MACUB (2021) Conference

Abstract: In this study light microscopic study analysis of adult zebrafish optic tectum maintained in organotypic culture revealed that reactivated cells (potential stem cells) are able to form embryonic neural tube-like structures amongst spongiform, degenerating brain tissue. Furthermore, I kept optic explants in organotypic culture conditions for up to seven days. Tissue chunks from 24, 48, 96 hours, and seven days were fixed as-is and processed for scanning electron microscopic analysis. Structures were viewed at relatively low magnifying power at each surviving time, and about 10-20 individual images were captured and later stitched together to create a composite image (montage) in Adobe Photoshop. Cellular features such as size, surface appearance, surface protrusions, location, and grouping were analyzed. Interesting areas were further imaged under higher magnifying power. This composite image analysis allowed the authors to see three-dimensional, spatial relationships between surviving and damaged/dying cells. Based on the actual sizes of recognizable structures, formation of blood vessels, cellular aggregates, granulated cells, and surface membranes such as pia mater could be detected.

Abstract: GABA (γ-aminobutyric acid) an inhibitory neurotransmitter in molluscs and other animals has not been well studied in bivalves. In humans, impairment of GABA neurotransmission can cause epilepsy. In the bivalve mollusc Crassostrea virginica, as well as other bivalves, serotonin is an excitatory neurotransmitter that increases beating rates of gill lateral cell cilia. Previously our lab demonstrated in C. virginica serotonin’s increase of cilia beating rates is blocked by applying GABA to the visceral or cerebral ganglia. Additionally, bicuculline methchloride, a GABAa receptor antagonist, blocked the effects of GABA. By using HPLC we previously detected GABA in low ng amounts in cerebral and visceral ganglia of C. virginica. Our immunofluorescence studies showed the presence of GABA neurons in cerebral and visceral ganglia; and that some serotonin neurons had GABA receptors on their soma. Recently the genome of C. virginica and other bivalves has begun to be mapped. By conducting BLAST searches of the NCBI (National Center for Biotechnology Information) database using DNA and protein sequences of C. virginica and other invertebrate and mammalian species we found matches for GABAa and GABAb receptor genes on C. virginica chromosomes 3 and 5, respectively. Various invertebrates had Percent Identity above 60%, while humans and mice had Percent Identity of about 40% to 50% for GABAa and GABAb. We hypothesize that the ligand binding sites (LBS) for GABAa and GABAb receptors in C. virginica are evolutionarily conserved and will closely match those of other animals. To study this, we conducted searches of the NCBI database for GABAa and GABAb LBS of C. virginica and compared them to other animals. We found GABAb LBS contained 4 amino acids (N, L, A, Y) in positions 34, 122, 123, 267 that were highly conserved in LBS of other bivalves, gastropods, insects, mice, rats and humans. GABAa LBS for C. virginica has not yet been identified. We did find LBS of other animals contained 2 amino acids (L, Y) that were highly conserved among the animals in which it has been identified. The C. virginica GABAa receptor does contain L and Y amino acids. The study complements our earlier physiology and cell biology studies demonstrating the presence and a function for GABA in C. virginica and shows the genome of C. virginica contains genes to produce GABA receptor LBS that are similar to those of other animals. This new information is valuable as it shows the simple nervous system of C. virginica can be used to conduct studies on GABA neurotransmission. This work was supported in part by grant 2R25GM06003 of the Bridge Program of NIGMS, NIH grant K12GM093854 07A1 IRACDA Program of Rutgers University and PSC CUNY grants 62344 00 50 and 63434 00 51.

Abstract:

Autophagy is a process in which cells degrade their unneeded or dysfunctional organelles or other components. Membrane originating from ER surrounds the components to be recycled and form autophagosomes. Autophagosomes fuse with lysosomes forming autophagolysosomes where the digestive enzymes of the lysosome breakdown the contents. Autophagy occurs under stressful certain condition including starvation, but may play a role in overall cellular maintenance in neurons. Decreased autophagosome activity has been associated with neurological-diseases such as Alzheimer’s disease. Multiple proteins are associated with autophagy and formation of autophagosomes such as GABARAP and LC3 proteins. LC3 is recruited to the autophagosomal membrane and used as measure autophagy. GABARAP plays an important role in recruitment to form autophagosomes, although the relationship between the actions of LC3 and GABARAP are still being investigated.. In this project, the regulation of GABARAP during starvation induced autophagy in HEK cells is investigated in comparison to LC3 investigated on various time. Results indicate that In 2 hrs but not 1 hr of starvation caused an increase of LC3 clustering, suggesting induction of autophagy. Co-expression of GABARAP while not not affecting the clustering of LC3 in unstimulated, did reduce LC3cluster in stimulated cell such as starvation condition.

Abstract:

Interaction within and between communities is an inevitable and important part of daily life. Previous research has surfaced a causal relationship between interracial interactions and a temporary depletion of executive functioning, namely, inhibitory control. Understanding the mechanisms involved in this phenomenon can shed light on how societal infrastructures and policies can be better informed and prepared to mitigate and account for these effects. One important translation of that intent into scientific practice is to extend the lens of past work to include a study on the branch of executive functioning known as flexible thinking. It is also vital in reaching a wholistic conclusion to further the existing studies on the mechanism of anxiety on this phenomenon, to see what other behavioral displays can provide new insights into this matter. With this foundation, the question becomes: What is the effect of interracial interaction on flexible thinking and behavioral displays. This will be examined using the traditional model of recorded interactions between the participants and a confederate of either the same minority status as them, or a different minority status in which they will be asked to answer questions both from racially charged topics as well as neutral ones. These interactions will ultimately be coded for specific quantitative behavioral display markers such as interaction length in seconds, number of pauses, perceived stress level, number of body movements, and number of smiles. The interaction will be followed by the participants performing the Wisconsin Sorting Task (a known measure of flexible thinking.) This will then be followed by a demographic survey, a debriefing, and finally, the participants will be compensated for their time. The results of this study were that some behavioral displays did show a statistically significant difference between groups, namely the interaction length for both racially charged and neutral topics, as well as body movements. The Flexible Thinking data was not statistically significant, though did show an interesting trend, particularly in percent error, which demonstrates a similar finding as that of past research on this topic. While these results leaves us curious, it points toward an abundance of potential research that if done under more traditional circumstances, such as in-person rather than over Zoom, show promise for some worthwhile discoveries. The intention to explore this phenomenon is fundamental in advancing our scientific awareness of this human response to interaction with those we perceive as different. Understanding this can lead to supporting much-needed reform in our educational policies, our healthcare system, our legal system, and so much more.

Abstract:

Worldwide, chronic pain (CP) affects over 1.5 billion people. Pain is an existing problem that is difficult to treat because we don’t quite yet understand what causes it. One way pain becomes chronic is if the brain changes post-injury. Evidence has emphasized the role of the hippocampus as central to the experience of pain itself and to CP’s associated comorbidities such as memory impairment, psychiatric mood alterations, and cognitive deficiencies.

Research in animal models has demonstrated that following CP conditions, there are cellular changes in the hippocampus. While most research regards neuroinflammation simply in terms of the number of activated glia, our laboratory strives to understand chronic pain by analyzing hippocampal glial cell morphology and arborization, giving insight into the complexity of glial processes beyond the mere quantification of cells. We hypothesize that peripheral injury results in neuroinflammation and morphological changes in astrocytes and glia in the chronic pain hippocampus.

Our laboratory used both the spared nerve injury (SNI) and tibia fracture model of CP. At three time points (3-week, 7-week, 20-week) post-injury, mice were tested for memory function (Y maze, social memory) and nociceptive indices (von Frey mechanical allodynia). Immunohistochemical (IHC) analysis was performed following the behavioral tests to measure glial presence (Iba1 and GFAP). Glial morphology and arborization were analyzed through Sholl analysis using Neuron J and Image J.

Sholl analysis of microglia revealed a reduction in glial processes and in increase in glial cell length post-injury, which are indicative of increases in glial complexity. Further analysis of glial complexity in terms of arborization and pruning will be conducted to reveal whether the morphology of the injured brain can provide insight into the pruning of neurons by glia in control versus injured conditions.

By looking at glia more closely, we may develop a better understanding of neuroinflammatory processes. In the future, we aspire to link these morphological changes to functional changes in glia, with the prospect of finding novel therapeutic treatments for the chronic pain patient.

Abstract: Alzheimer’s Disease is a brain disease characterized by a buildup of amyloid plaques and tau tangles in the brain that leads to inflammation, and the death of neuronal cells. The risk factors for this disease include age, family history, head trauma, poor sleep patterns, and obesity. Some of the common symptoms of Alzheimer’s include memory loss, difficulty focusing, and behavioral changes. One of the primary risk factors for developing Alzheimer’s disease is obesity, with later onset to induce hypophagia and weight loss. Although this major change in metabolism is highly prevalent in Alzheimer’s disease patients, the metabolic factors involved in the progression of the disease are poorly understood. This research aims to explore changes in metabolic factors associated with Alzheimer’s disease using the Appᴺᴸ⁻ᴳᶠ amyloid beta knock-in mouse model. Through blood assays and behavioral tests, cytokine and leptin levels, and memory tasks were measured in Alzheimer’s disease model mice at 6 weeks (young) and 7 months (old) of age. While memory in the Appᴺᴸ⁻ᴳᶠ was similar to control mice at 6 weeks of age, the mice failed memory tasks by 7 months of age. In young Appᴺᴸ⁻ᴳᶠ mice, a significant increase was found in 46 cytokines in blood sera, such as LeptinR, ProMMP-9, Lselectin, CTACK, Shh-N, Resistin, and TNF alpha. This rise occurred prior to plaque formation and cognitive decline. By 7 months, during moderate to severe disease, the changes were no longer significant. Young mice also had a significant decrease in leptin, a hormone signaling satiety, that increased by 7 months of age. These results show that metabolic changes occur prior to the symptoms of Alzheimer’s disease and may be involved in its onset. Further investigation will shed light on how these metabolic changes are involved with the progression of Alzheimer’s disease.

Abstract: Traumatic brain injury (TBI) is a significant public health concern that remains a leading cause of death, disability, and socioeconomic burden because there exist little to no therapeutic treatment. After a traumatic brain injury, the brain attempts self-repair through TBI-induced neurogenesis. However, the new neurons' capacity for recovery is restricted by changes in the microenvironment, such as reactive astrogliosis, which affect neuronal survival and axonal regeneration. Adenosine kinase (ADK), the critical adenosine-metabolizing enzyme, has been studied in several brain disorders, including epilepsy, schizophrenia, and stroke. Data from recent lab study reported an association between ADK expression levels and TBI-induced neurogenesis and cell proliferation in adult mice. Due to this data, we hypothesized that ADK inhibition promotes neuronal survival and differentiation after TBI. To address the underlying mechanistic links between ADK and TBI- induced neurogenesis, we used an in vitro model of a scratch-induced injury and immunocytochemistry. Neuronal cells derived from the cortices of wild-type embryos were cultured on coverslips and a scratch injury was induced four days after plating. Subsequent to the injury, each coverslip was treated with either media, the ADK inhibitor ITU, or vehicle (DMSO). Six days after the injury, the cells were stained with various markers to indicate cell death (TUNEL), neuronal growth (BDNF), neuron differentiation (MAP-2) and neuron activation (ERK1/2). Results indicate that ITU promoted cell survival after TBI. In addition, there was an increase in axon growth after the treatment with ITU. However, we observed that ITU-treated cells had fewer dendrites with shorter dendrite lengths, indicating a more immature phenotype as compared to VEH-treated cells. In summary, these data suggest that inhibition of ADK may promote cell survival and growth in an in vitro model of TBI.