Sports-related concussion data in high school, collegiate, and professional athletes is well documented. However, limited data exists in the middle-school-aged population. The purpose of this study was to better understand the mean number of diagnosed concussions among 9 to 14-year-old football and soccer players. Prior to the Fall 2019 season, 262 athletes from two youth sports leagues in the Greater Seattle Area self-reported all prior diagnosed concussions. Overall, a small percentage (20.61%) of athletes reported at least one previously diagnosed concussion (1 concussion, n = 45; 2 concussions, n = 7; 3+ concussions, n = 2). There was no significant difference in concussion history among athletes of the three sports. Football (n = 120), boys’ soccer (n = 71), and girls’ soccer (n = 71) reported a mean (SD) of 0.28 (0.57), 0.32 (0.77), and 0.14 (0.35) concussions, respectively. The mean number of diagnosed concussions was highest in boys’ soccer, then football, and lowest in girls’ soccer. Our results were different when compared to another study which shows that the concussion rates per 1,000 athlete exposures were highest in football, followed by girls’ soccer, and lowest in boys’ soccer. These results show that the number of youth concussions may be different among football, boys’ soccer, and girls’ soccer. Further research could provide a better understanding of concussion diagnoses in youth sports.

Alzheimer’s disease is a neurodegenerative disease that results in deterioration of memory and cognitive function. One of the hallmarks of Alzheimer’s disease (AD) is the formation of tangled fibrils of the Tau protein. Tau is a microtubule-associated protein found in healthy neurons; in the disease state, it can aggregate and impair normal neuronal functions. Caenorhabditis elegans is a powerful genetic model that has been used to elucidate the cellular and genetic pathways that are impacted by AD-associated proteotoxic stress. All previous C. elegans Tau models have neuronal specific expression. However, neurons are resistant to RNAi. Therefore, we generated a novel transgenic C. elegans model of Tau hyperphosphorylation that has been codon-optimized to express Tau in body wall muscles instead of neurons. Two models were developed: an overexpression (OE) line and a single copy insert (SCI) line. We measured the animal’s health with age in a series of phenotypic assays: egg-laying, growth, movement, paralysis, and lifespan analysis. The OE Tau line displayed a significantly lower egg laying rate, developmental delay by approximately 1 day, and significantly reduced speed in comparison to synchronized N2 populations. The SCI Tau line displayed a significantly lower egg laying rate, smaller adults, and no significant reductions in speed in comparison to synchronized N2 populations. These phenotypic characteristics provide a quick, robust metric by which to measure Tau toxicity with age. The muscle expression opens up the possibility of genome wide RNAi screening to identify the genetic pathways underlying cellular responses to Tau toxicity. We will be screening candidate genetic suppressors of Tau toxicity using feeding RNAi. These experiments could point to genetic targets for future genetic therapies for AD.

Post-traumatic stress disorder (PTSD) is a widespread disorder that diminishes the quality of life for millions of adults annually. Symptoms of PTSD include flashbacks and unwanted memories in those who have suffered a traumatic experience. Research labs across the world are working diligently on understanding the interactions between brain regions affected by PTSD, with much of its effects still unclear. Our lab is researching the brain’s neural interactions during traumatic events, such as in PTSD. We are studying the connection between two specific brain regions in a mouse model: locus coeruleus (LC) and dentate gyrus (DG). Both regions are crucial for understanding the neural interactions of PTSD as they are associated with many of its symptoms. The LC is responsible for modulating anxiety and arousal, while the DG is responsible for memory formation and recall. The LC does this by releasing norepinephrine (NE) during a state of anxiety or arousal. We are altering the activity of the LC via optogenetics and identifying its effect on the formation of new memories. We measure the formation of memories by analyzing the behavior of the mice after the activation of the brain region. We also track the release of NE by with fluorescent imaging of the brain after analysis of the behavior. Under a fluorescent microscope, we are able to identify the parts of the brain norepinephrine travelled to and its effect on the behavior of the mice. Data collected thus far suggests that the norepinephrine released from the LC to the DG is associated with the inhibition of memory formation and impaired recall. These findings will help us better understand the underlying neural mechanisms that cause PTSD and other neurological disorders involving memory.

Much of aging and longevity research is linked to the mitochondria; specifically mitochondrial dysfunction are an important factor in the etiology of age-related diseases. An important metabolic pathway for mitochondrial function is the Nicotinamide Adenine Dinucleotide (NAD+) biosynthesis pathway. NAD+ is a coenzyme found in hundreds of metabolic pathways within the body, and many are specific to high energy metabolic transformations within the mitochondria. This research introduces a multistep procedure which aims to quantify and identify specific metabolites within the NAD+ biosynthesis pathway. The procedure uses Liquid Chromatography-coupled Mass Spectrometry to detect and quantify fourteen metabolites in the NAD+ metabolome. This method can be used to analyze how specific mitochondrial dysfunction, for example deletion of the NADH Ubiquinone Oxidoreductase subunit 4 (Ndufs4), affects the NAD+ biosynthetic pathway, and to explore potential drug treatments for the improvement of such disorders.

 Over 30% of patients with epilepsy remain resistant to antiseizure drugs (ASD), despite over 20 therapies available. Individuals that do not achieve seizure control with two or more ASDs are considered “pharmacoresistant”. Limited preclinical studies have suggested that the early chronic administration of ASDs that selectively inactivate sodium channels may dramatically alter subsequent pharmacoresistance in chronic seizure models of epilepsy. However, it is unknown whether inhibition of slow inactivation state of sodium channels specifically leads to pharmacoresistance. Therefore, we sought to determine whether the chronic administration of lacosamide (LCM), which inhibits the slow-inactivation state of sodium channels, would lead to a similarly pharmacoresistant chronic seizure model. Male CF-1 mice were treated with an anticonvulsant dose of LCM (4.5 mg/kg, ip) or vehicle one hour prior to each corneal kindling session twice/day for three weeks until animals achieved the fully kindled state of five consecutive Racine stage 5 seizures. Once mice had achieved kindling criterion, they were given a two week stimulation-free period. We then tested the sensitivity of kindled seizures of both treatment groups to 9 mg/kg (ip) lacosamide. There were 7/9 vehicle-kindled mice (77.7%) versus 3/10 LCM-kindled mice that achieved kindling criterion (p=0.0698). There was also a significant time x treatment effect on kindled seizure severity (F (23, 391) = 2.169, p<0.002), demonstrating that chronic LCM administration significantly delayed acquisition of the fully kindled state. Further, administration of 9 mg/kg LCM reduced seizure severity in both LCM- and VEH-kindled mice, indicating that LCM-kindled mice are not resistant to escalating doses of LCM. To assess the mechanism of pharmacoresistance, immunohistochemistry data will be further discussed, specifically the differences in sodium channel subunit expression and neuroinflammation in LCM- versus VEH-kindled mice. This study provides insight into how ASD monotherapy early in the epileptogenesis process may influence pharmacoresistance and the development of the epilepsy.

Leigh syndrome is a severe mitochondrial disease that affects one in 40,000 newborn infants and typically results in death during early childhood. The disease is caused by genetic mutations that disrupt electron transport chain (ETC) function, which leads to serious impairment of energy production. Impaired energy production pushes cells with heavy energetic demands into a state of stress, which leads to neuronal dysfunction, progressive encephalopathy, loss of motor function, and respiratory failure. Therapeutics to treat Leigh syndrome are not available in the clinic. Recent studies in fly and mouse models of Leigh syndrome show that rapamycin improves survival and decreases neurological impairment. Rapamycin is a potent and specific inhibitor of the mechanistic Target Of Rapamycin (mTOR) signaling pathway, a crucial cellular nutrient-sensing regulatory pathway. We are interested in identifying other interventions to treat Leigh syndrome. In collaboration with researchers that use the mouse model to study Leigh syndrome, we are using the ND2 Drosophila melanogaster (fruit fly) Leigh syndrome model as a rapid screening tool to identify new interventions that prolong survival. The ND2 model contains a mutation in the mitochondrially-encoded ND2 gene that impairs ETC complex I function. To assess drug efficacy, we use a strategy where flies are treated during development, and post-developmental survival is measured. This strategy recapitulates treating Leigh syndrome in children, who are still developing. We have validated this approach by confirming that rapamycin extends adult lifespan when given only during development in our ND2 model. We are testing other interventions that regulate upstream or downstream elements of mTOR signaling or alter metabolism in a way that could improve mitochondrial function. Finding new interventions to treat Leigh syndrome could help improve thousands of children’s health outcomes and their survival.

Leigh syndrome (LS) is a pediatric form of mitochondrial disease which affects the central nervous system (CNS). LS is partly characterized by symmetric necrotizing lesions in the brainstem and cerebellum. Our laboratory utilizes the Ndufs4 (KO) mouse model of LS, as it closely resembles human LS, including the characteristic CNS lesions and the age of onset of disease. Ndufs4, which is also a causal LS gene in humans, is deleted in these mice. In addition to progressive CNS lesions, the Ndufs4 (KO) mice show ataxia and weight loss, and death occurs at a median of 55 postnatal days of age. Information regarding the temporal specificity and mechanisms underlying the pathogenesis of CNS lesions are unknown. Previously, our laboratory has discovered that the loss of Ndufs4 in the VGlut2 expressing glutamatergic neurons drives the CNS lesions and the aforementioned phenotypes of the KO mice. In order to characterize the early events in lesion formation in the CNS, we assess necrosis in the major cell types including VGlut2, GFAP, and Gad2 using GFP reporter lines. This is done by staining and imaging by confocal microscopy of the brain tissue of both the Ndufs4 (KO) and control mice from the cell-type specific GFP reporter lines at postnatal days 30 and 55, corresponding to pre- and post- disease respectively. Additionally, we will be collecting data from mice in more age groups, including at 25, 35, and 45 postnatal days of age. We expect that this will allow us to determine how defects in mitochondrial function lead to diseases such as Leigh Syndrome with tissue, region, and temporal specificity, and in turn, may allow a proposal for Leigh Syndrome treatment.

Dandy Walker malformation (DWM) is the most common human cerebellar malformation, affecting 1 in every 3000 live births. DWM is an imaging diagnosis that is characterized by three features: cerebellar vermis hypoplasia, an enlarged posterior fossa, and an enlarged fourth ventricle. Although recent advances in neuroimaging have improved diagnosis of DWM, virtually nothing is known about the cellular and histological defects that lead to DWM during brain development. One major reason is that little human specific data is available describing the histology of normal and abnormal human fetal cerebellar development. Currently, there is limited published fetal pathology of DWM. Few comparative analyses are available and most studies are confounded by lack of molecular confirmations of diagnoses. We have carried out the first comprehensive prenatal histo-pathological analysis of human DWM. Our results indicate a significant reduction in foliar complexity the developing human cerebellum. We also observe aberrations in the developmental trajectories of specific cell types like Purkinje cells, and progenitor zones like the rhombic lip. Significantly, proliferation and self-renewal of rhombic lip progenitors is reduced leading to hypoplasia, particularly of the posterior lobe. Through our analysis of the human fetal DW cerebellum, we begin to directly address the developmental pathology of human DWM beyond that of the mouse models that share similar pathology. Our studies will fundamentally improve our view and understanding of the biology of the human cerebellar development and give us insights on the developmental pathogenesis of DWM.