Fig. 4.

Optical slices through neighboring protoplasmic astrocytes filled with distinct fluorescent dyes. A, The major processes (arrows) of astrocytes were commonly seen to extend tangentially to the approaching processes of neighboring astrocytes. B, The processes emerging from two astrocytes with adjacent somata radiate parallel to or away from each other. C, Blood vessels (arrowhead) appeared to be capable of influencing the arrangement of astrocyte processes as they attempted to form end feet. Astrocyte on thefar right is highly elongated as it reaches for passing vessel. The center astrocyte (green) shows little overlap with its neighbors.D, One astrocyte (green) is seen to have its process “invade” the territory of its neighbor as both astrocytes form end feet on passing blood vessels. Scale bars, 15 μm.