Rolipram-induced improvement of cognitive function correlates with changes in hippocampal CREB phosphorylation, BDNF and Arc protein levels

Diabetics suffer from a higher risk of cognitive decline. cAMP response element-binding protein (CREB) is a transcription factor associated with memory and synaptic plasticity. Here, we investigated the molecular changes in the hippocampus correlated with diabetes associated cognitive decline (DACD) from a CREB-centered perspective in a rat model of type 2 diabetes. Furthermore, we tested the therapeutic effect of rolipram on DACD. High-fat diet and low-dose streptozocin were adopted to induce diabetes in SD rats. Results show that supplementation with rolipram for 23 days (0.5 mg/kg, once a day) improved the performance of diabetic rats in Morris water navigation task with increased level of CREB, brain-derived neurotrophic factor (BDNF), and Arc protein in the hippocampus. Rolipram, acting as an inhibitor of PDE4, was found to repair the imbalance in the CREB/BDNF/Arc pathway. This study may provide important insights into the mechanisms underlying DACD and provide new therapeutic targets for clinical treatment.