Inflammasomes are multimeric protein complexes involved in innate immune responses. Inflammasomes include a protein sensor, such as NLRP3 or pyrin, linked to the enzyme caspase-1 via the adaptor protein, ASC. Active caspase-1 is responsible for release of the cytokine interleukin (IL)-1ß and triggering inflammatory cell death. Inflammasomes are crucial in defense against pathogens. However, excess inflammasome activation is linked to diseases such as Alzheimer's, atherosclerosis, and other inflammatory conditions. Although inflammasomes are linked to several diseases, we do not fully understand how inflammasomes are activated. We are researching the role that potassium plays in inflammasome activation. To detect inflammasome activation, I measured released IL-1ß using enzyme-linked immunosorbent assays (ELISAs). I determined whether inflammasome activation requires potassium efflux by measuring IL-1ß released from cells stimulated in high extracellular potassium, which prevents potassium efflux. I found that IL-1ß release triggered by NLRP3 inflammasome activators is prevented when cells are stimulated in high extracellular potassium. However, IL-1ß release triggered by the pyrin inflammasome was not affected by high extracellular potassium. From these results, we conclude that the NLRP3 inflammasome is dependent on potassium efflux from the cell, whereas the pryin inflammasome is not. The implications of our research are two-fold. First, our findings argue against a long-standing hypothesis that high extracellular potassium blocks ASC binding. Both NLRP3 and pyrin need ASC, but our data show that only NLRP3 is affected by potassium concentration. This suggests that potassium affects NLRP3 activation at an unknown point. Second, understanding the role of potassium in regulating inflammasome activity provides a potential therapeutic target. There are drugs that regulate ion concentrations by controlling ion channel activity. Knowing whether an inflammasome pathway is potassium efflux dependent could be beneficial in limiting excess inflammasome activation that is linked to a variety of human diseases.

Abstinence-based treatment has long been considered the standard of care for people with alcohol use disorders (AUD). However, abstinence-based treatment fails to engage severely affected populations (e.g., homeless people affected by AUD) because many are not yet ready, willing or able to stop drinking. A recent randomized controlled trial tested the efficacy of a lower-barrier harm-reduction treatment for alcohol (HaRT-A), in which participants could define their own harm-reduction and quality-of-life (QoL) goals. The aim of this present secondary study was to describe participants’ own harm-reduction and QoL goals and document their achievement of these goals over the course of HaRT-A. Participants were people currently experiencing homelessness and AUD (N = 86) who attended the 4-session HaRT-A, during which interventionists elicited participants’ own harm-reduction and QoL goals. The Safer-drinking and Harm Reduction Efforts (SHaRE) form was administered to elicit and record participant-generated harm reduction goals, which were entirely participant-driven with no suggestions from study interventionists for any specific drinking-related goals. Directed content analysis was performed to classify participant-generated treatment goals. Results indicated that goals fell into 7 primary categories, the top 3 being drinking-related goals, quality of life goals, and health-related goals. These findings suggest that a client-driven, goals-setting approach could inform accessible and appropriate treatment and QoL-enhancing interventions for people experiencing homelessness and AUD.

Botox (botulinum toxin) is commonly used to reduce facial wrinkles, but it is also injected into the masseter muscles, the main jaw closing muscles, for cosmetic reasons or pain reduction. Botox blocks neurotransmission, leading to partial muscle paralysis and atrophy. Although these effects are considered safe and temporary, we previously found that a single treatment of the rabbit masseter with Botox caused muscle atrophy persisting for at least 12 weeks. However, some muscle fibers were unaffected or even enlarged. The purpose of this study was to determine if the changes observed were more or less severe in specific regions of the masseter, and if differences in fiber size correlated with the regional electromyographic (EMG) response to nerve stimulation. Rabbit masseters were injected unilaterally. Regional EMG was recorded before euthanasia at either 4 (n=4) or 12 weeks (n=5) post-injection. The regions corresponded with the three sites of injection, anterior, middle and posterior in the inferior part of the muscle. Superior regions were also examined for the 12-week sample. Least fiber diameter was measured in histological sections (40-60 fibers/region). Linear regression was used to correlate EMG and fiber diameter. In general (6/9 treated muscles) the region with the largest fibers showed the highest EMG, but at 4 weeks there was no linear correlation; all regions showed both atrophied fibers and low EMG. At 12 weeks, all regions of treated muscles had larger average diameters and some also had increased EMG. Positive correlations between fiber size and EMG were seen anteriorly (r2=0.66) and posteriorly (r2=0.43) and in the muscle as a whole, both inferiorly (r2=0.36) and superiorly (r2=0.76). These results indicate that Botox injections have adverse effects long after the initial injection. Although no regions are consistently more affected than others, there is a general correlation between fiber recovery and signal strength.

Methane reservoirs are commonly found throughout the world’s oceans and the release of methane from seafloor reservoirs is thought to make up 5 to 10% of the global atmospheric methane. In fact, the greatest deep-sea mass extinction in the last 97 Myr during the Paleocene-Eocene Thermal Maximum (PETM) may have been caused by methane release from seep sites along the upper continental slope margin. Recently, methane reservoirs along this margin have been gaining attention due to their potential to accelerate current global warming. Changes in seafloor pressure and temperature could destabilize these seafloor deposits and cause methane bubble plume release into the ocean. At SHR, an extensively studied active seep site located ~ 90 km offshore Oregon, discontinuity in methane plume release was observed, but still not well understood. Hence, using Acoustic Doppler Current Profiler (ADCP) and pressure data archived by the Ocean Observatories Initiative (OOI) Cabled Array, we are investigating the potential correlation between tides and the presence of methane plume at SHR. Our study detects methane plume structures based on the proxies of echo contrast caused by acoustic-bubble interaction. By analyzing the derived plume structures and their correlation with 226 tidal cycles, we expect a trend of plume release triggered by low tides. Our study provides the first high-temporal-resolution analysis on the methane plume release at SHR using OOI acoustic data. 

The goal of this project was to determine if mitochondrial biogenesis in zebrafish cone photoreceptors is circadian and/or regulated by light. Photoreceptors use more energy in darkness compared to light, and at night the number of mitochondria in zebrafish cones increases. We hypothesized that mitochondrial biogenesis would correlate with increased energy needs and increased mitochondrial number.  Zebrafish retinas from light/dark and dark-only cohorts were collected over a 24-hour cycle. Retinas were fixed and sectioned at 20 µm for immunohistochemistry. Sections were incubated with primary antibodies against mitochondrial biogenesis genes and cytochrome oxidase and imaged with confocal microscopy. Length measurements were taken from the center of single cone mitochondrial clusters. Retinas were also analyzed by Western blotting to assess cone mitochondrial protein content. 21 genes involved in mitochondrial biogenesis were analyzed via qPCR, in addition to ratios of mitochondrial DNA (mtDNA) to nuclear DNA (nDNA). Experiments were conducted in triplicate with three biological replicates and the ΔΔCt method was used to determine relative expression.  Immunohistochemistry revealed that cone mitochondrial clusters elongate 30% following dark onset. Western blot analysis is ongoing. mRNA transcripts for two genes involved with mitochondrial biogenesis, PolG1 and TFAM, increased roughly 6-fold and 3-fold respectively in the hours leading up to dark onset; transcripts for the mitochondrial fusion factor, Mfn2, increased 3-fold just prior to light onset. Cone mitochondrial clusters enlarge at night, and this is preceded by upregulation of mitochondrial biogenesis genes. Lastly, mitochondrial fusion prior to light onset may be followed by a decrease in mtDNA number. These effects occurred independently of light exposure. Overall, these results highlight a possible mechanism in photoreceptors to increase energy production in the dark while following the circadian clock.

The Bonneville Landslide dam, also known as the Bridge of the Gods, blocked the Columbia River about 550 years ago at the site of the modern Bonneville Dam, on the Washington-Oregon border. According to Klickitat lore, the Bridge of the Gods was created by the chief of all gods to join the lands north and south of the river. The dam’s failure, thought to be a result of the violent dispute between the chief’s sons, led to an outburst flood that drowned a forest and carved the Cascade Rapids. Sedimentary deposits from this dam break flood have been observed downstream, but the flood behavior and inundation pattern remains unknown. In this study, we created a paleo-digital elevation model (DEM) of the Columbia Valley Gorge landscape before the flood, which will serve as the basemap for numerical models of the flood. The paleo-DEM combines three data sets: 1) topographic data derived from the 1868 and 1901 U.S. Coast and Geodetic Survey historic topographic survey maps and bathymetric depth values from hydrographic sheets; 2) bathymetry of the Lower Columbia River with removed modern structures in Portland, validated by tide records from 1853 to 1876; and 3) bathymetry upstream from the Bonneville Dam, merged with adjacent topography and derived from NOAA data. In ArcGIS, we filled in data holes and modern channels and subtracted modern structures in an attempt to accurately represent the paleo-environment. Because the Columbia estuary is heavily influenced by tides, we used historic tide observations to create a low and high tide paleo-DEM to make preliminary analyses of how the tide might have influenced this flood. Once we know the paleo-topography of the Columbia Gorge, Portland basin, and Columbia Estuary, we can begin to numerically model this flood and explore its geomorphic impact.

When seeking to better understand specific bedrock river erosional processes due to flooding, numerical modeling can help answer many questions, specifically the extent to which floods contribute to setting the landscape. The eastern Himalaya experiences multiple flooding events of different magnitude: annual monsoon floods (10³m³/s) and centennial outburst floods (10⁵ m³/s). This region also experienced at least two ancient megafloods during the Holocene (10⁶ m³/s). Previous studies of flooding in the region have assessed the potential geomorphic role of the outburst floods and megafloods; however, the relative geomorphic impact of annual monsoon flooding remains unknown. To fully understand the relative erosive power of these eastern Himalayan floods, it is necessary to compare the hydraulics of outburst dam-break floods to the hydraulics of seasonal monsoon flow. To do this, we use the program GeoClaw to numerically simulate monsoon flood flow in this region. GeoClaw, which uses the 2D shallow water equations, has accurately been used to model outburst flooding events, including the centennial outburst floods and the ancient megafloods. By modifying the program to simulate constant monsoon discharge, we can analyze patterns of flow velocity and depth (GeoClaw outputs) to understand the spatial pattern of shear stress during monsoon floods. We expect to find that monsoon flow will yield lower magnitudes of shear stress and more homogeneous patterns of potential erosion compared to those observed for the outburst floods and megafloods. Understanding these erosional spatial patterns will help us better recognize the relative contributions of various magnitude floods and the extent to which each can set the landscape.

 Alcohol use disorder (AUD) is associated with both acute and chronic alcohol-related harm. Marginalized populations, such as those experiencing homelessness, are both less inclined to successfully achieve abstinence and at higher risk of experiencing alcohol-related harm. Identifying strategies for safer use are thus particularly important for this population. To this end, we analyzed interview data collected from 86 adults experiencing homelessness and AUD who received harm reduction treatment (HaRT-A) during the parent randomized controlled trial. Participants were administered the demographic and alcohol measures at baseline (week 0) and were provided with HaRT-A, at which point interventionists introduced a list of safer-drinking strategies. Participants’ endorsement of safer-drinking strategies was assessed at HaRT-A appointments at weeks 0, 1, 2, and 6. For the current analysis, we conducted a mixed methods approach to characterize and evaluate endorsement and implementation of safer-drinking strategies at week 0 and week 6. Findings indicated use of strategies to buffer the effects of alcohol (e.g., eating while drinking), change the manner in which one drinks (e.g., counting drinks), and reduce alcohol use. Quantitative analysis indicated all participants were able to successfully endorse and implement safer-drinking strategies over the course of the study. These findings support that people experiencing homelessness and AUD adopt strategies that minimize alcohol-related harm, including ways that change the amount and manner of drinking and buffering the effects of alcohol. This extends the findings from our parent study among chronically homeless individuals to people experiencing transitional or episodic homelessness.

Many psychiatric disorders, including substance abuse, have been linked to risky decision-making, but the mechanisms underlying these pathologies remain unclear. Cortical intratelencephalic and pyramidal tract (PT) neurons have distinct projections, morphology, and firing properties, but their role in behavioral regulation remains unknown. PT neurons have been identified in the orbitofrontal cortex (OFC), which is known to be heavily involved in the cognitive process of decision making. Based on previous studies in our lab demonstrating that inactivation of PT neurons increases reward preference, we hypothesized that PT neuron inhibition would increase risky decision-making. To test this hypothesis, rats were trained on a risky-decision task (RDT) in which they were trained to lever press for a food pellet reward. In order to target PT neurons in the OFC, CAV2-CRE virus was bilaterally injected into the pontine reticular nucleus (PnC), and an inhibitory Designer Receptor Exclusively-Activated by Designer Drugs (DREADD; DIO-hM4Di) was injected bilaterally into the OFC; this strategy allows selective expression of DREADDs in PT neurons. In the RDT, two options were presented: a “risky” choice associated with descending probability of administration (100%, 50%, 25%, and 12.5%) for delivery of four food pellets, or a “safe” lever that always delivers one food pellet. To evaluate response flexibility, rats underwent a reversal task whereby five consecutive responses on the active lever switched the “active” lever to the previously inactive one. In both tasks, rats underwent two sessions: in the test session, animals received an injection clozapine-N-oxide (CNO) to activate DREADDs, and in the control session, animals received an injection of vehicle (DMSO). Interestingly, we found that inhibiting PT neurons did not significantly alter decision-making or reversal-learning. Future studies will monitor activity of PT neurons using in vivo calcium imaging to determine the contribution of this cell population to decision-making tasks.

The Yerkes-Dodson law suggests that performance is optimal when physiological arousal is moderate. Prior research has shown that arousal induced by listening to music will affect task performance on a cognitive task. The goal of this study was to test whether different music tempos would affect arousal levels and performance on a cognitive task. We recruited 16 UW undergraduates and exposed them to different tempos of the same song while performing a math test. We tested their accuracy, completion time, and recorded their heart rate. Results suggest that accuracy was higher under moderate music tempo than slow but there was no difference between moderate and fast. Interestingly enough there was no difference in completion time or physiological arousal. Although we failed to establish an effect of arousal and completion time the fact that participants did better on accuracy when music tempo was moderate is in line with what we predicted. Music tempo could still be influential to performance and future research can be done to understand these effects by operationalizing performance differently. Future directions about ways to improve the study will be discussed especially whether music/music tempo affect people subjective arousal and physical arousal differently.

Risk taking is strongly associated with many disordered behaviors. Many studies implicate the orbitofrontal cortex (OFC) in such behaviors, though its modulation yields inconsistent results. This could be due to possible contrasting effects of intratelencephalic (IT) and pyramidal tract (PT) neurons, which have distinct morphologies and projections. Despite this, specific functionality differences are unknown. Given that 5-HT2A and D1 receptors have predominant expression in IT neurons over PT neurons, and antagonism of these receptors decreases risk-seeking, it was hypothesized that inhibition of all IT neuron activity in the OFC would also result in risk aversion. IT neurons in rats were inhibited during a risky-decision making task (RDT). To modulate IT neurons, an inhibitory designer receptor exclusively activated by designer drugs (DREADD) was injected into lateral OFC bilaterally, conjugated to CRE and FLP drivers injected into contralateral nucleus accumbens. In the full RDT, animals were presented with two levers: The “safe” lever delivered one pellet reward per press, while the “risky” lever delivered four pellets, with descending probability of reward administration (100%, 50%, 25%, 12.5%). Two test sessions were conducted whereby animals received intraperitoneal injections of clozapine-N-oxide (CNO) or a vehicle (DMSO) 30 minutes prior to task onset. Animals receiving CNO the first time received vehicle the second time. To determine if IT neurons were involved in perseverative responding, animals underwent a reversal task. They were presented with an active lever -which administered a food pellet per press -, and an inactive lever. Five consecutive responses on the active lever switched the inactive lever to the “active” lever. Results showed no significant changes in decision-making or reversal learning upon receiving CNO or vehicle. IT neuron modulation may need to be more temporally specific; future studies will focus on monitoring IT activity during decision-making paradigms to further elucidate their contributions within OFC.

The growing use of opioids in the United States has become a dangerous epidemic. The people most susceptible to overdosing on opioids are those who relapse after extended drug abstinence, whether forced or by choice. This study investigates the effects of heroin addiction on KCNQ channels in the basal ganglia, which plays an integral role in addiction.  More specifically, our research is focused on relapse after a prolonged period of no drug use. If the population of KCNQ channels are affected by heroin use and addiction, then these channels are a possible site for treatment to target. The drug retigabine, a KCNQ channel opener, has shown promise in reducing self-administration after abstinence by affecting dopamine levels in the striatum, a neurological center often involved in addiction. Given that dopamine release is critical in establishing and affecting addiction, retigabine is a likely candidate to diminish relapse behaviors and, therefore, reduce the occurrence of relapse-related overdoses. This study measures the effect of a global administration of retigabine. Catheters were surgically into the animals’ jugular vein to allow for self-administration of heroin with limited researcher interference. Over the course of three weeks, we ran our animals inoperant boxes for periods of self-administration following various drug availability periods and ending with forced abstinence. After two weeks of forced abstinence, the animals with high and low responding on self-administration were separated into three different treatment groups: Retigabine, XE991 — a  drug that has the opposite effects of retigabine — and a control solution (all administered intraperitoneally). Our animals then underwent one hour of continuous access self-administration where they could relapse. Behaviors such as drug intake, drug seeking, drug taking, and motivation to administer were measured across all six groups.The results from this study will provide evidence on the efficacy of retigabine in reducing relapse behavior after abstinence.