Microdomains for neuron-glia interaction: parallel fiber signaling to Bergmann glial cells

Astrocytes are considered a reticulate network of cells, through which calc ium signals can spread easily. In Bergmann glia, astrocytic cells of the ce rebellum, we identified subcellular compartments termed 'glial microdomains '. These elements have a complex surface consisting of thin membrane sheets , contain few mitochondria and wrap around synapses. To test for neuronal i nteraction with these structures, we electrically stimulated parallel fiber s. This stimulation increased intracellular calcium concentration ([Ca2+](i )) in small compartments within Bergmann glial cell processes similar in si ze to glial microdomains. Thus, a Bergmann glial cell may consist of hundre ds of independent compartments capable of autonomous interactions with the particular group of synapses that they ensheath.