Non-syndromic orofacial cleft (OFC), comprising cleft lip, cleft palate, or a combination of the two, is among the most common structural birth defects. OFC has both genetic and environmental underpinnings, though the genetic contribution is only partially understood. Members of the same gene regulatory networks associated with OFC are candidates to harbor the “missing heritability” for OFC. Van der Woude Syndrome (VWS) is an autosomal dominant condition characterized by cleft lip and/or palate, and lip pits. Mutations in IRF6, encoding the transcription factor Interferon Regulatory Factor-6, account for approximately 70% of VWS cases, mutations in GRHL3, a transcriptional target of IRF6, account for 5%, and it was recently found that mutations in PRKCi, encoding a kinase, account for 5% more. Published data support that IRF6 is phosphorylated and thereby activated by RIPK4. However, the kinases PRKCi and IKK1 are also required upstream of IRF6 activity. Regulatory interactions within this kinase cascade are unclear. The goal of this project is to shed light upon the kinase cascade encircling IRF6 to illustrate genetic causes of VWS and non-syndromic OFC and ultimately improve patient outcomes. I hypothesize that IRF6 phosphorylation is dependent upon RIPK4, which is activated by IKK1 and downstream of PRKCi activity, and all components are necessary for IRF6 activation. To test this hypothesis, I am conducting experiments injecting mRNA products from our genes of interest into zebrafish embryos and detecting phosphorylation activity within the harvested protein through immuno-precipitation and mass spectrometry analysis to determine protein-protein interactions. I anticipate that in the absence of RIPK4, the pool of Differentially Expressed Genes (DEGs) will align with the pool of DEGs in the absence of IKK1 and IRF6 respectively. Implications of these findings will ultimately give a stronger understanding of the molecular foundations of VWS and non syndromic OFC.

I investigate the effects of scopolamine-induced cholinergic disruption on the working memory performance of rhesus macaques. Working memory plays a critical role in cognitive function and relies heavily on cholinergic signaling in the brain. To explore this relationship, I designed and implemented a delayed match-to-sample (DMTS) task to optimize the accuracy and reliability of the data collected. The DMTS trials involve three phases: stimulus, delay, and choice. Monkeys are presented with a sample stimulus they must memorize. After a variable delay period of 5 to 30 seconds, they select the target image from a set of options. Performance is tracked by calculating the percentage of correct, incorrect, and omitted responses. Daily DMTS sessions provide longitudinal data on memory performance, allowing me to analyze patterns before and after scopolamine administration. I am also learning to analyze spike-spike coherence to investigate changes in neuronal synchronization associated with memory performance. Upon inducing amnesia-like conditions under scopolamine, an M1 muscarinic antagonist, the delayed match-to-sample task evaluates memory performance under baseline and drug-induced conditions. The primary objective of my project is to understand how scopolamine-induced disruptions affect working memory performance and to investigate the underlying cortical mechanisms involved. Based on existing literature and preliminary observations, I anticipate observing a measurable decline in memory performance following scopolamine administration, with older macaques likely exhibiting more pronounced deficits compared to younger macques. This project aims to contribute to the understanding of how cholinergic mechanisms influence working memory performance and to provide insights into the cognitive impairments associated with neurodegenerative diseases.

As the life expectancy for global populations rises, the prevalence of people affected by age-related morbidity has also increased. Although therapies and treatments are available to alleviate such diseases, they do not effectively address the fundamental cause of all such diseases age. One hallmark of age is cellular senescence. Senescence refers to the state of a cell in which it cannot divide anymore due to factors such as stress or damage to DNA. Although this mechanism is naturally preventative there can be many undesirable consequences. As senescent cells accumulate within aging tissues, inflammatory responses are promoted and may even spread senescence to neighboring cells. This causes more inflammation and elevates the risk of illnesses. Targeting these cells with therapeutics such as senolytic drugs presents a potential solution. A combination of senolytic drugs, Dasatinib + Quercetin (D+Q), has been shown to target and lyse senescent cells, thus increasing lifespan and reducing frailty in mice. This research study involves two groups of mice: old and old treated with D+Q, where D+Q was administered for 24 months. Mandibles were collected to evaluate levels of senescence (CDKN1A and CDKN2A, genes coding for p21 and p16, respectively) through RNA extraction and QRTPCR. Inflammation markers, IL1a and IL1b, were also examined as inflammation is frequently associated with senescence. Preliminary observations have shown decreased transcription of CDKN1A and CDKN2A in treated male mice in comparison to controls (p < 0.05 and p < 0.001, respectively) within aging alveolar bone. In addition, IL1a and IL1b were shown to have decreased expression in the treated male mice in comparison to the controls (p < 0.001, p < 0.05, respectively). This project was funded by the SenNET Grant (AG079753) and funded in part by the Dr. Douglass L. Morell Dentistry Research Fund.

The orofacial sensorimotor cortex plays an important role in controlling tongue and jaw movements, such as speaking and eating. Being able to reliably perform these movements has critical implications for people suffering from neurological diseases such as stroke and Alzheimer’s disease, which are known to affect orofacial functions. However, the features of the complex lingual function that drive motor cortical activity are still poorly understood. Here, we investigate how information in the orofacial primary motor cortex (MIo) varies based on factors such as availability of tactile sensation, axis of motion, and specific regions of the tongue. To answer this question, we tracked marker-based movements of the tongue and jaw while recording neural activity from implanted microelectrode arrays in the MIo of two rhesus macaques (Macaca mulatta) engaged in feeding. Decoding accuracies of models based on (i) axis of motion, i.e., antero-posterior (x-axis), supero-inferior (y-axis), medio-lateral (z-axis), (ii) tongue marker region (superficial vs. deep, anterior vs. intermediate vs. posterior), and (iii) local anesthesia applied to sensory branches of the trigeminal nerve, were then compared to evaluate the ability to predict marker position. Generally, decoding performance was best using the y-axis and worst with the z-axis. Additionally, model performance was best in the x-axis of posterior tongue markers. Lastly, we found significant differences in model performance between control and nerve block conditions across all motion axes, with the x-axis showing the largest decrease in performance post-nerve block. These findings indicate that information carried by MIo neurons differ as a function of the tongue's motion axis, region, available tactile information, and varying combinations of these factors. These have important implications for the development of evaluation tools, rehabilitation strategies, and neural prostheses to restore orolingual function in particular and limb sensorimotor function in general.