Figure 2: A photomicrograph showing the cerebral cortex in different groups of rat after 7 days. (a) The control group showing normal appearance of the nerve cells. (b) Group II showing mild vascular congestions (red arrow) and persistent vacuolations (bent arrow). (c) Group III showing mild vascular congestion (red arrow) and little perivascular edema (black arrow). (d) Group IV showing nearly normal morphological appearance of nerve cells with residual fine vacuolations (bent arrow) (haematoxyline and eosin ×400).