Dorsal-ventral gradient in vulnerability of CA1 hippocampus to ischemia: a combined histological and electrophysiological study

Transverse hippocampal slices were prepared after 7 days survival from rats subjected to 8 min of global incomplete ischemia by temporary occlusion of both carotid arteries and hypotension. The slices demonstrated a dorsal-ventral gradient in the amount of ischemic neuronal necrosis in the CA1 region. Histologically ischemic cell change decreased from 90% dorsoseptally to 10% ventrotemporally. Electrophysiological analysis of the number of slices with viable synaptic transmission in CA1 also revealed a septotemporal gradient in susceptibility to ischemia.