| Global cerebral ischemia produces an extensive bilateral degeneration of the CA;Global cerebral ischemia was produced in adult Mongolian gerbils by reversible bilateral common carotid artery occlusion. Ischemically-induced morphological alterations in the hippocampus and in cholinergic and serotonergic afferent inputs were characterized using neuron specific enolase immunocytochemistry, acetylcholinesterase histochemistry, and serotonin immunocytochemistry, respectively. Following transplantation into the ischemic hippocampi with cell suspensions derived from fetal Mongolian gerbil whole hippocampi, the survival of the transplanted neurons and innervation of the transplant by host-derived cholinergic and/or serotonergic afferent fibers were examined using the immunocytochemical and histochemical techniques. Alterations in spatial reference memory and spatial navigation were examined in a circular water-maze following the ischemic episode and again after bilateral intra-hippocampal transplantation.;The results of these studies indicate that transplanted fetal hippocampal neurons can survive in the ischemic host hippocampal formation and that they are innervated by both host-derived cholinergic and serotonergic afferent fibers which persist after the ischemic episode. In addition, comparisons between pre-transplantation and post-transplantation performances revealed that ischemically-induced spatial navigation deficits are ameliorated following transplantation. |
