Sustained downregulation of YY1-associated protein-related protein gene expression in rat hippocampus induced by repeated electroconvulsive shock.

YY1AP-related protein (YARP) is a structural homolog of YY1-associated protein (YY1AP), which has a YY1-binding domain. During perinatal development, YARP mRNA expression is increased at a late stage of embryonic neurogenesis. It is not known whether YARP expression is regulated during adult neurogenesis. Electroconvulsive shock (ECS), a model for a highly effective depression treatment, is known to induce hippocampal neurogenesis after repeated treatment, so we employed ECS to measure the expression of YARP mRNA. Northern blots revealed significantly decreased expression of the YARP gene after repeated ECS but not single ECS. In situ hybridization clearly demonstrated a reduction of YARP mRNA expression in the CA (CA1, CA2, and CA3) subfields. Although clonic-tonic seizure was induced not only by ECS but also by injection of kainic acid to the striatum, the regulation of YARP mRNA expression was different between ECS and kainic acid. YARP mRNA was decreased only by the ECS method, suggesting that YARP expression is different at embryonic and adult neurogenic stage.