Abstract
Glutamatergic and GABAergic gliotransmission is a compilation of studies on the ability of glial cells to release glutamate by exocytosis and GABA by bestrophin 1 channel.
The vesicular glutamate transporters (VGLUTs) are solely found in the membrane of vesicles and selectively transport glutamate into the vesicles. The presence of such proteins is a strong indication of the capability to exocytose glutamate.
In the first study I found significant amount of VGLUT1 in astrocytes of frontal cortex, stratum radiatum of the hippocampus, molecular layers of the hippocampus and the striatum. VGLUT1 was associated with synaptic-like microvesicles (SLMV). The second study revealed VGLUT3 in glial cells of cerebellum, CA3 hippocampus and frontal cortex. VGLUT3 was also associated to SLMV, although not the same vesicle pools as VGLUT1.
The last paper revealed significant, although very small levels of GABA in glial cells of CA1 hippocampus and cerebellum. In glial cells of the same regions there was an indistinguishable level of bestrophin 1 in wild type and bestrophin 1 knock out animals, both on protein and RNA level. These aspects make glial release of GABA through bestrophin 1 unlikely.