Abstract
In this study, we have examined the possible existence of astrocyte regional heterogeneity in thrombin effect on astrocyte stellation. Neonatal astrocytes were cultured for 2 weeks from six different regions of the neonatal rat brain, including the cerebral cortex, hippocampus, brainstem, midbrain, hypothalamus and cerebellum. Culture medium was changed to DMEM containing 8-CPT-cyclic AMP (cAMP) or isoproterenol plus various concentrations of thrombin for 2 hr. Thrombin effectively blocked both cAMP- and isoproterenol-induced cell stellation in a dose-dependent manner in all regional astrocytes except cerebellar astrocytes. RT-PCR analysis showed that thrombin receptor mRNA was expressed in all regional astrocytes, suggesting that cerebellar astrocytes may maintain a unique signaling pathway downstream of the thrombin receptor.
