title: Chronic corticosterone administration reduces dendritic complexity in mature, but not young granule cells in the rat dentate gyrus.
abstract: Our previous work has shown that exposure to the stress hormone corticosterone (40 mg/kg CORT) for two weeks induces dendritic atrophy of pyramidal neurons in the hippocampal CA3 region and behavioral deficits. However, it is unclear whether this treatment also affects the dentate gyrus (DG), a subregion of the hippocampus comprising a heterogeneous population of young and mature neurons.
  
  
  
  We examined the effect of CORT treatment on the dendritic complexity of mature and young granule cells in the DG.
  
  
  
  We utilized a Golgi staining method to investigate the dendritic morphology and spine density of young neurons in the inner granular cell layer (GCL) and mature neurons in the outer GCL in response to CORT application. The expressions of glucocorticoid receptors during neuronal maturation were examined using Western blot analysis in a primary hippocampal neuronal culture.
  
  
  
  Sholl analysis revealed that CORT treatment decreased the number of intersections and shortened the dendritic length in mature, but not young, granule cells. However, the spine density of mature and young neurons was not affected. Western blot analysis showed a progressive increase in the protein levels of glucocorticoid receptors (GRs) in the cultured primary hippocampal neurons during neuronal maturation.
  
  
  
  These data suggest that mature neurons are likely more vulnerable to chronic exposure to CORT; this may be due to their higher expression of GRs when compared to younger DG neurons.
authors: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong SAR.
authors: Suk-Yu
authors: SY
authors: Yau
authors: Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China.
authors: Ang
authors: A
authors: Li
authors: Department of Anesthesiology, The Third Xiangya Hospital of Central South University, Changsha, China.
authors: Jian-Bin
authors: JB
authors: Tong
authors: Division of Medical Sciences, The University of Victoria, British Columbia, Canada.
authors: Crystal
authors: C
authors: Bostrom
authors: Division of Medical Sciences, The University of Victoria, British Columbia, Canada.
authors: Brian R
authors: BR
authors: Christie
authors: State Key Laboratory of Brain and Cognitive Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR.|Laboratory of Neuropsychology, The University of Hong Kong, Hong Kong SAR.|Laboratory of Cognitive Affective Neuroscience, The University of Hong Kong, Hong Kong SAR.
authors: Tatia M C
authors: TM
authors: Lee
authors: Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China.|State Key Laboratory of Brain and Cognitive Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR.|Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR.|Co-innovation Center of Neuroregeneration, Jiangsu, China.
authors: Kwok-Fai
authors: KF
authors: So
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001284:Atrophy / Q000139:chemically induced; D002478:Cells, Cultured; D003345:Corticosterone / Q000494:pharmacology*; D003712:Dendrites / Q000187:drug effects* / Q000648:ultrastructure; D018891:Dentate Gyrus / Q000166:cytology* / Q000187:drug effects; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D008297:Male; D055495:Neurogenesis / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects* / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D016622:Silver Staining
chemical_list: D000893:Anti-Inflammatory Agents; D011965:Receptors, Glucocorticoid; D003345:Corticosterone
keywords: Corticosterone; Golgi staining; dendritic complexity; dentate gyrus; glucocorticoid receptors