Ectocellular in vitro and in vivo metabolism of cADP-ribose in cerebellum

1996 ◽  
Vol 320 (2) ◽  
pp. 665-671 ◽  
Author(s):  
Antonio DE FLORA ◽  
Lucrezia GUIDA ◽  
Luisa FRANCO ◽  
Elena ZOCCHI ◽  
Mario PESTARINO ◽  
...  
Keyword(s):  
Intracellular Calcium ◽  
Calcium Release ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Adult Rat ◽  
Transmembrane Glycoprotein ◽  
Adp Ribosyl Cyclase ◽  
Calcium Induced Calcium Release

CD38, a type II transmembrane glycoprotein predominantly expressed in blood cells, is a bifunctional ectoenzyme directly involved in the metabolism of cADP-ribose (cADPR). This is a potent Ca2+ mobilizer in several types of cells. The relationship between the ectocellular site of cADPR production and its intracellular calcium-related functions is poorly understood. Cultured rat cerebellar granule cells showed both enzymic activities of CD38, ADP-ribosyl cyclase and cADPR hydrolase, at a ratio of 16 to 1 respectively, and were immunostained by the anti-(human CD38) monoclonal antibody IB4. In these cells externally added cADPR and β-NAD+ (the precursor of cADPR), but not α-NAD+ or ADP-ribose, enhanced the peak of the depolarization-induced rise in intracellular Ca2+ concentration. This effect was inhibited by 1 µM ryanodine, suggesting a potentiation of calcium-induced calcium release by cADPR. CD38 ectoenzyme activities, ADP-ribosyl cyclase and cADPR hydrolase, were also demonstrated in vivo by microdialysis of adult rat cerebellum, where IB4 bound to granule neurons selectively. Trace amounts (11.5±3.8 nM) of NAD+ were detected by microdialysis sampling and sensitive assays in the basal interstitial fluid of the cerebellum. These results provide a link between ectocellular cADPR turnover and intracellular calcium mobilization in cerebellum.

Selective Modulation of Tonic and Phasic Inhibitions in Dentate Gyrus Granule Cells

2002 ◽  
Vol 87 (5) ◽  
pp. 2624-2628 ◽  
Author(s):  
Zoltan Nusser ◽  
Istvan Mody
Keyword(s):  
Dentate Gyrus ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Hippocampal Slices ◽  
Tonic Inhibition ◽  
Adult Rats ◽  
Adult Rat ◽  
Phasic Inhibition ◽  
The Mean

In some nerve cells, activation of GABAA receptors by GABA results in phasic and tonic conductances. Transient activation of synaptic receptors generates phasic inhibition, whereas tonic inhibition originates from GABA acting on extrasynaptic receptors, like in cerebellar granule cells, where it is thought to result from the activation of extrasynaptic GABAA receptors with a specific subunit composition (α6βxδ). Here we show that in adult rat hippocampal slices, extracellular GABA levels are sufficiently high to generate a powerful tonic inhibition in δ subunit–expressing dentate gyrus granule cells. In these cells, the mean tonic current is approximately four times larger than that produced by spontaneous synaptic currents occurring at a frequency of ∼10 Hz. Antagonizing the GABA transporter GAT-1 with NO-711 (2.5 μM) selectively enhanced tonic inhibition by 330% without affecting the phasic component. In contrast, by prolonging the decay of inhibitory postsynaptic currents (IPSCs), the benzodiazepine agonist zolpidem (0.5 μM) augmented phasic inhibition by 66%, while leaving the mean tonic conductance unchanged. These results demonstrate that a tonic GABAA receptor–mediated conductance can be recorded from dentate gyrus granule cells of adult rats in in vitro slice preparations. Furthermore, we have identified distinct pharmacological tools to selectively modify tonic and phasic inhibitions, allowing future studies to investigate their specific roles in neuronal function.

Effects of Buthus martensii Karsch scorpion venom on the release of noradrenaline from in vitro and in vivo rat preparations

1994 ◽  
Vol 72 (8) ◽  
pp. 855-861 ◽  
Author(s):  
Sylvain Foucart ◽  
Rui Wang ◽  
Pierre Moreau ◽  
Rémi Sauvé ◽  
Jacques de Champlain ◽  
...  
Keyword(s):  
Intracellular Calcium ◽  
Noradrenaline Release ◽  
Sympathetic Neurons ◽  
Scorpion Venom ◽  
Dependent Manner ◽  
Release Of Noradrenaline ◽  
Adult Rat ◽  
Isolated Atria

The aim of this study was to test the neuronal effects of the Chinese Buthus martensii Karsch (BMK) scorpion venom in vivo and in vitro in order to understand the mechanism involved in the cardiovascular pressor effect of this venom. In conscious unrestrained rats, administration of 100 μg/kg i.v. BMK venom induced an increase in blood pressure, which was associated with a significant increase in plasma noradrenaline. In isolated atria, BMK also induced an increase in the stimulation-induced release of [3H]noradrenaline in a dose-dependent manner. The modulatory effect of agents acting at sympathetic prejunctional adrenoceptors on [3H]noradrenaline release was not altered by BMK venom administration. Finally, it was observed that 100 μg/mL BMK venom increased the intracellular calcium concentration in acutely dissociated sympathetic neurons from adult rat superior cervical ganglion. This action appeared to be mainly due to an influx of extracellular calcium. BMK venom induced a small rise in intracellular calcium in the absence of external calcium, indicating that it may also mobilize calcium from intracellular stores. The results observed in this study suggest that BMK venom may induce pressor responses by releasing noradrenaline from the sympathetic nerve terminals and that activation of neuronal calcium channels may be involved in that process.Key words: scorpion venom, noradrenaline release, presynaptic modulation, intracellular calcium.

scholarly journals Bone Morphogenetic Protein-6 Promotes Cerebellar Granule Neurons Survival by Activation of the MEK/ERK/CREB Pathway

2009 ◽  
Vol 20 (24) ◽  
pp. 5051-5063 ◽  
Author(s):  
Bruna Barneda-Zahonero ◽  
Alfredo Miñano-Molina ◽  
Nahuai Badiola ◽  
Rut Fadó ◽  
Xavier Xifró ◽  
...  
Keyword(s):  
Bone Morphogenetic Proteins ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Neuroprotective Effect ◽  
High Potassium ◽  
Cerebellar Granule ◽  
Low Potassium ◽  
Creb Pathway

Bone morphogenetic proteins (BMPs) have been implicated in the generation and postnatal differentiation of cerebellar granule cells (CGCs). Here, we examined the eventual role of BMPs on the survival of these neurons. Lack of depolarization causes CGC death by apoptosis in vivo, a phenomenon that is mimicked in vitro by deprivation of high potassium in cultured CGCs. We have found that BMP-6, but not BMP-7, is able to block low potassium–mediated apoptosis in CGCs. The neuroprotective effect of BMP-6 is not accompanied by an increase of Smad translocation to the nucleus, suggesting that the canonical pathway is not involved. By contrast, activation of the MEK/ERK/CREB pathway by BMP-6 is necessary for its neuroprotective effect, which involves inhibition of caspase activity and an increase in Bcl-2 protein levels. Other pathways involved in the regulation of CGC survival, such as the c-Jun terminal kinase and the phosphatidylinositol 3-kinase (PI3K)-Akt/PKB, were not affected by BMP-6. Moreover, failure of BMP-7 to activate the MEK/ERK/CREB pathway could explain its inability to protect CGCs from low potassium–mediated apoptosis. Thus, this study demonstrates that BMP-6 acting through the noncanonical MEK/ERK/CREB pathway plays a crucial role on CGC survival.

The absence of pleiotrophin modulates gene expression in the hippocampus in vivo and in cerebellar granule cells in vitro

2016 ◽  
Vol 75 ◽  
pp. 113-121 ◽  
Author(s):  
Celia González-Castillo ◽  
Daniel Ortuño-Sahagún ◽  
Carolina Guzmán-Brambila ◽  
Ana Laura Márquez-Aguirre ◽  
Rita Raisman-Vozari ◽  
...  
Keyword(s):  
Gene Expression ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Cerebellar Granule

scholarly journals CEREBELLAR GRANULE CELLS IN VITRO

1970 ◽  
Vol 45 (2) ◽  
pp. 212-220 ◽  
Author(s):  
Fredrick J. Seil ◽  
Robert M. Herndon
Keyword(s):  
Granule Cell ◽  
Granular Layer ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Light And Electron Microscopy ◽  
Newborn Mouse ◽  
Newborn Mice ◽  
Cerebellar Cultures

The behavior of granule cells in mature cerebellar cultures derived from newborn mice was studied by light and electron microscopy. Many granule cells remained in the explants as an external granular layer. These cells were differentiated, as evidenced by formation of bundles of parallel fibers and by development of synapses between granule cell axons and Purkinje cell branchlet spines, and between Golgi cell axons and granule cell dendrites. Although the over-all architecture of the cerebellar explants after 18–33 days in vitro was similar to that of the newborn mouse, the evident differentiation of the granule cells suggested that interneuronal relationships resemble those of the mature cerebellum in vivo.

scholarly journals Loss of the Serine/Threonine Kinase Fused Results in Postnatal Growth Defects and Lethality Due to Progressive Hydrocephalus

2005 ◽  
Vol 25 (16) ◽  
pp. 7054-7068 ◽  
Author(s):  
Mark Merchant ◽  
Marie Evangelista ◽  
Shiuh-Ming Luoh ◽  
Gretchen D. Frantz ◽  
Sreedevi Chalasani ◽  
...  
Keyword(s):  
Target Genes ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Signal Transmission ◽  
Neuronal Cell ◽  
Ependymal Cells ◽  
Communicating Hydrocephalus ◽  
Hh Signaling

ABSTRACT The Drosophila Fused (Fu) kinase is an integral component of the Hedgehog (Hh) pathway that helps promote Hh-dependent gene transcription. Vertebrate homologues of Fu function in the Hh pathway in vitro, suggesting that Fu is evolutionarily conserved. We have generated fused (stk36) knockout mice to address the in vivo function of the mouse Fu (mFu) homologue. fused knockouts develop normally, being born in Mendelian ratios, but fail to thrive within 2 weeks, displaying profound growth retardation with communicating hydrocephalus and early mortality. The fused gene is expressed highly in ependymal cells and the choroid plexus, tissues involved in the production and circulation of cerebral spinal fluid (CSF), suggesting that loss of mFu disrupts CSF homeostasis. Similarly, fused is highly expressed in the nasal epithelium, where fused knockouts display bilateral suppurative rhinitis. No obvious defects were observed in the development of organs where Hh signaling is required (limbs, face, bones, etc.). Specification of neuronal cell fates by Hh in the neural tube was normal in fused knockouts, and induction of Hh target genes in numerous tissues is not affected by the loss of mFu. Furthermore, stimulation of fused knockout cerebellar granule cells to proliferate with Sonic Hh revealed no defect in Hh signal transmission. These results show that the mFu homologue is not required for Hh signaling during embryonic development but is required for proper postnatal development, possibly by regulating the CSF homeostasis or ciliary function.

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