Traumatic brain injury is responsible for over 200,000 hospitalizations every year and is especially common among contact sports players and military personnel, who may receive multiple mild traumatic brain injuries (mTBI, also called concussions) within a short period of time. How repeat injury affects decision making dynamics among this cohort of injured individuals is still poorly understood. GLM-HMM analysis has been offered as a way of inferring the hidden states of subjects during a task. In a mouse model of mTBI, we applied this GLM-HMM analysis to both naive and expert injured and sham mice performing a 2-cue odor discrimination task. All cohorts had a hidden state which placed high weights on previous baseline lick frequencies, indicating that trial-to-trial attention is largely maintained. Naive mice showed more variable state distributions compared to expert mice, indicating the heterogeneity of the initial phases of learning. Pooled analysis of naive mice also placed higher weights on their previous choices, indicating the presence of perseveration. Pooled analysis of expert mice showed high weights on licking in anticipation of the reward and low weights on bias and previous stimuli, indicating not only successful learning but also an ability to quickly change response based on new information. Within each group, there was substantial variability, indicating that mice, both injured and sham, learn in potentially different ways.

Head direction (HD) cells play a vital role not only in the fly’s visual navigation system, but also their olfactory system. The primary HD cells are ellipsoid body-protocerebral bridge-gall (E-PG) cells, which integrate environmental visual feedback in order to update the fly’s heading direction. Past work in the Frye lab shows that visual feedback is needed for odor navigation. If E-PG cells are silenced, flies can't receive visual feedback and make fine tuning heading adjustments. Thus, we hypothesized that silencing E-PG cells should impair their odor navigation. Additionally, visually clamping the background to the fly’s heading position disrupts visual feedback, which impairs the HD system to properly work. Thus, we hypothesized that a visual clamp should disrupt odor navigation. To test the first hypothesis, we magnetically tethered E-PG silenced flies, and transgene control flies in a high resolution customized olfactory magnetic tether (OMT) apparatus, and measured their heading angles relative to the odor plume position. For the second hypothesis, we tethered wild type population cage flies (PCF) and utilized the same apparatus and heading angle analysis. Based on our heading angle analysis relative to the odor plume, we conclude that genetically silencing E-PG cells, as well as utilizing a visual clamp impairs odor navigation in drosophila, demonstrating the importance of visual feedback and an intact HD system for odor navigation.

Fatty acids are essential to central nervous system function, aiding in energy storage, signaling, and membrane structure. Among dietary omega-3 and omega-6 fatty acids, docosahexaenoic acid (DHA) has been shown to restore olfactory neurogenesis in the aging brain via effects on the sub ventricular zone (SVZ). However, its specific impact on neural progenitors and stem cell populations remains unclear. Most prior studies used murine or neurosphere models that lack the complexity of the developing human brain. This study investigates DHA-BSA supplementation using human brain organoids derived from embryonic and induced pluripotent stem cells, providing a physiologically relevant model. Five experimental groups with varying supplementation times and matched controls were analyzed for changes in proliferation, progenitor populations, and neuronal activity. Preliminary findings suggest DHA could promote neural progenitor proliferation, indicated by increased Ki67-positive cells in neurogenic zones. DHA-treated organoids also show potentially more mature, active neurons (c-Fos). These results suggest that DHA may enhance neural stem cell populations. Future directions include quantifying current IHC data, additional staining, biological replicates, and single-cell RNA sequencing to further characterize DHA’s effects on neurogenesis. Overall, this study highlights the utility of brain organoids in modeling neurodevelopment and suggests DHA’s potential as a supplemental therapeutic agent for neurodegenerative diseases.

The goal of this study is to understand how attention levels and task-related performance can be affected by other external factors, a relationship that is still unclear and not fully understood. In this study, participants were given continuous performance and spatial memory tasks while EEG brain waves and videos of their behavior were collected to analyze their attention levels. On the day before the session, they were given questionnaires that assessed their stress, arousal, motivation, and attention levels in the last week. Immediately before and after the session, participants were given questionnaires that measured their stress, arousal, motivation, attention, and physical discomfort levels. These categories were compared against each other to identify any correlations between participants’ experiences during the last week and their attention levels during the task, as well as relationships between these factors for each individual. These relationships were then compared for the set of participants to analyze if and how this data can be applied to a larger group of individuals, which is particularly relevant in a classroom. Understanding how environmental factors can impact attention and motivation is needed to better engage students and improve learning. It can also help lead to insight into how disorders, such as attention-deficit hyperactivity disorder(ADHD), can be affected by external influences to better understand and treat such conditions.

Alzheimer’s disease has been widely studied due to its prevalence, effect on memory, and fatality rate–particularly among the elderly. Despite this, no cure and few treatments have been found. We created a novel cell model to identify genes that could lead to increased or decreased disease progression when overexpressed, with the goal of finding genetic targets for therapy. Disease progression is measured by the degree of tau aggregation in the cell model, which has been shown to be a viable method for measurement. This novel cell model utilizes HEK-293 cells containing pathological tau seeds extracted from human brains afflicted with Alzheimer’s disease, which is a more representative model than the current cell model being utilized, which contains tau pre-formed fibrils that are manufactured instead of extracted and may not provide results consistent with actual disease. These cells also express soluble tau protein to aggregate onto the pathological seeds, with both the soluble tau and the insoluble seeds being bound to GFP for visualization. This cell line provides multiple uses, from screening genes for their effects on tau aggregation or degradation, which provides drug targets for therapy, to allowing companies to test therapeutic candidates designed to affect tau aggregation. Gaining more representative technology for these tests can increase the validity of results and eventually lead to treatments, or maybe even a cure, for Alzheimers.