Effects of unilateral cerebral ischemia on the hippocampal theta depth profile in the ether-anesthetized mongolian gerbil

In gerbils ( Meriones unguiculatus) unilateral cerebral ischemia of 5 to 15 min resulted in selective destruction of the ipsilateral hippocampal CA1 stratum pyramidale. It also produced an obvious amplitude reduction in both superficial and deep θ rhythms recorded from damaged hippocampal formation. The presence of normal θ in the left normoxic hemisphere showed that the septohippocampal projections, integrity of which is essential for θ appearance, were spared by ischemia. These data have implications in relation to the two generators hypothesis of θ.