SH3GL2 and memory impairment: To determine whether the memory impairment in EEN1-/- mice is irreversible or can be reversed by expression of endophilin A1 in adult brain, we injected AAV vectors coexpressing endophilin A1 and GFP (AAV-GFP-2A-EEN1) or GFP only into bilateral hippocampal CA1 regions of 8-week-old endophilin A1 KO mice (Figure 3A).