Visualization and Quantification of Post-stroke Neural Connectivity and Neuroinflammation Using Serial Two-Photon Tomography in the Whole Mouse Brain

Frontiers in Neuroscience

Uma M. Selvaraj¹  Sankalp Gokhale¹  Apoorva D. Ajay¹  Vanessa O. Torres¹  Erik J. Plautz¹  Shazia Mirza¹  Denise M. O. Ramirez¹  Xiangmei Kong¹  Katherine Poinsatte¹  Dene Betz¹  Mark P. Goldberg¹  Ann M. Stowe²  Julian P. Meeks³ 

[1] Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Peter O'Donnell Jr. Brain Institute, Dallas, TX, United States;Department of Neurology, University of Kentucky, Lexington, KY, United States;Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX, United States;

关键词: stroke;    serial two-photon tomography;    whole brain imaging;    neural connectivity;    neuroinflammation;    CD8 T cells;   

DOI  :  10.3389/fnins.2019.01055

来源: DOAJ

【 摘 要 】

Whole-brain volumetric microscopy techniques such as serial two-photon tomography (STPT) can provide detailed information on the roles of neuroinflammation and neuroplasticity throughout the whole brain post-stroke. STPT automatically generates high-resolution images of coronal sections of the entire mouse brain that can be readily visualized in three dimensions. We developed a pipeline for whole brain image analysis that includes supervised machine learning (pixel-wise random forest models via the “ilastik” software package) followed by registration to a standardized 3-D atlas of the adult mouse brain (Common Coordinate Framework v3.0; Allen Institute for Brain Science). These procedures allow the detection of cellular fluorescent signals throughout the brain in an unbiased manner. To illustrate our imaging techniques and automated image quantification, we examined long-term post-stroke motor circuit connectivity in mice that received a motor cortex photothrombotic stroke. Two weeks post-stroke, mice received intramuscular injections of pseudorabies virus (PRV-152), a trans-synaptic retrograde herpes virus driving expression of green fluorescent protein (GFP), into the affected contralesional forelimb to label neurons in descending tracts to the forelimb musculature. Mice were sacrificed 3 weeks post-stroke. We also quantified sub-acute neuroinflammation in the post-stroke brain in a separate cohort of mice following a 60 min transient middle cerebral artery occlusion (tMCAo). Naive e450+-labeled splenic CD8+ cytotoxic T cells were intravenously injected at 7, 24, 48, and 72 h post-tMCAo. Mice were sacrificed 4 days after stroke. Detailed quantification of post-stroke neural connectivity and neuroinflammation indicates a role for remote brain regions in stroke pathology and recovery. The workflow described herein, incorporating STPT and automated quantification of fluorescently labeled features of interest, provides a framework by which one can objectively evaluate labeled neuronal or lymphocyte populations in healthy and injured brains. The results provide region-specific quantification of neural connectivity and neuroinflammation, which could be a critical tool for investigating mechanisms of not only stroke recovery, but also a wide variety of brain injuries or diseases.

【 授权许可】

Unknown