ASTROCYTES RELEASE GLUTAMATE AT NERVE TERMINALS
The role of glia in neurogenesis and synaptic transmission is a consolidated notion in the field of neuroscience. In recent years, the brain specialized glia’s cells called astrocytes have emerged as key modulators of synaptic transmission and neuronal excitability. In their activity those not neuronal cells can use the excitatory transmitter glutamate, but processes of the storage and release machinery have remained unclear.
Bezzi and his colleagues (Astrocytes contain a vesicular compartment that is competent for regulated exocytosis of glutamate. Nature Neuroscience 7, 613-620, 2004) show evidence that astrocytes release glutamate through a SNARE-dependent mechanism similar to the one occurring in neuronal synapses. Among the differences between neurons and astrocytes there are smaller vesicles in glial cells and difference in vesicle related proteins.