The Glia Connection of the Glutamate/Glutamine Shuttle

Problem statement: Glia cells outnumber neurons but their role in synaptic transmission is still matter of debate. The recycling of Glutamate, the main excitatory neurotransmitter, carried out by the glutamate/glutamine shuttle, requires the involvement of glia, suggesting their involvement in neurotransmission. Approach: This review focuses on novel functions of glia proteins involved in this cycle. Results: An activity-dependent interaction of glial glutamate transporters, the Na^_+/K+ ATPase, the glutamine and glucose transporters might support glutamatergic neurotransmission. Conclusion: Glia cells that surround glutamatergic contacts, respond to synaptic activity and modify accordingly, the amount and function of the proteins involved in their interaction with neurons thus assuring a synaptic transmission.