SNr astrocytes display spontaneous calcium activity that is partly dependent on neuronal activity.

<p>(<b>A</b>) Fluo-4 loaded cells in the SNr area of a rat sagittal acute slice. Only small cells (astrocytes, less than 10 µm in diameter) were loaded. GABAergic and dopaminergic neurons (with cell bodies from 20 to 40 µm in diameter <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041793#pone.0041793-Mailly1" target="_blank">[70]</a>) were not labelled in most cases. (<b>B</b>) Distribution of active (red frames) and non active (white frames) ROIs within the slice shown in A. (<b>C</b>) Example of typical fluorescence variations recorded in four SNr astrocytes. (<b>D</b>) Raster plot of fluorescence peaks detected in active ROIs described in B. (<b>E</b>) Example of the cumulative progress of the proportion of active astrocytes during recording over 5, 10, 15, 20, 25 and 30 minutes. (<b>F</b>) Effect of 500 nM TTX (<i>n</i> = 13 slices; <i>p</i><0.001) or 2 µM thapsigargin (Thapsi, <i>n</i> = 7 slices; <i>p</i><0.001) on the spontaneous calcium activity of astrocytes in the SNr.