Figure 1.
The various morphologies of GFAP-labeled astrocytes. (A) A typical mouse protoplasmic astrocyte demonstrating the stellate morphology. Scale bar = 20 μm. (B) The processes of astrocytes within the optic nerve head overlap and form a dense meshwork. The boundaries between neighboring astrocytes are not visible. Scale bar = 20 μm. (C) A typical mouse fibrous astrocyte in the white matter. Nuclear stain, blue. Scale bar = 10 μm. (D) The processes of astrocytes within the mouse retina overlap. Similar to the optic nerve, it is not clear where the boundaries of an astrocyte lie. Scale bar = 20 μm. (E) Varicose projection astrocytes reside in layers 5 to 6 of the human cortex and extend long processes characterized by evenly spaced varicosities. Inset: A varicose projection astrocyte from a chimpanzee cortex. Scale bar = 50 μm. (F) Primate-specific interlaminar astrocytes occupy layer 1 of the cortex. Yellow dotted line indicates the border between layers 1 and 2. Scale bar = 100 μm. (G) High-power image of layer 1 showing interlaminar astrocytes. Inset: The cell bodies. Scale bar = 10 μm. Panels A, C, E, F, and G adapted from Oberheim and others (2009).