Figure 2. Astrocyte-Neuron Communication Regulates Synaptic Activity.

Astrocytes maintain synaptic function through the uptake of ions and neuroactive molecules via channels, transporters, and receptors. This can elicit increases in Ca²⁺ activity through direct or indirect pathways. In response to Ca2⁺ activity astrocytes release neuroactive compounds, called ‘gliotransmitters’ such as glutamate, GABA, D-serine and ATP/adenosine to pre- and post- synaptic neurons. EAAT, excitatory amino acid (glutamate) transporter; GAT, GABA transporter; NCX, Na⁺-Ca²⁺ exchanger; mGluR, metabotropic glutamate receptor; IP₃, inositol trisphosphate; TRP ch, transient receptor potential channel; Best1, bestrophin1 channel permeable to glutamate/GABA/D-serine; AQP4, aquaporin-4.