title: Optical controlling reveals time-dependent roles for adult-born dentate granule cells.
abstract: Accumulating evidence suggests that global depletion of adult hippocampal neurogenesis influences its function and that the timing of the depletion affects the deficits. However, the behavioral roles of adult-born neurons during their establishment of projections to CA3 pyramidal neurons remain largely unknown. We used a combination of retroviral and optogenetic approaches to birth date and reversibly control a group of adult-born neurons in adult mice. Adult-born neurons formed functional synapses on CA3 pyramidal neurons as early as 2 weeks after birth, and this projection to the CA3 area became stable by 4 weeks in age. Newborn neurons at this age were more plastic than neurons at other stages. Notably, we found that reversibly silencing this cohort of ~4-week-old cells after training, but not cells of other ages, substantially disrupted retrieval of hippocampal memory. Our results identify a restricted time window for adult-born neurons essential in hippocampal memory retrieval.
authors.affiliation: Department of Neurobiology and Behavior, SUNY at Stony Brook, Stony Brook, New York, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Gu
authors.forename: Maithe
authors.initials: M
authors.lastname: Arruda-Carvalho
authors.forename: Jia
authors.initials: J
authors.lastname: Wang
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Janoschka
authors.forename: Sheena A
authors.initials: SA
authors.lastname: Josselyn
authors.forename: Paul W
authors.initials: PW
authors.lastname: Frankland
authors.forename: Shaoyu
authors.initials: S
authors.lastname: Ge
mesh_terms: D000367:Age Factors; D000818:Animals; D003216:Conditioning, Operant / Q000502:physiology; D018891:Dentate Gyrus / Q000166:cytology* / Q000254:growth & development*; D005260:Female; D018782:Maze Learning / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D055495:Neurogenesis / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D017966:Pyramidal Cells / Q000254:growth & development*; D011897:Random Allocation; D013997:Time Factors