A stereological investigation on the effects of forebrain ischemia on hippocampal neuron number in chick

Abstract

Seven days after 10 minutes bilateral occlusion of internal carotid arteries, the total neuron number and the volume of the hippocampus were estimated using the optical fractionator method for cell counting and Cavalieri's principle for volume estimation. After comparing with sham-operated animals, no significant difference in total neuron number was observed in hippocampi of ischemic chicks; a statistically significant increase in numerical density of hippocampal neurons in hippocampi of ischemic group (p<0.05) could well be explained as a decrease, although statistically insignificant, of the hippocampal volume. These results indicate that, the ischemia model and/or its duration is not sufficient to induce a detectable neuronal loss but it induces a reduction in the volume of hippocampus. It also indicates that 10 minutes ischemia is too short a test period to induce a neuronal cell loss in hippocampus of young domestic chicks.