Possible Implications of Ischemic Damage to Dentate Hilar Somatostatin Neurons in the Rat
Twenty minutes of 4-vessel occlusion ischemia in the rat typically induces selective damage to the CA-1 pyramidal cells and some CA-3c and hilar neurons in the dorsal hippocampus. To further characterize the ischemia vulnerable CA-3c/hilar neurons we quantitated somatostatin (SS) and cholecystokinin (CCK) cell somata detected by immunocytochemistry in this zone before and at day 1, 2, 3 and 4 after the insult. A significant (p≺0.01) 60–80% loss of CA-3c/hilar SS neurons was evident at the 2nd postischemic day while no CCK neurons were lost at this stage or later. At the 1st postischemic day the vulnerable SS neurons displayed homogeneously dispersed increased immunostaining in contrast to controls and ischemia resistant SS neurons, where the immunostaining was arranged like curled bands within the somata.