Control of glutamate clearance and synaptic efficacy by glial coverage of neurons

Analysis of excitatory synaptic transmission in the rat hypothalamic suprao ptic nucleus revealed that glutamate clearance and, as a consequence, gluta mate concentration and diffusion in the extracellular space, is associated with the degree of astrocytic coverage of its neurons. Reduction in glutama te clearance, whether induced pharmacologically or associated with a relati ve decrease of glial coverage in the vicinity of synapses, affected transmi tter release through modulation of presynaptic metabotropic glutamate recep tors, Astrocytic wrapping of neurons, therefore, contributes to the regulat ion of synaptic efficacy in the central nervous system.