Figure 3.

Morphological diversity of astroglia within and among species. (A) Laminar astrocytes are present in human cortical layer 1, and the cells extend long processes through layers 2 to 4. Protoplasmic astrocytes can be found in layers 2 to 6. Varicose projection astrocytes are located in layers 5 and 6 from where they extend mm‐long processes with regularly spaced varicosities. Fibrous astrocytes reside in the white matter. (B1) Main processes of mouse protoplasmic astrocytes (inset) are less extended and developed than human astroglia (main image). (B2) Accordingly, fine processes and the entire morphology of astrocytes in mice correspond to much smaller functional islands (inset) compared with human astroglia (main image). Scale bars: 150 µm (A), 20 µm (B); Adapted from (Oberheim et al., 2009).