Resistance of hippocampal CA-1 interneurons to 20 min of transient cerebral ischemia in the rat

The aim of this morphological study was to determine the vulnerability of hippocampal interneurons to ischemia in the adult rat. Two types of interneurons situated in the CA-1 stratum orients were investigated, the larger basket cells close to stratum pyramidale and the smaller basket cells close to the alveus. Male Wistar rats were subjected to 20 min of transient cerebral ischemia by means of 4-vessel occlusion and perfusion fixed 1, 2, 4, or 21 days later. In both Golgi-impregnated and in routinely stained sections the pyramidal cells and interneurons in the hippocampal CA-1 region were examined and counted. The study clearly demonstrated the selective vulnerability of the CA-1 pyramidal cells, as no ischemic cell damage to or loss of interneurons was found.