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Oscillatory synchrony between the hippocampus (HC) and the medial prefrontal cortex (mPFC) is a potential therapeutic target to facilitate HC-mPFC dependent decision-making. In rats, HC-mPFC local-field potential (LFP) coherence in the 4-12Hz (theta) range is strongly correlated with successful decision-making on SWM tasks. While several studies have reported on the relationship between HC-mPFC theta coherence and choice-accuracy on spatial alternation tasks, it is unknown if HC-mPFC theta coherence is causal to successful SWM choices. To this end, we aimed to either enhance or impair SWM decision-making based on the initiation of delayed-alternation (DA) task trials at points of either high or low HC-mPFC theta coherence. We predict that trials initiated at points of high coherence will result in higher choice accuracy in SWM-dependent DA tasks. Conversely, trials initiated at points of low coherence will be more likely to result in incorrect choices due to impaired SWM. We implanted rats with electrodes that targeted the dorsal hippocampus and the mPFC to record LFP. Rats were trained to perform a DA task with a variable delay at the choice-point. Using closed-loop technology developed in MATLAB, theta coherence was estimated in ½ second windows before rats were presented with choices on an automated T-maze. To ensure the presence of theta-states in the HC, rats ran on a treadmill located at the choice-point. Using rat-derived thresholds for “low” and “high” coherence, rats were only presented with a choice when coherence was sustained for two consecutive ½ second windows. Each day, rats experienced a 20-minute experimental session (‘low’ or ‘high’ coherence triggered trials), and a yoked-control session. During the yoked-control session, rats were presented with trials based solely on the duration of the delays in the previous high or low coherence session. This control session guarantees that any effects observed during the experimental trials are not an artifact of delay-duration. Here, we will present pilot data from an example rat.

DSU Summer Research Symposium 2021

Using Endogenous Brain Rythms to Impact Decision-Making on a Spatial Working Memory Task in Rats

This annual event showcases and celebrates the neuroscience research in Delaware.  Posters and talks highlight neuroscience research carried out by graduate students, undergraduate students, and research staff at all of Delaware’s research and education institutions. The Lounge section of the symposium allows real-time interactions and networking among attendees.  New this year is an expo of research core facilities in Delaware.  Check them out in the Research Cores section of our poster session, or see the logos below.

Delaware Neuroscience Symposium 2021

poster

Welcome to Delaware State University’s Annual Summer Research Symposium, and thank you for attending! Our symposium represents the culmination of students’ summer experiences in research at Delaware State University. This event showcases the work of college students working on faculty-led research projects, as well as middle and high school students experiencing research for the first time working in research groups. Whatever the case, this summer has been a unique experience for the students, and we hope a transformative one. Even for students who are not planning a career in scientific research, their summer experience has given them skills they will draw on for years to come. 
 Please join us on the mainstage and in Gather for the live event, and visit the recorded poster presentations any time.
 The student participants and organizers of the various summer programs at DSU would like to thank all of the research mentors who guided our summer program participants. There were many DSU faculty, graduate students, and other research and program staff who gave their time and energy to help our students have a fun and educational summer experience. Without their generosity and patience these summer programs would not be possible.
 For the research participants, we hope that you will maintain contact with your research mentors and colleagues. Science is a relatively small community made up of disciplinary “neighborhoods”. If you continue to work in a discipline, the other folks in that discipline will be like your neighbors that you run into regularly. Staying in contact with them will help you keep up with the news of the neighborhood, and open doors to educational and career opportunities. Whether you continue in science or take a different career path, for this summer you have been part of the world of research, and you will benefit from that perspective for the rest of your life.

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Welcome to Delaware State University’s Annual Summer Research Symposium, and thank you for attending!

Parkinson’s disease (PD) is the most prevalent neurodegenerative motor disease, mostly occurring in people over the ages of 65 years. Protein aggregation known as Lewy body is the hallmark for dopaminergic neuronal death in Parkinson’s disease pathology(1). PD patients initially experience motor deficits such as tremors and postural instability. As the disease progresses, patients lose complete control of physiological functions, which ultimately causes death. The current drugs available for the treatment of PD only alleviates the symptoms by boosting dopamine levels, but do not halt neurodegeneration. The main objective of this study is to evaluate the efficacy of a novel compound-6 by AptaBio as a potential therapeutic for Parkinson’s disease treatment. We analyzed whether this compound was efficacious in reducing PFF (Preformed fibrils of alpha-synuclein)-induced toxicity in N27 dopaminergic cells(3). The compound-6 not only enabled to increase cell viability and reduce cytotoxicity in vitro, but also reduced oxidative stress and minimized protein aggregation. We first tested the compound using a transgenic mouse model known as line 61(3). We demonstrate that the compound-6 successfully decreased motor deficits with stabilizing the levels of dopamine. However, we wanted to use an in vivo model that was more suitable to showcase the compound’s capability of halting neurodegeneration. Hence, we chose to use the PFF injected mouse model. Sonicated PFF was stereotaxically injected to the striatum of C57BL/6 male and female mice bilaterally (aged around 12 months). The PFF injection increases the phosphorylated alpha-synuclein and causes protein aggregation(2). After 4 to 5 months post injection, mice started showing Parkinsonian symptoms in behavior. At this stage, we gavaged the mice with the AptaBio compound-6 at two different doses of 5mg/kg and 25 mg/kg for 5 weeks. After gavaging we performed multiple behavioral tests such as hindlimb clasping, pole test, rotarod, nesting and grooming to measure whether motor function improved with the treatment as compared to PFF injected group that wasn’t treated. There was another group that was only injected with PBS, which was considered as positive controls since they do not show any motor deficits. Currently, we have finished all the behavioral tests and are finishing up data analysis for next 2 weeks. Taken together, our results are promising to show that the AptaBio compound-6 can be a novel and effective treatment for PD by halting neurodegeneration and promoting neuronal recovery.

AptaBio Compound-6 As a Potential Therapeutic for Parkinson’s disease models

Recognition of an α-helix and a complementary cleft are prevelant in many disease-relevant Protein-Protein Interactions (PPIs), and disruption of these PPIs is the focus of many drug discovery efforts. In the first part of our study, we used computational hot-spot analysis to illuminate critical residues in established PPIs involving an α-helix and a complementary cleft. In the second part of this research, we designed proteins to inhibit α-helix / complementary cleft PPIs involved in two distinct steps of the SARS-CoV-2 entry pathway. Previously, we have shown that helix-grafted proteins designed to mimic the HIV-1 gp41 C-peptide, inhibit an interaction involving HIV-1 gp41 N-peptide trimer, and gp41 C-peptide, resulting in the inhibition of HIV-1 entry in a live virus assay. Here, we used helix-grafted display to create novel proteins designed to inhibit two distinct steps in the SARS-CoV-2 entry pathway, which both rely on PPIs involving an α-helix and a complementary cleft. The design of these proteins, t

Targeting α-Helix-Dependent Protein-Protein Interactions In Two Steps of the SARS-CoV-2 Entry Pathway

COVID-19 is a new strain of Coronavirus that had not been discovered in humans previously. It is a disease brought about by SARS-CoV-2 that can trigger a respiratory tract infection. The pandemic has affected people’s lives negatively across the U.S. It was suggested that racial/ethnic minorities were mostly affected by the outburst of this pandemic according to data from the survey people took. The pandemic has affected employment according to the finding from the data filled out by the individuals. More people have lost their jobs because it was not considered essential. As a result, the poverty rate went up. This research will be carried out with community partner organizations, who will recruit participants from communities to take a structured survey and serology test. The purpose of this research is to explore the economic impact of COVID-19 in Delaware’s underserved communities. Specifically, this study will investigate unemployment and household income during the COVID-19 pandemic. The study will also examine whether there are differentials in unemployment and household income by race, gender, and educational level. The significance of this research is to understand the economic impact of the COVID-19 pandemic in underserved communities and bring awareness.

Economic impact of COVID-19 in Delware underserved communities.

Machine learning is an area of artificial intelligence that is responsible for advancements in a broad range of fields such as facial recognition, self-driving cars, fraud detection, and language translation. By utilizing the machine learning algorithms, it is possible to create personalized predictions for occurrence of a disease from a large set of data. The purpose of this study was to build a machine learning model from the Framingham Heart Study data set to predict the ten-year risk of coronary heart disease with a receiver operating characteristic area under the curve (ROC-AUC) of at least 0.70. The Framingham Heart Study is a long-term, cohort study with the purpose of determining the risk factors associated with cardiovascular diseases. We utilized a portion of these data that contained the records of 4,239 individuals. The R programming language was used to produce a series of machine learning models, including logistic regression, random forest, and support vector machine, and a stacked ensemble model composed of the previous three. The Framingham data set was split into training, validation, and testing sets. The training set was used to train the models, the validation set was used to tune the hyperparameters, and the testing set was used to assess the final performance of each model. The best performing model of the four was then selected as the final model. Each of the four models demonstrated similar performances with ROC-AUC scores ranging from 0.706 - 0.725. The logistic regression model, which was the simplest model of the four, was selected as the final model because it performed the best with a ROC-AUC of 0.725. The simplicity of this model makes it readily interpretable, thus increasing its value as a potential aid in the assessment of the risk for coronary heart disease. Our logistic regression model was then successfully incorporated into a Shiny app to make personalized predictions of the ten-year risk of coronary heart disease.

A Machine Learning Approach for Predicting the Ten-Year Risk of Coronary Heart Disease from the Framingham Heart Study Data

The Impact of Treatment Utilization Types on Generalized Anxiety Disorder and Major Depressive Episode among Soldiers.

Jasmine Sanchez Abstract Title: Genetic interaction between endu-2 and rnh-2 reveals their roles in neurogenesis in Caenorhabditis elegans RNase H2 is a ribonuclease/DNA repair factor that removes ribonucleotide leftovers from DNA. RNase H2 is essential for neurogenesis in animals. Mutations in the human RNase H2 genes cause Aicardi-Goutières syndrome, a severe and fatal neurological disorder. Dr. Ii’s research group found that mutations of C. elegans rnh-2 gene, which encodes the catalytic subunit of RNase H2, cause neuronal defects and behavioral changes. Endoribonuclease ENDU-2 plays a role in neurogenesis in nematodes and negatively regulates cold tolerance via apoptotic genes and the ADL neurons in C. elegans. Both endu-2 and rnh-2 are important for developing healthy neurons, but the relationship between these two genes is entirely unknown. C. elegans is a model organism widely used in Biomedical Research. A hermaphrodite has only 302 neurons and all of which corresponding behaviors have been identified. The power of C. elegans genetics has held the key to deciphering essential concepts in neuroscience and biomedicine for many years. In Aim 1, I performed 2 genetic crosses between the endu-2 mutant and the two rnh-2 mutants to isolate two different double mutants. Despite neither single mutant display sickness, we found synthetic lethal interactions between the mutations of these genes. Based on the results, the mechanism of the synthetic lethality appears to be due to accumulation of partial pathway defects in the same pathway. In Aim 2, I conducted “gene knockdown” using RNAi technique. We found that endu-2 gene knockdown moderately impaired the worm’s development, whereas rnh2 gene knockdown severely impaired the development and significantly increased its death rate. Surprisingly, an additional endu-2 knockdown reduced the severe defects of the rnh-2 single knockdown. This implies that endu-2 gene knockdown partially suppressed the defects caused by rnh-2 knockdown, suggesting endu-2 and rnh-2 function in the same pathway for neurogenesis.

Genetic interaction between endu-2 and rnh-2 reveals their roles in neurogenesis in Caenorhabditis elegans

We're investigating short and long term developmental neural deficits that could be caused by Caesarean Delivery in Prairie Vole offsprings. My focus within the experimental studies is to test social communications and behaviors of prairie vole pups during a series of tests to investigate the impact of birth mode (caesarean vs. vaginal) on postnatal thermoregulation.

Developmental Consequences of Caesarean Delivery in Prairie Voles

At the neuromuscular junction, binding of acetylcholine to receptors on the muscle causes an increase in intracellular calcium, leading to muscle contraction. Levamisole is an agonist for acetylcholine receptors (AChR) which effectively produces time-dependent paralysis. A voltage gated calcium channel (egl-19) facilities the movement of calcium into the cell promoting muscle stimulation. This influx of calcium then stimulates the release of calcium from the sarcoplasmic reticulum through unc-68. Calcium is then transported from the cytosol to the extracellular space where it can bind to troponin and myosin. After this, a membrane ATPase (mca-3) works to restore proper intracellular calcium levels. Thus, we would expect that the loss of this calcium-ATPase would cause increased intracellular calcium and faster paralysis than the wild type. However, in the paralysis assay the opposite phenotype is observed. MCA-3 only removes a single calcium ion from the cytoplasm per molecule of ATP. On the other hand, sarcoplasmic reticulum calcium-ATPases (SERCA) work together with membrane ATPases to lower cytoplasmic calcium levels by bringing calcium back to the sarcoplasmic reticulum. SERCAs are much more efficient and are able to transport two calcium ions per ATP molecule used (Ingesi and De Meis 1989). We hypothesize that sca-1 mutants will be levamisole hypersensitive, while mca-3 and unc-68 will be resistant to levamisole compared to controls.

Impact of Calcium-ATPase Activity on Bioenergetic Failure in Hyper-stimulated C. elegans

How biological programs evolved to support human cognition is an enduring question of interest. Yet, we still lack appropriate procedures to align ages across species. We collected 228 time points from abrupt and gradual changes in behavior, neuroanatomy, and transcription in humans and chimpanzees to identify corresponding ages across the two species. We also collected time points (e.g., mortality curves) from diverse populations (e.g., hunter-gatherers) in males and females to account for individual variation in corresponding ages across humans and chimpanzees. Corresponding ages are similar in the two species early in development (shortly after birth) but gradually diverge with age in the two species. The lifespan is extended across diverse human populations relative to chimpanzees, and is concomitant with biological pathways (e.g., brain atrophy) observed in aged humans but not in chimpanzees. The inclusion of time points from diverse populations yields improved estimates in predicting ages in humans and chimpanzees and shows old age as a distinctly human characteristic.

Finding corresponding ages between humans and great apes

Alzheimer’s disease (AD) is the most common form of dementia, accounting for 70 to 80% of all cases. The greatest risk factor for AD is aging; an estimated 30 million people are living with AD and over the next 30 years it is projected to increase to over 130 million worldwide. In addition, one in three seniors have died of AD or another dementing disease, and since 2000, deaths from Alzheimer’s disease have increased 89%. TDP-43 is the major pathological protein in motor neuron disease and frontotemporal dementia. Previously, TDP-43 pathology has been reported that in up to 50% of late-onset, sporadic cases of Alzheimer’s disease, the TDP-43 protein has been reported as an age-related co-pathology linked to dementia severity. TDP-43 proteinopathy in those over 80 has recently been recognized as an independent disease entity, limbic- predominant age-related TDP-43 encephalopathy (LATE). There are over one million people living with LATE in the United States. As LATE shares some of the clinical features of dementia seen in AD in addition to co-existing with AD, understanding mechanisms leading to the pathogenesis of LATE and co-morbid TDP-43 pathology could lead to the development of targeted therapeutics. We have developed an inducible cell-specific pathological model by introducing three familial ALS mutations in the human TDP-43 gene(3XTDP43). Utilizing the tetracycline inducible system, we drove 3XTDP43 specifically in the hippocampus (Camk2a-tTA). Ten-month old mice were used in this study where we performed fMRI, histology, Western blot, and solubility fractionations. Results show phosphorylated TDP-43 pathology and a distinct decrease in solubility. In addition, 3XTDP43 overexpression increases phosphorylation of endogenous tau which may indicate aggregation. Though the mice were imaged (fMRI) we have not evaluated those results as of yet. This model may provide a better understanding of the pathogenesis of TDP-43 proteinopathies.

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AptaBio Compound-6 As a Potential Therapeutic for Parkinson’s disease models

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