Physiological contribution of the astrocytic environment of neurons to intersynaptic crosstalk
| Autor: | Stéphane H. R. Oliet, Eva Syková, Dominique A. Poulain, Lydia Vargova, Richard Piet |
|---|---|
| Přispěvatelé: | Neurobiologie morphofonctionnelle, Université Bordeaux Segalen - Bordeaux 2-Institut François Magendie-IFR8-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Neuroscience, Institute of Experimental Medicine of the Academy of Sciences of the Czech Republic, ACI jeune chercheur, Inserm, FRM, Oliet, Stéphane |
| Rok vydání: | 2004 |
| Předmět: |
MESH: Neurons
MESH: Research Support Non-U.S. Gov't Synaptic Transmission Supraoptic nucleus Membrane Potentials MESH: Synapses Diffusion 0302 clinical medicine MESH: Animals gamma-Aminobutyric Acid Neurons 0303 health sciences MESH: Electrophysiology Multidisciplinary Glutamate receptor MESH: Diffusion MESH: Glutamic Acid Biological Sciences Electrophysiology Crosstalk (biology) Receptors Glutamate Biochemistry GABAergic [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] Supraoptic Nucleus medicine.drug MESH: Lactation MESH: Rats Synaptic cleft Glutamic Acid Neurotransmission Biology MESH: Receptors Glutamate gamma-Aminobutyric acid 03 medical and health sciences Glutamatergic MESH: Synaptic Transmission medicine Animals Lactation MESH: Membrane Potentials [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] Rats Wistar 030304 developmental biology MESH: Rats Wistar Rats MESH: Astrocytes Astrocytes Synapses MESH: Supraoptic Nucleus MESH: gamma-Aminobutyric Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America Proceedings of the National Academy of Sciences of the United States of America, National Academy of Sciences, 2004, 101, pp.2151-5. ⟨10.1073/pnas.0308408100⟩ Proceedings of the National Academy of Sciences of the United States of America, 2004, 101, pp.2151-5. ⟨10.1073/pnas.0308408100⟩ |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | Interactions between separate synaptic inputs converging on the same target appear to contribute to the fine-tuning of information processing in the central nervous system. Intersynaptic crosstalk is made possible by transmitter spillover from the synaptic cleft and its diffusion over a distance to neighboring synapses. This is the case for glutamate, which inhibits γ-aminobutyric acid (GABA)ergic transmission in several brain regions through the activation of presynaptic receptors. Such heterosynaptic modulation depends on factors that influence diffusion in the extracellular space (ECS). Because glial cells represent a physical barrier to diffusion and, in addition, are essential for glutamate uptake, we investigated the physiological contribution of the astrocytic environment of neurons to glutamate-mediated intersynaptic communication in the brain. Here we show that the reduced astrocytic coverage of magnocellular neurons occurring in the supraoptic nucleus of lactating rats facilitates diffusion in the ECS, as revealed by tortuosity and volume fraction measurements. Under these conditions, glutamate spillover, monitored through metabotropic glutamate receptor-mediated depression of GABAergic transmission, is greatly enhanced. Conversely, impeding diffusion with dextran largely prevents crosstalk between glutamatergic and GABAergic afferent inputs. Astrocytes, therefore, by hindering diffusion in the ECS, regulate intersynaptic communication between neighboring synapses and, probably, overall volume transmission in the brain. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|