High-Throughput Strategy for Profiling Sequential Section With Multiplex Staining of Mouse Brain

The brain modulates specific functions in its various regions. Understanding the organization of different cells in the whole brain is crucial for investigating brain functions. Previous studies have focused on several regions and have had difficulty analyzing serial tissue samples. In this study, we introduced a pipeline to acquire anatomical and histological information quickly and efficiently from serial sections. First, we developed a serial brain-slice-staining method to stain serial sections and obtained more than 98.5% of slices with high integrity. Subsequently, using the self-developed analysis software, we registered and quantified the signals of imaged sections to the Allen Mouse Brain Common Coordinate Framework, which is compatible with multimodal images and slant section planes. Finally, we validated the pipeline with immunostaining by analyzing the activity variance in the whole brain during acute stress in aging and young mice. By removing the problems resulting from repeated manual operations, this pipeline is widely applicable to serial brain slices from multiple samples in a rapid and convenient manner, which benefits to facilitate research in life sciences.

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Scatterometry Measurements With Scattered Light Imaging Enable New Insights Into the Nerve Fiber Architecture of the Brain

Frontiers in Neuroanatomy ◽

10.3389/fnana.2021.767223 ◽

2021 ◽

Vol 15 ◽

Author(s):

Miriam Menzel ◽

Marouan Ritzkowski ◽

Jan A. Reuter ◽

David Gräßel ◽

Katrin Amunts ◽

...

Keyword(s):

Human Brain ◽

Nerve Fiber ◽

Brain Tissue ◽

Scattered Light ◽

Polar Angle ◽

Nerve Fibers ◽

Fiber Architecture ◽

Whole Brain ◽

Tissue Samples ◽

The Brain

The correct reconstruction of individual (crossing) nerve fibers is a prerequisite when constructing a detailed network model of the brain. The recently developed technique Scattered Light Imaging (SLI) allows the reconstruction of crossing nerve fiber pathways in whole brain tissue samples with micrometer resolution: the individual fiber orientations are determined by illuminating unstained histological brain sections from different directions, measuring the transmitted scattered light under normal incidence, and studying the light intensity profiles of each pixel in the resulting image series. So far, SLI measurements were performed with a fixed polar angle of illumination and a small number of illumination directions, providing only an estimate of the nerve fiber directions and limited information about the underlying tissue structure. Here, we use a display with individually controllable light-emitting diodes to measure the full distribution of scattered light behind the sample (scattering pattern) for each image pixel at once, enabling scatterometry measurements of whole brain tissue samples. We compare our results to coherent Fourier scatterometry (raster-scanning the sample with a non-focused laser beam) and previous SLI measurements with fixed polar angle of illumination, using sections from a vervet monkey brain and human optic tracts. Finally, we present SLI scatterometry measurements of a human brain section with 3 μm in-plane resolution, demonstrating that the technique is a powerful approach to gain new insights into the nerve fiber architecture of the human brain.

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MEASUREMENT OF ELEMENTAL DISTRIBUTIONS IN MOUSE BRAIN BY USING SUBMILLI-PIXE CAMERA

International Journal of PIXE ◽

10.1142/s0129083510001951 ◽

2010 ◽

Vol 20 (01n02) ◽

pp. 45-50 ◽

Cited By ~ 1

Author(s):

K. FUJIKI ◽

S. MATSUYAMA ◽

K. ISHII ◽

H. YAMAZAKI ◽

A. TERAKAWA ◽

...

Keyword(s):

Mental Disease ◽

Disease Model ◽

Brain Slices ◽

Physiological Role ◽

Specific Area ◽

Whole Brain ◽

Model Mouse ◽

And Control ◽

The Brain

In a biological body, trace elements including metallic elements play important roles. Knowing their spatial distribution and amounts, we can find out some relations among a physiological role of the trace element in vivo, the function, and the disease appearance. In this study, we investigated a method to obtain elemental distributions in whole brain slice taken from mental disease model mice and control mice using in-air submilli-PIXE camera at Tohoku University. We administered 5-BrdU that was the analogue of the thymidine as a marker to detect a new born cell in especially the dentate gyrus of the hippocampus. We obtained the elemental distributions of the whole brain of subject and control mice. From elemental distributions of the brain of a mental disease model mouse, a brain contained light elements, such as P , S , Cl and K , which were uniformly distributed over the brain. Fe was accumulated in the specific area of brain. Elemental concentration of Fe was more than 10 times higher than that in the other. However, the accumulation of iron in brain slices was not observed in those of control mice. Zn is accumulated in the vicinity in hippocampus. Br was uniformly distributed over the brain. The submilli-PIXE camera will provide a powerful tool for this research.

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Refinements in the Organism as a Whole Rationale for Brain Death

The Linacre Quarterly ◽

10.1177/0024363919869795 ◽

2019 ◽

Vol 86 (4) ◽

pp. 347-358 ◽

Cited By ~ 1

Author(s):

James L. Bernat

Keyword(s):

Brain Death ◽

Theoretical Biology ◽

Conscious Awareness ◽

Control Of Respiration ◽

Biological Models ◽

Whole Brain ◽

Brain Functions ◽

And Control ◽

The Brain

Death can be defined as the permanent cessation of the organism as a whole. Although the organism as a whole is a century-old concept, it remains better intuited than analyzed. Recent concepts in theoretical biology including hierarchies of organization, emergent functions, and mereology have informed the idea that the organism as a whole is the organism’s critical emergent functions. Because the brain conducts the critical emergent functions including conscious awareness and control of respiration and circulation, the cessation of brain functions is death of the organism. A newer concept, the brain as a whole, may offer a superior criterion of death to the whole-brain criterion, because it more closely matches accepted clinical brain death tests and confirms the cessation of the organism’s emergent functions. Although the concepts of organism as a whole and brain as a whole remain vague and in need of rigorous biophilosophical analysis, their future precision will be restricted by the categorical limitations intrinsic to theoretical biological models.

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Detection of evoked acetylcholine release in mouse brain slices

The Analyst ◽

10.1039/c6an01758d ◽

2016 ◽

Vol 141 (23) ◽

pp. 6416-6421 ◽

Cited By ~ 9

Author(s):

R. Asri ◽

B. O'Neill ◽

J. C. Patel ◽

K. A. Siletti ◽

M. E. Rice

Keyword(s):

Cyclic Voltammetry ◽

Carbon Fiber ◽

Mouse Brain ◽

Neurotransmitter Release ◽

Acetylcholine Release ◽

Brain Slices ◽

Fast Scan Cyclic Voltammetry ◽

Carbon Fiber Microelectrode ◽

The Brain

The study of transmitter interactions in the brain requires methodology to detect stimulus-driven neurotransmitter release. This report introduces an enzyme-coated 7 μm carbon-fiber microelectrode used with fast-scan cyclic voltammetry to detect evoked acetylcholine release in mouse brain slices.

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Stress-induced microglial activation occurs through β-adrenergic receptor: noradrenaline as a key neurotransmitter in microglial activation

Journal of Neuroinflammation ◽

10.1186/s12974-019-1632-z ◽

2019 ◽

Vol 16 (1) ◽

Cited By ~ 8

Author(s):

Shuei Sugama ◽

Takato Takenouchi ◽

Makoto Hashimoto ◽

Hisayuki Ohata ◽

Yasuhiro Takenaka ◽

...

Keyword(s):

Laser Scanning ◽

Microglial Activation ◽

Acute Stress ◽

Underlying Mechanism ◽

Brain Regions ◽

Laser Scanning Microscopy ◽

Double Knockout ◽

Whole Brain ◽

Β Blocker ◽

The Brain

Abstract Background The involvement of microglia in neuroinflammatory responses has been extensively demonstrated. Recent animal studies have shown that exposure to either acute or chronic stress induces robust microglial activation in the brain. In the present study, we investigated the underlying mechanism of brain microglial activation by acute stress. Methods We first looked at the spatial distribution of the noradrenaline (NA)-synthesizing enzyme, DBH (dopamine β-hydroxylase), in comparison with NA receptors—β1, β2, and β3 adrenergic receptors (β1-AR, β2-AR, and β3-AR)—after which we examined the effects of the β-blocker propranolol and α-blockers prazosin and yohimbine on stress-induced microglial activation. Finally, we compared stress-induced microglial activation between wild-type (WT) mice and double-knockout (DKO) mice lacking β1-AR and β2-AR. Results The results demonstrated that (1) microglial activation occurred in most studied brain regions, including the hippocampus (HC), thalamus (TM), and hypothalamus (HT); (2) within these three brain regions, the NA-synthesizing enzyme DBH was densely stained in the neuronal fibers; (3) β1-AR and β2-AR, but not β3-AR, are detected in the whole brain, and β1-AR and β2-AR are co-localized with microglial cells, as observed by laser scanning microscopy; (4) β-blocker treatment inhibited microglial activation in terms of morphology and count through the whole brain; α-blockers did not show such effect; (5) unlike WT mice, DKO mice exhibited substantial inhibition of stress-induced microglial activation in the brain. Conclusions We demonstrate that neurons/microglia may interact with NA via β1-AR and β2-AR.

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Assessing the replicability of spatial gene expression using atlas data from the adult mouse brain

PLoS Biology ◽

10.1371/journal.pbio.3001341 ◽

2021 ◽

Vol 19 (7) ◽

pp. e3001341

Author(s):

Shaina Lu ◽

Cantin Ortiz ◽

Daniel Fürth ◽

Stephan Fischer ◽

Konstantinos Meletis ◽

...

Keyword(s):

Gene Expression ◽

Linear Regression ◽

Mouse Brain ◽

Cell Biology ◽

Adult Mouse ◽

Brain Area ◽

Adult Mouse Brain ◽

Whole Brain ◽

Spatial Expression ◽

The Brain

High-throughput, spatially resolved gene expression techniques are poised to be transformative across biology by overcoming a central limitation in single-cell biology: the lack of information on relationships that organize the cells into the functional groupings characteristic of tissues in complex multicellular organisms. Spatial expression is particularly interesting in the mammalian brain, which has a highly defined structure, strong spatial constraint in its organization, and detailed multimodal phenotypes for cells and ensembles of cells that can be linked to mesoscale properties such as projection patterns, and from there, to circuits generating behavior. However, as with any type of expression data, cross-dataset benchmarking of spatial data is a crucial first step. Here, we assess the replicability, with reference to canonical brain subdivisions, between the Allen Institute’s in situ hybridization data from the adult mouse brain (Allen Brain Atlas (ABA)) and a similar dataset collected using spatial transcriptomics (ST). With the advent of tractable spatial techniques, for the first time, we are able to benchmark the Allen Institute’s whole-brain, whole-transcriptome spatial expression dataset with a second independent dataset that similarly spans the whole brain and transcriptome. We use regularized linear regression (LASSO), linear regression, and correlation-based feature selection in a supervised learning framework to classify expression samples relative to their assayed location. We show that Allen Reference Atlas labels are classifiable using transcription in both data sets, but that performance is higher in the ABA than in ST. Furthermore, models trained in one dataset and tested in the opposite dataset do not reproduce classification performance bidirectionally. While an identifying expression profile can be found for a given brain area, it does not generalize to the opposite dataset. In general, we found that canonical brain area labels are classifiable in gene expression space within dataset and that our observed performance is not merely reflecting physical distance in the brain. However, we also show that cross-platform classification is not robust. Emerging spatial datasets from the mouse brain will allow further characterization of cross-dataset replicability ultimately providing a valuable reference set for understanding the cell biology of the brain.

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Genetic Identification of GnRH Receptor Neurons: A New Model for Studying Neural Circuits Underlying Reproductive Physiology in the Mouse Brain

Endocrinology ◽

10.1210/en.2010-1208 ◽

2011 ◽

Vol 152 (4) ◽

pp. 1515-1526 ◽

Cited By ~ 51

Author(s):

Shuping Wen ◽

Iris N. Götze ◽

Oliver Mai ◽

Christian Schauer ◽

Trese Leinders-Zufall ◽

...

Keyword(s):

Mouse Brain ◽

Sexual Behaviors ◽

Gnrh Receptor ◽

Reproductive Physiology ◽

Genetic Identification ◽

Brain Areas ◽

Brain Functions ◽

Model Sets ◽

Lh Rh ◽

The Brain

Abstract GnRH signaling regulates reproductive physiology in vertebrates via the hypothalamic-pituitary-gonadal axis. In addition, GnRH signaling has been postulated to act on the brain. However, elucidating its functional role in the central nervous system has been hampered because of the difficulty in identifying direct GnRH signaling targets in live brain tissue. Here we used a binary genetic strategy to visualize GnRH receptor (GnRHR) neurons in the mouse brain and started to characterize these cells. First, we expressed different fluorescent proteins in GnRHR neurons and mapped their precise distribution throughout the brain. Remarkably, neuronal GnRHR expression was only initiated after postnatal day 16, suggesting peri- and postpubertal functions of GnRH signaling in this organ. GnRHR neurons were found in different brain areas. Many GnRHR neurons were identified in areas influencing sexual behaviors. Furthermore, GnRHR neurons were detected in brain areas that process olfactory and pheromonal cues, revealing one efferent pathway by which the neuroendocrine hypothalamus may influence the sensitivity towards chemosensory cues. Using confocal Ca2+ imaging in brain slices, we show that GnRHR neurons respond reproducibly to extracellular application of GnRH or its analog [D-TRP6]-LH-RH, indicating that these neurons express functional GnRHR. Interestingly, the duration and shape of the Ca2+ responses were similar within and different between brain areas, suggesting that GnRH signaling may differentially influence brain functions to affect reproductive success. Our new mouse model sets the stage to analyze the next level of GnRH signaling in reproductive physiology and behavior.

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A whole-brain connectivity map of mouse insular cortex

10.1101/2020.02.10.941518 ◽

2020 ◽

Cited By ~ 3

Author(s):

Daniel A. Gehrlach ◽

Thomas N. Gaitanos ◽

Alexandra S. Klein ◽

Caroline Weiand ◽

Alexandru A. Hennrich ◽

...

Keyword(s):

Brain Connectivity ◽

Insular Cortex ◽

Structural Basis ◽

Subcortical Structures ◽

Whole Brain ◽

Brain Functions ◽

Complex Functions ◽

Cell Type Specific ◽

Cortical Regions ◽

The Brain

AbstractThe insular cortex (IC) plays key roles in emotional and regulatory brain functions and is affected across psychiatric diseases. However, the brain-wide connections of the mouse IC have not been comprehensively mapped. Here we traced the whole-brain inputs and outputs of the mouse IC across its rostro-caudal extent. We employed cell-type specific monosynaptic rabies virus tracings to characterize afferent connections onto either excitatory or inhibitory IC neurons, and adeno-associated viral tracings to label excitatory efferent axons. While the connectivity between the IC and other cortical regions was highly reciprocal, the IC connectivity with subcortical structures was often unidirectional, revealing prominent top-down and bottom-up pathways. The posterior and medial IC exhibited resembling connectivity patterns, while the anterior IC connectivity was distinct, suggesting two major functional compartments. Our results provide insights into the anatomical architecture of the mouse IC and thus a structural basis to guide investigations into its complex functions.

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Intranasal Delivery of Collagen-Loaded Neprilysin Clears Beta-Amyloid Plaques in a Transgenic Alzheimer Mouse Model

Frontiers in Aging Neuroscience ◽

10.3389/fnagi.2021.649646 ◽

2021 ◽

Vol 13 ◽

Author(s):

Christian Humpel

Keyword(s):

Mouse Model ◽

Mouse Brain ◽

Brain Slices ◽

Beta Amyloid ◽

Intranasal Delivery ◽

Degrading Enzyme ◽

Amyloid Aβ ◽

Potent Drug ◽

The Brain ◽

Ad Mouse Model

Alzheimer’s disease (AD) is pathologically characterized by extracellular beta-amyloid (Aβ) plaques and intraneuronal tau tangles in the brain. A therapeutic strategy aims to prevent or clear these Aβ plaques and the Aβ-degrading enzyme neprilysin is a potent drug to degrade plaques. The major challenge is to deliver bioactive neprilysin into the brain via the blood-brain barrier. The aim of the present study is to explore if intranasal delivery of neprilysin can eliminate plaques in a transgenic AD mouse model (APP_SweDI). We will test if collagen or platelets are useful vehicles to deliver neprilysin into the brain. Using organotypic brain slices from adult transgenic APP_SweDI mice, we show that neprilysin alone or loaded in collagen hydrogels or in platelets cleared cortical plaques. Intransasal delivery of neprilysin alone increased small Aβ depositions in the middle and caudal cortex in transgenic mice. Platelets loaded with neprilysin cleared plaques in the frontal cortex after intranasal application. Intranasal delivery of collagen-loaded neprilysin was very potent to clear plaques especially in the middle and caudal parts of the cortex. Our data support that the Aβ degrading enzyme neprilysin delivered to the mouse brain can clear Aβ plaques and intranasal delivery (especially with collagen as a vehicle) is a fast and easy application. However, it must be considered that intranasal neprilysin may also activate more plaque production in the transgenic mouse brain as a side effect.

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Heterogeneity and developmental dynamics of LYVE-1 perivascular macrophages distribution in the mouse brain

10.1101/2021.10.08.463501 ◽

2021 ◽

Author(s):

Marie Karam ◽

Guy Malkinson ◽

Isabelle V BRUNET

Keyword(s):

Mouse Brain ◽

Brain Region ◽

Dependent Manner ◽

Tissue Sections ◽

Brain Physiology ◽

Brain Functions ◽

Perivascular Macrophages ◽

Developmental Dynamics ◽

The Brain ◽

Virchow Robin Space

Brain perivascular macrophages (PVMs) belong to border-associated macrophages. PVMs are situated along blood vessels in the Virchow-Robin space and are thus found at a unique anatomical position between the endothelium and the parenchyma. Owing to their location and phagocytic capabilities, PVMs are regarded as important components that regulate various aspects of brain physiology in health and pathophysiological states. Here, used LYVE-1 to identify PVMs in the mouse brain. We used brain-tissue sections and cleared whole-brain to learn how they are distributed within the brain and across different developmental postnatal stages. We find that LYVE-1+ PVMs associate with the vasculature in a brain-region-dependent manner, where the hippocampus shows the highest density of LYVE-1+ PVMs. We show that their postnatal distribution is developmentally dynamic and peaks at P10-P20 depending on the brain region. We further demonstrate that their density is reduced in the APP/PS1 mouse model of Alzheimers Disease. In conclusion, our results show an unexpected heterogeneity and dynamics of LYVE-1+ PVMs, and support an important role for this population of PVMs during development and in regulating brain functions in steady-state and disease conditions.

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