title: Hippocampus-based contextual memory alters the morphological characteristics of astrocytes in the dentate gyrus.
abstract: Astrocytes have been reported to exist in two states, the resting and the reactive states. Morphological changes in the reactive state of astrocytes include an increase in thickness and number of processes, and an increase in the size of the cell body. Molecular changes also occur, such as an increase in the expression of glial fibrillary acidic protein (GFAP). However, the morphological and molecular changes during the process of learning and memory have not been elucidated. In the current study, we subjected Fvb/n mice to contextual fear conditioning, and checked for morphological and molecular changes in astrocytes. 1 h after fear conditioning, type II and type III astrocytes exhibited a unique status with an increased number of processes and decreased GFAP expression which differed from the typical resting or reactive state. In addition, the protein level of excitatory excitatory amino acid transporter 2 (EAAT2) was increased 1 h to 24 h after contextual fear conditioning while EAAT1 did not show any alterations. Connexin 43 (Cx43) protein was found to be increased at 24 h after fear conditioning. These data suggest that hippocampus-based contextual memory process induces changes in the status of astrocytes towards a novel status different from typical resting or reactive states. These morphological and molecular changes may be in line with functional changes.
authors.affiliation: Department of Pharmacology and Biomedical Sciences, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, 110-799, Seoul, Republic of Korea.
authors.forename: Moonseok
authors.initials: M
authors.lastname: Choi
authors.affiliation: Department of Pharmacology and Biomedical Sciences, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, 110-799, Seoul, Republic of Korea.
authors.forename: Sangzin
authors.initials: S
authors.lastname: Ahn
authors.affiliation: Department of Pharmacology and Biomedical Sciences, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, 110-799, Seoul, Republic of Korea.
authors.forename: Eun-Jeong
authors.initials: EJ
authors.lastname: Yang
authors.affiliation: Department of Pharmacology and Biomedical Sciences, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, 110-799, Seoul, Republic of Korea.
authors.forename: Hyunju
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Microbiology, School of Medicine, Ewha Womans University, 911-1, Mok-6-dong, Yangcheonku, Seoul, 158-710, Republic of Korea.
authors.forename: Young Hae
authors.initials: YH
authors.lastname: Chong
authors.affiliation: Department of Pharmacology and Biomedical Sciences, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, 110-799, Seoul, Republic of Korea. hyisun@snu.ac.kr.|Seoul National University College of Medicine, Seoul National University Bundang Hospital, Sungnam, 463-707, Republic of Korea. hyisun@snu.ac.kr.|Seoul National University College of Medicine, Bundang Hospital, Sungnam, Bundang-Gu, Republic of Korea. hyisun@snu.ac.kr.|Neuroscience Research Institute, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, Seoul, Republic of Korea. hyisun@snu.ac.kr.
authors.forename: Hye-Sun
authors.initials: HS
authors.lastname: Kim
mesh_terms: D015074:2-Aminoadipic Acid / Q000008:administration & dosage; D000818:Animals; D001253:Astrocytes / Q000473:pathology*; D048430:Cell Shape; D003213:Conditioning, Psychological; D018031:Connexin 43 / Q000378:metabolism; D018891:Dentate Gyrus / Q000473:pathology*; D000076122:Disks Large Homolog 4 Protein; D027342:Excitatory Amino Acid Transporter 2 / Q000378:metabolism; D005239:Fear; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D051528:Guanylate Kinases / Q000378:metabolism; D006624:Hippocampus / Q000502:physiology*; D008565:Membrane Proteins / Q000378:metabolism; D008568:Memory / Q000502:physiology*; D051379:Mice
chemical_list: D018031:Connexin 43; D000076122:Disks Large Homolog 4 Protein; C501447:Dlg4 protein, mouse; D027342:Excitatory Amino Acid Transporter 2; D005904:Glial Fibrillary Acidic Protein; D008565:Membrane Proteins; D015074:2-Aminoadipic Acid; D051528:Guanylate Kinases
keywords: Astrocyte; Connexin 43; EAATs; GFAP; Hippocampus-based contextual memory; Morphological changes