title: Knockdown of the glucocorticoid receptor alters functional integration of newborn neurons in the adult hippocampus and impairs fear-motivated behavior.
abstract: Glucocorticoids (GCs) secreted after stress reduce adult hippocampal neurogenesis, a process that has been implicated in cognitive aspects of psychopathology, amongst others. Yet, the exact role of the GC receptor (GR), a key mediator of GC action, in regulating adult neurogenesis is largely unknown. Here, we show that GR knockdown, selectively in newborn cells of the hippocampal neurogenic niche, accelerates their neuronal differentiation and migration. Strikingly, GR knockdown induced ectopic positioning of a subset of the new granule cells, altered their dendritic complexity and increased their number of mature dendritic spines and mossy fiber boutons. Consistent with the increase in synaptic contacts, cells with GR knockdown exhibit increased basal excitability parallel to impaired contextual freezing during fear conditioning. Together, our data demonstrate a key role for the GR in newborn hippocampal cells in mediating their synaptic connectivity and structural as well as functional integration into mature hippocampal circuits involved in fear memory consolidation.
authors.affiliation: Department of Medical Pharmacology, Leiden University Medical Center/Leiden Amsterdam Center for Drug Research, Leiden, The Netherlands.
authors.forename: C P
authors.initials: CP
authors.lastname: Fitzsimons
authors.forename: L W A
authors.initials: LW
authors.lastname: van Hooijdonk
authors.forename: M
authors.initials: M
authors.lastname: Schouten
authors.forename: I
authors.initials: I
authors.lastname: Zalachoras
authors.forename: V
authors.initials: V
authors.lastname: Brinks
authors.forename: T
authors.initials: T
authors.lastname: Zheng
authors.forename: T G
authors.initials: TG
authors.lastname: Schouten
authors.forename: D J
authors.initials: DJ
authors.lastname: Saaltink
authors.forename: T
authors.initials: T
authors.lastname: Dijkmans
authors.forename: D A
authors.initials: DA
authors.lastname: Steindler
authors.forename: J
authors.initials: J
authors.lastname: Verhaagen
authors.forename: F J
authors.initials: FJ
authors.lastname: Verbeek
authors.forename: P J
authors.initials: PJ
authors.lastname: Lucassen
authors.forename: E R
authors.initials: ER
authors.lastname: de Kloet
authors.forename: O C
authors.initials: OC
authors.lastname: Meijer
authors.forename: H
authors.initials: H
authors.lastname: Karst
authors.forename: M
authors.initials: M
authors.lastname: Joels
authors.forename: M S
authors.initials: MS
authors.lastname: Oitzl
authors.forename: E
authors.initials: E
authors.lastname: Vreugdenhil
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000235:genetics; D003214:Conditioning, Classical / Q000502:physiology; D003345:Corticosterone / Q000378:metabolism; D003712:Dendrites / Q000378:metabolism / Q000648:ultrastructure; D049229:Dendritic Spines / Q000378:metabolism / Q000648:ultrastructure; D005239:Fear; D005822:Genetic Vectors / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology*; D066298:In Vitro Techniques; D008569:Memory Disorders / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D009042:Motivation / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D055495:Neurogenesis / Q000235:genetics*; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D011863:Radioimmunoassay; D011965:Receptors, Glucocorticoid / Q000172:deficiency*
chemical_list: D009419:Nerve Tissue Proteins; D034741:RNA, Small Interfering; D011965:Receptors, Glucocorticoid; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D003345:Corticosterone