Differential expression patterns of mRNAs for members of the fibroblast growth factor receptor family, FGFR‐1–FGFR‐4, in rat brain

Abstract

We have examined the region‐specific expression of mRNAs for four members of rat FGF receptor family, FGFR‐1, FGFR‐2, FGFR‐3, and FGFR‐4, in rat brain by in situ hybridization. The FGFR‐1, FGFR‐2, and FGFR‐3 mRNAs were expressed widely but differentially in the brain. However, the FGFR‐4 mRNA was not expressed in the brain. The FGFR‐1 mRNA was strongly expressed in several regions including the hippocampus, cerebellum, and pedunculoptine tegmental nucleus. The FGFR‐2 mRNA expression was high in the choroid plexus, and moderate in the fiber‐rich regions (the corpus callosum, external capsule, and internal capsule) and the olfactory bulb. The FGFR‐3 mRNA was expressed diffusely in the brain. We have also examined the cellular localization of these mRNAs in the brain. Although the FGFR‐1 mRNA was expressed preferentially in neurons, the FGFR‐2 and FGFR‐3 mRNAs were expressed preferentially in glial cells. The present findings that the FGFR‐1, FGFR‐2, and FGFR‐3 mRNAs were expressed widely but with region‐and cell‐specificity in the brain indicate that these receptors have different roles in the brain.