Neuron-glia interactions in glutamatergic neurotransmission: roles of oxidative and glycolytic adenosine triphosphate as energy source

A Schousboe, H M Sickmann, Lasse Kristoffer Bak, I Schousboe, F S Jajo, S A A Faek, H S Waagepetersen

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

    43 Citationer (Scopus)

    Abstract

    Glutamatergic neurotransmission accounts for a considerable part of energy consumption related to signaling in the brain. Chemical energy is provided by adenosine triphosphate (ATP) formed in glycolysis and tricarboxylic acid (TCA) cycle combined with oxidative phosphorylation. It is not clear whether ATP generated in these pathways is equivalent in relation to fueling of the energy-requiring processes, i.e., vesicle filling, transport, and enzymatic processing in the glutamatergic tripartite synapse (the astrocyte and pre- and postsynapse). The role of astrocytic glycogenolysis in maintaining theses processes also has not been fully elucidated. Cultured astrocytes and neurons were utilized to monitor these processes related to glutamatergic neurotransmission. Inhibitors of glycolysis and TCA cycle in combination with pathway-selective substrates were used to study glutamate uptake and release monitored with D-aspartate. Western blotting of glyceraldehyde-3-P dehydrogenase (GAPDH) and phosphoglycerate kinase (PGK) was performed to determine whether these enzymes are associated with the cell membrane. We show that ATP formed in glycolysis is superior to that generated by oxidative phosphorylation in providing energy for glutamate uptake both in astrocytes and in neurons. The neuronal vesicular glutamate release was less dependent on glycolytic ATP. Dependence of glutamate uptake on glycolytic ATP may be at least partially explained by a close association in the membrane of GAPDH and PGK and the glutamate transporters. It may be suggested that these enzymes form a complex with the transporters and the Na(+) /K(+) -ATPase, the latter providing the sodium gradient required for the transport process. © 2011 Wiley-Liss, Inc.
    OriginalsprogEngelsk
    TidsskriftJournal of Neuroscience Research
    Vol/bind89
    Udgave nummer12
    Sider (fra-til)1926-34
    Antal sider9
    ISSN0360-4012
    DOI
    StatusUdgivet - 1 dec. 2011

    Emneord

    • Det tidligere Farmaceutiske Fakultet

    Citationsformater