Thymosin beta4 is a major actin-sequestering molecule. Here, we report a prominent upregulation of thymosin beta4 in the hippocampus following entorhinal deafferentation. Northern blotting displayed a transient increase of thymosin beta4 mRNA in the deafferented hippocampus by 1.8, 2.3, 1.3 and 1.1-fold of controls, respectively, at 1, 3, 7 and 15 days post-lesion. In-situ hybridization confirmed that the induction of thymosin beta4 mRNA specifically occurred in the entorhinally denervated zones of the hippocampus. The double labeling of in-situ hybridization for thymosin beta4 mRNA with isolectin B4 cytochemistry showed that isolectin B4-positive microglial cells are responsible for deafferentation-induced thymosin beta4 mRNA expression. The results suggest that thymosin beta4 may participate in the process of microglial activation, which is the earliest event in lesion-induced plasticity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.