Humans have limited ability to regenerate many tissues. In instances such as limb loss or spinal cord injuries there is a dramatic decrease in quality of life and there are few therapeutic options to help recover from these serious injuries. My research characterizes how epigenetic changes affect tail regeneration in the frog, Xenopus tropicalis. Xenopus tadpoles have significant regenerative abilities when they are developing but that ability is lost as they age and undergo metamorphosis. This transition in regenerative ability makes them a great model for understanding the molecular differences between tissue that can regenerate and tissue that can not. Other advantages of Xenopus for epigenetic studies of regeneration include a well-characterized diploid genome and many well-established molecular tools. Previous work by our group has shown that the accessibility of chromatin undergoes drastic remodeling in which many of the genes are made inaccessible shortly after injury in the Xenopus tail. These genes are then reopened during regeneration. These changes are likely due in large part to histone deacetylases (HDACs) and histone acetyltransferases (HATs). We hypothesize that HDACs are necessary for causing the initial inaccessibility of the chromatin and that HATs are necessary for the reopening of chromatin for regeneration. We used an Assay for Transposase-Accessible Chromatin and sequencing (ATAC-Seq) to show that the chromatin does not undergo its normal shift toward inaccessibility over the course of regeneration when tadpoles are treated with HDAC inhibitors, coupled with a reduction in regenerative ability. This study will help us identify how histone acetylation directs changes in chromatin accessibility. Additionally, with immunohistochemistry we can study specific sites of histone acetylation and validate these antibodies for future epigenetic research. Our study of large-scale epigenetic changes during regeneration will help characterize how epigenetic gene regulation enables regeneration.

There is currently a lack of research in how transgender adolescent populations are affected by sleep and depressive symptoms. Sleep is incredibly important for teens, and there are links between depression and negative sleep outcomes. The purpose of this study is to examine correlations between gender, depression, and sleep in adolescents. I am using all data from a previous study that was comparing sleep and obesity in 100 cis-gendered adolescents aged 12 to 18. I am using this data to determine if a significant correlation exists between gender, objective sleep measures including total sleep time, sleep onset, wake after sleep onset, sleep efficiency (measured via Actigraphy), and depressive symptoms (measured via Center for Epidemiologic Studies Depression Scale, with scores of 16 or higher considered positive for significant depressive symptoms). An ANOVA test is being used to analyze for a significant correlation between gender, mean sleep time in minutes, and the presence or absence of depressive symptoms. The analysis of this data determines whether or not gender has a role in sleep and depressive outcomes, thereby determining the need for a further study of sleep and depressive symptoms in transgender adolescent populations.

Degeneration of mechanosensory hair cells in the inner ear leads to complications in hearing and balance. Calcium plays an important role in hair cell function and failure to maintain calcium homeostasis is an underlying cause of hair cell death. We used hair cells in the zebrafish lateral line as our model, to explore the role of endoplasmic reticulum (ER)-mitochondrial calcium flow in hair cell damage. We utilized ER-GCaMP-150 for these studies, a new low-affinity calcium indicator made distinctly to look at calcium concentrations in the ER. Injection of zebrafish embryos with ER-GCaMP-150 expressed under a hair cell specific promoter allowed for visualization of ER Ca²⁺  concentrations under a high-resolution microscope. To date we have confirmed expression of ER-GCaMP in our zebrafish models and quantified Ca²⁺ transfer between the ER and mitochondria. Examining changes in calcium concentrations of hair cell organelles provides the opportuninty to gain more insight into the intracellular mechanisms underlying hearing loss.

BrainNet is a system designed to be the first multi-person direct brain-to-brain interface in human brains. This interface combines electroencephalography (EEG) to record brain signals and Transcranial Magnetic Stimulation (TMS) to deliver information to the brain. Through this interface, three subjects will collaborate to complete a Tetris-like block game using direct brain-to-brain communication. Two of the three subjects are designated as "senders", whose brain signals are decoded by real time EEG data analysis. The decoding process extracts information about their decisions to rotate a Tetris block before it is dropped to fill the line. Then, this information is transmitted via TCP and directly delivered through magnetic stimulation of the occipital cortex to the brain of the "receiver", who cannot see the game screen. The receiver integrates the information s/he acquired from the senders and conveys this information back through EEG to the computer, which completes the intended action of either turning the block or keeping it in the same position. The performance of this brain network is evaluated in terms of the accuracies attained in (1) decoding decisions through EEG analysis, (2) delivering information through TMS, and (3) making correct group-level decisions during the block game. This interface enables for the very first time simple transmission of information directly among three brains without any verbal or physical action. Our preliminary result has shown proof of successful communication between the senders and the receiver with 14 out of 15 trails correct. BrainNet enables direct brain-to-brain communication of simple information between multiple humans, and is a step forward towards ultimate brain-to-brain communication.