FETAL HIPPOCAMPAL TRANSPLANTS ATTENUATE CA3 PYRAMIDAL CELL-DEATH RESULTING FROM FLUID PERCUSSION BRAIN INJURY IN THE RAT

Transplantation of fetal neural tissue has been demonstrated to preven t neuronal loss in a number of CNS injury models including spinal cord contusion, However, no studies have examined the neuroprotective role of fetal transplants in models of traumatic brain injury, The present study examined the ability of fetal neural grafts to attenuate neuron al loss resulting from lateral fluid percussion (FP) brain injury in t he rat, Lateral FP in the rat elicits a focal contusion within the par ietal/temporal cortex and induces cell death in a subset of hippocampa l CA3 pyramidal neurons, To examine potential neuroprotective effects of fetal neural grafts, either E16 fetal hippocampus, E16 fetal cortex , or sterile lactated Ringers was stereotaxically transplanted directl y into contused cortex 2 days after FP brain injury, The effects of fe tal transplants upon adjacent injured hippocampal CA3 regions were the n assessed at 4 weeks after grafting utilizing quantitative image anal ysis, Both fetal cortex and hippocampal grafts survived within contuse d cortex, Fetal hippocampal grafts significantly attenuated CA3 cell d eath resulting from lateral fluid percussion, while fetal cortical tra nsplants induced a small, but nonsignificant, amelioration of CA3 pyra midal loss, Thus, neuroprotection by fetal grafts appeared to be tissu e specific with hippocampal, but not cortical, fetal transplants signi ficantly reducing posttraumatic CA3 loss, In summary, fetal neural tra nsplantation can ameliorate hippocampal cell death following experimen tal brain injury.