FIG 3. Photomicrographs of neurons and astrocytes (original magnification x160). A–D, Neuronal morphology indicated by hematoxylin-eosin staining, and E–H, astrocytic changes indicated by double staining with GFAP plus S-100 protein.

A, Many normal neurons and one dark neuron with perineural vacuoles (arrow) are present in the contralateral nonischemic caudoputamen.

B, At the end of 30 minutes of ischemia when ADC had initially decreased, some neurons show slightly shrunken perikarya and nuclei (arrow).

C, After 90 minutes of reperfusion and recovery of ADC to normal, most neurons are moderately shrunken and surrounded by swollen cellular processes and are scalloped in appearance (arrows). Neuropil shows marked vacuolation (_*), indicative of swollen dendrites and astrocytic processes.

D, After 12 hours of reperfusion and a subsequent or second decrease in ADC, most neurons are severely shrunken (arrows), and the neuropil shows extensive vacuolation, and possibly some vasogenic edema (_*).

E, Dark purple reaction product demarcates S-100 protein in astrocytic nuclei; brown reaction product indicates GFAP in the cytoplasm and processes of astrocytes (arrow) in the contralateral nonischemic caudoputamen.

F, At the end of 30 minutes of ischemia, astrocytes are moderately swollen (arrows).

G, After 90 minutes of reperfusion, astrocytes are severely swollen (arrow) with less intranuclear S-100 reactivity and watery appearance.

H, After 12 hours of reperfusion, astrocytes have begun to disintegrate and lose nearly all S-100 immunoreactivity within their nuclei (arrow). At this time, some GFAP has moved into the extracellular space (arrowhead).