Rouach

Neuroglial Interactions in Cerebral Physiopathology

Principal Investigator: Nathalie ROUACH, DR2 Inserm

Erc Consolidator grant 2016 (5 years)

Recent data suggest that astrocytes play an important role in behavioral states and cognitive functions. Indeed, astrocytes integrate neuronal inputs through their membrane channels, receptors and transporters, and can transmit information by clearing or releasing a number of neuroactive substances. This has been proposed to modulate neuronal excitability, synaptic activity and plasticity, and even control slow oscillations in vivo.

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Rouach-Fig1-partB

Simultaneous astroglial calcium imaging and field potential recording in hippocampal slices showing synchronous calcium oscillations in astrocytes during neuronal bursts. Scale bars, upper panel: DF/Fo 10 %, 20s; lower panel: 0.5 mV, 20s.

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However, although the exciting concept of gliotransmission has been reported, its modalities and specific impact on various levels of neuronal activity are still unclear. Indeed, understanding the molecular basis of neuroglial interactions has been limited and is unlikely to be answered by conventional biological techniques, due to the lack of a selective pharmacology for gliotransmission. In fact, a major technical limit to the study of neuroglial interactions is to act selectively on astrocytes, as they possess many receptors, transporters and transmitters identical to the neuronal ones; in addition, since the physiopathological consequences of the bidirectional communication between neurons and astrocytes are not fully understood, it is unclear whether changes in astroglial properties regulate neuronal activity, or rather represent an accompanying phenomenon. Therefore the nature and molecular mechanisms of astroglial contribution to neuronal activity remain unclear.

In this context, the main goal of our group is to determine whether and how astrocytes play an active and direct role in information processing. We want to unravel the molecular modalities and functional outcomes of neuroglial interactions in physiological and pathological conditions. More precisely, we want to understand how neurons and glia communicate in various regimes of activity and determine the outcome of disrupting their communication on neuronal functions, including their excitability, synaptic transmission, plasticity and synchronization. To overcome the present conceptual and experimental difficulties in the field of neuroglial interactions, we have developed a challenging novel interdisciplinary approach combining electrophysiology, imaging, molecular biology, biochemistry, mathematical modeling and new pharmacological strategies and molecular tools targeted to astrocytes, which permit to analyze and act selectively on populations of astrocytes.  Indeed, a particularly original aspect of our research in this field consists in using tools targeting specifically astrocytes: either pharmacological tools, delivered intracellularly in single astrocytes through a patch pipette and then diffusing in the gap-junction mediated network, molecular tools, such as knockout mice for astrocytic proteins, novel engineered lentiviral vectors targeting specifically astrocytes or mathematical simulation tools.

Rouach - Fig2

A) Simultaneous recording of hippocampal evoked neuronal activity and delivery of pharmacological tools and dye (sulforhodamin-B, red) in a single astrocyte through a patch pipette, diffusing in the extensive gap junction-mediated astroglial networks. B) Delivery to astroglial networks in inhibited in connexin knockout mice.

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Using this multidisciplinary and innovative strategy, our goal is to decipher the specific role of key astroglial properties, such as calcium signaling, membrane ionic currents, as well as connexin and pannexin-mediated transmission in basal synaptic activity, synaptic plasticity, synchronous physiological and pathological network activities in situ and in vivo.

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A) Recording of evoked neuronal activity at the CA1 Schaffer collateral synapse (NeuN staining (red) of hippocampal neuronal layers and S100 staining (green) of astrocytes). B) Infrared image of a pyramidal cell recorded by patch-clamp. C) CA1 pyramidal cell recorded by patch-clamp and filled with biocytin.

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Selected Publications

- Curry, N., Ghézali, G., Kaminski Schierle, G.S., Rouach, N. & Kaminski, C.F. (2017), Correlative STED and Atomic Force Microscopy on Live Astrocytes Reveals Plasticity of Cytoskeletal Structure and Membrane Physical Properties during Polarized Migration. Front Cell Neurosci 11, 104. 

- Dallérac, G., Moulard, J., Benoist, J.-F., Rouach, S., Auvin, S., Guilbot, A., Lenoir, L. & Rouach, N. (2017), Non-ketogenic combination of nutritional strategies provides robust protection against seizures. Sci Rep 7, 5496.

- Meunier, C., Wang, N., Yi, C., Dallerac, G., Ezan, P., Koulakoff, A., Leybaert & L. & Giaume, C. (2017), Contribution of astroglial Cx43 hemichannels to the modulation of glutamatergic currents by D-serine in the mouse prefrontal cortex. J. Neurosci. 

- Vasile, F., Dossi, E. & Rouach, N. (2017), Human astrocytes: structure and functions in the healthy brain. Brain Struct Funct 222, 2017–2029. 

- Dossi, E., Vasile, F., Rouach, N., (2017), Human astrocytes in the diseased brain. Brain Res. Bull.

- Lee, C.-Y., Dallérac, G., Ezan, P., Anderova, M. & Rouach, N. (2016), Glucose Tightly Controls Morphological and Functional Properties of Astrocytes. Front Aging Neurosci 8, 82. 

- Boulay, A.-C., Cisternino, S. & Cohen-Salmon, M. (2016), Immunoregulation at the gliovascular unit in the healthy brain: A focus on Connexin 43. Brain Behav. Immun. 56, 1–9.

- Dallérac, G. & Rouach, N. (2016), Astrocytes as new targets to improve cognitive functions. Prog. Neurobiol. 144, 48–67.

- Boillot, M., Lee, C.-Y., Allene, C., Leguern, E., Baulac, S. & Rouach, N. (2016), LGI1 acts presynaptically to regulate excitatory synaptic transmission during early postnatal development. Sci Rep 6, 21769.

- Chever, O., Dossi, E., Pannasch, U., Derangeon, M. & Rouach, N. (2016), Astroglial networks promote neuronal coordination. Sci Signal 9, ra6.

- Ghézali G., Dallérac G. & Rouach N. (2016), Perisynaptic astroglial processes: dynamic processors of neuronal information. Brain Struct Funct 221, 2427–2442.

- Boulay, A.-C., Mazeraud, A., Cisternino, S., Saubaméa, B., Mailly, P., Jourdren, L., Blugeon, C., Mignon, V., Smirnova, M., Cavallo, A., Ezan, P., Avé, P., Dingli, F., Loew, D., Vieira, P., Chrétien, F. & Cohen-Salmon, M. (2015a), Immune quiescence of the brain is set by astroglial connexin 43. J. Neurosci. 35, 4427–4439.

- Boulay, A.-C., Saubaméa, B., Cisternino, S., Mignon, V., Mazeraud, A., Jourdren, L., Blugeon, C. & Cohen-Salmon, M. (2015b), The Sarcoglycan complex is expressed in the cerebrovascular system and is specifically regulated by astroglial Cx30 channels. Front Cell Neurosci 9, 9.

- Boulay, A.-C., Saubaméa, B., Declèves, X. & Cohen-Salmon, M. (2015c), Purification of Mouse Brain Vessels. J Vis Exp e53208.

- Olsen M.L., Khakh B.S., Skatchkov S.N., Zhou M., Lee C.J. & Rouach N. (2015), New Insights on Astrocyte Ion Channels: Critical for Homeostasis and Neuron-Glia Signaling. J. Neurosci. 35, 13827–13835.

- Cheung G., Sibille J., Zapata J. & Rouach N. (2015), Activity-Dependent Plasticity of Astroglial Potassium and Glutamate Clearance. Neural Plast. 109106.

- Sibille, J., Zapata, J., Teillon, J., and Rouach, N. (2015a). Astroglial calcium signaling displays short-term plasticity and adjusts synaptic efficacy. Front Cell Neurosci 9, 189.

- Dao Duc, K., Lee, C.Y., Parutto, P., Cohen, D., Segal, M., Rouach, N., and Holcman, D. (2015). Bursting reverberation as a multiscale neuronal network process driven by synaptic depression-facilitation. PLoS ONE 10, e0124694.

- Sibille J., Dao Duc K., Holcman D. & Rouach N. (2015), The Neuroglial Potassium Cycle during Neurotransmission: Role of Kir4.1 Channels. PLoS Comput. Biol. 11, e1004137.

- Seidel J.L., Faideau M., Aiba I., Pannasch U., Escartin C., Rouach N., Bonvento G. & Shuttleworth C.W. (2015), Ciliary neurotrophic factor (CNTF) activation of astrocytes decreases spreading depolarization susceptibility and increases potassium clearance. Glia 63, 91–103.

- Abudara V., Roux L., Dallérac G., Matias I., Dulong J., Mothet J.P., Rouach N. & Giaume C. (2015), Activated microglia impairs neuroglial interaction by opening Cx43 hemichannels in hippocampal astrocytes. Glia 63, 795-811. 

- Cheung, G., Chever, O., and Rouach, N. (2014), Connexons and pannexons: newcomers in neurophysiology. Front Cell Neurosci 8, 348.

- Chever, O., Pannasch, U., Ezan, P., and Rouach, N. (2014a), Astroglial connexin 43 sustains glutamatergic synaptic efficacy. Philos. Trans. R. Soc. Lond., B, Biol. Sci. 369, 20130596.

- Chever O., Lee C.-Y. & Rouach N. (2014), Astroglial connexin43 hemichannels tune Basal excitatory synaptic transmission. J. Neurosci. 34, 11228–11232.

- Dossi E., Blauwblomme T., Nabbout R., Huberfeld G. & Rouach N. (2014), Multi-electrode array recordings of human epileptic postoperative cortical tissue. Journal of Visualized Experiments, Oct 26;(92).

- Sibille J., Pannasch U. & Rouach N. (2014), Astroglial potassium clearance contributes to short-term plasticity of synaptically-evoked currents at the tripartite synapse. The Journal of Physiology, 592: 87-102.

- Pannasch U., Freche D., Dallérac G., Ghézali G., Escartin C., Ezan P., Cohen-Salmon M., Benchenane K., Abudara V., Dufour A., Lübke J.H.R., Déglon N., Knott G., Holcman D. & N. Rouach (2014), Connexin 30 sets synaptic strength by controlling astroglial synapse invasion, nature neuroscience, Vol. 17, No.4, 549–558.

- Escartin C. & Rouach N. (2013), Astroglial networking contributes to neurometabolic coupling. Front Neuroenergetics 5, 4.

- Boulay, A.-C., Burbassi, S., Lorenzo, H.-K., Loew, D., Ezan, P., Giaume, C. & Cohen-Salmon, M. (2013a), Bmcc1s interacts with the phosphate-activated glutaminase in the brain. Biochimie 95, 799–807.

- Boulay, A.-C., del Castillo, F.J., Giraudet, F., Hamard, G., Giaume, C., Petit, C., Avan, P. & Cohen-Salmon, M. (2013b), Hearing is normal without connexin30. J. Neurosci. 33, 430–434. 

- Pannasch U. & Rouach N. (2013), Emerging role for astroglial networks in information processing: from synapse to behavior. Trends in Neurosciences. Volume 36, Issue 7, 405-417.

- Dallérac G., Chever O. & Rouach N. (2013), How do astrocytes shape synaptic transmission ? Insights from electrophysiology. Frontiers in Cellular Neuroscience, 7:159. 

- Pannasch U., Sibille J. & Rouach N. (2012), Dual electrophysiological recordings of synaptically-evoked astroglial and neuronal responses in acute hippocampal slices. The Journal of Visualized Experiments (JoVE) e4418.

- Freche D., Lee C.Y., Rouach N. & Holcman D. (2012), Synaptic transmission in neurological disorders dissected by a quantitative approach. Communicative and Integrative Biology, 5, 448-452.

- Arama, J., Boulay, A.-C., Bosc, C., Delphin, C., Loew, D., Rostaing, P., Amigou, E., Ezan, P., Wingertsmann, L., Guillaud, L., Andrieux, A., Giaume, C. & Cohen-Salmon, M. (2012), Bmcc1s, a novel brain-isoform of Bmcc1, affects cell morphology by regulating MAP6/STOP functions. PLoS ONE 7, e35488.

- Pannasch U., Derangeon M., Chever O. & Rouach N. (2012), Astroglial gap junctions shape neuronal network activity. Communicative and Integrative Biology, 5:248-54.

- Ezan, P., André, P., Cisternino, S., Saubaméa, B., Boulay, A.-C., Doutremer, S., Thomas, M.-A., Quenech’du, N., Giaume, C. & Cohen-Salmon, M. (2012), Deletion of astroglial connexins weakens the blood-brain barrier. J. Cereb. Blood Flow Metab. 32, 1457–1467.

- Pannasch U., Vargova L., Reingruber J., Ezan P., Holcman D., Giaume C., Sykova E. & Rouach N. (2011), Astroglial networks scale synaptic activity and plasticity. Proceedings of the National Academy of Science (USA). 108:8467-72.

- Freche D., Pannasch U., Rouach N. & Holcman D. (2011), Synapse geometry and receptor dynamics modulate synaptic strength. PLoS One. 6(10):e25122.

- Mehmood T., Schneider A., Sibille J., Marques Pereira P., Pannetier S., Ammar M., Dembele D., Thibault-Carpentier C., Rouach N. & Hanauer A. (2011), Transcriptome profile reveals AMPA receptor dysfunction in the hippocampus of the Rsk2-knockout mice, an animal model of Coffin-Lowry Syndrome. Human Genetics, 129:255-69.

- Giaume C., Koulakoff A., Roux L., Holcman D. & Rouach N. (2010), Astroglial networks: a step further in neuroglial and gliovascular interactions. Nature Reviews Neuroscience, 11:87-99.

- Rouach N. (2009), Astroglial connexins fuel synapses. Médecine Science, 25:102-4.

- Froger, N., Orellana, J.A., Cohen-Salmon, M., Ezan, P., Amigou, E., Sáez, J.C. & Giaume, C. (2009), Cannabinoids prevent the opposite regulation of astroglial connexin43 hemichannels and gap junction channels induced by pro-inflammatory treatments. J. Neurochem. 111, 1383–1397.

- Rouach N., Koulakoff A., Ezan P., Willecke K. & Giaume C. (2008), Astroglial metabolic networks sustain hippocampal synaptic transmission. Science, 322:1551-5.

- Tomita S., Byrd R.K., Rouach N., Bellone C., Venegas A., O'Brien J., Kim K.S., Olsen O., Nicoll R.A. & Bredt D.S. (2007), AMPA receptors and stargazin-like transmembrane AMPA receptor-regulatory proteins mediate hippocampal kainate neurotoxicity. Proceedings of the National Academy of Science (USA), 104:18784-8.

- Rouach N., Pébay A., Même W., Cordier J., Ezan P., Etienne E., Giaume C. & Tencé M. (2006), S1P inhibits gap junctions in astrocytes: involvement of G and Rho GTPase/ROCK. European Journal of Neuroscience, 23:1453-64.

- Houades V., Rouach N., Ezan P., Kirchhoff F., Koulakoff A. & Giaume C. (2006), Shapes of astrocyte networks in the juvenile brain. Neuron Glia Biology, 2:3-14

- Rouach N., Byrd K., Petralia R.S., Munoz-Elias G., Adesnik H., Tomita S., Karimzadegan S., Kealey C., Bredt D.S. & Nicoll R.A. (2005), TARP gamma-8 controls hippocampal AMPA receptors number, distribution and synaptic plasticity. Nature Neuroscience, 8(11):1525-33.

- Kato A., Rouach N., Nicoll R.A. & Bredt D.S. (2005), Activity-dependent NMDA receptor degradation mediated by retrotranslocation and ubiquitination. Proceedings of the National Academy of Science (USA). 102: 5600-5.

- Rouach N., Segal M., Koulakoff A., Giaume C. & Avignone E. (2003), Carbenoxolone blockade of neuronal network activity in culture is not mediated by gap junctions. The Journal of Physiology, (London). 553:729-745.

- Rouach N. & Nicoll R. (2003), Endocannabinoids contribute to short-term, but not long-term mGluR induced depression in the hippocampus. European Journal of Neuroscience, 18:1017-1020.

- Rouach N., Tencé M., Glowinski J.& Giaume C. (2002), Costimulation of NMDA and muscarinic neuronal receptors modulates gap junctional communication in striatal astrocytes. Proceedings of the National Academy of Science (USA), 99:1023-1028.

- Rouach N., Glowinski J. & Giaume C. (2000), Activity-dependent neuronal control of gap junctional communication in astrocytes. The Journal of Cell Biology, 149 (7):1513-1526.

People

Group leader:
Rouach Nathalie, DR2 INSERM

Senior researchers:
Cohen-Salmon Martine, CR1 CNRS
Armelle Rancillac, CR1 INSERM
Calvo Charles-Felix, CR1 CNRS
Dallérac Glenn, CR1 CNRS

Postdoctoral fellows:
Boulay Anne-Cécile, ATER Univ.
Dossi Elena, CDD CDF
Bataveljic Danijela, CDD CDF
Cresto Noemie, CDD CDF (ANR)

PhD Students:
Pillet Laure-Elise, CDD Univ. 50%
Capano Anna, CDD Univ.
Mazare Noemie, CDD Univ.
Vasile Flora, CDD CDF (Observatoire des memoires B2V)
Cartailler-szylak Jérôme, CDD Univ.
Visser Josien, CDD CDF (Marie Curie ITN)

Technical staff:
Ribot Jérôme, IR CDF
Ezan Pascal, AI CDF
Moulard Julien, CDD IE CDF