title: Structural abnormality of the hippocampus associated with depressive symptoms in heart failure rats.
abstract: Heart failure (HF) is characterized by a blood supply which is insufficient to meet the body's demand. HF can potentially affect the brain and is associated with a high prevalence of depression. However, the mechanisms by which the two are related remain largely unclear. Structural abnormalities of the ventral hippocampus have been observed in depression but have never been reported in HF. In this study, we thus investigated structural brain abnormality in HF using voxel-based morphometry (VBM) and histological analysis in a rat model of HF. T2-weighted images were obtained in rats with HF (n = 20) and sham rats (n = 17) and VBM was used to produce gray matter concentration (GMC) maps. Twenty-four hour locomotor activity was used as a sign of depressive behavior. Brains of HF and sham rats (n = 8, each) were fixed and histologically analyzed for the measurement of neurogenesis, the number of astrocytes and neurite outgrowth in the ventral hippocampus. VBM demonstrated significant GMC decrease in the hippocampus, which was restricted to the ventral segment. Similarly, neurogenesis and neurite outgrowth were significantly decreased and the number of astrocytes was significantly increased in HF rats as compared with sham rats in the ventral hippocampus. GMC values in the ventral hippocampus were significantly and negatively correlated with 24 hour locomotor activity in HF rats. In conclusion, the present study has demonstrated for the first time that the structural abnormality of the ventral hippocampus is associated with depressive symptoms in HF rats.
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan. Electronic address: hd.suzuki.1870031@cardio.med.tohoku.ac.jp.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Sumiyoshi
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Matsumoto
authors.affiliation: Centre for Advanced Biomedical Imaging (CABI), Department of Medicine and Institute of Child Health, University College London (UCL), UK.
authors.forename: Ben A
authors.initials: BA
authors.lastname: Duffy
authors.affiliation: Department of Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Yoshikawa
authors.affiliation: Centre for Advanced Biomedical Imaging (CABI), Department of Medicine and Institute of Child Health, University College London (UCL), UK.
authors.forename: Mark F
authors.initials: MF
authors.lastname: Lythgoe
authors.affiliation: Department of Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yanai
authors.affiliation: Department of Nuclear Medicine and Radiology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Taki
authors.affiliation: Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
authors.forename: Ryuta
authors.initials: R
authors.lastname: Kawashima
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shimokawa
mesh_terms: D000818:Animals; D003863:Depression / Q000150:complications* / Q000473:pathology*; D004195:Disease Models, Animal; D006333:Heart Failure / Q000473:pathology* / Q000523:psychology*; D006624:Hippocampus / Q000473:pathology*; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D017208:Rats, Wistar
keywords: Depression; Heart failure; Hippocampus; Histology; Voxel based morphometry