neuroscience research day saturday, september 17, 2016 ... · neuroscience research day –...

Neuroscience Research Day – Saturday, September 17, 2016 Poster Abstracts

Name (University & Position)

Vivek Lawana Iowa State University, Graduate Student, Dr. Arthi Kanthasamy

Poster Number 1

Title c-Abl regulates rotenone-induced inflammatory response via the activation of NLRP3 inflammasome

Abstract Multiple evidences support the hypothesis that exposure to pesticides increases the risk of PD. Emerging evidence indicates that intracellular inflammasome complex namely NLRP3 complex is involved in the recognition and execution of host inflammatory response. Thus in the present study we investigated the hypothesis that NLRP3 inflammasome activation is linked to rotenone- induced microglial activation which is dependent upon a priming stimulus by a pathogen associated molecular pattern (PAMP) or damage associated molecular pattern (DAMP) respectively. We employed primary microglia, BV-2 microglial cell culture, and an in vivo endotoxin model of neurodegeneration to address the stated hypothesis. We found that LPS priming accelerated rotenone-induced NLRP3 inflammasome activation that was associated with the activation of caspase-1 and subsequent proteolytic processing and release of IL-18 and IL1β as well as the release of TNFα and IL-6 as assessed via WB analysis and Luminex multiplex technology. Mechanistic studies revealed c-Abl/PKCδ kinase signaling axis as a proximal signal that exacerbated rotenone-induced NLRP3 inflammasome activation, that is mediated via mitochondrial and autophagolysosomal system (ALS) dysfunction and accompanying downregulation of TFEB, a lysosomal transcription factor. Intriguingly, gene silencing and pharmacological inhibition of c-Abl attenuated NLRP3 inflammasome activation, mitochondrial and ALS dysfunction and PKCδ activation; while, c-Abl overexpression potentiated that response in LPS primed rotenone treated microglial cells. Furthermore, using an in vivo LPS model of neurodegeneration we showed that c-Abl upregulation positively correlated with NLRP3 inflammasome activation and accompanying sickness-like behavior. Our findings demonstrate for the first time that c-Abl/PKCδ signaling axis is a key regulator of NLRP3 inflammasome activation which is mediated partly via dysregulation of ALS and mitochondrial function during rotenone-induced microglial activation (supported by NS088206).


Emily Kozik Grinnell College, Undergraduate Student, Dr. Don Sakaguchi

Poster Number 2

Title Characterization of Adult Hippocampal Progenitor Cells on Poly (ε-caprolactone) Microfibers

Abstract Cell-based therapies hold considerable promise towards the development of repair strategies for the damaged and diseased brain. Current nervous system regenerative approaches have yielded minimal results. However, advances in biomaterials coupled with neural stem cells provides new platforms for neural


tissue engineering. Polymers such as Poly (ε-caprolactone) (PCL) are relatively simple to fabricate and can act as a scaffold to direct alignment of cell processes and may promote cell differentiation. Adult hippocampal progenitor cells (AHPCs) are multipotent neural stem cells that can differentiate into the fundamental cells of the central nervous system (CNS): neurons, astrocytes, and oligodendrocytes. In this study, the proliferation, differentiation, and adhesion of AHPCs on PCL microfibers was investigated. AHPCs were cultured for 7 days in vitro on PCL microfibers of various diameters including 5 μm, 20 μm, and 35 μm. Immunocytochemistry experiments were conducted using antibodies to label specific characteristics of differentiated cells. Ki67 antibody labeled proliferating cells and anti-Nestin labeled neural progenitor cells. Neurons were identified using TuJ1 and MAP2ab antibodies and glial cells were identified using GFAP and RIP antibodies. Preliminary results have shown that cells differentiate, proliferate and adhered to all PCL fiber diameters. This study demonstrates the potential application of PCL microfibers as effective scaffolding that supports the growth and differentiation of neural stem cells. Future studies will provide a detailed characterization of stem cell differentiation and function using additional in vitro and in vivo models.


Kasandra Diaz Iowa State University, Graduate Student, Research conducted at Chicago University, Drs. Miriam Domowicz & Nancy Schwartz

Poster Number 3

Title Assessing Gliogenesis in a Multifactorial Murine Neonatal Brain Injury Model System

Abstract The third trimester of pregnancy is a critical period during development. Premature birth, intrauterine infections, and perinatal trauma during the third trimester of pregnancy have been linked to neurocognitive disabilities in humans. Interestingly, this period coincides with glial cell (astrocytes and oligodendrocytes) maturation in the brain. However, it remains unclear how different types of trauma/injuries may affect this process, leading to associated neurocognitive disabilities. We developed an injury model in neonatal mice with combinations of brain injuries to examine the effects on differentiation and maturation of respective glial subtypes. Postnatal day 6 (P6) mouse pups underwent sham (C), stab-alone (S), or stab-plus-lipopolysaccharide (S+LPS) treatments. At P10, the pups were harvested and gene expression changes in astrocyte, neuron, oligodendrocyte, and precursor cell markers were assessed using mRNA in situ hybridization and qPCR. The data obtained so far suggest that shortly following injury, neural stem cell and glial precursor populations may be attempting to repopulate the injury region. To further test our findings, we are developing protocols to double label cells co-expressing mRNA markers of stem cells (Sox2), astrocyte and oligodendrocyte precursors (Sox9 and Olig2) by fluorescent in situ hybridization and analyzing proliferation markers (phospho


histone 3 and Ki67) in the injury site as well as the sub-ventricular zone after injury. This model is advantageous because it allows for the contralateral uninjured side of the brain to be used as an internal control decreasing experimental variability from animal to animal while assessing gene expression responses to individual components of the compound injury, thus yielding possible mechanisms of the altered switch in cell maturation.


Jaden Roddick & Abodalrahman Algamdy Minnesota State University @ Mankato, Undergraduate Students, Dr. Rachel Cohen

Poster Number 4

Title Analysis of amygdala morphology and neurogenesis in green anole lizard in breeding versus non-breeding season.

Abstract Steroid hormones and their derivatives play a major role in the reproductive system. Studying the effects of the hormones on the brain can lead us to further information regarding the process of the reproductive system. Because the amygdala is responsible for reproductive behaviors, such as copulation, we will use this area of the brain to retrieve desired data. We are examining the relationship between steroid hormone and neuron size, number and neurogenesis in the amygdala. We are using the green anole lizard (Anolis carolinensis) as a model organism to study neurogenesis in the amygdala. Green anoles are seasonally breeding animals and exhibit unique behavioral and physiological differences in the breeding season compared to the non- breeding season. These behavioral differences are likely caused by seasonal changes in circulating steroid hormone levels. Green anoles were caught in natural habitat during the breeding season, transferred to the laboratory, and gonadectomized. A capsule containing either testosterone, estradiol, or left empty was inserted under the anole’s skin. The animals were injected with BrdU for three days after the treatment. After one month, brains were collected, sectioned, and placed on slides. BrdU and Hu markers were applied to the slides to display the presence of new neurons. Sections of brain we used to count cell number and soma size were treated with Nissl stain. Measurements were taken using a microscope to examine the sections of brain. We expect to see a decrease in neuron number in the amygdala during the breeding season.


Hyejoo Kang Minnesota State University @ Mankato, Undergraduate Student, Dr. Rachel Cohen

Poster Number 5

Title The effect of steroid hormones on neuronal size and number in two brain regions important for reproduction

Abstract Steroid hormones, such as testosterone (T) and its metabolites (estradiol, E2, and dihydrotestosterone, DHT), are critical for the production of reproductive behavior. These hormones play a role in neural plasticity, such as changes in


neuronal size change and brain region volume. Our study is examining the role of steroid hormones in maintaining the morphology of brain areas involved in reproduction, such as the ventromedial hypothalamus (VMH) and preoptic area (POA). We are using the green anole lizard (Anolis carolinensis) as a model because they are seasonally dimorphic, with more reproductive behaviors and higher steroid hormones in the breeding compared to non-breeding season. We treated our animals with different steroid hormones: T, DHT, E2, and blank capsules as a control. We collected the brains, sectioned the tissue and measured neuron size, number and density in the VMH and POA. We are expecting to find smaller and increased numbers of neurons in the animals treated with steroid hormones compared to the controls. This result would support the idea that steroid hormones are critical for the maintenance of brain areas important for reproduction.


Abdiasis Abdilahi Minnesota State University @ Mankato, Undergraduate Student, Dr. Rachel Cohen

Poster Number 6

Title Seasonal variation in the dorsolateral and medial cortex of green anole lizards

Abstract The hippocampus is a region of the brain involved in spatial learning and memory, and has been shown to add new neurons in adult animals. Steroid hormones, specifically testosterone (T) and its metabolites (estradiol, E2, and dihydrotestosterone, DHT), have been shown to play a role in the addition of adult-born neurons to the brain. The green anole lizard, Anolis carolinensis, is a seasonally breeding animal that exhibits seasonally dimorphic behaviors, as well as seasonal anatomical differences in the brain. The pronounced differences between the breeding and non-breeding seasons make this lizard an excellent model for the study of how steroid hormone differences impact the brain. We examined the volume of and addition of new adult-born neurons to the dorsolateral and medial cortex in the lizard, which is analogous to the mammalian hippocampus. We sectioned brain tissue from breeding and non-breeding animals, performed a Nissl stain, and are measuring volume of the regions. We expect that the region will be larger in the breeding season due to the increase of territorial and courtship behaviors. We also treated animals with T, DHT, E2 or nothing as a control and performed an immunohistochemistry to examine how steroid hormones impact neurogenesis. We expect to see significantly more neurogenesis in the dorsolateral and medial cortex of T, DHT, E treated animals in comparison to the untreated group. Our experimental results may provide a greater understanding of the mechanisms that regulate the neural control of reproduction and territorial behaviors.


Abbie Burney Iowa State University, Undergraduate Student, Dr. Jeff Trimarchi

Poster Number 7



Bhavika Patel Iowa State University, Graduate Student, Dr. Don Sakaguchi

Poster Number 8

Title Characterization of Neural Progenitor Cell Differentiation on Poly (ε-caprolactone) Microfibers

Abstract Various biocompatible polymers have been used to fabricate biomimetic 3-D scaffolding platforms in order to organize and deliver cells to the nervous system. Recently, microfiber-based systems have been developed with the goal of guiding cell alignment for applications in axon regeneration and directed cell migration. In this study poly (ε-caprolactone) (PCL), a biodegradable synthetic polymer was used to fabricate microfibers at various diameters (5 μm, 20 μm, and 35 μm) using a microfluidics approach. Microfibers may mimic the microenvironment and provide a more complex 3-D platform in which cells can differentiate and proliferate. To test this idea, these microfibers were used as 3-D substrates for culturing multipotent adult hippocampal progenitor cells (AHPCs). In this preliminary study we have investigated the adhesion, proliferation, and differentiation of rat AHPCs growing on PCL microfibers. A panel of cell type specific antibodies was used to identify neural progenitors, neurons and glial cells. Proliferating cells were immunolabeled with Ki67 antibody, neural progenitor/stem cells detected with Nestin antibody, neuronal cell differentiation characterized by TuJ1 and MAP2ab antibodies and glial cell differentiation characterized by GFAP and RIP antibodies. Preliminary results have indicated that the PCL microfibers support cell adhesion, survival, proliferation and differentiation of the AHPCs. Specifically, smaller fiber

Title Investigating the Expression of Calcium Channels in Retinal Ganglion Cells

Abstract Recent studies estimate that there are at least 30 different types of retinal ganglion cell in the mouse eye. Ganglion cells are the connection between the eye and the brain and have very important functions in how we visualize different images. These are also the cells that die in glaucoma, which is the second leading cause of blindness. Even though the 30 types have been characterized by their sizes, shapes and electrical properties, the genetics of each type is unknown. This includes the genes that make the different types unique. The goal of my project is to begin to characterize the differences between these cells on a genetic level. In lab, there is a type of mouse that has been engineered to express a red fluorescent protein in 8 different types of ganglion cells. Previously, students isolated red cells from the mouse retinas and identified large sets of mRNAs that were expressed in each cell. Through these mRNAs, we were able to predict which genes define which ganglion cells. From these predictions I chose six calcium channels to further characterize in ganglion cells. By pinpointing what makes different types of ganglion cells unique researchers will be able to better identify how sensitive these different cells are to disease-causing genetic insults and be able to more thoroughly assess the quantity and quality of their production from different stem cell experiments.


diameters have more cell attachment than larger diameters while a wavy fiber morphology may favor cell proliferation. Transplantation of neural progenitor/stem cells within a PCL microfiber scaffolding construct may provide important biological and topographic cues that facilitate the survival, differentiation and integration of transplanted cells.


Alyson Williamson & Hayley LeBlanc Drake University, Graduate Student & Undergraduate Student, Dr. Craige Wrenn

Poster Number 9

Title Study of daily genistein ingestion on spatial memory and olfaction in triple transgenic Alzheimer’s mice

Abstract Alzheimer’s Disease (AD) is a neurodegenerative disease characterized by the accumulation of beta amyloid plaques and the formation of neurofibrillary tau tangles. These plaques and tangles lead to the learning and memory deficits characteristic of AD. Estrogen and estrogen-like compounds have been shown to slow the development of plaques and tangles. Though estrogen receptors are found in the male hippocampus, it is unclear how estrogen affects learning and memory in the male hippocampus. Male triple-transgenic (3xTg-AD) mice mimic the pathology and learning and memory deficits of AD in humans. To examine the potential effects on the male hippocampus, 3xTg-AD mice were either fed a dose of 10 mg/kg of genistein, a phytoestrogen found in soy, or a placebo of sucrose and tested behaviorally in the Morris Water Maze and Olfactory Habituation-Dishabituation tasks. The 3xTg-AD mice had significantly longer swim paths to find a hidden platform as well as a lack of selective search in the platform location when the platform was removed. There was no significant difference between the 3xTg-AD and wildtype mice during the olfactory task of habituation-dishabituation. As the pathology of the AD develops in the 3xTg-AD mice, the mice will be retested to examine the differences in learning and memory. Presently, the 3xTg-AD were impaired in successfully learning the location of a hidden platform but were not impaired in their olfactory abilities. Authors: H. R. LeBlanc, A. C. Williamson, and C. C. Wrenn


Matt Jefferson Iowa State University, Graduate Student, Dr. Marian Kohut

Poster Number 10

Title Gene Expression Profile of the Interferon Pathway in the Brains of Diet-Induced Obese Mice

Abstract Diet-induced obesity (DIO) has a known capacity to perturb CNS tissue homeostasis through its promotion of low-grade, systemic inflammation. Inflammation has routinely been identified as an underlying pathological component in numerous neurological diseases. While multiple signaling pathways converge to produce the highly orchestrated inflammatory response, the role of the interferon pathway within the brain following DIO remains relatively unknown. In an effort to shed potentially novel insight into the


transcriptional activity of Type I interferon signaling pathway in the brains of DIO mice, we have characterized relative gene expression patterns using quantitative RT-PCR. Microdissections were performed on the striatum (STR), cerebral cortex (CTX), substantia nigra (SN), and hippocampus (HP) of male C57BL/6 mice following 12 weeks of a high-fat diet (60% kcal from fat) and qRT-PCR completed with RT2 profiler arrays (Qiagen). Key results have indicated that the greatest trends of interferon-related activity were observed across the SN, CTX, and STR, with the up-regulation of interferon-inducible genes (IFI30, IFIT3, IFITM1, and IFITM2). The CTX alone demonstrated up-regulated of interferon α genes (IFNA4, IFNAR1, and IFNAR2), while JAK/STAT genes were preferentially up-regulated in the SN. These findings link our observations of Type I interferon pathway activation in the brain with inflammation routinely observed by others following DIO, and may provide vital mechanistic insight that could ultimately aid the development of therapeutics directed at mitigating neuroinflammation.


Rebecca Chowdhury Iowa State University, Graduate Student, Dr. Jeff Trimarchi

Poster Number 11

Title Using CRISPRs to examine vertebrate retina development in a zebrafish model

Abstract Our goal is to understand how specific intrinsic factors control retinal cell fate decisions and neuronal maturation processes. Ath5/Math5 is a highly conserved transcription factor essential for retinal ganglion cell development in the developing mouse and zebrafish retina. Using single cell transcriptome profiling, we characterized individual mouse Math5+ cells and zebrafish Ath5+ cells and identified several genes whose expression tracks closely with Math5/Ath5. We further assayed the expression of these genes in the zebrafish retina by section and whole-mount in-situ hybridization. Given their expression patterns, we hypothesize that these candidate genes (Plk3, Trim9, Rassf4 and Ikzf5) will play important roles in either retinal cell fate determination or the differentiation of early-born retinal neurons. Using the CRISPR-Cas9 genome editing system, we have successfully generated mutations in these genes in zebrafish. We are examining retinal development in these mutant fish, with a specific focus on the early-generated cell types. We have observed that CRISPR-mediated mutations in Plk3 (Polo-like kinase 3) appear to lead to changes in the number of a subset of amacrine cells in the zebrafish retina, while some Rassf4 mutants show a thinning of the optic nerve. Taken together, our single cell transcriptomic approach coupled with genome editing is a powerful method for dissecting the precise networks of genes controlling early development of the retina.


Lauren Laboissonniere Iowa State University, Graduate Student, Dr. Jeff Trimarchi

Poster Number 12

Title Investigating transcriptomes of developing chick retinal cells


Abstract The vertebrate retina is comprised of 7 cell types, 6 neuronal and 1 glial, all arising from a common pool of progenitors. These progenitors use genetic networks to pursue cell fates and to develop the appropriate combination of mature cells. Our goal is to characterize groups of genes central to this decision for the various cell types in the chicken retina. Individual cells were isolated from chicken retinas between the developmental timepoints of embryonic day (E)3 and E15. Individual cDNA libraries were generated for each cell and hybridized to Affymetrix microarray chips. To confirm our findings, we employed in situ hybridization on sectioned retinas. We were able to uncover a number of cells at varying timepoints which are developing RGCs based on their gene expression of known markers. Among these cells, we identified a small number expressing both ganglion and amacrine cell markers, suggesting a large overlap in gene expression between these two populations. We also uncovered cells in the process of deciding between multiple cell fates. Cells in the midst of this dynamic transition, in particular, are invaluable for the identification of novel transcription factors that play a role in the cell fate decision-making process. This project found multiple cells expressing genes specific to more than one population, suggesting possible plasticity between cell fates. We were able to validate our novel gene discoveries through in situ as well as to observe new expression profiles for some genes which had previously been uncharacterized.


Gregory Mlynarczyk Iowa State University, Graduate Student, Dr. Diana Peterson

Poster Number 13

Title Blast Induced Traumatic Brain Injury: Rodent Models

Abstract Over the last 10 years a large proportion of our military personnel have been exposed to blast trauma from explosive devices. These exposures have resulted in mild to severe traumatic brain injuries (TBI) with a variety of symptoms (e.g., depression, tinnitus, learning and memory problems, attentional problems, etc). To understand and begin to find appropriate treatment options for blast-induced traumas, appropriate models of study must be developed. For this talk, we describe a rodent model for frontally directed blast-pressure wave induced traumatic brain injury. The model was tested on a variety of rodent species (rat: Long Evans; mouse: CB57B, SMN2), and behavioral experiments performed to identify similarities between this rodent model, alternate rodent models, and human TBI cases. Results showed both depression and tinnitus in exposed animals; however, the percentage of animals affected varied by species. Differences between the current results and those of other studies may be attributed to variations in animal strain, direction of injury, and model of injury induction. These results indicate that the method of injury and animal strain may alter study outcomes and should be examined when comparing across animal studies.



Marson Putra Iowa State University, Graduate Student, Dr. Thimmasettap Thippeswamy

Poster Number 14

Title The Roles of Fyn and Tau in Epilepsy

Abstract Epilepsy is the 4th most common neurological disorder, characterized by unprovoked recurrent seizures after a brain insult. Fyn-Tau interaction has been implicated in epileptogenesis and neurodegeneration in Alzheimer’s Disease (AD) models. While genetically ablated tau appears to be protective against seizures in AD models, the roles of Fyn and tau in epileptogenic events are still unknown. Whether Fyn and/or tau ablation can attenuate early epileptogenic events in epileptic mice model remain to be elucidated. Here, we demonstrate the effects of genetic deletion of fyn and/or tau in pentylenetetrazole (PTZ)-induced epilepsy mouse model. We used 3 genetically engineered genotypes; fyn-/-, tau-/-, double knockout (KO) fyn-/-+tau-/- and euthanized them at 24h post-PTZ treatment. The tau-/- and fyn-/-+tau-/ rarely showed convulsive motor seizures (CMS, stage 3 and above), reduced seizures severity and duration, and prolonged the latency to the onset of CMS. In fyn-/-, there was only a modest decline in seizure severity and no difference in latency was observed when compared to the wild type. However, a higher mortality rate was observed in fyn-/- in contrast to other knockout mice. Despite these findings, all KO mice demonstrated a significant reduction in neurodegeneration (FJB+NeuN positive cells) in the hippocampus. Furthermore, reactive astrogliosis and microgliosis were also significantly reduced in all KO mice. In Western blot, we found that the levels of inwardly-rectifying potassium (Kir 4.1) channels were restored in all KO groups which were downregulated in the PTZ-treated wild-type. Our results indicate that reducing fyn and/or tau dampens seizures, neurodegeneration, and reactive gliosis.


Christine Klecker Minnesota State University @ Mankato, Graduate Student, Dr. Rachel Cohen

Poster Number 15

Title Seasonal and sex effects on StAR gene expression in the green anole lizard

Abstract A seasonally breeding animal only mates during certain times of the year to allow birthing to be at an optimal time of survival for their young. The green anole lizard (Anolis carolinensis) is an excellent model to study the regulation of steroid hormone production because they have distinct hormonal and behavioral differences between sexes and seasons. Steroidogenesis is under the control of the hypothalamus-pituitary-gonadal (HPG) axis system. In this system, the anterior pituitary produces luteinizing hormone (LH), and follicle-stimulating hormone (FSH). LH functions to regulate ovulation and activate steroidogenesis, specifically triggering an increase in steroidogenic acute regulatory protein (StAR) activity. StAR regulates the rate limiting step in this pathway; the delivery of cholesterol from the outer to the inner mitochondrial membrane. We tested the hypothesis that season and sex differences in the green anole lizard will


impact mRNA expression levels of StAR in the gonads and brain. Adult male and female lizards were captured from the wild during both the breeding (BS) or non-breeding seasons (NBS). Gonads, brains, and blood were collected and stored at -80 °C. The brain and gonad RNA was extracted, reverse transcribed into cDNA and then StAR gene expression were measured by qPCR (normalized to β actin). With an n of 3 for each group preliminary results of StAR expression in the brain shows a trend (p= 0.060) that during the BS StAR expression levels are decreased when compared to NBS. Preliminary results for gonad StAR expression levels showed no significant difference between any of the groups (p= 0.901). These preliminary results suggest that StAR gene expression is potentially expressed differently between the green anole BS and NBS in the brain, and may be a potential reason for the distinct phenotypic differences in the anole between the different seasons.


Lindy Brastrom University of Iowa, Graduate Student, Dr. Diane Slusarski

Poster Number 16

Title Modeling Congenital and Age-Related Eye Diseases in the Zebrafish

Abstract Eye disease and visual impairment coupled with age-related vision loss are a significant public health concern. Modern genomics has enabled the identification of an unprecedented number of genetic variants associated with blinding disorders. Zebrafish pose many advantages as a human eye disease model. By 5 days-post-fertilization (dpf) zebrafish have quantifiable behavioral responses to visual stimuli. Our lab has adapted vision testing in zebrafish to facilitate high-throughput in vivo screens: Visual Interrogation of Zebrafish maNipulations (VIZN) and OptoMotor Response (OMR). VIZN uses interruptions in constant light to garner a startle response. This vision startle assay looks at the ability of the fish to see in a general capacity. Automated data collection and software to handle the large spreadsheets have been developed to optimize the number of screens we can accomplish. While the VIZN assay works for disorders leading to complete blindness, there is a need to test for partial vision loss such as those exhibited in cataracts. We are currently adapting OMR to assay partial vision loss. This is done by stripes of white and black passing under a plate of fish. Fish that can see will respond by orienting their body perpendicular to the lines while those with impairment will be unable to respond and fail to orient. The goal is to combine both assays to evaluate the spectrum of visual impairments. We are currently assessing conditions to test for partial vision impairment. These tests will allow us to screen many genes related to loss of vision quickly and efficiently.


Elizabeth Sandquist Iowa State University, Post-doc, Dr. Don Sakaguchi & Dr. Jeff Essner

Poster Number 17

Title A xenotransplant model for neural progenitor cell plasticity


Abstract Regeneration of the central nervous system (CNS) using transplanted cells has been a long-studied goal. Guided differentiation of transplanted progenitors toward neural lineages involves a balance between internal and environmental regulation. To determine the relative influence of these factors and the differentiation potential of multipotent progenitor cells, a zebrafish xenotransplant system was developed. Upon transplantation into blastula-stage zebrafish, the ability of mammalian adult hippocampal progenitor cells (AHPCs) to form zebrafish chimeras may be used to indicate expanded differentiation potential. Adult hippocampal progenitor cells survived transplantation into blastula-stage zebrafish which was observed up to five days following. Transplanted cells were found throughout the embryo, though the CNS appeared as the main region where cells established. Optimal growth temperature is different for zebrafish and mammalian cells at 29 and 37 oC, respectively. Thus, experiments were performed to evaluate the effects of a temperature of 34 oC on zebrafish development and progenitor cell survival, proliferation, and differentiation. Altered temperature showed little effect on zebrafish survival and development as indicated by body length. Preliminary immunocytochemical analyses indicated that culture of AHPCs at the altered temperature had little effect on survival and cell fate. This supports zebrafish xenotransplantation for the investigation of progenitor cell plasticity and regulation. Experiments to characterize transplanted hippocampal progenitor cells will help to determine the differential plasticity of these cells and the role of environmental factors. Knowledge of adult progenitor cell plasticity and regulation of cell fate will assist in the guided differentiation of transplanted cells for therapeutic regeneration.


Andrew Zaman Iowa State University, Graduate Student, Dr. Elizabeth Stegemoller

Poster Number 18

Title Determinants of Physical Activity in Persons with Parkinson’s Disease

Abstract Objectives: This study’s goal is to 1) examine what determinants are important for exercise in persons with PD; and 2) determine an appropriate theory to explain exercise behavior in persons with PD. Methods: In a sample of 12 persons diagnosed with mild to moderate PD, we conducted semi-structured interviews to examine how participants’ current physical activity levels compared to their 1) motivational factors; 2) barriers to exercise; and 3) other lifestyle factors. Participants were also asked about their interest in various interventions. Results: The belief that exercise delays symptom progression and helps to maintain physical health were motivating factors for persons with Parkinson’s. Exercisers tended to be more motivated by social aspects than non-exercisers. Non-exercisers felt that having an exercise partner would help them to become more active. Conclusions: Educating persons with Parkinson’s on the cognitive and emotional benefits of exercise may help to increase activity level. Researchers suggest that interventions should aim to create a positive social


environment for individuals. Lastly, researchers believe that an appropriate theory would include social factors, knowledge factors, and self-efficacy. More data is currently being collected.


Micah Watson Simpson College, Undergraduate Student, Dr. Justin Brown

Poster Number 19

Title Restraint as a Model of Stress in Aplysia

Abstract We are using Aplysia californica to better understanding the effects of stress on the nervous system. Previous research on Aplysia and other marine invertebrates has established models of stress using noxious stimulation, hyper/hypothermia, hyper/hyposalinity, and mechanical stimulation. It remains unclear if these stressors converge on the same behavioral and biological mechanisms. Here we compared two models of stress: 1) noxious stimulation consisting of brief shocks to the tail and 2) physically restraining consisting of three days of isolation in a small container. Our goal was to determine is both models induced similar stress responses. We used measures of decreased feeding behavior as a correlate of stress. We found that both noxious shock and physical restraint inhibit feeding which suggests that both conditions induce stress. We plan to test models of hyper/hypothermia and hyper/hyposalinity to see if these experiences also induce a stress response that decreases feeding. In addition, we also plan to examine hormone levels to see if the different stressors converge on the same biological mechanism.


Edmund Norris Iowa State University, Graduate Student, Dr. Joel Coats

Poster Number 20

Title Exploring the relationship between PaOA1 receptor modulation and the insecticidal character of monoterpenoids

Abstract Octopamine is a biogenic amine that has been implicated in the regulation of numerous physiological roles, such as reproduction, learning-and-memory, and nerve stimulation, to name a few. Previous studies have demonstrated that octopamine has a limited role in mammalian systems and thus octopamine receptors represent a promising target for the development of safer insecticides. Compounds identified to act upon these receptors would thus have little to no effect in mammalian and other non-target organisms. To-date, we have developed a line of Chinese Hamster Ovary cells (CHO) that are stably expressing an α-adrenergic like octopamine receptor that has been isolated from the American cockroach (Periplaneta 12mericana). Functionality of this receptor was screened using a calcium liberation detection assay using Fluo-4 NW dye (Invitrogen Tech.) Functional screening determined that octopamine is the preferred ligand with an EC50 of 89.6nM and tyramine, a closely related biogenic amine, binds with a lower affinity with an EC50 of 463nM. To date, we have made significant progress screening monoterpenoids against this receptor


for positive and negative modulation. Our goal is to further characterize the biological significance of positive and negative modulation in this receptor by comparing this data set to American cockroach injection assays. So far, we have characterized the toxicity of more than 15 monoterpenoids that have also been screened for positive and negative modulation of the octopamine receptor. This project will better elucidate which monoterpenoid characteristics modulate receptor binding, and whether or not this bioactivity is related to insecticidal potential.


Brandon Klinedinst Iowa State University, Graduate Student, Dr. Auriel Willette, Dr. Elizabeth Stegemoller & Dr. Ranjan Maitra

Poster Number 21

Title Effects of Insulin Resistance on the Acceleration of Atrophy in Prefrontal and Medial Temporal Lobes

Abstract The comprehensive etiology of neurodegenerative diseases like Alzheimer’s, Dementia, and Parkinson’s Disease is currently a frontier of research. An appropriate first step is to test for comorbidity with the etiologies of other aspects of aging, including cardiovascular disease and metabolic syndrome. Here a novel approach was used to examine the effects of insulin resistance on brain atrophy, which is a hallmark prognosis of neurodegeneration. Confirmatory factor analysis was utilized on longitudinal brain volume data on 750 subjects from the ADNI cohort to extract location, acceleration, velocity, and jerk from the time domain. These elements of change-over-time were used to calculate trajectories of atrophy for each subject. Definite integration was then used to calculate area under the curve (AUC). Statistical analysis of the AUC values were used to determine if there were significant differences in both mean volume and variation between subjects with normal HOMAIR (a measure of insulin resistance) and subjects with elevated HOMAIR. Results indicate significant differences in prefrontal areas. More modest effects were observed in regions of the medial temporal lobe. Due to the known connections between insulin resistance, deterioration of beta islet cells of the pancreas, and long-chain saturated fatty acids from animal products, it warrants further investigation to elucidate the relationships between modern dietary shifts in western populations over the last century and the onset and progression of neurodegeneration.


Najiba Mammadova Iowa State University, Graduate Student, Dr. Heather Greenlee & Dr. Don Sakaguchi

Poster Number 22

Title Accumulation of phosphorylated α-synuclein (p129S) and retinal pathology in a mouse model of Parkinson’s Disease


Abstract Parkinson’s disease (PD), is a neurodegenerative disorder characterized by accumulation of misfolded α-synuclein within the central nervous system (CNS). In this study, we used a transgenic mouse model (TgM83) expressing the human A53T mutated α-synuclein, associated with familial Parkinson’s disease. To investigate in-vivo transmission of synucleinopathy, TgM83 mice were intracerebrally (IC) inoculated with brain homogenates from clinically ill TgM83 mice. This triggered acceleration of pathology, creating a “seeded” model of synucleinopathy. Non-motor clinical phenotypes of Parkinson’s disease such as visual dysfunction are increasingly studied. Retinal pathology associated with Parkinson’s disease has not been previously described. We assessed retinal tissues of TgM83 mice, using immunofluorescence for phosphorylated α-synuclein (pSer129), glial fibrillary acidic protein (GFAP), microglia marker CD11b, and phospho-PHF-tau (AT-270). Retinas of TgM83 mice presented with activation of Müller glia and microglia, loss of photoreceptor cells, and accumulation of phosphorylated α-synuclein, and phospho-tau detected at 8 months. IC inoculation with phosphorylated α-synuclein, resulted in acceleration of retinal pathology. We show increased microglial activation, pSer129 immunoreactivity, significant loss of photoreceptor cells, and AT-270 immunoreactivity detected at 5 months. Our work shows that pathologies caused by accumulation of misfolded α-synuclein, are distinct from those induced by the disease model. Our results suggest that pathological α-synuclein may seed misfolding, causing acceleration of retinal pathology. Our work provides insight into the effect of Parkinson’s disease on the retina, and may contribute to a better understanding of visual symptoms experienced by patients.


Kendra Clark Iowa State University, Graduate Student, Dr. Julie Kuhlman

Poster Number 23

Title Identification of Glial Markers in the Developing Enteric Nervous System

Abstract The enteric nervous system (ENS), the largest division of the peripheral nervous system provides intrinsic innervation to the gastrointestinal tract via neurons and glia. Disorders such as intestinal aganglionosis (Hirschsprung’s Disease), hyperganglionosis, and hypoganglionosis are associated with the number and distribution of enteric neurons and glia during development. Using the zebrafish, Danio rerio, we are specifically interested in understanding the specification and differentiation of ENS glia. Relatively little is known about the enteric glia in zebrafish and many of the current immunohistochemical approaches are confounded by the uncertainty of cross-reactivity patterns between species. In an effort to identify glial specific markers we have been screening a panel of ‘glial’ markers in both adult and larval stage intestinal tissue. We are confirming our results with a combination of in situ hybridization and investigating the expression or lack of expression of these glial markers in the ENS mutant colourless (cls), a mutant reported to lack glia.



Garrett Schmidt-McCormack Iowa State University, Graduate Student, Dr. Nick Jeffery

Poster Number 24

Title Analysis of molecular phenotype of dorsal root ganglion cells following cruciate ligament transection

Abstract The anterior cruciate ligament (ACL) functions as a sensory organ as well as a mechanical stabilizer to the knee. Deficits in proprioception, changes in reflex latencies, and feelings of “giving way” following injury and even reconstruction suggest that this sensory role is vital for the stability and function of the leg and may not always be regained despite adequate mechanical stability. Past research has shown altered knee proprioception in clinical measurements, and delayed latency of the hamstring reflex after ACL injury and treatment. However, molecular and cellular mechanisms underlying neural changes after ACL injury are not well understood. In this preliminary study, we have investigated the long-term phenotypic changes in response to cruciate ligament injury in cells of the dorsal root ganglia (DRG) receiving afferent input from the knee joint in an animal model. To this end, the right cranial cruciate ligament (CCL) of adult male Sprague-Dawley rats was transected or sham operated. After a three-week recovery period, the lumbar 4 and 5 DRGs from each side were removed. We extracted RNA from the DRG of each side and used a Qiagen RT2 preAMP qPCR array for synaptic plasticity. Gene expression levels on the side ipsilateral to CCL injury were compared to those on the contralateral (control) side. No conclusions could be drawn from the results of this assay, but changes in Mmp9 and Ntf4 were observed. Further work, including immunohistochemistry will investigate proteins involved in synaptic plasticity, and proteins associated with mechanoreceptors.


Tovah Wolf Iowa State University, Graduate Student, Dr. Auriel Willette

Poster Number 25

Title Metabolic Dysfunction Task-Induced Emotional Stress Reactivity: Neural and Cognitive Correlates in Middle-aged Adults

Abstract Pre-diabetes and type 2 diabetes (T2D) (i.e., hyperglycemia) etiology is characterized by insulin resistance (IR) and systemic inflammation caused by obesity. These factors can cause deficits in cognitive and affective processing, particularly increased psychological stress reactivity. Despite the prevalence of obesity and hyperglycemia, their neural correlates are unknown. We wished to determine how pre-T2D and T2D were related to psychophysiological, behavioral, and hormonal measures of stress reactivity and negative affect predisposition. Among 331 adults from the Midlife in the United States (MIDUS) study, we determined startle eye-blink response (EBR) to international affect picture system (IAPS) stimuli. Frontal alpha asymmetry, a well-established biomarker of negative affect predisposition, was determined with resting


electroencephalography (EEG). Finally, cognitive performance and cortisol output were gauged during an arithmetic stressor task. Fasting glucose and insulin characterized hyperglycemia or the homeostatic model assessment of IR (HOMA-IR). Higher HOMA-IR strongly corresponded to greater EBR for “unpleasant” versus “pleasant” stimuli [R2=0.218, p=.020]. Participants with hyperglycemia vs. euglycemia showed greater right frontal alpha asymmetry [p=.011] and worse arithmetic performance [p=.040]. Baseline urinary cortisol was also dysregulated in hyperglycemic individuals [p=.025]. These results suggest that hyperglycemia may increase stress sensitization at the neuronal, endocrine, and behavioral levels.


Aron Nakama Iowa State University, Graduate Student, Dr. Stephan Schneider

Poster Number 26

Title Cell identity communication in embryogenesis conducted via neural recognition proteins

Abstract Background: All types of neural cells express surface proteins that constitute a recognition code for each cell type within the nervous system. Current hypotheses suggest neural recognition code allows for the specific wiring exhibited by the approximately 86 trillion synapses in the adult human brain. Recognition codes confer cellular and subcellular identity to create specific cell-cell interactions and create cellular and tissue polarities. We have evidence to suggest that some of the cellular machinery of this complex code is utilized in early embryogenesis where it might contribute to cellular identities in asymmetric cell division systems. Here we study the expression of several quintessential neuronal recognition proteins in the spiral-cleaving organism Platynereis dumerilii during early embryogenesis. Results: mRNA transcript expression levels for cell adhesion proteins and intracellular binding partners: N-cadherin, Nectin, Afadin, Latrophilin 3, Teneurin, Neuroglian, Contactin, Neurexin IV, Neuroligin, PCD11X, Magi2 exhibit a strong maternal contribution in the early embryo relative to later time points. Similarly, fate determinants Numb and Brat, that interact with Par3, along with components of the Notch/Delta system all exhibit a high maternal contribution. Conclusions: Our data suggest that these ‘neural’ transcripts may function in general cellular processes to establish and maintain cell adhesion-mediated polar properties of early embryonic cells. The conspicuous expression of these types of genes at early time points suggests that ‘neural’ recognition proteins may have first evolved to mediate essential cell-cell interactions during early stages of embryogenesis before being exploited by the nervous system in later stages to confer neural recognition codes.



Dr. Stacey DeJong University of Iowa, Faculty DeJong SL, Werner LA, Najdawi FR, Monga A, Darling WG, Shields RK

Poster Number 28

Title Associations between cortical excitability, muscle force production and motor control at the wrist in healthy adults.

Abstract Background: Recently we developed a novel method to map the motor cortex using transcranial magnetic stimulation (TMS). Our approach expands upon traditional methods by assessing cortical excitability for multiple upper limb muscles simultaneously. This pilot study determined whether measures of cortical excitability, obtained with our new method, are related to motor performance. Methods: Eight healthy people participated (5 female, ages 22-56


Dr. Auriel Willette Iowa State University, Faculty

Poster Number 27

Title The synergistic role of mitochondrial gene function and family history on clinical and brain outcomes in Alzheimer’s disease

Abstract INTRODUCTION: There is tremendous interest in finding novel genetic risk factors for Alzheimer’s disease (AD) among individuals lacking the Apolipoprotein E ε4 allele (non-APOE4’s). Translocase of the Outer Mitochondrial Membrane-kD40 (TOMM40), which affects mitochondrial function, is a gene with strong linkage disequilibrium to APOE. A TOMM40 variable poly-T length polymorphism at rs10524523 within intron 6 may increase risk for late-onset AD (LOAD). Specifically, the “very long” (VL) poly-T length predicts faster memory decline and earlier age of LOAD onset, compared to the “short” (S) poly-T length. Some results have been mixed, however. AD family history (FH) also affects mitochondrial function, and may modulate effects of TOMM40 on memory decline and brain atrophy in memory-related regions. METHODS: For 912 non-APOE4 late middle-aged adults at risk for AD, and 365 aged adults across the AD spectrum, linear mixed models gauged FH and TOMM40 interactions on memory and brain volume changes between baseline and up to 10 years later. RESULTS: For FH negative participants, gene-dose preservation of memory and memory-related brain regions like medial temporal lobe was seen, in both cohorts, for VL hetero- or homozygous carriers vs. S carriers (highest Cohen’s D=1.73). For FH positive, by contrast, VL carriers showed precipitous gene-dose related memory decline and medial temporal atrophy (highest Cohen’s D=1.84). Similar gene-dose effects were seen for a mitochondrial function biomarker. DISCUSSION: FH status robustly modulates the effects of TOMM40 on memory, brain atrophy, and mitochondrial function across decades and different disease phases. These results may clarify the mixed TOMM40 literature.


years). Monophasic TMS pulses were applied to 16-18 target sites, arranged in a grid pattern over the right primary motor cortex using MRI-guided neuronavigation. Each site received 5 pulses at 4 stimulus intensities (40, 60, 80 and 100% of maximum stimulator output). Motor-evoked potentials (MEPs) were recorded from extensor carpi radialis (ECR), flexor carpi radialis (FCR) and 7 other muscles on the left side, contralateral to TMS. Each muscle’s optimal cortical site was defined as the site where the lowest stimulus intensity produced the largest MEP amplitude. For that site, MEP amplitudes were plotted against stimulus intensity, and the area under the stimulus-response curve served as a measure of cortical excitability. Maximum voluntary isometric force production was measured with hand-held dynamometry. Motor control was quantified using a custom-designed cursor tracking task. Results: Cortical excitability of the FCR correlated with wrist flexion force (r=0.91, p<0.001), and cortical excitability of ECR correlated with wrist extension force (r=0.61, p=0.05). Associations between higher cortical excitability and better motor control approached statistical significance (p<0.20). Conclusion: Our alternative method of cortical mapping with TMS produces cortical excitability measures that are related to motor performance.

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