Rg1 can improve memory impairment and depression-like behavior in 3 × Tg-AD mice by upregulating the expression of the depression and memory-related proteins complexin-2 (CPLX2), synapsin-2 (SYN2), and synaptosomal-associated protein 25 (SNP25) (Nie et al., 2017). Here, SYN2 is linked to Alzheimer disease.