The neural plasticity showing the ability of nervous system to change its structure and function is a well-documented fact. However regional variation within a CNS structure to undergo plastic changes has been shown by limited studies. Along medial-lateral sequences of parasagittal sections, the molecular layer thickness of primary fissure borderlands in rat cerebellar left hemisphere was studied to assess the regional difference in plasticibility. Despite the homogeneity of cerebellar histology, this study showed that there is a significant interlobular difference between ML thicknesses of Prf borderlands. In addition, it revealed that the thickness alters in a significant trend within each borderland. The quantitative heterogeneity of cerebellar architecture such as variation of cortical thickness may provide some evidences to show that different regions of a homogenous cortex, even two adjacent borderlands and areas within them, can have different potentials for plasticity