Aims: The glutamate transporters EAAT3 and EAAT4 are expressed in neurons and glial cells. They contribute to the cellular uptake of glutamate and thus to the clearance of the excitatory transmitter from the extracellular space. During ischemia, extracellular accumulation of glutamate may trigger excitotoxicity. Energy depletion leads to activation of the AMP-activated protein kinase (AMPK), a serine/threonine kinase enhancing energy production and limiting energy expenditure. Effects of AMPK include stimulation of glucose uptake by both, facilitative and Na2+-coupled transport. Nothing is known about AMPK-sensitive regulation of glutamate transporters. The present study thus explored the possibility that AMPK regulates EAAT3 and/or EAAT4. Methods: EAAT3 or EAAT4 were expressed in Xenopus oocytes with and without wild type AMPK, constitutively active gR70QAMPK a1b1g1(R70Q)) or kinase dead aK45RAMPK mutant (a1(K45R) b1g1) and electrogenic glutamate transport was determined by dual electrode voltage clamp experiments. EAAT3 and EAAT4 membrane abundance were determined by confocal microscopy. Results: In EAAT3- and in EAAT4- expressing oocytes but not in oocytes injected with water or expressing gR70QAMPK alone, the addition of glutamate to the extracellular bath generated a current (Ig), which was half maximal (KM) at ~ 74 mM (EAAT3) or 4 mM (EAAT4) glutamate concentration. Coexpression of gR70QAMPK or of wild type AMPK did not affect KM but significantly decreased the maximal current (by ~ 30–50%). Coexpression of aK45RAMPK did not appreciably affect Ig in EAAT3- or EAAT4-expressing oocytes. According to confocal microscopy coexpression of gR70QAMPK or of wild type AMPK reduced the membrane abundance of EAAT3 and EAAT4 in EAAT3- or EAAT4-expressing oocytes. Conclusion: The observations show that AMPK down regulates Na+-coupled glutamate transport.