title: Glycogen distribution in the microwave-fixed mouse brain reveals heterogeneous astrocytic patterns.
abstract: In the brain, glycogen metabolism has been implied in synaptic plasticity and learning, yet the distribution of this molecule has not been fully described. We investigated cerebral glycogen of the mouse by immunohistochemistry (IHC) using two monoclonal antibodies that have different affinities depending on the glycogen size. The use of focused microwave irradiation yielded well-defined glycogen immunoreactive signals compared with the conventional periodic acid-Schiff method. The IHC signals displayed a punctate distribution localized predominantly in astrocytic processes. Glycogen immunoreactivity (IR) was high in the hippocampus, striatum, cortex, and cerebellar molecular layer, whereas it was low in the white matter and most of the subcortical structures. Additionally, glycogen distribution in the hippocampal CA3-CA1 and striatum had a 'patchy' appearance with glycogen-rich and glycogen-poor astrocytes appearing in alternation. The glycogen patches were more evident with large-molecule glycogen in young adult mice but they were hardly observable in aged mice (1-2 years old). Our results reveal brain region-dependent glycogen accumulation and possibly metabolic heterogeneity of astrocytes. GLIA 2016;64:1532-1545.
authors.affiliation: Laboratory for Neuron-Glia Circuitry, RIKEN Brain Science Institute, Wako, Saitama, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Oe
authors.affiliation: Oral and Maxillofacial Anatomy, Graduate School of Oral Sciences, Tokushima University, Tokushima, Japan.
authors.forename: Otto
authors.initials: O
authors.lastname: Baba
authors.affiliation: Laboratory of Biochemistry Frontiers, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ashida
authors.affiliation: Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Kouichi C
authors.identifier: 0000-0001-7053-0507
authors.initials: KC
authors.lastname: Nakamura
authors.affiliation: Laboratory for Neuron-Glia Circuitry, RIKEN Brain Science Institute, Wako, Saitama, Japan.|Saitama University Brain Science Institute, Saitama, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Hirase
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D002531:Cerebellum / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008810:Mice, Inbred C57BL; D008872:Microwaves
chemical_list: D006003:Glycogen
keywords: aging; astrocytes; focused microwave irradiation; glycogen; immunohistochemistry