| First Author | Takuma K | Year | 2014 |
| Journal | Behav Brain Res | Volume | 272 |
| Pages | 269-78 | PubMed ID | 25014004 |
| Mgi Jnum | J:217120 | Mgi Id | MGI:5613084 |
| Doi | 10.1016/j.bbr.2014.07.005 | Citation | Takuma K, et al. (2014) An enriched environment ameliorates memory impairments in PACAP-deficient mice. Behav Brain Res 272:269-78 |
| abstractText | We previously found that juvenile pituitary adenylate cyclase-activating polypeptide (PACAP)-knockout (PACAP(-/-)) mice reared in an enriched environment (EE) for 4 weeks showed attenuated hyperactivity, jumping behavior, impairments in social interaction, and depression-like behavior. The present study examined the effects of EE on memory function and memory-related protein levels in PACAP(-/-) mice. Eight-week-old PACAP(-/-) mice displayed fear memory dysfunction in a contextual fear conditioning test and cognitive impairments in a novel object recognition test. Rearing of 4-week-old PACAP(-/-) mice in an EE for 4 weeks ameliorated these memory impairments. The beneficial effects of EE were also observed 2 weeks after a return to housing in a standard environment (SE). This suggests that the effects of EE on impaired memory are long-lasting. In both wild-type and PACAP(-/-) mice, EE increased the protein levels of the NMDA receptor NR2B subunit, phospho-ERK, phospho-CaMKII, and brain-derived neurotrophic factor (BDNF) in the hippocampus, and decreased neurotrophin-3 levels, whereas it did not affect nerve growth factor and glial cell-derived neurotrophic factor levels. Increased levels of NR2B, phospho-ERK, phospho-CaMKII and BDNF were not observed 2 weeks after a return to housing in a SE. These findings suggest that living in an EE engenders long-lasting reductions in memory impairments in PACAP(-/-) mice. The present study also implies that increases in hippocampal memory-related protein and BDNF levels are responsible for the beneficial effects of an EE, but not for the maintenance of these effects. |
