Using neurobehavioral tests, immunohistochemistry, and western blot, we found that TAT‐LBD‐Ngn2 significantly improved both spatial and contextual learning and memory impairments in a long term by promoting adult neurogenesis, and increasing the expression of brain derived neurotrophic factor (BDNF) but not nerve growth factor (NGF). Here, BDNF is linked to memory impairment.