry. mRNA for Patched homolog 1 (Ptch1), a receptor for Hh family members, was expressed in S100β-positive astrocytes and Shh mRNA was expressed in HuC/D-positive neurons, implying that the Hh signaling pathway contributes to neuro-glial interactions. To test this hypothesis, we next examined the effects of recombinant SHH N-terminal protein (rSHH-N) on the functions of cultured cerebellar astrocytes. rSHH-N up-regulated Hh signal target genes such as Ptch1 and Gli-1, a key transcription factor of the Hh signaling pathway. Although activation of Hh signaling by rSHH-N or purmorphamine influenced neither glutamate uptake nor gliotransmitters release, inhibition of the Hh signaling pathway by cyclopamine, neutralizing antibody against SHH or intracellular Ca(2+) chelation decreased glutamate and ATP release from cultured cerebellar astrocytes. On the other hand, cyclopamine, neutralizing antibody against SHH or Ca(2+) chelator hardly affected D-serine secretion. Various kinase inhibitors attenuated glutamate and ATP release, while only U0126 reduced D-serine secretion from the astrocytes. These results suggested that the Hh signaling pathway sustains the release of glutamate and ATP and participates in neuro-glial interactions in the adult mouse brain. We also propose that signaling pathways distinct from the Hh pathway govern D-serine secretion from adult cerebellar astrocytes. PMID:26694649

  3. Hereditary Cerebellar Ataxias: A Korean Perspective

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    Ji Sun Kim

    2015-05-01

    Full Text Available Hereditary ataxia is a heterogeneous disorder characterized by progressive ataxia combined with/without peripheral neuropathy, extrapyramidal symptoms, pyramidal symptoms, seizure, and multiple systematic involvements. More than 35 autosomal dominant cerebellar ataxias have been designated as spinocerebellar ataxia, and there are 55 recessive ataxias that have not been named systematically. Conducting genetic sequencing to confirm a diagnosis is difficult due to the large amount of subtypes with phenotypic overlap. The prevalence of hereditary ataxia can vary among countries, and estimations of prevalence and subtype frequencies are necessary for planning a diagnostic strategy in a specific population. This review covers the various hereditary ataxias reported in the Korean population with a focus on the prevalence and subtype frequencies as the clinical characteristics of the various subtypes.

  4. Study of light scattering by a granulated coated sphere - a model of granulated blood cells

    NARCIS (Netherlands)

    M.A. Yurkin; D. de Kanter; A.G. Hoekstra

    2008-01-01

    We performed extensive simulations of light scattering by granulated coated sphere model using the discrete dipole approximation and varying model parameters in the ranges of sizes and refractive indices of granulated blood cells. We compared these results with predictions of Maxwell-Garnett effecti

  5. Gene expression signature of cerebellar hypoplasia in a mouse model of Down syndrome during postnatal development

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    Vitalis Tania

    2009-03-01

    Full Text Available Abstract 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

  6. Lack of connexin43-mediated Bergmann glial gap junctional coupling does not affect cerebellar long-term depression, motor coordination, or eyeblink conditioning

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    Mika Tanaka

    2008-04-01

    Full Text Available Bergmann glial cells are specialized astrocytes in the cerebellum. In the mature cerebellar molecular layer, Bergmann glial processes are closely associated with Purkinje cells, enclosing Purkinje cell dendritic synapses with a glial sheath. There is intensive gap junctional coupling between Bergmann glial processes, but their significance in cerebellar functions is not known. Connexin43 (Cx43, a major component of astrocytic gap junction channels, is abundantly expressed in Bergmann glial cells. To examine the role of Cx43-mediated gap junctions between Bergmann glial cells in cerebellar functions, we generated Cx43 conditional knockout mice with the S100b-Cre transgenic line (Cx43fl/fl:S100b-Cre, which exhibited a significant loss of Cx43 in the Bergmann glial cells and astrocytes in the cerebellum with a postnatal onset. The Cx43fl/fl:S100b-Cre mice had normal cerebellar architecture. Although gap junctional coupling between the Bergmann glial cells measured by spreading of microinjected Lucifer yellow was virtually abolished in Cx43fl/fl:S100b-Cre mice, electrophysiologic analysis revealed that cerebellar long-term depression could be induced and maintained normally in thier cerebellar slices. In addition, at the behavioral level, Cx43fl/fl:S100b-Cre mice had normal motor coordination in the rotarod task and normal conditioned eyelid response. Our findings suggest that Cx43-mediated gap junctional coupling between Bergmann glial cells is not necessary for the neuron-glia interactions required for cerebellum-dependent motor coordination and motor learning.

  7. Mathematical modelling of the citric acid cycle for the analysis of glutamine isotopomers from cerebellar astrocytes incubated with [1(-13)C]glucose.

    Science.gov (United States)

    Merle, M; Martin, M; Villégier, A; Canioni, P

    1996-08-01

    A mathematical model of the citric acid cycle devoted to the analysis of 13C-NMR data was developed for determining the relative flux of molecules through the anaplerotic versus oxidative pathways and the relative pyruvate carboxylase versus pyruvate dehydrogenase activities. Different variants of the model were considered depending on the reversibility of the conversion of fumarate into malate and oxaloacetate. The model also included the possibility of orientation-conserved transfer of the four-carbon citric acid cycle intermediates, leading to conversion of succinyl-CoA C1 into either malate C1 or C4. It was used to analyse NMR data from glutamine isotopomers produced by cerebellar astrocytes incubated with [1-13C]glucose. Partial cycling (39%) between oxaloacetate and fumarate was evident from the analysis. Application of the model to glutamate isotopomers from granule cells incubated with [1-13C]glucose [Martin, M.. Portais, J.C.. Labouesse. J., Canioni. P, & Merle, M. (1993) Eur. J. Biochem. 217, 617-625] indicated that total cycling of oxaloacetate into fumarate was, in this case, required to get the best fit. The results emphasized some important differences in carbon metabolism between cerebellar astrocytes and granule cells concerning the sources of carbon fuelling the citric acid cycle and the carbon fluxes on different pathways.

  8. Anomalous Cerebellar Anatomy in Chinese Children with Dyslexia.

    Science.gov (United States)

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

  10. Anomalous cerebellar anatomy in Chinese children with dyslexia

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    Ying-Hui eYang

    2016-03-01

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

  11. Cerebellar Hemangioblastoma and Von Hippel-Lindau Disease

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    J. Gordon Millichap

    2002-02-01

    Full Text Available Six pediatric patients with cerebellar hemangioblastoma were screened for germline or somatic mutations of the von Hippel-Landau gene, in a study at Stanford University Medical Center, Palo Alto, CA.

  12. Bilateral cerebellar activation in unilaterally challenged essential tremor

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    Marja Broersma

    2016-01-01

    Conclusions: Our results expand on previous findings of bilateral cerebellar involvement in ET. We have identified specific areas in the bilateral somatomotor regions of the cerebellum: lobules V, VI and VIII.

  13. Cerebellar giant cell glioblastoma multiforme in an adult

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    Sudhansu Sekhar Mishra

    2014-01-01

    Full Text Available Cerebellar glioblastoma multiforme (GBM is a rare tumor that accounts for only 1% of all cases of GBM and its giant cell variant is even much rarely encountered in adults. A case of cerebellar giant cell GBM managed at our institution reporting its clinical presentation, radiological and histological findings, and treatment instituted is described. In conjunction, a literature review, including particular issues, clinical data, advances in imaging studies, pathological characteristics, treatment options, and the behavior of such malignant tumor is presented. It is very important for the neurosurgeon to make the differential diagnosis between the cerebellar GBM, and other diseases such as metastasis, anaplastic astrocytomas, and cerebellar infarct because their treatment modalities, prognosis, and outcome are different.

  14. Unilateral absence of cerebellar hemisphere: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Erdogan, N.; Ozturk, O. [Department of Radiology, Erciyes University Faculty of Medicine, Kayseri (Turkey); Kocakoc, E. [Department of Radiology, Women' s Hospital, Sivas (Turkey); Bekar, D. [Department of Neurology, City Hospital, Sivas (Turkey)

    2002-01-01

    We describe a 38-year-old woman with absence of right cerebellar hemisphere incidentally discovered by MR imaging. No cerebellar abnormality was detected on neurological examination. Tissue probably representing dysgenetic cerebellar tissue with no corticomedullary differentiation was present, connected to the right superior cerebellar peduncle. Ipsilateral enlargement of the pons and cerebral peduncle were additional findings. Although the terms ''aplasia'' or ''agenesis'' have been used to describe this entity, intrauterine destruction is the presumed pathogenetic mechanism in our case, and therefore these terms have been avoided. Asymmetry of pons and mesencephalon may be related to compensatory reorganisation or to the impairment of sequential development of nuclei and neural tracts. (orig.)

  15. Cerebellar infarct patterns: The SMART-Medea study

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    Laurens J.L. De Cocker, MD

    2015-01-01

    Conclusions: Small cerebellar infarcts proved to be much more common than larger infarcts, and preferentially involved the cortex. Small cortical infarcts predominantly involved the posterior lobes, showed sparing of subcortical white matter and occurred in characteristic topographic patterns.

  16. Adult-onset cerebellar Ataxia: a clinical and genetic Survey

    NARCIS (Netherlands)

    E. Brusse (Esther)

    2011-01-01

    textabstractCerebellar ataxias represent a heterogeneous group of neurodegenerative disorders. Two main categories are distinguished: hereditary and sporadic ataxias. Sporadic ataxias may be symptomatic or idiopathic. The clinical classification of hereditary ataxias is nowadays being replaced by an

  17. Back to front: cerebellar connections and interactions with the prefrontal cortex

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    Thomas C Watson

    2014-02-01

    Full Text Available Although recent neuroanatomical evidence has demonstrated closed-loop connectivity between prefrontal cortex and the cerebellum, the physiology of cerebello-cerebral circuits and the extent to which cerebellar output modulates neuronal activity in neocortex during behavior remain relatively unexplored. We show that electrical stimulation of the contralateral cerebellar fastigial nucleus (FN in awake, behaving rats evokes distinct local field potential (LFP responses (onset latency ~13 ms in the prelimbic (PrL subdivision of the medial prefrontal cortex. Trains of FN stimulation evoke heterogeneous patterns of response in putative pyramidal cells in frontal and prefrontal regions in both urethane-anaesthetized and awake, behaving rats. However, the majority of cells showed decreased firing rates during stimulation and subsequent rebound increases; more than 90% of cells showed significant changes in response. Simultaneous recording of on-going LFP activity from FN and PrL while rats were at rest or actively exploring an open field arena revealed significant network coherence restricted to the theta frequency range (5-10 Hz. Granger causality analysis indicated that this coherence was significantly directed from cerebellum to PrL during active locomotion. Our results demonstrate the presence of a cerebello-prefrontal pathway in rat and reveal behaviorally dependent coordinated network activity between the two structures, which could facilitate transfer of sensorimotor information into ongoing neocortical processing during goal directed behaviors.

  18. Real-World-Time Simulation of Memory Consolidation in a Large-Scale Cerebellar Model.

    Science.gov (United States)

    Gosui, Masato; Yamazaki, Tadashi

    2016-01-01

    We report development of a large-scale spiking network model of the cerebellum composed of more than 1 million neurons. The model is implemented on graphics processing units (GPUs), which are dedicated hardware for parallel computing. Using 4 GPUs simultaneously, we achieve realtime simulation, in which computer simulation of cerebellar activity for 1 s completes within 1 s in the real-world time, with temporal resolution of 1 ms. This allows us to carry out a very long-term computer simulation of cerebellar activity in a practical time with millisecond temporal resolution. Using the model, we carry out computer simulation of long-term gain adaptation of optokinetic response (OKR) eye movements for 5 days aimed to study the neural mechanisms of posttraining memory consolidation. The simulation results are consistent with animal experiments and our theory of posttraining memory consolidation. These results suggest that realtime computing provides a useful means to study a very slow neural process such as memory consolidation in the brain.

  19. Real-World-Time Simulation of Memory Consolidation in a Large-Scale Cerebellar Model.

    Science.gov (United States)

    Gosui, Masato; Yamazaki, Tadashi

    2016-01-01

    We report development of a large-scale spiking network model of the cerebellum composed of more than 1 million neurons. The model is implemented on graphics processing units (GPUs), which are dedicated hardware for parallel computing. Using 4 GPUs simultaneously, we achieve realtime simulation, in which computer simulation of cerebellar activity for 1 s completes within 1 s in the real-world time, with temporal resolution of 1 ms. This allows us to carry out a very long-term computer simulation of cerebellar activity in a practical time with millisecond temporal resolution. Using the model, we carry out computer simulation of long-term gain adaptation of optokinetic response (OKR) eye movements for 5 days aimed to study the neural mechanisms of posttraining memory consolidation. The simulation results are consistent with animal experiments and our theory of posttraining memory consolidation. These results suggest that realtime computing provides a useful means to study a very slow neural process such as memory consolidation in the brain. PMID:26973472

  20. Facial stimulation induces long-term depression at cerebellar molecular layer interneuron–Purkinje cell synapses in vivo in mice

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    De-Lai eQiu

    2015-06-01

    Full Text Available Cerebellar long-term synaptic plasticity has been proposed to provide a cellular mechanism for motor learning. Numerous studies have demonstrated the induction and mechanisms of synaptic plasticity at parallel fiber–Purkinje cell (PF–PC, parallel fiber–molecular layer interneurons (PF–MLI and mossy fiber–granule cell (MF–GC synapses, but no study has investigated sensory stimulation-evoked synaptic plasticity at MLI–PC synapses in the cerebellar cortex of living animals. We studied the expression and mechanism of MLI–PC GABAergic synaptic plasticity induced by a train of facial stimulation in urethane-anesthetized mice by cell-attached recordings and pharmacological methods. We found that 1 Hz, but not a 2 Hz or 4 Hz, facial stimulation induced a long-term depression (LTD of GABAergic transmission at MLI–PC synapses, which was accompanied with a decrease in the stimulation-evoked pause of spike firing in PCs, but did not induce a significant change in the properties of the sensory-evoked spike events of MLIs. The MLI–PC GABAergic LTD could be prevented by blocking cannabinoid type 1 (CB1 receptors, and could be pharmacologically induced by a CB1 receptor agonist. Additionally, 1 Hz facial stimulation delivered in the presence of a metabotropic glutamate receptor 1 (mGluR1 antagonist, JNJ16259685, still induced the MLI–PC GABAergic LTD, whereas blocking N-methyl-D-aspartate (NMDA receptors during 1 Hz facial stimulation abolished the expression of MLI–PC GABAergic LTD. These results indicate that sensory stimulation can induce an endocannabinoid (eCB-dependent LTD of GABAergic transmission at MLI–PC synapses via activation of NMDA receptors in cerebellar cortical Crus II in vivo in mice. Our results suggest that the sensory stimulation-evoked MLI–PC GABAergic synaptic plasticity may play a critical role in motor learning in animals.

  1. Synaptic responses evoked by tactile stimuli in Purkinje cells in mouse cerebellar cortex Crus II in vivo.

    Directory of Open Access Journals (Sweden)

    Chun-Ping Chu

    Full Text Available BACKGROUND: Sensory stimuli evoke responses in cerebellar Purkinje cells (PCs via the mossy fiber-granule cell pathway. However, the properties of synaptic responses evoked by tactile stimulation in cerebellar PCs are unknown. The present study investigated the synaptic responses of PCs in response to an air-puff stimulation on the ipsilateral whisker pad in urethane-anesthetized mice. METHODS AND MAIN RESULTS: Thirty-three PCs were recorded from 48 urethane-anesthetized adult (6-8-week-old HA/ICR mice by somatic or dendritic patch-clamp recording and pharmacological methods. Tactile stimulation to the ipsilateral whisker pad was delivered by an air-puff through a 12-gauge stainless steel tube connected with a pressurized injection system. Under current-clamp conditions (I = 0, the air-puff stimulation evoked strong inhibitory postsynaptic potentials (IPSPs in the somata of PCs. Application of SR95531, a specific GABA(A receptor antagonist, blocked IPSPs and revealed stimulation-evoked simple spike firing. Under voltage-clamp conditions, tactile stimulation evoked a sequence of transient inward currents followed by strong outward currents in the somata and dendrites in PCs. Application of SR95531 blocked outward currents and revealed excitatory postsynaptic currents (EPSCs in somata and a temporal summation of parallel fiber EPSCs in PC dendrites. We also demonstrated that PCs respond to both the onset and offset of the air-puff stimulation. CONCLUSIONS: These findings indicated that tactile stimulation induced asynchronous parallel fiber excitatory inputs onto the dendrites of PCs, and failed to evoke strong EPSCs and spike firing in PCs, but induced the rapid activation of strong GABA(A receptor-mediated inhibitory postsynaptic currents in the somata and dendrites of PCs in the cerebellar cortex Crus II in urethane-anesthetized mice.

  2. Impairments in motor coordination without major changes in cerebellar plasticity in the Tc1 mouse model of Down syndrome.

    Science.gov (United States)

    Galante, Micaela; Jani, Harsha; Vanes, Lesley; Daniel, Hervé; Fisher, Elizabeth M C; Tybulewicz, Victor L J; Bliss, Timothy V P; Morice, Elise

    2009-04-15

    Down syndrome (DS) is a genetic disorder arising from the presence of a third copy of human chromosome 21 (Hsa21). Recently, O'Doherty et al. [An aneuploid mouse strain carrying human chromosome 21 with Down syndrome phenotypes. Science 309 (2005) 2033-2037] generated a trans-species aneuploid mouse line (Tc1) that carries an almost complete Hsa21. The Tc1 mouse is the most complete animal model for DS currently available. Tc1 mice show many features that relate to human DS, including alterations in memory, synaptic plasticity, cerebellar neuronal number, heart development and mandible size. Because motor deficits are one of the most frequently occurring features of DS, we have undertaken a detailed analysis of motor behaviour in cerebellum-dependent learning tasks that require high motor coordination and balance. In addition, basic electrophysiological properties of cerebellar circuitry and synaptic plasticity have been investigated. Our results reveal that, compared with controls, Tc1 mice exhibit a higher spontaneous locomotor activity, a reduced ability to habituate to their environments, a different gait and major deficits on several measures of motor coordination and balance in the rota rod and static rod tests. Moreover, cerebellar long-term depression is essentially normal in Tc1 mice, with only a slight difference in time course. Our observations provide further evidence that support the validity of the Tc1 mouse as a model for DS, which will help us to provide insights into the causal factors responsible for motor deficits observed in persons with DS.

  3. Sex differences in cerebellar synaptic transmission and sex-specific responses to autism-linked Gabrb3 mutations in mice.

    Science.gov (United States)

    Mercer, Audrey A; Palarz, Kristin J; Tabatadze, Nino; Woolley, Catherine S; Raman, Indira M

    2016-01-01

    Neurons of the cerebellar nuclei (CbN) transmit cerebellar signals to premotor areas. The cerebellum expresses several autism-linked genes, including GABRB3, which encodes GABAA receptor β3 subunits and is among the maternal alleles deleted in Angelman syndrome. We tested how this Gabrb3 m-/p+ mutation affects CbN physiology in mice, separating responses of males and females. Wild-type mice showed sex differences in synaptic excitation, inhibition, and intrinsic properties. Relative to females, CbN cells of males had smaller synaptically evoked mGluR1/5-dependent currents, slower Purkinje-mediated IPSCs, and lower spontaneous firing rates, but rotarod performances were indistinguishable. In mutant CbN cells, IPSC kinetics were unchanged, but mutant males, unlike females, showed enlarged mGluR1/5 responses and accelerated spontaneous firing. These changes appear compensatory, since mutant males but not females performed indistinguishably from wild-type siblings on the rotarod task. Thus, sex differences in cerebellar physiology produce similar behavioral output, but provide distinct baselines for responses to mutations. PMID:27077953

  4. Status epilepticus increases mature granule cells in the molecular layer of the dentate gyrus in rats

    Institute of Scientific and Technical Information of China (English)

    Zhaoliang Liang; Fei Gao; Fajun Wang; Xiaochen Wang; Xinyu Song; Kejing Liu; Ren-Zhi Zhan

    2013-01-01

    Enhanced neurogenesis in the dentate gyrus of the hippocampus following seizure activity, especially status epilepticus, is associated with ectopic residence and aberrant integration of newborn granule cells. Hilar ectopic granule cells may be detrimental to the stability of dentate circuitry by means of their electrophysiological properties and synaptic connectivity. We hypothesized that status epilepticus also increases ectopic granule cells in the molecular layer. Status epilepticus was induced in male Sprague-Dawley rats by intraperitoneal injection of pilocarpine. Immunostaining showed that many doublecortin-positive cells were present in the molecular layer and the hilus 7 days after the induction of status epilepticus. At least 10 weeks after status epilepticus, the estimated number of cells positive for both prospero homeobox protein 1 and neuron-specific nuclear protein in the hilus was significantly increased. A similar trend was also found in the molecular layer. These findings indicate that status epilepticus can increase the numbers of mature and ectopic newborn granule cells in the molecular layer.

  5. Rat basophilic leukemia cells express syntaxin-3 and VAMP-7 in granule membranes.

    Science.gov (United States)

    Hibi, T; Hirashima, N; Nakanishi, M

    2000-04-29

    In neuronal cells, it is generally agreed that SNARE proteins underlie the release of neurotransmitter. It is controversial, however, whether they also work functionally in the degranulation of RBL-2H3 cells because the expression of SNARE proteins has not been confirmed and the degranulation is not inhibited by tetanus toxin which cleaves one of SNARE proteins, VAMP-2. We investigated the expression and the localization of SNARE proteins including VAMP-7 which is insensitive to tetanus toxin. RT-PCR analysis showed the existence of SNARE proteins, including syntaxin-2, -3, -4, SNAP-23, VAMP-2, and VAMP-7. Experiments using GFP-conjugated proteins revealed that VAMP-7 was localized only in granule membranes, whereas syntaxin-3 was in both the plasma and granule membranes. Upon antigen stimulation, these proteins in granule membranes moved to the cell surface due to the fusion of granules with the plasma membrane. The results suggest the involvement of SNARE proteins in the degranulation of RBL-2H3 cells.

  6. The Clinical Differentiation of Cerebellar Infarction from Common Vertigo Syndromes

    OpenAIRE

    Nelson, James A.; Viirre, Erik

    2009-01-01

    This article summarizes the emergency department approach to diagnosing cerebellar infarction in the patient presenting with vertigo. Vertigo is defined and identification of a vertigo syndrome is discussed. The differentiation of common vertigo syndromes such as benign paroxysmal positional vertigo, Meniere’s disease, migrainous vertigo, and vestibular neuritis is summarized. Confirmation of a peripheral vertigo syndrome substantially lowers the likelihood of cerebellar infarction, as do ind...

  7. Cerebellar Neuroblastoma in 2.5 Years Old Child

    OpenAIRE

    Pedram, Mohammad; Vafaie, Majid; Fekri, Kiavash; Haghi, Sabahat; Rashidi, Iran; Pirooti, Chia

    2013-01-01

    Neuroblastoma is the third most common malignancy of childhood, after leukemia and brain tumors. Only 2% of all neuroblastoma occur in the brain. Primary cerebellar neuroblastoma is an specific subset of Primitive Neuroectodermal Tumors (PNET). Meduloblastoma is a relatively common and well-established entity, consisting of primitive and multipotential cells that may exhibit some evidence of neuroblastic or gliad differentiation. But cerebellar neuroblastoma with ultrastractural evidence of s...

  8. Cerebellar medulloblastoma in a 65 year old Indian male.

    Directory of Open Access Journals (Sweden)

    Jaiswal A

    2000-04-01

    Full Text Available A case of cerebellar medulloblastoma in a 65 year old male is reported. Cerebellar medulloblastoma is classically seen during childhood, and less than 25% of these tumours are found in adults below 40 years of age. Rarely, cases are reported above the age of 40 years. So far only three cases have been reported in patients aged above 64 years and none of these case reports are from India.

  9. Cerebellar contributions to neurological soft signs in healthy young adults.

    Science.gov (United States)

    Hirjak, Dusan; Thomann, Philipp A; Kubera, Katharina M; Stieltjes, Bram; Wolf, Robert C

    2016-02-01

    Neurological soft signs (NSS) are frequently found in psychiatric disorders of significant neurodevelopmental origin, e.g., in patients with schizophrenia and autism. Yet NSS are also present in healthy individuals suggesting a neurodevelopmental signature of motor function, probably as a continuum between health and disease. So far, little is known about the neural mechanisms underlying these motor phenomena in healthy persons, and it is even less known whether the cerebellum contributes to NSS expression. Thirty-seven healthy young adults (mean age = 23 years) were studied using high-resolution structural magnetic resonance imaging (MRI) and "resting-state" functional MRI at three Tesla. NSS levels were measured using the "Heidelberg Scale." Cerebellar gray matter volume was investigated using cerebellum-optimized voxel-based analysis methods. Cerebellar function was assessed using regional homogeneity (ReHo), a measure of local network strength. The relationship between cerebellar structure and function and NSS was analyzed using regression models. There was no significant relationship between cerebellar volume and NSS (p < 0.005, uncorrected for height, p < 0.05 corrected for spatial extent). Positive associations with cerebellar lobule VI activity were found for the "motor coordination" and "hard signs" NSS domains. A negative relationship was found between lobule VI activity and "complex motor task" domain (p < 0.005, uncorrected for height, p < 0.05 corrected for spatial extent). The data indicate that in healthy young adults, distinct NSS domains are related to cerebellar activity, specifically with activity of cerebellar subregions with known cortical somatomotor projections. In contrast, cerebellar volume is not predictive of NSS in healthy persons. PMID:25708455

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

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Sajdel-Sulkowska

    2008-01-01

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

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

    OpenAIRE

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

    2014-01-01

    Cerebellar ataxia is a progressive neuro-degenerative disease that has multiple genetic versions, each with a characteristic pattern of anatomical degeneration that yields distinctive motor and cognitive problems. Studying this pattern of degeneration can help with the diagnosis of disease subtypes, evaluation of disease stage, and treatment planning. In this work, we propose a learning framework using MR image data for discriminating a set of cerebellar ataxia types and predicting a disease ...

  12. Formation of volutin granules in Corynebacterium glutamicum.

    Science.gov (United States)

    Pallerla, Srinivas Reddy; Knebel, Sandra; Polen, Tino; Klauth, Peter; Hollender, Juliane; Wendisch, Volker F; Schoberth, Siegfried M

    2005-02-01

    Volutin granules are intracellular storages of complexed inorganic polyphosphate (poly P). Histochemical staining procedures differentiate between pathogenic corynebacteria such as Corynebacterum diphtheriae (containing volutin) and non-pathogenic species, such as C. glutamicum. Here we report that strains ATCC13032 and MH20-22B of the non-pathogenic C. glutamicum also formed subcellular entities (18-37% of the total cell volume) that had the typical characteristics of volutin granules: (i) volutin staining, (ii) green UV fluorescence when stained with 4',6-diamidino-2-phenylindole, (iii) electron-dense and rich in phosphorus when determined with transmission electron microscopy and X-ray microanalysis, and (iv) 31P NMR poly P resonances of isolated granules dissolved in EDTA. MgCl2 addition to the growth medium stimulated granule formation but did not effect expression of genes involved in poly P metabolism. Granular volutin fractions from lysed cells contained polyphosphate glucokinase as detected by SDS-PAGE/MALDI-TOF, indicating that this poly P metabolizing enzyme is present also in intact poly P granules. The results suggest that formation of volutin is a more widespread phenomenon than generally accepted. PMID:15668011

  13. Neurons of the Dentate Molecular Layer in the Rabbit Hippocampus

    OpenAIRE

    Sancho-Bielsa, Francisco J.; Navarro-López, Juan D.; Gregori Alonso-Llosa; Asunción Molowny; Xavier Ponsoda; Javier Yajeya; Carlos López-García

    2012-01-01

    The molecular layer of the dentate gyrus appears as the main entrance gate for information into the hippocampus, i.e., where the perforant path axons from the entorhinal cortex synapse onto the spines and dendrites of granule cells. A few dispersed neuronal somata appear intermingled in between and probably control the flow of information in this area. In rabbits, the number of neurons in the molecular layer increases in the first week of postnatal life and then stabilizes to appear permanent...

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

    Science.gov (United States)

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

    2016-11-01

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

  15. Transplantation and Stem Cell Therapy for Cerebellar Degenerations.

    Science.gov (United States)

    Cendelin, Jan

    2016-02-01

    Stem cell-based and regenerative therapy may become a hopeful treatment for neurodegenerative diseases including hereditary cerebellar degenerations. Neurotransplantation therapy mainly aims to substitute lost cells, but potential effects might include various mechanisms including nonspecific trophic effects and stimulation of endogenous regenerative processes and neural plasticity. Nevertheless, currently, there remain serious limitations. There is a wide spectrum of human hereditary cerebellar degenerations as well as numerous cerebellar mutant mouse strains that serve as models for the development of effective therapy. By now, transplantation has been shown to ameliorate cerebellar function, e.g. in Purkinje cell degeneration mice, Lurcher mutant mice and mouse models of spinocerebellar ataxia type 1 and type 2 and Niemann-Pick disease type C. Despite the lack of direct comparative studies, it appears that there might be differences in graft development and functioning between various types of cerebellar degeneration. Investigation of the relation of graft development to specific morphological, microvascular or biochemical features of the diseased host tissue in various cerebellar degenerations may help to identify factors determining the fate of grafted cells and potential of their functional integration. PMID:26155762

  16. Verbal Memory Impairments in Children after Cerebellar Tumor Resection

    Directory of Open Access Journals (Sweden)

    Matthew P. Kirschen

    2008-01-01

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

  17. Antimicrobial-Coated Granules for Disinfecting Water

    Science.gov (United States)

    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.

  18. MEMBRANE-COATING GRANULES OF KERATINIZING EPITHELIA.

    Science.gov (United States)

    MATOLTSY, A G; PARAKKAL, P F

    1965-02-01

    The purpose of this study has been to obtain information on the development of the envelop of horny cells that resists the action of keratinolytic agents. Toward this end the epidermis, oral mucosa, and tongue epithelium of various vertebrates, as well as the isolated envelopes of horny cells, were examined by electron microscopy. It was found that small cytoplasmic granules (1,000 to 5,000 A) that develop within differentiating epithelial cells move toward the cell periphery, and after fusion with the plasma membrane, empty their contents into the intercellular spaces. The content of the granules spreads over the cell surfaces, and subsequently a thickened and coated cell envelope is formed that resists the action of keratinolytic agent. The membrane-coating granule is regarded as a specific differentiation product of the keratinizing epithelium. It contains numerous inner membranes and is assumed to engage in synthetic activities such as, perhaps, the formation of polysaccharides.

  19. Reappraisal of Bergmann glial cells as modulators of cerebellar circuit function

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    Chris I De Zeeuw

    2015-07-01

    Full Text Available Just as there is a huge morphological and functional diversity of neuron types specialized for specific aspects of information processing in the brain, astrocytes have equally distinct morphologies and functions that aid optimal functioning of the circuits in which they are embedded. One type of astrocyte, the Bergmann glial cell of the cerebellum, is a prime example of a highly diversified astrocyte type, the architecture of which is adapted to the cerebellar circuit and facilitates an impressive range of functions that optimize information processing in the adult brain. In this review we expand on the function of the Bergmann glial cell in the cerebellum to highlight the importance of astrocytes not only in housekeeping functions, but also in contributing to plasticity and information processing in the cerebellum.

  20. Cerebellar cytokine expression in a rat model for fetal asphyctic preconditioning and perinatal asphyxia

    DEFF Research Database (Denmark)

    Vlassaks, Evi; Brudek, Tomasz; Pakkenberg, Bente;

    2014-01-01

    was decreased 96 h postfetal asphyxia. When applied as preconditioning stimulus, fetal asphyxia attenuates the cerebellar cytokine response. These results indicate that sublethal fetal asphyxia may protect the cerebellum from perinatal asphyxia-induced damage via inhibition of inflammation.......Asphyctic brain injury is a major cause of neuronal inflammation in the perinatal period. Fetal asphyctic preconditioning has been shown to modulate the cerebral inflammatory cytokine response, hereby protecting the brain against asphyctic injury at birth. This study was designated to examine...... the effects of perinatal asphyxia and fetal asphyctic preconditioning on the inflammatory cytokine response in the cerebellum. Fetal asphyxia was induced at embryonic day 17 by clamping the uterine vasculature for 30 min. At term birth, global perinatal asphyxia was induced by placing the uterine horns...