Expression and Localization of Pituitary Adenylate Cyclase-Activating Polypeptide-Specific Receptor (PAC1R) After Traumatic Brain Injury in Mice

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a pleiotropic peptide and a well known strong neuroprotectant in various neuronal conditions. PACAP has some receptors and it acts via these receptors. PACAP type 1 receptor (PAC1R) is known as the main receptor of PACAP in neuronal damages. On the other hand, the expression and localization of PAC1R have not been elicited well in traumatic brain injury (TBI). In this study, the expression and the cellular localization of PAC1R were investigated immunohistochemically after TBI in mouse controlled cortical impact (CCI) model. The PAC1R positive cells were expressed from 3 h in the peri-contusional area and observed to 7days after the TBI. Using double-immunohistochemistry, the PAC1R immunopositive cells were co-localized with the microglia on 1day and with microglia and astrocyte on 7 days after TBI. These results suggest that PACAP and PAC1R might play an important role in traumatic brain injury as well as other conditions.