Arcadlin induction affects dendritic spine density in the hippocampal dentate gyrus after cerebral ischemia

Dendritic spine morphological changes occur in the brain after cerebral ischemia. Arcadlin, a non-clustered protocadherin δ2, is induced in a neuronal activity and reduces the dendritic spine density via endocytosis of N-cadherin. Cerebral ischemia induces neuronal activity but the expression of Arcadlin and its role in the ischemic brain are not clear. In this study, we analyzed Arcadlin expression and dendritic spine changes after cerebral ischemia using a highly reproducible mouse model of middle cerebral artery occlusion (MCAO). We found that Arcadlin mRNA was significantly upregulated in the hippocampal dentate gyrus (DG) at 4 hours after MCAO. Dendritic spine density in the ipsilateral DG was lower than in sham mice. These results suggest that Arcadlin may be involved in the reduction in the dendritic spine density. We are performing the comparison of dendritic spine density between MCAO and Sham using Arcadlin KO mice.