Environmental enrichment and physical exercise revert behavioral and electrophysiological impairments caused by reduced adult neurogenesis

It is well known that adult neurogenesisoccurs in two distinct regions, the subgranular zoneof the dentate gyrusand the subventricular zonealong the walls of the lateral ventricles. Until now, the contribution of these newly born neurons to behavior and cognition is still uncertain. The current study tested the functional impacts of diminished hippocampal neurogenesison emotional and cognitive functions in transgenic Gfap-tk mice. Our results showed that anxiety-related behavior evaluated both in the elevated plus mazeas well as in the open field, social interaction in the sociability test, and spatial working memory in the spontaneous alternationtest were not affected. On the other hand, recognition and emotional memory in the object recognition test and contextual fear conditioning, and hippocampal long-term potentiationwere impaired in transgenic mice. Furthermore, we evaluated whether environmental enrichmenttogether with physical exercisecould improve or even restore the level of adult neurogenesis, as well as the behavioral functions. Our results clearly demonstrated that environmental enrichmenttogether with physical exercisesuccessfully elevated the overall number of progenitor cells and young neurons in the dentate gyrusof transgenic mice. Furthermore, it led to a significant improvement in object recognition memoryand contextual fear conditioning, and reverted impairments in hippocampal long-term potentiation. Thus, our results confirm the importance of adult neurogenesisfor learning and memory processesand for hippocampal circuitry in general. Environmental enrichmentand physical exercisebeneficially influenced adult neurogenesisafter it had been disrupted and most importantly recovered cognitive functions and long-term potentiation. © 2016 Wiley Periodicals, Inc.