Glycogen synthase kinase 3 (GSK-3), a regulator of glycogen metabolism, has been well known to be involved in a variety of intracellular signaling, and a lot of GSK-3 inhibitors has been used for the treatment of CNS disorders including Alzheimer's disease (AD) [79] , Parkinson's disease [80] , stroke, traumatic brain injury, and bipolar disorders [81] .