An NINDS Grant NS05033 (JCC) supported this work. The University of Connecticut RAC, SURF and OUR programs provided additional support.

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The authors have nothing to disclose.

We present tools and protocols that can be used to evaluate the integrity of the brain&#8217;s ventricular system in mice and in humans. These tools, however, can also be applied to other brain structures or organ systems that undergo changes due to injury, disease, or during the process of aging 14,21,22. The strategies presented take advantage of software that allows the alignment of cross-sectional and longitudinal MRI sequences to generate 3D volume representations of specific regions or structures of inte...

An ependymal cell monolayer lines the ventricular system of the brain providing bi-directional barrier and transport functions between the cerebral spinal fluid (CSF) and interstitial fluid (ISF) 1-3. These functions help to keep the brain toxicant-free and in physiological balance 2,3. In humans loss of portions of this lining through injury or disease does not appear to result in regenerative replacement as found in other epithelial linings; rather loss of ependymal cell coverage appears to result in periventricular astrogliosis with a meshwork of astrocytes covering regions denuded of ependymal cells at the ventricle surface. Serious repercussions to important CSF/ISF exchange and clearance mechanisms would be predicted to result from loss of this epithelial layer 1,2,4-7.
A common feature of human aging is enlarged lateral ventricles (ventriculomegaly) and associated periventricular edema as observed by MRI and fluid-attenuated inversion recovery MRI (MRI/FLAIR) 8-14. To investigate the relationship between ventriculomegaly and the cellular organization of the ventricle lining, postmortem human MRI sequences were matched with histological preparations of lateral ventricle periventricular tissue. In cases of ventriculomegaly, substantial areas of gliosis had replaced ependymal cell coverage along the lateral ventricle wall. When ventricle expansion was not detected by MRI-based volume analysis, the ependymal cell lining was intact and gliosis was not detected along the ventricle lining 6. This combinatorial approach represents the first comprehensive documentation detailing changes in cellular integrity of the lateral ventricle lining using wholemount preparations of portions or the entire lateral ventricle wall and 3D modeling of ventricle volumes 6. Several diseases (Alzheimer&#8217;s disease, schizophrenia) and injuries (traumatic brain injury) show ventriculomegaly as an early neuropathological feature. Denudation of areas of the ependymal cell lining thereby would be predicted to interfere with normal ependymal cell function and compromise the homeostatic balance between CSF/ISF fluid and solute exchange. Thus, a more thorough examination of changes to the ventricular system, its cellular composition, and the consequence to underlying or neighboring brain structures will ultimately begin to reveal more about the neuropathology associated with ventricle enlargement.
The lack of multimodal imaging data, and in particular longitudinal data sequences, together with limited access to corresponding histological tissue samples makes analysis of human brain pathologies difficult. Modeling phenotypes found in human aging or disease can often be achieved with mouse models and animal models become one of our best means to explore questions about human disease initiation and progression. Several studies in healthy young mice have described the cytoarchitecture of the lateral ventricle walls and the underlying stem cell niche 4,7-15. These studies have been extended to include 3D modeling and cellular analysis of the ventricle walls through aging 6,15. Neither periventricular gliosis nor ventriculomegaly are observed in aged mice, rather mice display a relatively robust subventicular zone (SVZ) stem cell niche subjacent to an intact ependymal cell lining 6,15. Thus, striking species-specific differences exist in both the general maintenance and integrity of the lateral ventricle lining during the process of aging 6,15. Therefore, to best use mice to interrogate conditions found in humans, differences between the two species need to be characterized and appropriately considered in any modeling paradigm. Here, we present procedures to evaluate longitudinal changes to the lateral ventricles and associated periventricular tissue in both humans and mouse. Our procedures include 3D rendering and volumetry of both mouse and human ventricles, and use of immunohistochemical analysis of whole mount preparations of periventricular tissue to characterize both cellular organization and structure. Together these procedures provide a means to characterize changes in the ventricular system and associated periventricular tissue.

<table><tbody><tr><td>Phosphate buffered saline (PBS)</td><td>Life Technologies</td><td>21600-069</td><td></td></tr><tr><td>Paraformaldehyde (PFA)</td><td>Electron Microscopy Sciences</td><td>19210</td><td>Use at 4% in PBS, 4 &amp;deg;C</td></tr><tr><td>Normal Horse Serum</td><td>Life Technologies</td><td>16050</td><td>10% in PBS-TX (v/v)</td></tr><tr><td>Normal Goat Serum</td><td>Life Technologies</td><td>16210</td><td>10% in PBS-TX (v/v)</td></tr><tr><td>Triton X-100 (TX)</td><td>Sigma-Aldrich</td><td>T8787</td><td>0.1% in PBS (v/v)</td></tr><tr><td>Vibratome</td><td>Leica</td><td>VT1000S</td><td></td></tr><tr><td>Fluorescence Microscope</td><td>Zeiss</td><td>Imager.M2</td><td></td></tr><tr><td>Camera</td><td>Hamamatsu</td><td>ORCA R2</td><td></td></tr><tr><td>Microscope Stage Controller</td><td>Ludl Electronic Products</td><td>MAC 6000</td><td></td></tr><tr><td>Stereology software</td><td>MBF Bioscience</td><td>Stereo Investigator 11</td><td></td></tr><tr><td>Stereology software</td><td>ImageJ/NIH</td><td>NIH freeware</td><td></td></tr><tr><td>3D Reconstruction software</td><td>MBF Bioscience</td><td>Neurolucida Explorer</td><td></td></tr><tr><td>Confocal Microscope</td><td>Leica</td><td>TCS SP2</td><td></td></tr><tr><td>MRI Software</td><td></td><td></td><td></td></tr><tr><td>Freesurfer</td><td>https://surfer.nmr.mgh.harvard.edu/fswiki/DownloadAndInstall</td><td>Segmentation and Volume</td><td></td></tr><tr><td>ITK-Snap</td><td>http://www.itksnap.org/pmwiki/pmwiki.php</td><td></td><td>Segmentation and Volume</td></tr><tr><td>Multi-image Analysis GUI (Mango)</td><td>http://ric.uthscsa.edu/mango/</td><td></td><td>Longitudinal overlay</td></tr><tr><td>Whole Mount Equipment</td><td></td><td></td><td></td></tr><tr><td>22.5&amp;deg; microsurgical straight stab knife</td><td>Fisher Scientific</td><td>NC9854830</td><td></td></tr><tr><td>parafilm</td><td></td><td></td><td></td></tr><tr><td>wax bottom dissecting dish&amp;nbsp;</td><td></td><td></td><td></td></tr><tr><td>pins</td><td></td><td></td><td></td></tr><tr><td>fine forceps</td><td></td><td></td><td></td></tr><tr><td>aquapolymount</td><td></td><td></td><td></td></tr><tr><td>Dissecting Microscope</td><td>Leica</td><td>MZ95</td><td></td></tr><tr><td>Whole Mount Antibodies</td><td></td><td></td><td></td></tr><tr><td>mouse anti-b-catenin</td><td>BD Bioschiences, San Jose, CA, USA</td><td></td><td>1:250</td></tr><tr><td>goat anti-GFAP</td><td>Santa Cruz Biotechnology</td><td></td><td>1:250</td></tr><tr><td>rabbit anti-AQP4 (aquaporin-4)</td><td>&amp;nbsp;Sigma-Aldrich</td><td></td><td>1:400</td></tr><tr><td>Coronal Antibodies</td><td></td><td></td><td></td></tr><tr><td>Anti-S100&amp;beta; antibody</td><td>Sigma-Aldrich</td><td></td><td>1:500</td></tr><tr><td>4&amp;rsquo;,6-diamidino-2-phenylindole (DAPI)</td><td>Life Technologies</td><td>D-1306</td><td>10 &amp;micro;g/ml in PBS</td></tr></tbody></table>

3d modeling of the lateral ventricles and histological characterization of periventricular tissue in humans and mouse

The ventricular system carries and circulates cerebral spinal fluid (CSF) and facilitates clearance of solutes and toxins from the brain. The functional units of the ventricles are ciliated epithelial cells termed ependymal cells, which line the ventricles and through ciliary action are capable of generating laminar flow of CSF at the ventricle surface. This monolayer of ependymal cells also provides barrier and filtration functions that promote exchange between brain interstitial fluids (ISF) and circulating CSF. Biochemical changes in the brain are thereby reflected in the composition of the CSF and destruction of the ependyma can disrupt the delicate balance of CSF and ISF exchange. In humans there is a strong correlation between lateral ventricle expansion and aging. Age-associated ventriculomegaly can occur even in the absence of dementia or obstruction of CSF flow. The exact cause and progression of ventriculomegaly is often unknown; however, enlarged ventricles can show regional and, often, extensive loss of ependymal cell coverage with ventricle surface astrogliosis and associated periventricular edema replacing the functional ependymal cell monolayer. Using MRI scans together with postmortem human brain tissue, we describe how to prepare, image and compile 3D renderings of lateral ventricle volumes, calculate lateral ventricle volumes, and characterize periventricular tissue through immunohistochemical analysis of en face lateral ventricle wall tissue preparations. Corresponding analyses of mouse brain tissue are also presented supporting the use of mouse models as a means to evaluate changes to the lateral ventricles and periventricular tissue found in human aging and disease. Together, these protocols allow investigations into the cause and effect of ventriculomegaly and highlight techniques to study ventricular system health and its important barrier and filtration functions within the brain.

Contour tracing of the mouse lateral ventricles based on immunostained 50 &#181;m coronal sections and 3D reconstructions (Figure 3) allows volume data to be collected in different experimental paradigms using mouse as a model system for disease or injury. Critical to this procedure is the exclusion of regions where the lateral ventricle walls adhere to each other. By subsegmenting regions of the ventricles and designating a different color for each region (Figure 3C), contiguous section...

Watch this Scientific Journal Video about 3D Modeling of the Lateral Ventricles and Histological Characterization of Periventricular Tissue in Humans and Mouse at JoVE.com

3D Modeling of the Lateral Ventricles and Histological Characterization of Periventricular Tissue in Humans and Mouse

Using MRI scans (human), 3D imaging software, and immunohistological analysis, we document changes to the brain&#8217;s lateral ventricles. Longitudinal 3D mapping of lateral ventricle volume changes and characterization of periventricular cellular changes that occur in the human brain due to aging or disease are then modeled in mice.

The ventricular system carries and circulates cerebral spinal fluid (CSF) and facilitates clearance of solutes and toxins from the brain. The functional ...

3d-modeling-lateral-ventricles-histological-characterization

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

14.0K Views.  University of Connecticut. Using MRI scans (human), 3D imaging software, and immunohistological analysis, we document changes to the brain’s lateral ventricles. Longitudinal 3D mapping of lateral ventricle volume changes and characterization of periventricular cellular changes that occur in the human brain due to aging or disease are then modeled in mice. 

Video: 3D Modeling of the Lateral Ventricles and Histological Characterization of Periventricular Tissue in Humans and Mouse

Mouse Models of Periventricular Leukomalacia

We describe a protocol for establishing mouse models of periventricular leukomalacia (PVL). PVL is the predominant form of brain injury in premature infants and the most common antecedent of cerebral palsy. PVL is characterized by periventricular white matter damage with prominent oligodendroglial injury. Hypoxia/ischemia with or without systemic infection/inflammation are the primary causes of PVL. We use P6 mice to create models of neonatal brain injury by the induction of hypoxia/ischemia with or without systemic infection/inflammation with unilateral carotid ligation followed by exposure to hypoxia with or without injection of the endotoxin lipopolysaccharide (LPS). Immunohistochemistry of myelin basic protein (MBP) or O1 and electron microscopic examination show prominent myelin loss in cerebral white matter with additional damage to the hippocampus and thalamus. Establishment of mouse models of PVL will greatly facilitate the study of disease pathogenesis using available transgenic mouse strains, conduction of drug trials in a relatively high throughput manner to identify candidate therapeutic agents, and testing of stem cell transplantation using immunodeficiency mouse strains.

We established mouse models of periventricular leukomalacia (PVL), the predominant brain injury in premature infants characterized by periventricular white matter lesions. Hypoxia/ischemia with/without systemic infection are the primary causes of PVL. Unilateral carotid ligation and hypoxia exposure with/without lipopolysaccharide injection creates PVL-like lesions in P6 mice.

We describe a protocol for establishing mouse models of periventricular leukomalacia (PVL). PVL is the predominant form of brain injury in premature ...

Cerebrovascular Casting of the Adult Mouse for 3D Imaging and Morphological Analysis

Vascular imaging is crucial in the clinical diagnosis and management of cerebrovascular diseases, such as brain arteriovenous malformations (BAVMs). Animal models are necessary for studying the etiopathology and potential therapies of cerebrovascular diseases. Imaging the vasculature in large animals is relatively easy. However, developing vessel imaging methods of murine brain disease models is desirable due to the cost and availability of genetically-modified mouse lines. Imaging the murine cerebral vascular tree is a challenge. In humans and larger animals, the gold standard for assessing the angioarchitecture at the macrovascular (conductance) level is x-ray catheter contrast-based angiography, a method not suited for small rodents.
In this article, we present a method of cerebrovascular casting that produces a durable skeleton of the entire vascular bed, including arteries, veins, and capillaries that may be analyzed using many different modalities. Complete casting of the microvessels of the mouse cerebrovasculature can be difficult; however, these challenges are addressed in this step-by-step protocol. Through intracardial perfusion of the vascular casting material, all vessels of the body are casted. The brain can then be removed and clarified using the organic solvent methyl salicylate. Three dimensional imaging of the brain blood vessels can be visualized simply and inexpensively with any conventional brightfield microscope or dissecting microscope. The casted cerebrovasculature can also be imaged and quantified using micro-computed tomography (micro-CT)1. In addition, after being imaged, the casted brain can be embedded in paraffin for histological analysis.
The benefit of this vascular casting method as compared to other techniques is its broad adaptation to various analytic tools, including brightfield microscopic analysis, CT scanning due to the radiopaque characteristic of the material, as well as histological and immunohistochemical analysis. This efficient use of tissue can save animal usage and reduce costs. We have recently demonstrated application of this method to visualize the irregular blood vessels in a mouse model of adult BAVM at a microscopic level2, and provide additional images of the malformed vessels imaged by micro-CT scan. Although this method has drawbacks and may not be ideal for all types of analyses, it is a simple, practical technique that can be easily learned and widely applied to vascular casting of blood vessels throughout the body.

In this article, we present a simple, practical technique for cerebrovascular casting that is easy to perform and can be utilized to image the vascular tree of the adult mouse brain.

Vascular imaging is crucial in the clinical diagnosis and management of cerebrovascular diseases, such as brain arteriovenous malformations (BAVMs). ...

Modification of a Colliculo-thalamocortical Mouse Brain Slice, Incorporating 3-D printing of Chamber Components and Multi-scale Optical Imaging

The ability of the brain to process sensory information relies on both ascending and descending sets of projections. Until recently, the only way to study these two systems and how they interact has been with the use of in vivo preparations. Major advances have been made with acute brain slices containing the thalamocortical and cortico-thalamic pathways in the somatosensory, visual, and auditory systems. With key refinements to our recent modification of the auditory thalamocortical slice1, we are able to more reliably capture the projections between most of the major auditory midbrain and forebrain structures: the inferior colliculus (IC), medial geniculate body (MGB), thalamic reticular nucleus (TRN), and the auditory cortex (AC). With portions of all these connections retained, we are able to answer detailed questions that complement the questions that can be answered with in vivo preparations. The use of flavoprotein autofluorescence imaging enables us to rapidly assess connectivity in any given slice and guide the ensuing experiment. Using this slice in conjunction with recording and imaging techniques, we are now better equipped to understand how information processing occurs at each point in the auditory forebrain as information ascends to the cortex, and the impact of descending cortical modulation. 3-D printing to build slice chamber components permits double-sided perfusion and broad access to networks within the slice and maintains the widespread connections key to fully utilizing this preparation.

Using multiple angles to cut the mouse pup brain, we improve upon a previously-described acute brain slice which captures the connections between most of the major auditory midbrain and forebrain structures.

The ability of the brain to process sensory information relies on both ascending and descending sets of projections. Until recently, the only way to study ...

A Pipeline to Characterize Structural Heart Defects in the Fetal Mouse

Congenital heart diseases (CHDs) are major causes of infant death in the United States. In the 1980s and earlier, most patients with moderate or severe CHD died before adulthood, with the maximum mortality during the first week of life. Remarkable advances in surgical techniques, diagnostic approaches, and medical management have led to marked improvements in outcomes. To address the critical research needs of understanding congenital heart defects, murine models have provided an ideal research platform, as they have very similar heart anatomy to humans and short gestation rates. The combination of genetic engineering with high-throughput phenotyping tools has allowed for the replication and diagnosis of structural heart defects to further elucidate the molecular pathways behind CHDs. The use of noninvasive fetal echocardiography to screen the cardiac phenotypes in mouse models coupled with the high fidelity of Episcopic fluorescence image capture (EFIC) using Episcopic confocal microscopy (ECM) histopathology with three-dimensional (3D) reconstructions enables a detailed view into the anatomy of various congenital heart defects. This protocol outlines a complete workflow of these methods to obtain an accurate diagnosis of murine congenital heart defects. Applying this phenotyping protocol to model organisms will allow for accurate CHD diagnosis, yielding insights into the mechanisms of CHD. Identifying the underlying mechanisms of CHD provide opportunities for potential therapies and interventions.

This article details murine congenital heart disease (CHD) diagnostic methods using fetal echocardiography, necropsy, and Episcopic fluorescence image capture (EFIC) using Episcopic confocal microscopy (ECM) followed by three-dimensional (3D) reconstruction.

Congenital heart diseases (CHDs) are major causes of infant death in the United States. In the 1980s and earlier, most patients with moderate or severe ...

Developmental Biology

Utilizing 3D Printing Technology to Merge MRI with Histology: A Protocol for Brain Sectioning

Magnetic resonance imaging (MRI) allows for the delineation between normal and abnormal tissue on a macroscopic scale, sampling an entire tissue volume three-dimensionally. While MRI is an extremely sensitive tool for detecting tissue abnormalities, association of signal changes with an underlying pathological process is usually not straightforward. In the central nervous system, for example, inflammation, demyelination, axonal damage, gliosis, and neuronal death may all induce similar findings on MRI. As such, interpretation of MRI scans depends on the context, and radiological-histopathological correlation is therefore of the utmost importance. Unfortunately, traditional pathological sectioning of brain tissue is often imprecise and inconsistent, thus complicating the comparison between histology sections and MRI. This article presents novel methodology for accurately sectioning primate brain tissues and thus allowing precise matching between histology and MRI. The detailed protocol described in this article will assist investigators in applying this method, which relies on the creation of 3D printed brain slicers. Slightly modified, it can be easily implemented for brains of other species, including humans.

The overall goal of this protocol is to accurately align magnetic resonance imaging (MRI) image volumes with histology sections via the creation of customized 3D-printed brain holders and slicer boxes.

Magnetic resonance imaging (MRI) allows for the delineation between normal and abnormal tissue on a macroscopic scale, sampling an entire tissue volume ...

Exploring Deep Space - Uncovering the Anatomy of Periventricular Structures to Reveal the Lateral Ventricles of the Human Brain

Anatomy students are typically provided with two-dimensional (2D) sections and images when studying cerebral ventricular anatomy and students find this challenging. Because the ventricles are negative spaces located deep within the brain, the only way to understand their anatomy is by appreciating their boundaries formed by related structures. Looking at a 2D representation of these spaces, in any of the cardinal planes, will not enable visualisation of all of the structures that form the boundaries of the ventricles. Thus, using 2D sections alone requires students to compute their own mental image of the 3D ventricular spaces. The aim of this study was to develop a reproducible method for dissecting the human brain to create an educational resource to enhance student understanding of the intricate relationships between the ventricles and periventricular structures. To achieve this, we created a video resource that features a step-by-step guide using a fiber dissection method to reveal the lateral and third ventricles together with the closely related limbic system and basal ganglia structures. One of the advantages of this method is that it enables delineation of the white matter tracts that are difficult to distinguish using other dissection techniques. This video is accompanied by a written protocol that provides a systematic description of the process to aid in the reproduction of the brain dissection. This package offers a valuable anatomy teaching resource for educators and students alike. By following these instructions educators can create teaching resources and students can be guided to produce their own brain dissection as a hands-on practical activity. We recommend that this video guide be incorporated into neuroanatomy teaching to enhance student understanding of the morphology and clinical relevance of the ventricles.

This paper demonstrates the effective use of a fiber dissection method to reveal the superficial white matter tracts and periventricular structures of the human brain, in three-dimensional space, to aid student comprehension of ventricular morphology.

Anatomy students are typically provided with two-dimensional (2D) sections and images when studying cerebral ventricular anatomy and students find this ...

Induction and Micro-CT Imaging of Cerebral Cavernous Malformations in Mouse Model

Mutations in the CCM1 (aka KRIT1), CCM2, or CCM3 (aka PDCD10) gene cause cerebral cavernous malformation (CCM) in humans. Mouse models of CCM disease have been established by tamoxifen induced deletion of Ccm genes in postnatal animals. These mouse models provide invaluable tools to investigate molecular mechanism and therapeutic approaches for CCM disease. An accurate and quantitative method to assess lesion burden and progression is essential to harness the full value of these animal models. Here, we demonstrate the induction of CCM disease in a mouse model and the use of the contrast enhanced X-ray micro computed tomography (micro-CT) method to measure CCM lesion burden in mouse brains. At postnatal day 1 (P1), we used 4-hydroxytamoxifen (4HT) to activate Cre recombinase activity from the Cdh5-CreErt2 transgene to cleave the floxed allele of Ccm2. CCM lesions in mouse brains were analyzed at P8. For micro-CT, iodine based Lugol&#39;s solution was used to enhance contrast in brain tissue. We have optimized the scan parameters and utilized a voxel dimension of 9.5 &#181;m, which lead to a minimum feature size of approximately 25 &#181;m. This resolution is sufficient to measure CCM lesion volume and number globally and accurately, and provide high-quality 3-D mapping of CCM lesions in mouse brains. This method enhances the value of the established mouse models to study the molecular basis and potential therapies for CCM and other cerebrovascular diseases.

This protocol demonstrates the induction of cerebral cavernous malformation disease in a mouse model and uses contrast enhanced micro computed tomography to measure lesion burden. This method enhances the value of established mouse models to study the molecular basis and potential therapies for cerebral cavernous malformation and other cerebrovascular diseases.

Mutations in the CCM1 (aka KRIT1), CCM2, or CCM3 (aka PDCD10) gene cause cerebral cavernous malformation (CCM) in humans. Mouse models of CCM disease have ...

Medicine

Large-scale Three-dimensional Imaging of Cellular Organization in the Mouse Neocortex

The mammalian neocortex is composed of many types of excitatory and inhibitory neurons, each with specific electrophysiological and biochemical properties, synaptic connections, and in vivo functions, but their basic functional and anatomical organization from cellular to network scale is poorly understood. Here we describe a method for the three-dimensional imaging of fluorescently-labeled neurons across large areas of the brain for the investigation of the cortical cellular organization. Specific types of neurons are labeled by the injection of fluorescent retrograde neuronal tracers or expression of fluorescent proteins in transgenic mice. Block brain samples, e.g., a hemisphere, are prepared after fixation, made transparent with tissue clearing methods, and subjected to fluorescent immunolabeling of the specific cell types. Large areas are scanned using confocal or two-photon microscopes equipped with large working distance objectives and motorized stages. This method can resolve the periodic organization of the cell type-specific microcolumn functional modules in the mouse neocortex. The procedure can be useful for the study of three-dimensional cellular architecture in the diverse brain areas and other complex tissues.

Here we describe a procedure for tissue clearing, fluorescent labeling, and large-scale imaging of mouse brain tissue which, thereby, enables visualization of the three-dimensional organization of cell types in the neocortex.

The mammalian neocortex is composed of many types of excitatory and inhibitory neurons, each with specific electrophysiological and biochemical ...

A Micro-CT-based Method for Characterizing Lesions and Locating Electrodes in Small Animal Brains

Lesion and electrode location verification are traditionally done via histological examination of stained brain slices, a time-consuming procedure that requires manual estimation. Here, we describe a simple, straightforward method for quantifying lesions and locating electrodes in the brain that is less laborious and yields more detailed results. Whole brains are stained with osmium tetroxide, embedded in resin, and imaged with a micro-CT scanner. The scans result in 3D digital volumes of the brains with resolutions and virtual section thicknesses dependent on the sample size (12&#8211;15 and 5&#8211;6 &#181;m&#160;per voxel for rat and zebra finch brains, respectively). Surface and deep lesions can be characterized, and single tetrodes, tetrode arrays, electrolytic lesions, and silicon probes can also be localized. Free and proprietary software allows experimenters to examine the sample volume from any plane and segment the volume manually or automatically. Because this method generates whole brain volume, lesions and electrodes can be quantified to a much higher degree than in current methods, which will help standardize comparisons within and across studies.

This article describes a straightforward method to prepare small animal brains for micro-CT imaging, in which lesions can be quantified and electrodes located with high precision in the context of the whole brain.

Lesion and electrode location verification are traditionally done via histological examination of stained brain slices, a time-consuming procedure that ...

Modeling Stroke in Mice: Focal Cortical Lesions by Photothrombosis

Stroke is a leading cause of death and acquired adult disability in developed countries. Despite extensive investigation for novel therapeutic strategies, there remain limited therapeutic options for stroke patients. Therefore, more research is needed for pathophysiological pathways such as post-stroke inflammation, angiogenesis, neuronal plasticity, and regeneration. Given the inability of in vitro models to reproduce the complexity of the brain, experimental stroke models are essential for the analysis and subsequent evaluation of novel drug targets for these mechanisms. In addition, detailed standardized models for all procedures are urgently needed to overcome the so-called replication crisis. As an effort within the ImmunoStroke research consortium, a standardized photothrombotic mouse model using an intraperitoneal injection of Rose Bengal and the illumination of the intact skull with a 561 nm laser is described. This model allows the performance of stroke in mice with allocation to any cortical region of the brain without invasive surgery; thus, enabling the study of stroke in various areas of the brain. In this video, the surgical methods of stroke induction in the photothrombotic model along with&#160;histological analysis are demonstrated.

Described here is the photothrombotic stroke model, where a stroke is produced through the intact skull by inducing permanent microvascular occlusion using laser illumination after administration of a photosensitive dye.

Stroke is a leading cause of death and acquired adult disability in developed countries. Despite extensive investigation for novel therapeutic strategies, ...