Glutamate Mediated Astrocytic Filtering of Neuronal Activity
Figure 2
Inference of model networks from experimental data.
A, The experimental culture of Fig. 2, with neurons segmented in red, astrocytes in green and unresponsive cells in blue. Scale bar is 75 µm. B, Model networks constructed using the experimental data of A. Fine grey lines delineate the Voronoi diagram computed from the experimental cell positions; green circles denote model astrocytes and dark green cells with a lightning symbol denote stimulated model astrocytes. Wide dark grey lines show the GJC connections between astrocytes. Scale bar is 75 µm. Model networks were inferred according to this process for each experiment. C, Close-up view of the Voronoi tesselation (light gray and blue lines) associated with an immunostaining image (in red the neuronal marker NeuN and in green the astrocytic marker GFAP). Astrocyte A will be GJC coupled to astrocytes B1 through B7 as they share boundaries of their anatomical domains (thick blue lines). D, Resulting distribution of astrocyte coupling degree. Most model astrocytes are connected to very few neighbors (n = 373). The inset shows the distribution of the size of connected astrocyte clusters (n = 146). It can be seen that most astrocytes are isolated but some experiments contain very large clusters of up to 60 astrocytes (indicated by stars).