Figure 3.

Local signaling mediated by ionotropic receptors and transporters in astroglial perisynaptic processes. Synaptic release of neurotransmitters (glutamate and/or ATP) activates ionotropic receptors and glutamate transporter, which generate Na⁺ and Ca²⁺ influx. Increase in [Na⁺]_i can assume a signaling role through modulating neurotransmitter transporters, switching the reverse mode of NCX and stimulating Na⁺/K⁺ pump. This in turn can influence synaptic transmission and plasticity by affecting the time kinetics of glutamate removal from the cleft and through stimulating local metabolic support via the lactate shuttle.