Strain‐specific differential expression of astrocytes and microglia in the mouse hippocampus

Abstract

IntroductionGenetic background influences neurotransmitter expression and function of the hippocampus. Genetic background influences the phenotype of the hippocampus, but expression of neuroglia in hippocampus has not been well established dependent on various mouse strains.ObjectivesIn this study, we investigated the effects of genetic background on cell population of astrocytes and microglia in eight widely used inbred strains (C57BL/6J, A/J, BALB/c, C3H/HeJ, FVB, 129/SvJ, DBA/1, and DBA/2) and one outbred strain (ICR).MethodsIn all mouse strains, glial fibrillary acidic protein (GFAP)‐immunoreactive astrocytes and ionized calcium‐binding adaptor molecule 1 (Iba‐1)‐immunoreactive microglia were found in almost all layers of hippocampal CA1‐4 regions and the dentate gyrus.ResultsWe observed significant differences in the number of astrocytes and microglia. In the CA1 and CA3 regions, the number of GFAP‐immunoreactive astrocytes was highest in the C3H/HeJ strain, and lowest in the 129/SvJ and FVB strains. In the polymorphic layer of the dentate gyrus, the number was highest in the DBA/1 strain and lowest in the 129/SvJ strain. Among the nine mouse strains, the number of Iba‐1‐immunoreactive microglia was highest in the CA1 and CA3 regions in the ICR and in the dentate gyrus of the C57BL/6 strain. The CA1 region of the FVB strain and the CA3 region and dentate gyrus of DBA/2 had the lowest number of Iba‐1‐immunoreactive microglia.ConclusionThese results suggest that the numbers of astrocytes and microglia differ depending on the mouse strain and these differences may be related to strain‐dependent function of astrocytes.

Glial Fibrillary Acidic Protein and Ionized Calcium-Binding Adapter Molecule 1 Immunostaining Score for the Central Nervous System of Horses With Non-suppurative Encephalitis and Encephalopathies

“…In this study, normal astrocytes (grade 0) appeared as staining in a range of 0 to 30 astrocytes/×200 magnification that were well-ramified with minimal contact between cells and tightly connected with blood vessels as also described in the spinal cord of horses by Meneses et al (27) and in fibrous astrocytes from the cerebral cortex in control horses from Regina et al (28). Studies in other animal species describe a similar morphology in non-altered CNS of dogs (29), mice (30), and rats (31), but cattle have a higher number of GFAP+ cells and nonaltered astrocytes approximate morphologically to our grade 1 for horses (32). Limited or no proliferation of astrocytes was observed in mouse models of Alzheimer's disease and amyotrophic lateral sclerosis (33)(34)(35).…”

“…Resting microglia were found in all four non-altered equine brains used as controls, in non-lesioned areas bordering lesions, and in CNS regions completely lesion-free (but in cases with alterations in other sections). A similar morphology of resting microglia was described in early studies of microglia features (23), in mice (30), and the equine non-altered controls from an experimental study with Trypanosoma evansi infection (2). A mild microglial activation (grade 1) was characterized by a range of 6 to 30 Iba1+ cells/×200 magnification, and the morphological alterations were discrete, inclined to the beginning of cellular processes retraction.…”

Uncovering sex differences of rodent microglia

“…A series of factors such as different ages, species, brain regions, and methods in these studies may account for this discrepancy [ 86 ]. In research settings, microglia have to be dissociated from the CNS into a single-cell suspension using both mechanical dissociation and enzymatic dissociation in order to facilitate culture or analyses.…”

A Low Cost Antibody Signal Enhancer Improves Immunolabeling in Cell Culture, Primate Brain and Human Cancer Biopsy

“…A prominent presence of astrocytes has been previously detected in the dentate gyrus-CA3 hippocampal region of rodents (Kim et al, 2018) (Idris et al, 2019). Immunocytofluorescence in MDCK monolayer cells using Claudin 2 and Claudin 4 antibodies has previously revealed their localization in both the plasma membrane and in subcellular membrane organelles, although the antibody signal is not always easy to detect, especially in the case of Claudin 4.…”