Tag: Neuroscience

Exploring the effect of bacterial signaling pathways on zebrafish neuro-immune development

Presenter: Dana Zaidan – Neuroscience

Faculty Mentor(s): Joseph Bruckner, Judith Eisen

Session: (In-Person) Poster Presentation

The gut microbiota has been linked to human health and development. We found that the gut microbiota is required for normal zebrafish social behavior, but how it influences the brain development required for social behavior is not well understood. We previously identified a population of zebrafish forebrain neurons that are also required for normal social behavior. By raising zebrafish “germ-free”, we found that the microbiota is required for normal forebrain neuronal arborization.

Microglia are brain-resident immune cells that remodel neurons and are excellent candidates for mediating interactions between the microbiota and the brain. We previously discovered that the microbiota promotes forebrain microglial abundance. We also found that neuronal arborization and microglial abundance are restored in germ-free fish after colonization with several different zebrafish-associated bacterial strains, suggesting that the microbiota might influence social neurodevelopment by a mechanism common to many bacteria. One pathway we explored involves a class of host proteins that receive bacterial signals called the Toll-like receptor (TLR) proteins. We also explored if and how proteins present in bacterial cell walls are sensed by host mechanisms in the brain. Identifying the signaling components that link the microbiota and brain development will clarify our understanding of how host-microbe interactions can influence human health.

Wearable Microfluidic Colorimetric Sweat Sensors for Real-Time Personalized Hydration Monitoring

Presenter: Albert Yim – Neuroscience

Faculty Mentor(s): Jonathan Reeder

Session: (In-Person) Poster Presentation

Continuous, real-time sweat analysis is an underdeveloped field with promising applications ranging from aiding clinical health care to tracking athletic performance. Noninvasive, biochemical metrics indicative of physical exertion, hydration, and injury risk are highly sought-after. Currently, microfluidic devices allow for noninvasive collection and storage of sweat through precisely engineered microchannels but lack a method to record continuous sweat rates. Sweat rate and biomarker composition are highly variant between individuals, requiring a personalized hydration feedback approach. The biomarker variance is significantly attributed to sweat rate, making rate normalized biomarker concentrations from recorded continuous sweat rates indicative of performance metrics. Photolithography was used to create molds with designed microchannels. SIS was used to create a soft, flexible device to collect, store, and analyze sweat. UVO treatment increased efficiency of device bonding and fabrication. Colorimetric reagents were used as the basis for a gradient system to characterize a continuous sweat rate. This was analyzed using video documentation and a pressure-driven flow pump at set flow rates to emulate sweating. Data obtained was suggestive this system was able to measure a continuous sweat rate but was not conclusive. Further research as the sources of inconsistency in results would be required before this would become a feasible method to measure biomarker changes.

Investigating sexual dimorphic P-granule structures during germ cell development in C. elegans

Presenter: Madison Studer – Neuroscience

Faculty Mentor(s): Acadia DiNardo, Diana Libuda

Session: (In-Person) Poster Presentation

Proper egg and sperm development is crucial for the faithful passage of the genome from one generation to the next. To prevent infertility and genomic instabilities linked to congenital disabilities, the process of sperm and egg development is tightly regulated by small RNA pathways. These pathways silence genes that disrupt the genome and maintain silencing across generations independent of DNA sequence, termed transgenerational epigenetic inheritance. In Caenorhabditis elegans, the components of small RNA pathways localize to P-granules, liquid-like condensates that form around the nuclei of developing sperm and eggs. ZNFX-1, a recently discovered structural P-granule component, is required for genome maintenance and fertility. Although ZNFX-1 is known to be involved in transgenerational epigenetic inheritance during egg development, the role of ZNFX-1 during sperm development remains unknown. Preliminary data from the Libuda Lab suggests that ZNFX-1 has sex-specific localization, indicating distinct sex-specific mechanisms for genome maintenance in egg and sperm development. To determine the sexually dimorphic localization patterns of ZNFX-1 during sperm and egg development, I am examining GFP-tagged ZNFX-1 localization in wild type and mutant P-granule strains. This work will reveal the sex-specific role of ZNFX-1 in small RNA pathways and provide insights into the molecular mechanisms that maintain genomic integrity and fertility.

Utilizing Drosophila to investigate novel regulatory pathways for the Hox gene Sex Combs Reduced

Presenter: Alanna Sowles – Neuroscience

Faculty Mentor(s): Kristen Lee, Chris Doe

Session: (In-Person) Poster Presentation

Across species, Hox genes are necessary for an organism’s anatomical development, including the nervous system. Interestingly, these proteins continue functioning within neurons of mature organisms. This research seeks to determine the functional purpose of Hox genes post-development, as these mechanisms could provide novel etiological insight into neurodevelopmental disorders. Drosophila melanogaster is an effective tool for this investigation because fly neurons are similar to mammals, and gene expression of individual neurons is easily manipulated. Within this model, I will utilize the well-characterized Pair1 pre-motor neuron, which expresses the Hox gene Sex combs reduced (Scr). I hypothesize that Scr is functioning in a conserved molecular pathway to preserve the morphology and function of Pair1 neurons. Past research provides intuitive candidates for exploring these mechanisms, like Pair1 proteins Hb and Bcd. RNAi-facilitated knockdown had no significant impact on Scr expression, prompting exploration of alternative genes. Using published resources, several genes with expression patterns similar to Scr were selected and visualized with GFP-tagged proteins. Colocalization of these genes with Scr was assessed via immunohistochemistry, revealing 8 promising candidates for further analysis. Scr expression will be measured after knockdown experiments are repeated for each gene. The results will hopefully illuminate novel regulatory pathways of Scr beyond development.

The Relationship Between Students’ Approach to Learning and Future Thinking in a Science Class

Presenter: Madeleine Smith – Neuroscience, Psychology, and Educational Foundations

Faculty Mentor(s): Jenefer Husman, Sara Hodges

Session: (In-Person) Poster Presentation

Supporting student motivation in post-secondary introductory science courses is an important step in increasing student retention in STEM fields. Prior research has focused on a variable- centered approach to students’ motivation to learn, but a person-centered approach to looking at the relationship between self-regulated learning and motivation variables is necessary. Additionally, research suggests that students’ future goals and their perception of the future influences their performance in school. This study aimed to identify the relationship between future thinking and motivational and self-regulated learning profiles. 385 participants were recruited from an introductory science course at a large Northwest university and completed an online self-report survey on their motivation, goal orientation, self-regulation, knowledge building strategies, and future thinking. K-means cluster analysis indicated that there are three motivational and self-regulated learning profiles. A multinomial logistic regression was conducted and showed that students’ actions towards their future goals are a stronger predictor of their profile adoption than the clarity of their future goals. Understanding the relationship between students’ future thinking and their adoption of learning profiles can help post-secondary science instructors alter course structure to support student motivation and self-regulated learning.

The Role of Microbiota in the Development of Insulin-Producing Cells in Drosophila melanogaster

Presenter: Nicole Mullen – Neuroscience

Faculty Mentor(s): Karen Guillemin, Steph VanBeuge

Session: (Virtual) Poster Presentation

Resident gut bacteria have the capacity to influence aspects of animal metabolism. Previous research in the Guillemin lab showed that in zebrafish, gut bacteria promote the expansion of insulin- producing cells (IPC) in the pancreas through a secreted bacterial protein, Beta-cell expansion factor A (BefA). This research investigates the role of gut bacteria and BefA to promote IPC development in the fruit fly, Drosophila melanogaster. In Drosophila, there are ~7 IPCs located in each lobe of the brain. Our first aim was to test the effect of germ-free (GF) rearing on IPC numbers in Drosophila. Our second aim tested whether feeding flies BefA could restore IPC numbers in GF flies. We compared the number of IPCs present in GF, conventionally-reared (CV), and GF flies fed BefA. Tissue-specific GAL4UAS/GFP in all groups made IPCs visible after dissection. Our results showed that GF flies have fewer IPCs per lobe than CV flies, indicating that microbiota is required for normal IPC numbers. Further, feeding BefA caused a statistically significant increase in IPC numbers in GF larvae compared to CV. However, transgenic expression of BefA, using the UAS/GAL4 system, yielded a trending but not a significant expansion of IPCs in GF flies. This could be due to the low levels of BefA produced through transgenic expression. These results indicate that the microbiota has a powerful effect on metabolic pathways, and cell development, and can influence the normal development of the fly brain.

Spatial Location and Memory Integration

Presenter: Dahlia Mohd Razif – Business Administration, Human Physiology, Neuroscience, Psychology

Faculty Mentor(s): Lea Frank, Dasa Zeithamova

Session: (In-Person) Poster Presentation

Memory is flexible and can be influenced by other items or events that we have encountered. Memory integration refers to the concept that related memories are stored in the brain as overlapping representations which form a memory link that allow us to make new inferences or extract related information. Studies have shown that memory integration is enhanced by time proximity when items or events occur within a close time frame but not much is known regarding how spatial positioning affects memory integration. 160 participants will be split into a spatial overlapping condition and a no spatial overlapping condition. This experiment consists of a study trial, an associative inference test and an associative memory test. During the study trial, participants will be presented with object images positioned relative to base object images. For the associative inference test and memory test, object images will be presented as cues to evaluate the extent that participants can integrate the associations that share the common element of the base object as well as remember presented pairs during the study trial. As the date of submission of this abstract is prior to data collection, conclusions have not been realized. We hypothesize that spatial overlapping of items will result in diminished memory integration due to interference. This research can help deepen our understanding of how the brain encodes separate items and creates an integrated representation of the shared information.

The benefits of intergenerational family support on post-partum depression in the Tunisian Health Examination Survey

Presenter: Ava Hearn − Neuroscience

Faculty Mentor(s): Josh Snodgrass, Alicia DeLouize

Session: (In-Person) Oral Panel—Healthy Considerations

Postpartum depression (PPD) is considered the most common maternal morbidity in many parts of the world, yet while maternal health is increasingly prioritized in global health initiatives, the factors leading to the development of PPD are not fully understood. Lack of social support has been cited as one of the most important contributors to postpartum depression, but social support outside of partner relationships has not been widely investigated. Given trends in global aging and the increased presence of tri-generational families worldwide, it is important to examine whether the presence of co-residential grandparents influences the health and well-being of new mothers. Although this relationship has been the focus of recent interest in wealthy nations, research has yet to explore the impact of grandparent support in low- and middle-income countries. The present study uses sociodemographic and health data from the Tunisian Health Examination Survey to look at how family structures in this northern African setting affect postpartum depression. We hypothesized that postpartum depression would be lower with the presence of co-residential grandparents. It was found that new mothers living in a multigenerational household (M = 0.00) had less depression than those that did not live in a multigenerational household.

The Role of Synaptic Adhesion Molecules in Electrical Synapse Formation in Zebrafish

Presenter: Margaret Grivette − Neuroscience

Faculty Mentor(s): Adam Miller, Jen Michel

Session: (In-Person) Poster Presentation

Chemical and electrical synapses work together to shape brain function but little is known about the regulation of electrical synapse formation4. Chemical synapses are junctions that send neurotransmitters across the gap to the receiving neuron. Electrical synapses are physically connected by connexin proteins which are supported by scaffolding proteins that allow charged ions to diffuse between neural cells1. ZO1b is a MAGUK scaffolding protein required for the formation and function of electrical synapses. It contains three PDZ binding domains that bring other proteins together to organize multiple interactions 1,2. Kirrel proteins belong to the transmembrane immunoglobulin superfamily of cell adhesion proteins and have a cytoplasmic PDZ binding domain (PBD). Kirrel 3 is particularly important because alterations in the gene are associated with intellectual disability and the Kirrel 3 protein has recently been found to help build synapses in the mouse hippocampus 3. To determine whether Kirrels may play a role in electrical synapse formation in zebrafish, we tested whether the predicted Kirrel 3 PDB binds to ZO1b PDZ domains using an in vitro binding assay. We found that the Kirrel 3 C-terminus binds to PDZ1 of ZO1b. This interaction is dependent upon the predicted PDB since removal of the last 6 amino acids of the Kirrel 3 tail abolished the interaction.

Active Olfactomotor Movements in Head-Fixed Mice

Presenter(s): Isabelle Cullen — Neuroscience

Faculty Mentor(s): Dr. Matt Smear, Dr. Avinash Singh

Session: (In-Person) Oral Panel—Stimuli and Response

Olfactomotor responses are respiratory, orofacial, and locomotive movements used during olfactory sampling and in response to odors (Rabell et al. 2017, Kurnikova, Deschênes, and Kleinfeld 2019, Findley et al. 2020, Johnson et al 2003, Wesson et al 2008, Jones and Urban 2018). Altered sensory sampling behaviors, such as eye movement, temperature insensitivity, and excessive sniffing, have been identified in individuals with Autism Spectrum Disorder (ASD). In addition, Rozenkrantz et al. (2015) showed that olfactomotor behavior is affected in children with ASD. These children do not modulate sniffing behavior to aversive odors despite correctly identifying odors as unpleasant, suggesting an altered unconscious motor response. To investigate the neural mechanisms underlying olfactomotor sampling, we investigated respiratory and orofacial responses to odor using wildtype mice. Wildtype mice are exposed to 2-phenylethanol (attractive odor), 2-methylbutyric acid (aversive odor), alpha-pinene (neutral odor), or clear air in the course of a behavioral session. We record respiration with an intranasal thermistor, and track orofacial movements using DeepLabCut. Our preliminary results in wildtype mice (n=2) suggest that mice alter their sniffing speed and nose movement in response to odor stimuli. This work will shed light on active olfaction and help us understand more about naturalistic olfactomotor behaviors.