Huntington’s disease (HD) is a rare dominant disorder that affects nearly 30,000 individuals in the United States alone. Typically, symptoms of the disease have a delayed onset and manifest themselves in individuals between 30 and 50 years old. Due to this timing, the leading theory in the field was that HD has a late development in those who carry the gene for it. However, this study will explore the alternative theory that, while HD typically manifests itself later in life, the disorder may develop relatively early in an individual’s life. Looking specifically at early development, the central objective was to explore the role of a specific protein, GLUT3, in the development of HD in mice models. This protein is essential for providing glucose, the main energy source of the brain. We hypothesize that the reduced levels of GLUT3 in HD brains play an important role in the development of the disease. The three techniques that were used to test this theory were electrophysiology, immunohistochemistry, and western blots. Together, these methods show that in presymptomatic mice models, the neurons and different regions of the brain develop abnormally, leading to increased excitation and altered structures. These findings are significant because they prove that prior to the physical manifestations of HD, GLUT3 deficiencies in the brain are contributing to different development. With a better understanding of how it develops, healthcare options could be aimed at prevention instead of treatment in order to improve the quality of life for those living with HD.

Cachexia, or muscle wasting, is a common symptom among advanced cancer patients. It results in decreased physical endurance and disrupts a patient’s capacity to carry out every day tasks while contributing to one third of cancer-related fatalities. Fatigue is a complex, multifactorial symptom that can be directly tied to cachexia and inflammatory changes within the brain. A study indicates that tumor-released extracellular vehicles (EVs) may be involved in cancer-related cachexia in the mouse Lewis Lung Carcinoma (LLC) model of cancer (Zhou et al., 2020). EVs are small vesicles that are secreted from various cell types and are involved in cellular communication. Zhou et al showed that amiloride treatment could reduce tumor released EVs and alleviate cachexia. While fatigue in the LLC model is likely associated with cachexia (Vichaya et al., 2020), we seek to determine if this treatment can also block the development of fatigue, assessed by voluntary wheel running, as well as if it blocks cancer-related increases in brain Ilb mRNA expression. We will inject adult male C57B16/J mice with 5 x 10^5 LLC cells. Once tumors can be palpated, we will start treating mice with 2 mg/kg/day amiloride or saline. Over the weeks, we will monitor tumor growth and voluntary wheel running. Finally, tissue will be collected. We hypothesize that tumor-bearing mice treated with amiloride will present less wheel running deficits than the control group. We also anticipate that they will show reduced tumor-related changes within brain tissue. Keywords: tumors, Lewis Lung Carcinoma, amiloride, cachexia, fatigue, extracellular vehicles.

Ischemic stroke is an acquired brain injury with sex dependent outcomes and the influence of sex on neuroinflammatory responses to ischemic brain injury remains unclear. Systemic and resident immune cell response to post-stroke ischemic injury and the extent of these responses extending beyond the acute phase to 30-days post injury, are not well documented in male and female mice undergoing the traditional filament method to induce ischemia. In this descriptive study we document the presence of brain immune cells using immunohistochemistry methods 30-days post-stroke and assess the relationship between immune cell response/presence to infarct size in male and female mice. Male and female mice underwent middle cerebral artery occlusion for 45 minutes followed by reperfusion. MRIs were taken at 48hrs and 30-days post-stroke after which brain tissue was collected for fluorescence immunohistochemistry methods. Immune cell populations were identified using immunohistochemical staining using antibodies to target: B cell (CD45/B220); T cell (CD3ε); microglia (IBA1 and TMEM119); Phagocytosis marker (CD68). Following confocal or widefield microscopy for image acquisition, ImageJ software was used to quantify the area of positive staining using consistent thresholding parameters. To assess microglia morphologic responses in relation to the residual infarct or “scar” remaining at 30-days, microglia confocal images were obtained in 3 regions: contralateral and ipsilateral regions that were distal and adjacent to “scar”. An ImageJ based skeleton analysis method was used to quantify indicators of microglia ramified morphology: endpoints/cell and process length/cell. Data collection is ongoing. Descriptive statistics will be used to summarize finalized data; sex and region differences (microglia morphology) will be tested using two-way ANOVA with Tuckey’s post-hoc. Pearson’s correlation will be used to describe relationships between immune cell presence and infarct volume.

Microglia are glial cells located throughout the brain and spinal cord. Microglia account for 10–15% of all cells found within the brain. They act as the first and main form of active immune defense in the central nervous system. A sub-population of microglia in the mouse brain is known as the Hoxb8 microglia. The Hoxb8 is an important gene during development. This population has been implicated in the pathology of Trichotillomania, an obsessive compulsive- spectrum disorder (OCD) that involves recurrent, irresistible urges to pull out body hair. Hoxb8 mutant mice display humanistic behavior like excessive grooming behavior and hair removal like humans with Trichotillomania. The project is investigating the distribution of Hoxb8 microglia vs non Hoxb8 microglia in the barrel cortex via the chronic sensory deprivation model. The model allows Hoxb8 microglia to adapt in response to different stimuli. Mice rely on their whiskers as their primary means of encoding information about the environment. Sensory deprivation will focus on the whisker to the barrel cortex as a source. It will involve sensory deprivation of whiskers daily and quantifying Hoxb8 as well as non-Hoxb8 microglia density from brain slices, brain dissection and immunohistochemical procedures. The results can provide a foundation to examine the impact of sensory deprivation model on Hoxb8 microglia function. It may provide a novel research direction for the future to utilize sensory deprivation models as a tool to treat the patients with neuropsychiatric disorders and neurodegenerative diseases, such as anxiety and Alzheimer's disease, respectively.