High resolution electron and light microscopy analysis of branchlets in astrocytes. (A) Orthogonal slices through a confocal volume of a dye-filled astrocyte. Box-counting fractal analysis was performed to determine the local DF across the astrocyte territory. The vast majority of the territory has a DF of ∼1.7, extending from the soma to the periphery, as shown by the color scale bar. (B) Electron microscopic volume of an entire Golgi-impregnated astrocyte. Three perisomatic (yellow) and three peripheral (cyan; one of them is behind a yellow one in the view shown) subvolumes (∼680 µm3 each) have been extracted to determine surface area and volume of astrocyte branchlets. (C) Close-up views of astrocyte processes in perisomatic and peripheral subvolumes demonstrating dense network of fine branchlets in both regions. The entire astrocyte is rendered in 3-D in Video 4.
