Currently, various methods of creating engineered heart muscle cell, or cardiomyocyte, patches are being researched. These cardiomyocytes patches have shown therapeutic potential for implantation over injured or killed heart tissue. Current research often focuses on deriving these cardiomyocytes from stem cells, but these stem cell-derived cardiomyocytes are often not as mature as adult cardiomyocytes. Growing these cells on patterned as opposed to flat surfaces, or substrates, also affects the maturity of the cells. This project is the development of automatic video analysis software for cardiomyocytes. This provides a method of automatically quantifying contraction strength and orientation of cardiomyocytes, therefore providing an indicator of the maturity of the analyzed cells. Furthermore, the analysis program can simultaneously measure voltage-sensitive dyes in order to provide information about calcium levels as electrical signals called action potentials travel throughout the cells. This computational analysis will be performed upon human embryonic stem cell (hESC) derived cardiomyocyte tissue, as well as primary adult cardiomyocyte tissue isolated from rat hearts, grown on both flat substrate as well as nanopatterned substrate. Primary cardiomyocyte tissue is anticipated to show greater contractility, higher levels of alignment, and faster action potential propagation than the hESC-derived cardiomyocyte tissue due to its greater maturity. Furthermore, cardiomyocytes grown onto nanopatterned substrate are expected to show greater contractility, alignment, and action potential propagation than those cells plated onto flat substrates. The program in development can be used to automatically create a quantitative measurement of cardiomyocyte maturity levels across a wide array of various experiments. Being able to use the same computational analysis on different experiments both allows for easy comparison of results as well as substantiating the resultant data. Ultimately, this project provides simple automatic quantification of certain key properties of cardiomyocytes based upon videos of their contractions.

Duchenne muscular dystrophy (DMD), an incurable disease that causes severe morbidity and mortality, affects one in every 3600 male children in the United States. Stem cell therapy and cell replacement therapy have been utilized as possible solutions to the disease; however, there has only been limited success due to two major deficiencies: the lack of blood vessels in the regenerating tissues resulting in oxygen deficiency, and the lack of proper structural cues resulting in the disorganization and un-differentiation of the stem cells. Previous research has demonstrated the angiogenic and myogenic potentials of sphingosine-1-phosphate (S1P). Moreover, muscle tissues in human body have highly organized nanoscaled structures that guide the organization and differentiation of muscle cells. We designed nanopatterned muscle patches conjugated with S1P, and proposed if the patches would allow better cell survival, retention, and long-term functionality. We developed biodegradable S1P-conjugated nanopatterned muscle patches with capillary force lithography (CFL), chemical conjugation, and culturing of undifferentiated muscle cells in vitro. The patches’ biochemical, structural, and functional properties were characterized. We also evaluated the force generation, the long-term potential of regeneration, and the synchronization of the engrafted tissue of the patches within the limb muscle of mice. We anticipated proper vascularization of the patches and that the implanted cells would develop into differentiated, mature, and functional skeletal muscle cells due to the bio-mimicking mechanical cues provided by the nanopattterns. This project aimed to develop fully functional muscle cell patches which could be engrafted into patients with DMD and thereby treating the disease. In addition, the experiment would also improve our understanding in the response of muscle cells to topographical cues.

Capillary Force Lithography (CFL) is one of the novel techniques that established recently for fabricating biomimetic substratum of tissue engineering. This approach of making nano-scale scaffold allows us to fabricate complex design of polymer substrates at low-cost. One practical challenge to further application of CFL to biomedical science is biocompatibility of the materials used in CFL. Most of the materials used for CFL are only biocompatible in vitro, but not in vivo. 2-hydroxyethyl methacrylate (HEMA) is introduced as a good alternative biomaterial with exceptional biocompatibility. We recently succeeded in fabricating nano-structured pHEMA via CFL. We confirmed the structure of pHEMA nano-substrate with SEM imaging and AFM measurement. We hypothesized that biocompatibility of HEMA will enhance the cell contact with the nano-substrate, which will let cells penetrate through the grooves. Cells penetrating through the nano-grooves can benefit from increased surface area for cells to contact with polymer substrate, and allow cells to efficiently interact with glycan present on the surface to achieve more biomimetic environment.

As Korea is becoming internationally noticed due to its technology and pop culture, it is becoming more important for the rest of the world to understand its culture. One promising route to a deeper understanding of culture is through the study of its children's literature as an early medium that educates and socializes children into the native culture by exposing them to social norms present within the texts. Translating Korean children's literature into English requires a sophisticated but enlightening balancing act: a balance between the two languages often referred to as having "mirror image structures," a balance between the author's story and covert cultural messages, and a balance between the translator's literal and liberal approaches. To contribute to the cultural understanding, this project aims to experiment with various ways of balancing, in an effort to maximally retain cultural imagery and voices of the characters in each story, while conveying the sense and sounding elegant in translated work. The focus is on translating at least five different speech styles in Korean into what is structurally one in English. This project aims to contribute towards finding the best method in conveying the author's message both precisely while maintaining botha aesthetic and cultural values within the text for non-Korean readers.

Atmospheric carbon dioxide, the primary greenhouse gas associated with climate change, has been rising steadily since the beginning of the industrial era. Most C3 plants are likely to benefit from higher concentrations of CO₂ which is the substrate of photosynthesis. However, with more carbon dioxide available to photosynthesize, the growth of plants is often limited by other resources: notably, nitrogen. Recent research with specific strains of endophytes, bacterial or fungal organisms living within plants, shows positive symbiosis to supply the needed nitrogen to the host plants in elevated carbon dioxide scenarios. In this study, medium grain M206 rice (Oryza sativa) was inoculated with 9 strains of endophytes from native poplar (Populus trichocarpa) and willow (Salix sitchensis). The inoculated rice and uninoculated control were then put in CO₂ enrichment chambers to replicate current atmospheric and future elevated levels of carbon dioxide. I hypothesize that 1) the endophytes will give the rice plants an advantage in both ambient and elevated chambers when compared to the control because of the biologically fixed nitrogen the endophytes will provide, and 2) this advantage will be more pronounced in elevated CO₂ than in ambient CO₂. Tests concerning photosynthetic capacity, water use efficiency, and overall biomass will be used to determine significant differences. If conclusive, endophytes may be a means to capitalize on the benefits of increasing atmospheric CO₂ while curbing the negative impacts of excessive nitrogen fertilizer use by modern cropping systems on climate change.

Extensive green roofs provide environmental, economic, and aesthetic benefits. Some benefits include: improvement of storm water management, conservation of energy, mitigation of urban heat island effects, reduction of noise and air pollution, provision and enhancement of habitat for urban biodiversity and sequestration of carbon. However, although green roofs may reduce the volume and velocity of storm water runoff, studies have shown that the quality of green roof runoff is decreased from higher levels of water-soluble nitrates and phosphorus being leached from fertilizers present in green roof substrate. Biochar, a by-product of the pyrolysis of organic materials thermally decomposed to produce energy, has proven to provide multiple environmental benefits including the reduction of pollutants from fertilizers, increased water-holding capacity, and potential carbon sink capabilities. This project will evaluate the impact biochar has on the quality of runoff leached from green roof soils, as well as water-retention abilities. Two different types of 7% (v/v) biochar, added to a green roof soil mix currently used in a permanent installation at the University of Washington, will be tested. 5 cm deep green roof trays with and without biochar will be planted with common green roof species: Allium cernuum (nodding onion), Festuca glauca (blue fescue), and Anaphalis margaritacea (western pearly everlasting), and unplanted trays with and without biochar will also be tested as controls. Controlled “rainfall” events will be conducted on the green roof trays, and runoff will be collected and analyzed for nutrient content and electrical conductivity. An appropriate substrate composition is essential to reap the full environmental benefits that extensive green roofs could provide. Amending green roof soils with biochar may be the key to improving storm water runoff quality and potentially mitigating a future source of water pollution.

We have developed nanoparticle-based combination antivirals (ARVs) as an effective strategy for oral or topical HIV prevention. Currently, most candidate-microbicides consist mostly of gels, which have demonstrated poor efficacy in clinical trials. Studies have supported the successful impact of highly active antiretroviral therapy (HAART) as a standard of care for HIV/AIDS affected individuals, which has motivated the investigation of the topical delivery of combination antiretroviral drugs. The proposed work has the potential to address the delivery challenges brought upon by the diverse classes of ARV drugs. The primary appeal for this approach lies in the combination delivery of drugs with different properties and mechanisms of actions to minimize chances of resistance and improve efficacy. Here we show that individual ARV drugs can be encapsulated into poly (lactic-co-glycolic acid) PLGA nanoparticles with sizes ranging between 250-300 nm, zeta potentials of about ≥-20 mV, and high drug loading and encapsulation efficiency, as measured by dynamic light scattering (DLS) and high-performance liquid chromatography (HPLC), respectively. Furthermore, we found that these ARV drug-encapsulated nanoparticles demonstrated potent anti-HIV activity against HIV-1 BaL infection of TZM-bl cells. The effect of combination delivery of these ARV drug-encapsulated nanoparticles was evaluated to identify synergistic drug combinations and favorable drug-drug interactions. Our results demonstrate the potential for this drug delivery system as an effective strategy for HIV prevention. Successful outcomes of this endeavor could have profound implications on microbicide research and a potentially viable female-controlled prevention method for HIV.

The field of tissue engineering is becoming increasingly aware of the role that the extracellular matrix (ECM) plays in driving cellular structure and function, especially in highly anisotropic skeletal muscle. Skeletal muscle is a cell dense tissue composed of bundles of aligned myotubes responsible for lateral contraction. Replication of this organization is critical for engineering physiologically-relevant tissue constructs. The fibrous nature of the ECM has led us to the use of bio-inspired topographical line patterns on the nanoscale. We employ UV-assisted capillary force lithography to generate polyurethane-based substrates which stimulate cell elongation and alignment. By incorporating glycidyl methacrylate into our substrates, we present a novel method for engrafting a brush polymer coating of the temperature responsive polymer p(N-isopropylacrylamide) (NIPAAm) onto nano-topographically defined substrates. Seeded with C2C12 mouse skeletal myoblasts, these substrates allow for the harvest of intact cell sheets without the use of enzymes. Using a gelatin coated plunger, these cell sheets are stacked to form tri-layer thick tissue constructs. This study explores the effects of a 3D microenvironment on mature myotube formation and the ability of our NIPAAm-based system to control myotube dimension in 3D by altering nanotopography dimension as well as layer number and the timing of differentiation, contributing to the understanding of the 3D microenvironment in regulating the skeletal muscle cell niche. In addition to paving the way for clinically-significant cell-based therapies, this work may prove vital to the development of advanced in vitro drug screening platforms for patients suffering from muscular dystrophy.

Polymers represent a versatile class of chemical compounds that have a wide range of impact in the field of medicine as implantable devices, tissue engineering scaffolds, and drug delivery vehicles. Synthetic polymers such as polyurethane acrylate (PUA) have been used to provide mechanistic cues in the form of altered nanotopography to help guide migration and differentiation in stem cells. To promote cell-biomaterial interactions to elicit desired cellular responses, these surfaces still must be modified. Chemical crosslinking reagents have been applied to engineer surfaces to enhance biological performance; however, they have limitations due to non-ideal reaction environments as well as their low coupling efficiencies with bioactive molecules and their potential converse effects under physiological conditions. Therefore, controlling the surface properties remains a challenge to induce enhanced interaction at the biomaterial interface. Material binding peptides were shown to possess specificity and high affinity to several inorganic surfaces such as gold or silica while offering easy conjugation with biomolecules. This peptide-based surface functionalization, if applied to polymers, can provide a more efficient and robust method of providing biological cues to synthetic polymers. Herein, we demonstrate a simple single-step incubation process that promotes noncovalent binding of bifunctional peptides on polymer surfaces. One end of the peptide possesses high binding affinity for the polymer substrate while the other end contains a bio-functional motif such as the RGD domain, which allows integrin-mediated cell adhesion. When combined with the topographical cues of an anisotropically nanopatterned polymer substrate, a flexible platform can be established to pursue many different research thrusts, such as enhanced stem cell differentiation. Specifically, we plan to use the established platform to uncover the underlying mechanisms of adhesion, morphology, and differentiation in C2C12 mouse myoblasts.

 A significant challenge in intravaginal vaccination against mucosal pathogens concerns the immune privileged environment in the genital tract, which prevents migration of immune cells in the absence of inflammation. Dendritic cells (DC), the major antigen-presenting cell to T cells in lymph nodes, play a particularly important role in generating an effective immune response to vaccination. Our goal is to explore a new intravaginal vaccination strategy utilizing chemokines - short biological peptides that activate cells - to recruit DCs. We intravaginally administered CpG, MIP-3 Alpha and Beta-Defensin 2 to female C57BI/6J mice (Jackson Laboratories). Mice were euthanized after 24 hours and cells were isolated from both the spleen and reproductive tract. DCs were quantified using fluorescent activated cell sorting (FACS). We have demonstrated that DCs are actively recruited to vaginal mucosal tissues following intravaginal administration of the chemotactic peptides MIP-3 Alpha and Beta-Defensin 2. Future work will involve time course studies of DC recruitment and the delivery of nanoparticle encapsulated chemokines.

Despite strong public support for school counseling intervention programs, there remains a lack of state and federal funding for such programs. Typical of national trends, Seattle area schools in low-income communities suffer from a severe lack of funding for intervention programs. As a counseling intern in one of Seattle’s urban elementary and middle schools (PK-8), I have seen the impact that school counselors and interventions programs can have on a student’s personal and academic achievement. But, not much is known about whether the group interventions work as well as other forms of interventions. The hypothesis of this study is that the effectiveness of individual counseling combined with group intervention has a more significant impact than a singular approach. The methodological approach of this research is to conduct a literature review of current areas of effectiveness of school counseling programs in elementary schools; I will also conduct an interview with my practicum instructor, a school counselor. I anticipate that a combined approach is more useful because it gives students an opportunity to talk about academic and personal topics, allowing them to see that they are not alone. This study has implications for the planning and funding of elementary school interventions.

Research over the years has shown that effective oral hygiene with brushing and flossing can help reduce bleeding, gingivitis and plaque buildup. When bacterial plaque is left alone or removed improperly, it can lead to further dental disease such as caries. During orthodontic treatment, fixed appliances such as brackets are bonded to the teeth and archwires connect the brackets. These appliances make it especially hard for orthodontic patients to brush and floss effectively on their own, and failure to do so leads to an increase in plaque and gingivitis seen in the orthodontic population. A pilot study at the University of Washington’s Center for Pediatric Dentistry (CPD) will assess development of white spot lesions during orthodontic treatments. White spot lesions are the first sign of a caries lesion on enamel that can be detected with the naked eye. Pediatric orthodontic patients from CPD will be enrolled in this pilot study. Study participants will be randomly assigned to one of two oral hygiene regimens. Group A will use the WaterPik Water Flosser with orthodontic tip (dental water jet irrigation system) in conjunction with daily oral hygiene and Group B will use floss with a threader in conjunction with daily oral hygiene. Both groups will manually brush their teeth with fluoridated toothpaste twice daily as part of daily oral hygiene maintenance. The White Spot Lesion Index will be used to evaluate white spots. The primary objective of this study is to evaluate prevalence of white spots in fixed orthodontic cases following these assigned oral hygiene regimens. Secondary objectives include assessment of safety and of plaque and gingival status for both groups. Intraoral examinations will be performed; and visible plaque index and bleeding on Marginal Probing scored at each follow-up evaluation. Study participants will be evaluated at every orthodontic appointment for a minimum of 18 months.

Paternal effect mutations provide experimental tools to identify the unique contributions that fathers provide to their offspring. We are studying the ddbt (deadbeat) gene of Drosophila melanogaster, which encodes a chromosomal protein that is incorporated into spermatid nuclei during spermatogenesis and is required for normal embryogenesis. Embryos fathered by ddbt mutant males have extensive chromosome damage and embryogenesis terminates prematurely. This study asks whether ddbt-induced damage is a consequence of improper mitotic chromosome segregation in the embryo, or if the damage is independent of chromosome segregation. To address these alternatives, ddbt males will be mated to females carrying the giant nuclei (gnu) mutation. This maternal effect mutation permits repeated rounds of DNA replication but prevents chromosome segregation in the embryo. If DNA replicates to the same extent in embryos produced by gnu mothers and ddbt fathers compared to those of control fathers, this would suggest that ddbt-induced breaks occur during chromosome segregation. The alternative is that the chromosomes of ddbt fathers have preexisting damage, in which case replication would arrest due to preexisting DNA breaks. We are examining nuclear size and morphology in experimental and control embryos using confocal microscopy and assay for chromosome damage using techniques that detect breaks in DNA. Investigation of ddbt promises to improve our understanding of the paternal contributions to embryonic development.

Exposure to vocalizations from members of their own species can influence how infants learn to hear and communicate. Eptesicus fuscus is a social mammal that lives in large colonies and uses many types of vocalizations for both communication and echolocation. We hypothesize that due to the fact that they live in large, well organized social groups, big brown bats should be social learners. In order to test this, we presented altered calls that have been raised or lowered in frequency and bandwidth to bats as they developed from infancy to adulthood. In order to limit exposure to natural maternal vocalizations, pups were reversibly deafened with silicon earplugs whenever they were in the presence of other bats. Every other day, we isolated the pups, removed the earplugs, presented altered calls and recorded the pups’ response. At the end of the study, we tested changes in the organization of the auditory nuclei by measuring frequencies of neurons in several layers the inferior colliculus (IC), a central nucleus in the auditory system in response to auditory stimulation. We compared these results to each infant's twin, as Eptesicus fuscus is usually born in pairs. This gives us a genetically similar control raised in identical conditions. Our results suggest a divergence in call frequency beginning in week two, related to the exposure to lowered artificial stimuli. There is also a shift in the organization of the bands of the IC, with larger low frequency bands and smaller high frequency bands. This suggests that the pups not only altered their vocalizations in response to altered stimuli, but that the frequency organization in auditory structures of the brain remains plastic beyond birth. Humans, like bats, are social mammals, and research into mechanisms of IC plasticity may provide some insight into the development of human hearing.

GCS1 is a protein that plays a crucial role in angiosperm plant fertilization. Surprisingly, comparative studies show that GCS1-like proteins exist within a wide variety of eukaryotic species. In Drosophila, the protein Pskl is predicted to have a GCS1-like domain that affects male gametes, but its exact role in sperm formation and sperm function is not well characterized. Studying Pskl is imperative towards broadening our understanding of sexual reproduction in eukaryotes. Comparisons of Pskl to its homologs in angiosperms, algae, and protists may provide insight into mechanisms of fertilization that are evolutionarily conserved across diverse species. Furthermore, defining how the protein works could contribute to the development of reproductive therapeutics or drugs that inhibit the procreation of illness-causing organisms. The goal of this research is to understand how Pskl regulates fertility by defining its functional domains. Through gene deletions generated by imprecise excisions of a transposable element called MiMIC, analysis of both the molecular and phenotypic consequences can improve our understanding of sequences necessary for normal pskl expression. If male flies with the chromosomal derivative are sterile or have reduced fertility, then removed sequences flanking the MiMIC insertion site are likely crucial for successful fertilization. Alternatively, generated deletions may extend in either or both direction of the insertion site and impact viability, shedding light on whether pskl or its adjacent genes are essential for development. In this report, we describe the nature and consequences of the transposon excisions in pskl, both molecularly and phenotypically.

Estrogen has been shown to directly influence auditory function, with high levels of estrogen receptor expression in the central auditory system of mice correlated with elevated high-frequency auditory thresholds. These findings and others raise the possibility that hormonal modulation might be used to treat some hearing deficiencies. The big brown bat, Eptesicus fuscus, provides a unique opportunity to study an easily accessible, complex auditory pathway in a highly social mammalian species. Bats experience large seasonal differences in both estrogen levels and behavior. During fall mating season, males produce “song” calls to attract females. During winter torpor, a state of decreased physiological activity, the need for hearing is greatly reduced. During spring gestation, estrogen levels are high to support a healthy pregnancy and, after giving birth, females are sensitive to the call frequency of their pups. We hypothesized that seasonally fluctuating estrogen levels in the bat brain have a direct effect on auditory processing which varies throughout the year. We measured blood estrogen levels of male and female bats over the course of the year, and recorded sound-evoked responses of single neurons in the central nucleus of the inferior colliculus (IC), the midbrain auditory center. We specifically measured changes in basic response properties such as call selectivity, frequency tuning, and threshold changes. Afterwards, we perfused the bat, sliced the brain into 40µ sections, and stained for estrogen receptors. These measurements enabled us to correlate blood estrogen levels with both estrogen receptor expression throughout the central auditory system of the brain and functional measurements of neural sensitivity and selectivity across the audible frequency range.

Because of its unique immune characteristics, the vaginal tract is highly susceptible to attacks from sexually transmitted infections (STIs) and other pathogens. Therefore, there is a need for vaccines that can be delivered directly to the vaginal mucosa and locally protect against STIs. Due to the high vascularization of the vaginal tract, free drug may traffic to other parts of the body before it has the ability to noticeably impact the mucosal immune environment. To address these challenges, we propose utilizing a vaccine encapsulating, lipid nanoparticle that is capable of storing drug, that can be retained in the vaginal tract until it directly interacts with local immune cells capable of mounting a strong local immune response. The Woodrow Lab (at the University of Washington Department of Bioengineering) has been working on developing a protocol to synthesize a stable, biocompatible lipid nanoparticle that can encapsulate a multi-component vaccine. The particles are synthesized by cross-linking together concentric polar-lipid bilayers to form stable nanoparticles. The multi-bilayer cross-linked nature of these nanoparticles increases stability and allows them to be retained within the tissue longer than simple single-bilayer particle systems. Here we show that our particles exhibit better material efficiency and have the potential to encapsulate greater levels of drug than similar lipid particle platforms. Through electron microscopy we have demonstrated that our protocol successfully produces particles with the characteristic uniform multi-bilayer morphology that we expected. We are currently working on optimizing our production process for scale-up production of the particles for larger trials. In future experiments we plan to encapsulate vaccine in the particles and use in vivo mouse models to demonstrate that our particle-vaccine system creates a more potent and longer lasting immune response than free vaccine alone. This method of vaccine delivery may prove effective at preventing several STIs including herpes and HIV.

One of the current challenges in developing an effective microbicide is the ability to provide both short-term and long-lasting protection against HIV with a single application. In this project we seek to develop a nanofiber material that will be used to deliver HIV neutralizing antibodies from poly(vinyl) alcohol (PVA) nanofibers of different degree of hydrolysis to be used as a female controlled vaginal microbicide, using bovine serum albumin (BSA) as a model release protein. We hypothesize that the differences in the degree of hydrolysis of PVA will allow for controllable release of the BSA protein, because a higher degree of hydrolysis allows for a more crystalline structure, which may slow release. PVA was chosen for the nanofibers because of its quick-dissolving abilities and biocompatibility. We are using two compositions of PVA, 87-88% and 99+% degree of hydrolysis. We optimized electrospinning parameters to create PVA nanofibers with high mass yield and consistent fiber diameters that will be used to deliver the antibodies. The time to dissolution was measured by visually determining when no distinguishable fiber pieces were present when added to water at 37C. We found the time to dissolution of 87-88% degree of hydrolysis nanofibers to be approximately 15 minutes compared to greater than 3 days for the 99+% degree of hydrolysis. We incorporated 1% and 2% w/v BSA as a model protein in the PVA nanofibers. Using enzyme-linked immunosorbent assay (ELISA) we characterized the protein release of the fibers and compared the relationship between degree of hydrolysis and release patterns of the proteins. We expect that this project will provide a proof of concept for antibody encapsulating nanofibers for vaginal drug delivery.

In natural environments, animals seeking resources face potential perils associated with foraging behavior, namely predation. Thus, animals must balance their needs with risks by utilizing adaptive behavioral strategies. One such strategy is hypothesized to be provided by the fear system through adapting foraging behavior in the presence of environmental threats. The advent of new molecular biological techniques such as Designer Receptors Exclusively Activated by Designer Drugs (DREADD) and optogenetics has provided novel approaches to investigating the amygdala’s modulating role in fear behavior. DREADDs are based on the G-protein coupled receptor pathways in which the receptors are activated by systemic injections of clozapine-N-oxide to stimulate or inhibit neurons initially and affect a host of downstream cellular signaling pathways that results in changes to cell function. Optogenetics uses receptors that immediately open in response to certain wavelengths of light to allow the passage of relevant ions in order to activate or inhibit the cells. The current project utilizes these targeted approaches to remotely activate or inhibit the basolateral amygdala and the central amygdala. The animal's ability of fear learning will be assessed using the Pavlovian fear conditioning paradigm. The effect of activating or inhibiting the amygdala in a semi-naturalistic setting will be evaluated using the Robogator paradigm. After habituation and training, rats will be placed in the chamber in which a predatory presence, known as a Robogator, will surge and snap when the animals attempt to grab a food pellet. The analyzed behavioral results in control animals and experimental DREADD and optogenetic animals can be compared to affirm the use of DREADD and optogenetic in behavioral research while providing new information as to how different groups of neurons and their connectivity in the amygdala affect fear behavior.

Stress can have a major impact on the cognitive functions of the brain in both humans and animals. One of the possible areas affected is the hippocampus, a structure known to be important in consolidation of short and long-term declarative memory and spatial memory. Previous studies have shown that stress can reduce long-term potentiation, impair spatial memory, and affect the firing rate of location-specific place cells in rats. This study aims to investigate the effects of temporary hippocampus impairment during stress on risky foraging behaviors in rats using APV, an NMDA receptor antagonist that inhibits the synaptic plasticity of local neurons at the site of injection. Rats were trained to retrieve food pellets from a simulated foraging environment and return to a safe nest, and APV infusions were then made via implanted cannulas into the rats’ hippocampus 30 min prior to stress. Foraging behavior in the presence of a robot predator was assessed in comparison to control rats infused with artificial cerebrospinal fluid. Hippocampal dysfunction is hypothesized to contribute to faulty contextual fear conditioning and memory formation, thus rats with an impaired hippocampus may exhibit excessive, contextually-inappropriate fear behavior in the presence of an artificial predator. The results of this study may help us understand the affects of stress and its role in the behaviors of individuals with post-traumatic stress disorder.