title: Neuropathological changes in brain cortex and hippocampus in a rat model of Alzheimer's disease.
abstract: Alzheimer's disease (AD) is a neurodegenerative disorder with progressive loss of cognitive abilities and memory loss. The aim of this study was to compare neuropathological changes in hippocampus and brain cortex in a rat model of AD.
  
  
  
  Adult male Albino Wistar rats (weighing 250-300 g) were used for behavioral and histopathological studies. The rats were randomly assigned to three groups: control, sham and Beta amyloid (ABeta) injection. For behavioral analysis, Y-maze and shuttle box were used, respectively at 14 and 16 days post-lesion. For histological studies, Nissl, modified Bielschowsky and modified Congo red staining were performed. The lesion was induced by injection of 4 muL of ABeta (1-40) into the hippocampal fissure.
  
  
  
  In the present study, ABeta (1-40) injection into hippocampus could decrease the behavioral indexes and the number of CA1 neurons in hippocampus. ABeta injection CA1 caused ABeta deposition in the hippocampus and less than in cortex. We observed the loss of neurons in the hippocampus and cerebral cortex and certain subcortical regions. Y-maze test and single-trial passive avoidance test showed reduced memory retention in AD group.
  
  
  
  We found a significant decreased acquisition of passive avoidance and alternation behavior responses in AD group compared to control and sham group (P<0.0001). Compacted amyloid cores were present in the cerebral cortex, hippocampus and white matter, whereas, scattered amyloid cores were seen in cortex and hippocampus of AD group. Also, reduced neuronal density was indicated in AD group.
authors: Dept. of Pathology, Science and Research Branch Islamic Azad University, Tehran, Iran.|Dept. of  Histology and Neuroscience, School of Medicine, Iran University of Medical Sciences, Tehram, Iran.|Anti-Microbial Resistance Research Center, Iran University of Medical Sciences, Tehran, Iran; 4Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.|Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors: Maliheh
authors: M
authors: Nobakht
authors: Dept. of Pathology, Science and Research Branch Islamic Azad University, Tehran, Iran.
authors: Seyed Mohammad
authors: SM
authors: Hoseini
authors: Dept. of Pathology, Science and Research Branch Islamic Azad University, Tehran, Iran.
authors: Pejman
authors: P
authors: Mortazavi
authors: Dept. of Pathology, Science and Research Branch Islamic Azad University, Tehran, Iran.
authors: Iraj
authors: I
authors: Sohrabi
authors: Dept. of Anatomy, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.|Dept. of Anatomy, School of Medicine, Bushehr University of Medical Science, Bushehr, Iran.
authors: Banafshe
authors: B
authors: Esmailzade
authors: Dept. of Pathology, Science and Research Branch Islamic Azad University, Tehran, Iran.
authors: Nahid
authors: N
authors: Rahbar Rooshandel
authors: Veterinary Medicine, Faculty of Specialized Veterinary Science, Tehran University of Veterinary Sciences, Tehran, Iran.
authors: Shila
authors: S
authors: Omidzahir
mesh_terms: D000544:Alzheimer Disease / Q000473:pathology*; D000818:Animals; D001362:Avoidance Learning; D002452:Cell Count; D016923:Cell Death; D002540:Cerebral Cortex / Q000473:pathology*; D003224:Congo Red; D004195:Disease Models, Animal; D006624:Hippocampus / Q000473:pathology*; D020287:In Situ Nick-End Labeling; D008297:Male; D018782:Maze Learning; D009474:Neurons / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013194:Staining and Labeling
chemical_list: D003224:Congo Red