Virginia Research Day 2022

Medical Student Research Biomedical

04 Development Of A Novel Brain Atlas Of Acmomys Cahirinus (Spiny Mice)

Teresa Nguyen, OMS II, Dr. Shekar Mohan, Department of Physiology and Pharmacology, LUCOM Corresponding author: tnguyen62@liberty.edu

Liberty University College of Osteopathic Medicine

Introduction: Acoymys cahirinus, or more commonly known as the African spiny mouse is an emerging rodent research model in the field of regenerative medicine. However, the African spiny mouse is not a commonly used model organism in neuroscience research. African spiny mice pups can be behaviorally assessed postnatally due to notable, advanced brain development in utero. Thus, the African spiny mouse can potentially be a suitable research model for neurological studies. The aim of this project was to create a neuroanatomy atlas of the African spiny mouse brain. Methods: Three-month-old male spiny mice were transcardially perfused with PBS and 4% paraformaldehyde, and post-fixed with 4%

paraformaldehyde for 72 hrs. The brain tissue was then cryoprotected with 15% sucrose overnight and 30% sucrose in PBS for another 24hrs. Next, brain tissue was frozen using 2-methylbutane and stored at -20°C until ready to use. Leica CM 1860 UV cryostat was used to section frozen brain tissue at -26°C and thickness of the sections was 20 µm. Hematoxylin and eosin were used to stain the tissues. Keyence BZ-Z810 microscope was used to image the slides using lens x4 PlanApo (ƛ) NA 0.20. Using a stitching software, the images were stitched together, and paint software was used to label the images. Results: Structures implicated in withdrawal and addiction were identified by comparing the sections to the Allen Brain Atlas. We identified

structures such the hippocampus, nucleus accumbens, and the amygdala. Conclusion: This study remains in-progress, as there were a number of technical difficulties when sectioning frozen adult brain tissue. Our preliminary results show that frozen spiny mice brain tissue can be sectioned, stained and imaged for analysis. Our method shows us promise in developing a brain atlas specific to spiny mice. Future work will involve sectioning areas of the brain involved in addiction i.e., VTA and NAc. Also, optimizing a immunohistochemistry protocol will be important for the further categorization of cells types in the brain tissue from spiny mice.

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