Embryonic neural transplants across a major histocompatibility barrier: survival and specificity of innervation.

The ability of embryonic tissue to survive cross-transplantation between histologically incompatible rat strains was examined by transplanting septal neurons from Sprague Dawley fetuses to adult Wistar rats (Ag-B6 to Ag-B2 histocompatibility haplotype). Transplants were found to survive without rejection over a period of 3 months. Furthermore, the laminar pattern of cholinergic innervation was similar to that of homogenic septal transplants and of intrinsic septal projections. These results suggest that embryonic neural tissue transplanted across major histocompatibility barriers are capable of survival for extended periods of time, and are in support of the concept of the privileged nature of embryonic tissue as a source of material for cross-transplantation.