title: Early maternal deprivation affects dentate gyrus structure and emotional learning in adult female rats.
abstract: BACKGROUND
  Stress elicits functional and structural changes in the hippocampus. Early life stress is one of the major risk factors for stress-related pathologies like depression. Patients suffering from depression show a reduced hippocampal volume, and in women, this occurs more often when depression is preceded by childhood trauma. However, the underlying mechanisms that account for a reduced hippocampal volume are unknown.
  
  
  OBJECTIVE
  We examined the effects of maternal absence on structure and function of the hippocampus in female offspring.
  
  
  METHODS
  We studied whether 24 h of maternal deprivation (MD) on postnatal day 3 altered adult neurogenesis, individual neuronal morphology and dentate gyrus (DG) structure in young adult female rats. In addition, functional alterations were addressed by studying synaptic plasticity in vitro, and spatial as well as emotional learning was tested.
  
  
  RESULTS
  Adult females that were subjected to MD revealed significant reductions in DG granule cell number and density. In addition, DG neurons were altered in their dendritic arrangement. No effects on the rate of adult neurogenesis were found. Furthermore, MD did not alter synaptic plasticity in vitro, neither under normal nor high-stress conditions. In addition, spatial learning and contextual fear conditioning were comparable between control and MD animals. However, MD animals showed an improved amygdala-dependent fear memory.
  
  
  CONCLUSIONS
  Although early life stress exposure did not impair hippocampus-dependent functioning in female offspring, it irreversibly affected DG structure by reducing cell numbers. This may be relevant for the reduced hippocampal volume observed in depression and the increased vulnerability of women to develop depression.
authors.affiliation: Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands. c.a.oomen@uva.nl
authors.forename: Charlotte A
authors.initials: CA
authors.lastname: Oomen
authors.forename: Heleen
authors.initials: H
authors.lastname: Soeters
authors.forename: Nathalie
authors.initials: N
authors.lastname: Audureau
authors.forename: Lisa
authors.initials: L
authors.lastname: Vermunt
authors.forename: Felisa N
authors.initials: FN
authors.lastname: van Hasselt
authors.forename: Erik M M
authors.initials: EM
authors.lastname: Manders
authors.forename: Marian
authors.initials: M
authors.lastname: Joëls
authors.forename: Harm
authors.initials: H
authors.lastname: Krugers
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Lucassen
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal; D018891:Dentate Gyrus / Q000378:metabolism*; D003863:Depression / Q000209:etiology*; D005239:Fear; D005260:Female; D006624:Hippocampus / Q000378:metabolism; D007858:Learning; D008426:Maternal Deprivation; D055495:Neurogenesis; D009473:Neuronal Plasticity; D051381:Rats; D017208:Rats, Wistar; D013315:Stress, Psychological / Q000150:complications*; D013569:Synapses / Q000378:metabolism