Neural transplantation of horseradish peroxidase-labeled hippocampal cell suspensions in an experimental model of cerebral ischemia

One of the major obstacles in assessing the use of neuronal transplants to replace cells that are lost because of ischemia is the inability to identify and distinguish homotypically-transplanted cells from similar cells in the host brain. This chapter discusses the use of horseradish peroxidase (HRP) to label cell suspensions of fetal rodent hippocampus that were injected into the hippocampi of post-ischemic rats to determine whether homotypically transplanted cells could be distinguished from those of the host. When homotypic cells are to be transplanted and are labeled with HRP, a label is required, which might help in distinguishing cells of transplant origin from those of the host. One factor influencing the transplant survival appears to be the placement of the cells within the hippocampus. Whether the minor differences in histocompatibility between the donor tissue and host in combination with the cytotoxicity factors influence cellular survival is an issue that remains to be resolved. The chapter suggests that neural transplantation may be feasible for treatment for focal lesions produced during ischemia. Sufficient cell growth and development that occurred in the four vessel occlusion (VO) animals, justify further transplantation experiments in this model.