C-JUN, KROX-24, AND C-FOS EXPRESSION IN HIPPOCAMPAL GRAFTS PLACED IN EXCITOTOXIC HIPPOCAMPAL-LESIONS OF THE RAT

Hippocampal transplants were examined for the expression of three specific immediate early gene encoded proteins in order to establish if grafted immature tissue maintains the basic molecular program necessary for gene transcription after grafting to excitotoxic (ibotenic acid-induced) lesions in adult host rat brains. The transplants were derived from newborn donor rats and were analyzed immunocytochemically for the presence of c-JUN, KROX-24, and c-FOS transcription factors 5 months after grafting. The expression and distribution patterns of these genes in the host hippocampus were identical to those in hippocampal neurons of normal untreated animals. c-JUN-, KROX-24-, and c-FOS-labeled neurons were also present in the transplants, where KROX-24 and c-FOS exhibited a distribution similar to host hippocampus. In contrast, c-JUN was more extensively expressed in the transplants, suggesting a molecular response to the grafting conditions and the actual graft-host brain interactions. (C) 1995 Academic Press, Inc.