Abudara, V.

Giaume, C.

Koulakoff, A.

Rouach, Nathalie

Willecke, K.

HAL AMU

Astroglial Metabolic Networks Sustain Hippocampal Synaptic Transmission

Astrocytes provide metabolic substrates to neurons in an activity-dependent manner. However, the molecular mechanisms involved in this function, as well as its role in synaptic transmission, remain unclear. Here, we show that the gap-junction subunit proteins connexin 43 and 30 allow intercellular trafficking of glucose and its metabolites through astroglial networks. This trafficking is regulated by glutamatergic synaptic activity mediated by AMPA receptors. In the absence of extracellular glucose, the delivery of glucose or lactate to astrocytes sustains glutamatergic synaptic transmission and epileptiform activity only when they are connected by gap junctions. These results indicate that astroglial gap junctions provide an activity-dependent intercellular pathway for the delivery of energetic metabolites from blood vessels to distal neurons. Glucose, transported by the blood, is themajor source of energy used by the brainfor neuronal activity (1). It has been pro-posed that neurons obtain most of their energy from extracellular lactate, a glucose metabolite produced by astrocytes (2). Indeed, astrocytes pro-vide by their perivascular endfeet (3, 4) and pro-cesses a physical link between the vasculature an

Astroglial Metabolic Networks Sustain Hippocampal Synaptic Transmission

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