J.P.B. was supported by MRES, and S.S. was supported by Conicit-UCV (Venezuela). This work was supported by the DRET, ARC, and AFM. We thank Drs. B. Pessac, B. Rudkin, and N. Tillakaratne for their kind gifts of C8s and PC12 cells and GAD cDNA, C. Ghaemmaghami for HPLC determinations, and C. Michoudet for critical comments and technical help.

  • 1
    Alliot F. & Pessac B. (1984) Astrocytic cell clones derived from established cultures of 8 day postnatal mouse cerebella.Brain Res. 306,283291.
  • 2
    Alves P.M., McKenna M.C., Sonnewald U. (1995) Lactate metabolism in mouse brain astrocytes studied by 13C NMR spectroscopy. Neuroreport 6,22012204.
  • 3
    Bakken I.J., White L.R., Aasly J., Unsgard G., Aasly J., Sonnewald U. (1998) (U-13C) glutamate metabolism in astrocytes during hypoglycemia and hypoxia. J. Neurosci. Res. 51,636645.
  • 4
    Balázs R., Machiyama Y., Hammond B.J., Julian T., Richter D. (1970) The operation of the gamma-aminobutyrate bypath of the tricarboxylic acid cycle in brain tissue in vitro.Biochem. J. 116,445467.
  • 5
    Bartlett W.P. & Banker G.A. (1984) An electron microscopic study of the development of axon and dendrites by hippocampal neurons in culture. I. Cells which develop without intercellular contacts.J. Neurosci. 4,19441953.
  • 6
    Berridge M.V. & Tan A.S. (1993) Characterization of the cellular reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) : subcellular localization, substrate dependence, and involvement of mitochondrial electron transport in MTT reduction.Arch. Biochem. Biophys. 303,474482.
  • 7
    Blakemore W.F. & Franklin R.J.M. (1991) Transplantation of glial cells into the CNS.Trends Neurosci. 14,323327.
  • 8
    Bradford M.M. (1976) A rapid and sensitive method for the quantification of microgram quantities of protein utilizing the principle of protein-dye binding.Anal. Biochem. 72,248254.
  • 9
    Bröer S., Rahman B., Pellegri G., Pellerin L., Martin J.L., Verleysdonk S., Hamprecht B., Magistretti P.J. (1997) Comparison of lactate transport in astroglial cells and monocarboxylate transporter 1 (MCT1) expressing Xenopus laevis oocytes.J. Biol. Chem. 272,3009630102.
  • 10
    DeLuca M. & McElroy W.D. (1984) Two kinetically distinguishable ATP sites in firefly luciferase.Biochem. Biophys. Res. Commun. 123,764770.
  • 11
    Demestre M., Boutelle M., Fillenz M. (1997) Stimulated release of lactate in freely moving rats is dependent on the uptake of glutamate.J. Physiol. (Lond.) 499,825832.
  • 12
    De Montigny P., Stobaugh J.F., Givens R.S., Carlson R.G., Srinivasackar K., Sternson L.A., Higuchi T. (1987) Naphthalene-1,3-dicarboxaldehyde/cyanide ion : a rationally designated fluorogenic reagent for primary amines.Anal. Chem. 79,10961101.
  • 13
    Denner L.A. & Wu J. -Y. (1985) Two forms of rat brain glutamic acid decarboxylase differ in their dependence on free pyridoxal phosphate.J. Neurochem. 44,957965.
  • 14
    Desagher S., Glowinski J., Premont J. (1997) Pyruvate protects neurons against hydrogen peroxide-induced toxicity.J. Neurosci. 17,90609067.
  • 15
    Erecińska M. & Silver I.A. (1990) Metabolism and role of glutamate in mammalian brain.Prog. Neurobiol. 35,245296.
  • 16
    Erecińska M., Nelson D., Daikhin Y., Yudkoff M. (1996) Regulation of GABA level in rat brain synaptosomes : fluxes through enzymes of the GABA shunt and effects of glutamate, calcium, and ketone bodies.J. Neurochem. 67,23252334.
  • 17
    Erlander M.G., Tillakaratne N.J.K., Feldblum S., Patel N., Tobin A.J. (1991) Two distinct glutamate decarboxylases.Neuron 7,91100.
  • 18
    Geng M., Saito H., Nishiyama N. (1997) Protective effects of pyridoxal phosphate against glucose deprivation-induced damage in cultured hippocampal neurons.J. Neurochem. 68,25002506.
  • 19
    Gorovits R., Avidan N., Avisar N., Shaked I., Vardimon L. (1997) Glutamine synthetase protects against neuronal degeneration in injured retinal tissue.Proc. Natl. Acad. Sci. USA 94,70247029.
  • 20
    Greene L.A. & Tischler A.S. (1976) Establishment of a noradrenergic clonal line of rat adrenal pheochromocytoma cells which respond to nerve growth factor.Proc. Natl. Acad. Sci. USA 73,24242428.
  • 21
    Harris K. & Miller R.J. (1989) Excitatory amino acid-evoked release of (3H) GABA from hippocampal neurons in primary culture. Brain Res. 482,2333.
  • 22
    Hassel B., Bachelard H., Jones P., Fonnum F., Sonnewald U. (1997) Trafficking of amino acids between neurons and glia in vivo. Effects of inhibition of glial metabolism by fluoroacetate.J. Cereb. Blood Flow Metab. 17,12301238.
  • 23
    Hassel B., Johannessen C.U., Sonnewald U., Fonnum F. (1998) Quantification of the GABA shunt and the importance of the GABA shunt versus the 2-oxoglutamate dehydrogenase pathway in GABAergic neurons.J. Neurochem. 71,15111518.
  • 24
    Ho D.Y., Saydam T.C., Fink S.L., Lawrence M.S., Sapolsky R.M. (1995) Defective herpes simplex virus vectors expressing the rat brain glucose transporter protect cultured neurons from necrotic insults.J. Neurochem. 65,842850.
  • 25
    Izumi Y., Benz A.M., Zorumski C.F., Olney J.W. (1994) Effects of lactate and pyruvate on glucose deprivation in rat hippocampal slices.Neuroreport 5,617620.
  • 26
    Izumi Y., Benz A.M., Katsuki H., Zorumski C.F. (1997) Endogenous monocarboxylates sustain hippocampal synaptic function and morphological integrity during energy deprivation.J. Neurosci. 17,94489457.
  • 27
    La Gamma E.F., Weisinger G., Lenn N.J., Strecker R.E. (1993) Genetically modified primary astrocytes as cellular vehicles for gene therapy in the brain.Cell Transplant. 2,207214.
  • 28
    Larsson O.M., Gram L., Schousboe I., Schousboe A. (1986) Differential effects of gamma-vinyl GABA and valproate on GABA-transaminase from cultured neurons and astrocytes.Neuropharmacology 25,617625.
  • 29
    Lawrence M.S., Ho D.Y., Dash R., Sapolsky R.M. (1995) Herpes simplex virus vectors overexpressing the glucose transporter gene protect against seizure-induced neuron loss.Proc. Natl. Acad. Sci. USA 92,72477251.
  • 30
    Löscher W. (1980) Effect of inhibitors of GABA transaminase on the synthesis, binding, uptake, and metabolism of GABA.J. Neurochem. 34,16031608.
  • 31
    Lowry O.H., Rosebrough N.J., Farr A.L., Randall R.J. (1951) Protein measurement with the Folin phenol reagent.J. Biol. Chem. 193,265275.
  • 32
    Mattson M.P., Zhang Y., Bose S. (1993) Growth factors prevent mitochondrial dysfunction, loss of calcium, homeostasis, and cell injury, but not ATP depletion in hippocampal neurons deprived of glucose.Exp. Neurol. 121,113.
  • 33
    McKenna M.C., Sonnewald U., Huang X., Stevenson J., Zielke H.R. (1996) Exogenous glutamate concentration regulates the metabolic fate of glutamate in astrocytes.J. Neurochem. 66,386393.
  • 34
    McKenna M.C., Sonnewald U., Johnsen S.F. (1998) γ-Aminobutyric acid (GABA) modulates glutamate metabolism in astrocytes. (Abstr.) J. Neurochem. 70 (Suppl.),S19A.
  • 35
    Meier T.J., Ho D.Y., Sapolsky R.M. (1997) Increased expression of calbindin D28k via herpes simplex virus amplicon vector decreases calcium ion mobilization and enhances neuronal survival after hypoglycemic challenge.J. Neurochem. 69,10391047.
  • 36
    Mosmann T. (1983) Rapid colorimetric assay for cellular growth and survival : application to proliferation and cytotoxicity assays.J. Immunol. Methods 65,5563.
  • 37
    Mucke L., Oldstone M.B.A., Morris J.C., Nerenberg M.I. (1991) Rapid activation of astrocyte-specific expression of GFAP-lacZ transgene by focal injury.New Biol. 3,465474.
  • 38
    Paulsen R.E. & Fonnum F. (1988) Regulation of transmitter γ-aminobutyric acid (GABA) synthesis and metabolism illustrated by the effect of γ-vinyl GABA and hypoglycemia. J. Neurochem. 50,11511157.
  • 39
    Pellerin L. & Magistretti P.J. (1994) Glutamate uptake into astrocytes stimulates aerobic glycolysis : a mechanism coupling neuronal activity to glucose utilization.Proc. Natl. Acad. Sci. USA 91,1062510629.
  • 40
    Pellerin L., Stolz M.T., Sorg O., Martin J.L., Deschepper C.F., Magistretti P.J. (1997) Regulation of energy metabolism by neurotransmitters in astrocytes in primary cultures and in an immortalized cell line.Glia 21,7483.
  • 41
    Pereira C., Santos M.S., Oliveira C. (1998) Metabolic inhibition increases glutamate susceptibility on a PC12 cell line.J. Neurosci. Res. 51,360370.
  • 42
    Porter T.G., Spink D.C., Martin S.B., Martin D.L. (1985) Transaminations catalysed by brain glutamate decarboxylase.Biochem. J. 231,705712.
  • 43
    Ridet J.L., Malhotra S.K., Privat A., Gage F.H. (1997) Reactive astrocytes : cellular and molecular cues to biological function.Trends Neurosci. 20,570577.
  • 44
    Rothstein J.D., Martin L., Levey A.I., Dykes-Hoberg M., Jin L., Wu D., Nash N., Kuncl R.W. (1994) Localization of neuronal and glial glutamate transporters.Neuron 13,713725.
  • 45
    Sacchettoni S.A., Benchaibi M., Sindou M., Belin M.F., Jacquemont B. (1998) Glutamate-modulated production of GABA in immortalized astrocytes transduced by a glutamic acid decarboxylase-expressing retrovirus,Glia 22,8693.
  • 46
    Saji M. & Reis D.J. (1987) Delayed transneuronal death of substantia nigra neurons prevented by γ-aminobutyric acid agonist. Science 235,6669.
  • 47
    Silver I.A. & Erecińska M. (1997) Energetic demands of the Na+/K+ ATPase in mammalian astrocytes.Glia 21,3545.
  • 48
    Sonnewald U., Westergaard N., Schousboe A. (1997) Glutamate transport and metabolism in astrocytes.Glia 21,5663.
  • 49
    Stanimirovic D., Ball R., Durkin J.P. (1997) Stimulation of glutamate uptake and Na,K-ATPase activity in rat astrocytes exposed to ischemia-like insults.Glia 19,123134.
  • 50
    Swanson R.A., Yu A.C.H., Chan P.H., Sharp F.R. (1990) Glutamate increases glycogen content and reduces glucose utilization in primary astrocyte culture.J. Neurochem. 54,490496.
  • 51
    Tsacopoulos M. & Magistretti P.J. (1996) Metabolic coupling between glia and neurons.J. Neurosci. 16,877885.
  • 52
    Walz W. & Mukerji S. (1988) Lactate release from astrocytes and neurons : a comparison.Glia 1,366370.
  • 53
    Waniewski R.A. & Martin D.L. (1986) Exogenous glutamate is metabolized to glutamine and exported by rat primary astrocyte cultures.J. Neurochem. 47,304313.
  • 54
    Weiss S. (1988) Excitatory amino acid-evoked release of γ-[3H]aminobutyric acid from striatal neurons in primary culture. J. Neurochem. 51,435441.
  • 55
    Westergaard N., Larsson O.M., Jensen B., Schousboe A. (1992) Synthesis and release of GABA in cerebral co-cultured with astrocytes from cerebral cortex or cerebellum.Neurochem. Int. 20,567575.
  • 56
    Westergaard N., Sonnewald U., Schousboe A. (1995) Metabolic trafficking between neurons and astrocytes : the glutamate/glutamine cycle revisited.Dev. Neurosci. 17,203211.
  • 57
    Westergaard N., Drejer J., Schousboe A., Sonnewald U. (1996) Evaluation of the importance of transamination versus deamination in astrocytic metabolism of U-13C glutamate. Glia 17,160168.
  • 58
    Wiesinger H., Hamprecht B., Dringen R. (1997) Metabolic pathways for glucose in astrocytes.Glia 21,2234.
  • 59
    Wood T. (1968) The inhibition of pyruvate kinase by ATP.Biochem. Biophys. Res. Commun. 31,779785.
  • 60
    Yu A.C.H., Lee Y.L., Eng L.F. (1992) Glutamate as an energy substrate for neuronal-astrocytic interactions.Prog. Brain Res. 94,251259.
  • 61
    Yudkoff M., Nissim I., Hummeler K., Medow M., Pleasure D. (1986) Utilization of (15N) glutamate by cultured astrocytes. Biochem. J. 234,185192.