title: Deficient neurogenesis in forebrain-specific presenilin-1 knockout mice is associated with reduced clearance of hippocampal memory traces.
abstract: To examine the in vivo function of presenilin-1 (PS1), we selectively deleted the PS1 gene in excitatory neurons of the adult mouse forebrain. These conditional knockout mice were viable and grew normally, but they exhibited a pronounced deficiency in enrichment-induced neurogenesis in the dentate gyrus. This reduction in neurogenesis did not result in appreciable learning deficits, indicating that addition of new neurons is not required for memory formation. However, our postlearning enrichment experiments lead us to postulate that adult dentate neurogenesis may play a role in the periodic clearance of outdated hippocampal memory traces after cortical memory consolidation, thereby ensuring that the hippocampus is continuously available to process new memories. A chronic, abnormal clearance process in the hippocampus may conceivably lead to memory disorders in the mammalian brain.
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
authors.forename: R
authors.initials: R
authors.lastname: Feng
authors.forename: C
authors.initials: C
authors.lastname: Rampon
authors.forename: Y P
authors.initials: YP
authors.lastname: Tang
authors.forename: D
authors.initials: D
authors.lastname: Shrom
authors.forename: J
authors.initials: J
authors.lastname: Jin
authors.forename: M
authors.initials: M
authors.lastname: Kyin
authors.forename: B
authors.initials: B
authors.lastname: Sopher
authors.forename: M W
authors.initials: MW
authors.lastname: Miller
authors.forename: C B
authors.initials: CB
authors.lastname: Ware
authors.forename: G M
authors.initials: GM
authors.lastname: Martin
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: R B
authors.initials: RB
authors.lastname: Langdon
authors.forename: S S
authors.initials: SS
authors.lastname: Sisodia
authors.forename: J Z
authors.initials: JZ
authors.lastname: Tsien
mesh_terms: D000544:Alzheimer Disease / Q000235:genetics; D016564:Amyloid beta-Protein Precursor / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D001923:Brain Chemistry / Q000235:genetics; D004594:Electrophysiology; D006624:Hippocampus / Q000254:growth & development* / Q000473:pathology; D008565:Membrane Proteins / Q000172:deficiency* / Q000235:genetics*; D008568:Memory / Q000502:physiology*; D008569:Memory Disorders / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009474:Neurons / Q000473:pathology; D053764:Presenilin-1; D016548:Prosencephalon / Q000254:growth & development* / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D016564:Amyloid beta-Protein Precursor; C078201:Aplp1 protein, mouse; D008565:Membrane Proteins; D053764:Presenilin-1; D012333:RNA, Messenger