Journal: Biomolecules

Article Title: A Combination of Heavy Metals and Intracellular Pathway Modulators Induces Alzheimer Disease-like Pathologies in Organotypic Brain Slices

doi: 10.3390/biom14020165

Figure Lengend Snippet: Spreading of human amyloid-beta (hAβ42) and P301S aggregated tau (aggTau) in postnatal wild-type and transgenic organotypic brain slices. Brain slices were prepared from postnatal day 8–10 wild-type (WT) C57BL6 mice or transgenic (TG) amyloid precursor protein _Swedish–Dutch–Iowa (APP_SDI) mice. Collagen hydrogels with hAβ42, P301S aggTau, or a mix of both was loaded after 1 week in culture. Collagen hydrogels with an empty load were included as negative controls. Slices were cultured for 8 weeks, fixed and analyzed by immunohistochemistry for Aβ using the antibody clone 6E10 or for tau using the antibodies Tau5 or AT8. Images were taken at the 20× magnification with a field size of 523 × 392 µm, which were quantified using ImageJ (Version 5.5.0). ( A ) Quantification of the number of Aβ+ cells in the ventral areas of WT and TG APP_SDI slices. ( B ) Quantification of the Aβ+ fiber density. ( C ) Quantification of the number of Tau5+ cells in the ventral areas of WT and TG APP_SDI slices. ( D ) Quantification of the Tau5+ fiber density. The corresponding fiber densities were calculated by counting the number of times fibers crossed a predefined grid on the same image used to analyze the number of Aβ+ or Tau5+ cells. Note that no mature Aβ plaques or tau neurofibrillary tangles were observed in these postnatal slices. Values are given as mean ± SEM for each group and the values in parentheses represent the number of analyzed animals. The dots represent individual raw data values. Statistical analyses were performed using a one-way ANOVA with a Fisher’s LSD post-hoc test. * p < 0.05, *** p < 0.001 signifies comparisons against the respective (−) groups. § p < 0.05, §§§ p < 0.001 signifies comparisons between hAβ42 + P301S aggTau and hAβ42 groups. # p < 0.05 signifies comparisons between hAβ42+ P301S aggTau and P301S aggTau groups.

Article Snippet: The fixed coronal brain cryosections of transgenic mice expressing human tau (hTau) were commercially obtained from QPS Austria GmbH (Grambach, Austria).

Techniques: Transgenic Assay, Cell Culture, Immunohistochemistry

Journal: Biomolecules

Article Title: A Combination of Heavy Metals and Intracellular Pathway Modulators Induces Alzheimer Disease-like Pathologies in Organotypic Brain Slices

doi: 10.3390/biom14020165

Figure Lengend Snippet: Characterization of amyloid-beta (Aβ) plaques and tau neurofibrillary tangles (NFT) in post-mortem human and transgenic mouse slices. Tissue sections from the temporal lobe of a human Alzheimer’s disease (AD) patient ( A – D ) were probed for the appearance of Aβ plaques and tau NFT. Following the deparaffinization and antigen retrieval protocols, the slices were subject to immunohistochemistry. ( A ) The lack of a primary antibody (w/o) served as a negative control with background staining. ( B ) An Aβ plaque was detected by using the Aβ antibody clone 6E10 with a dense plaque core and the surrounding corona. ( C ) Tau containing NFTs were visualized in human tissue sections with a densely stained cytoplasm and unstained nuclei. ( D ) A representative image displayed the pyramid-shaped tau NFT (green; AlexaFluor-488), Aβ plaques (red; Thiazine Red dye) and nuclei (blue; DAPI). ( E ) Slices from transgenic (TG) amyloid precursor protein _Swedish–Dutch–Iowa (APP_SDI) mice ( F – H ) exhibited no staining without a primary antibody (w/o). ( F ) Slices from TG APP_SDI mice displayed numerous Aβ plaque structures. ( G ) Slices from a TG mouse model expressing the human tau protein were commercially obtained and probed for tau NFTs, which could be detected with intracellular staining and unstained nuclei. ( H ) A representative image from the human tau-expressing TG mice showed strong staining in neuronal cells detected by AT8 antibody (green; AlexaFluor-488) with nuclear staining (blue; DAPI). Scale bar in G = 50 µm in ( A – C ); 27 µm in ( D ); 100 µm in ( E – G ); 27 µm in ( H ).

Article Snippet: The fixed coronal brain cryosections of transgenic mice expressing human tau (hTau) were commercially obtained from QPS Austria GmbH (Grambach, Austria).

Techniques: Transgenic Assay, Immunohistochemistry, Negative Control, Staining, Expressing

Journal: Biomolecules

Article Title: A Combination of Heavy Metals and Intracellular Pathway Modulators Induces Alzheimer Disease-like Pathologies in Organotypic Brain Slices

doi: 10.3390/biom14020165

Figure Lengend Snippet: Culturing of adult slices from wild-type (WT) and transgenic (TG) animals. ( A ) Composite image of a half-brain adult slice shows AT8+ immunoreactivity after 9 weeks of culture with the magnified image showing representative AT8+ immunoreactivity in the ventral areas. ( B ) Acute fresh slices from 3 different adult WT animals (day 0) were collected and frozen immediately. Conversely, adult WT slices were cultured for 9 weeks and then compared via Western blotting. The acute slices display a strong signal for neurofilament and GFAP, whereas cultured slices show a severely reduced signal indicating the general decline of viability post-culture. ( C ) Adult slices from TG amyloid precursor protein _Swedish–Dutch–Iowa (APP_SDI) mice were incubated with collagen hydrogels containing human amyloid-beta 42 (hAβ42) or P301S aggregated tau (aggTau) for 9 weeks. A significantly increased number of AT8+ cells were quantified in the ventral areas between hAβ42- or P301S aggTau-loaded hydrogels and the empty hydrogels (minus group). The number of AT8+ cells were counted from the ventral regions and the values are reported as mean ± SEM. ( D ) Adult WT slices were supplemented with either scopolamine, wortmannin, MHY1485, lead and cadmium (50, 10, 50, 100, 100 nM final concentration, respectively) or normal media after 4 weeks of culture and then further cultured for 4 weeks. Slices were fixed and immunostained with the Aβ clone 6E10 or AT8 antibodies. No significant differences were found in the groups treated with the combination treatment and normal slice media. Images were quantified using ImageJ. Raw optical density measurements were inverted by correcting for slice background for each image such that 0 represents white and 255 represents black. Values are generated from an average of two images from left and right hemispheres per animal and values in parentheses indicate the number of analyzed animals. Statistical analyses were performed using a student’s t -test with equal variance, where p values < 0.05 represent significance versus the Minus (−) group (* p < 0.05, ** p < 0.01).

Article Snippet: The fixed coronal brain cryosections of transgenic mice expressing human tau (hTau) were commercially obtained from QPS Austria GmbH (Grambach, Austria).

Techniques: Transgenic Assay, Cell Culture, Western Blot, Incubation, Concentration Assay, Generated

Journal: eLife

Article Title: Microglial trogocytosis and the complement system regulate axonal pruning in vivo

doi: 10.7554/eLife.62167

Figure Lengend Snippet:

Article Snippet: Other , Allen Brain Map Human Multiple Cortical Areas SMART-seq data set , Allen Institute for Brain Science , , .

Techniques: Recombinant, Plasmid Preparation, RNAscope, Multiplex Assay, Software, Transformation Assay

Journal: Journal of Psychiatry & Neuroscience : JPN

Article Title: Reduced signal propagation elicited by frontal transcranial magnetic stimulation is associated with oligodendrocyte abnormalities in treatment-resistant depression

doi: 10.1503/jpn.220102

Figure Lengend Snippet: Schematic diagram showing how combined TMS-EEG and MRI data were used to assess signal propagation in this study. (A) Brain neural activities comprise 3 main categories: noncausal correlated activity in the resting state; neural activity elicited by a specific task, which is assessed with endogenous neural activity specific to the task modality, elicited in the specific neural module corresponding to the task; and causal neural activity with a clear input–output relationship using an external mechanical physical stimulus as a probe. The first 2 categories have a limitation: although they can be used to evaluate local activity as the sum of the interactions between regions in the entire brain, they cannot be used to evaluate activity in the local brain region itself. The third category (extrinsic neural stimulation targeting specific brain regions using TMS as a probe) is characterized by its ability to evaluate both neural activity at the stimulation site and neural activity originating from the stimulation site to other regions to determine causal relationships, independent of neural activity from regions other than the stimulation site. (B) Rationale for using TMS-EEG to assess signal propagation in the present study. TMS-evoked neural activities (within and between regions) that show significant signal propagation from the stimulation site to other specific brain regions or neural networks are propagated in a causal manner. (C) An overview of TMS-EEG data analysis. First, for reconstruction of the TEP signal source, we manually registered EEG channel locations on individual MRI spaces, along with anatomic landmarks. Then, we projected EEG source activations onto individual surface spaces using forward and inverse modelling of EEG sources. Finally, to compare signal propagation from the stimulation site to each brain network between the TRD and healthy control groups, we extracted dSPM current densities from the 7 networks defined by Yeo and colleagues. To investigate the cellular-level abnormalities that would be associated with the signal propagation abnormalities, we examined correlations between the interregional profiles of cell-specific gene expression using the Allen Human Brain Atlas data set and the interregional profiles of altered signal propagation from our TMS-EEG data. dlPFC = dorsolateral prefrontal cortex; dSPM = dynamic statistical parametric mapping; EEG = electroencephalography; HC = healthy control; ROI = region of interest; TEP = TMS-evoked potential; TMS = transcranial magnetic stimulation; TRD = treatment-resistant depression.

Article Snippet: We conducted cell-specific gene expression analysis using postmortem brain data generated from 6 healthy donors in the Allen Human Brain Atlas genetics data set.

Techniques: Activity Assay, Control, Gene Expression