May 21, 2021 Mary Gates Hall

THE BRAIN,BEHAVIOR AND HEALTH O-4H Session Moderator: Kristina Adams Waldorf, Obstetrics & Gynecology Join Room 2:45 PM to 4:15 PM

* Note: Titles in order of presentation.

Acute Efficacy of Antiseizure Drugs in the 6 Hz Focal in the anticonvulsant efficacy of clinically-approved ASDs to Seizure Model in 2 Knockout Mice better inform management of focal seizures in patients with Leanne Marie Lehmann, Senior, Neuroscience AD. UW Honors Program Mentor: Melissa Barker-Haliski, Pharmacy Investigating the Role LC-NPS Release in the OFC Recent studies have indicated that some patients with Could Play in Anxiety Related Behavior Alzheimer’s disease (AD) experience undetected focal Kat Motovilov, Senior, Bioengineering seizures, which could contribute to and/or worsen overall dis- Mentor: Michael Bruchas, Anesthesiology & Pain Medicine ease burden (e.g. cognitive function and neuropsychiatric co- Mentor: Kasey Girven, Department of Anesthesiology morbidities). Genetic variants in presenilin 2 (PSEN2) are Neuropeptide S (NPS) is a neuropeptide produced primarily associated with early-onset AD and result in a loss of normal in two regions of the hindbrain, the locus coeruleus (LC) and PSEN2 function. Patients with PSEN2 mutations also expe- the Kolliker-Fuse nucleus. The LC-NPS population is partic- rience seizures more frequently than age-matched individuals ularly interesting because of the LC’s role in norepinephrine without AD. There are over 30 clinically approved antiseizure production and subsequent transmission throughout the brain. drugs (ASDs), which have been proposed to be effective in Previous work has found that when NPS is injected into the controlling these seizures, and thus reducing disease burden. amygdala, it results in an anxiolytic phenotype, implicating ASD efficacy and tolerability is not, however, frequently de- NPS and its G- coupled receptor (NPSr1) in anxiety- termined in aged rodent seizure models nor in rodent mod- related behaviors. Using fluorescent in situ hybridization, a els with AD-associated genotypes. This project thus aimed method which allows visualization of single RNA molecules to establish the dose-dependent efficacy of mechanistically- within cells via fluorescent probes, we found preliminarily, distinct approved ASDs in the well-established mouse 6 Hz that the orbitofrontal cortex (OFC) has dense expression of model of focal seizures, using both female and male PSEN2 NPSr1 RNA. This is significant as the OFC is involved in knockout (KO) mice. Seizure susceptibility in PSEN2 vari- higher-order cognition including social, reward-learning, and ant mouse models of AD is generally understudied; most anxiety-like behaviors. For example, OFC neurons respond work previously has been conducted in precursor to social interaction as well as food cues, and inactivation of protein-overexpressing models. We thus first quantified the the OFC results in increased anxiety-like behavior. The LC median convulsant current (CC50) in the 6 Hz model of fo- is also known to send projections to the OFC that have been cal seizures with male and female PSEN2 KO mice aged 3- largely unexplored. Therefore, to better understand and char- 4 months. The CC50 of female PSEN2 KO mice was 34.4 acterize the connection between the LC and OFC we utilized mA [95% confidence intervals 30.4-38.5]; in males it was in vivo fiber photometry to assess endogenous OFC-NPSr1 41.9 mA [39.3-46.9]. Candidate ASDs (valproic acid, lamot- activity during reward-learning, social interaction, and innate rigine, carbamazepine, levetiracetam, and perampanel) were behaviors. Our studies aim to uncover the functional role of then administered via intraperitoneal (IP) injection in a dose- LC-NPS release in the OFC. related manner to assess dose-related seizure control in the 6 Hz test. Preliminary results indicate that PSEN2 KO mice may be more sensitive to administration of valproic acid than wild-type mice. This study is definitively addressing whether loss of normal PSEN2 function promotes any overt changes

Undergraduate Research Program 1 www.uw.edu/undergradresearch Biased Signaling in a Mu-opioid Receptor Mediated about the molecular mechanisms of forgetting, despite its im- Circuit Drives Motivated Behaviors portance in human health. Here, we take advantage of the Corinna Sydelle Oswell, Senior, Neuroscience nematode C. elegans – a living animal with a simple nervous Levinson Emerging Scholar, Mary Gates Scholar, system of 302 neurons – to explore the mechanisms behind Innovations in Pain Research Scholar, UW Honors Program forgetting. In particular, we focus on the decay of associative Mentor: Michael Bruchas, Anesthesiology & Pain Medicine olfactory learning and the regulation of this decay after expe- Mentor: Daniel Castro, Anesthesiology rience of pathogenic bacteria. Previous studies have shown Opioids like morphine or fentanyl have high therapeutic value that worms acquire an associative memory linking starvation as analgesics for acute and chronic pain. Unfortunately, they experience and the olfactory response. After prolonged ex- also have a high propensity for abuse. Previous research has posure to a preferred odor during starvation, worms exhibit indicated that the rewarding and analgesic properties of opi- a diminished response towards the preferred odor. However, oids may be dissociated in the brain, though how they do so upon returning to a food source, the attractive response to- remains unresolved. Endogenous and exogenous opioids act ward the preferred odor recovers within 3-4 hours, indicat- on four specialized 7 transmembrane g-protein coupled re- ing the loss of the associative olfactory memory. We found ceptors (GPCRs). One of these opioid receptors is the mu- that the rate of memory loss, quantified by measuring the opioid peptide receptor (MOPR), which is thought to be the time course of recovery of the olfactory response, depends primary target of morphine and fentanyl. The nucleus accum- on the type of food source (bacterial strain) that worms expe- bens (NAc) has long been recognized as a significant reward rience. Specifically, exposing worms to pathogenic bacteria center of the brain that has a high density of MOPR’s. Cur- PA14, compared to the regular food source OP50, leads to a rent work in the lab by Dr. Castro and myself has shown that quicker loss of the associative olfactory memory. Our results a circuit from the dorsal raphe nucleus (DRN) to the NAc further show that the acceleration of memory loss is mediated underlies MOPR control of reward and motivation. Specifi- by a conserved transcription factor DAF-16/FOXO, as daf-16 cally, we have shown that MORs are activated by the endoge- mutants exhibited similar rates of memory loss regardless of nous ligand enkephalin on DRN terminals in the medial shell OP50 or PA14 experience. Together, these findings demon- of NAc to enhance motivation. While these studies clarify strate an unexpected role of DAF-16/FOXO in memory decay the NAc MOPR motivational circuit, they leave unresolved induced by exposure to pathogens. what intracellular mechanisms are recruited by MOPRs to modulate neural activity. This is of great interest consider- Ventral Tegmental Area GABAergic Inhibition of ing that various properties of opioids (analgesia vs. reward Ventral Accumbens Shell Cholinergic Interneurons vs. respiration) may be driven by one of two different sig- Promotes Reward Reinforcement naling pathways, the G-Protein pathway or the beta- Sofia Shirley, Senior, Biochemistry pathway. Therefore, the primary goal of my project is to de- Mary Gates Scholar, Innovations in Pain Research termine which pathway is specifically recruited in this circuit Scholar to drive enhanced motivation. We will use optogenetic and Mentor: Michael Bruchas, Anesthesiology & Pain Medicine targeted viral modulation approaches to manipulate the DRN Mentor: Raajaram Gowrishankar, Anesthesiology and Pain to NAc circuit and determine whether distinct signaling cas- Medicine cades mediate MOPR control of motivation. These results Reward is a driving force for animal and human behavior. will be the first investigation into how specific signaling cas- Reinforcing behaviors with rewards leads to enhanced learn- cades contribute to motivated behaviors in a cell-type, tempo- ing ability, which can either promote behaviors that increase rally restricted, in vivo manner. survival, or lead to maladaptive behaviors. The nucleus ac- cumbens (NAc) and ventral tegmental area (VTA) are brain Pathogenic Bacteria Accelerates Forgetting in C. elegans regions established to be involved in reward processing and Through a DAF-16/FOXO-Mediated Response have significant neural connectivity. Recent studies have Rd Pant, Senior, Neuroscience identified a long-range GABAergic neural circuit connect- Mary Gates Scholar ing these two regions, however previous studies focus pri- Mentor: Jihong Bai, Basic Sciences, Fred Hutchinson marily on dopaminergic neurons. These inhibitory GABAer- Cancer Research Center gic neurons synapse with cholinergic interneurons within the Mentor: Manuel Rosero, Basic Science, Fred Hutch Cancer NAc shell (NAcSh). Further, the dorsal and ventral subdi- Research Center visions within the NAcSh have been shown to have differ- Learning and forgetting are two key processes that keep our ent neural connectivity. To investigate the role of this cir- memories in balance. In the past few decades, we have cuit, I performed fiber photometry recordings of neural activ- learned a great deal about mechanisms associated with mem- ity in GABAergic terminals in the dorsal and ventral NAcSh ory formation and consolidation. However, little is known during reward reinforced behavior in mice. The recordings show an increase in GABAergic neural during reward con-

2 sumption in the ventral, but not the dorsal, NAcSh. I also pothesis that oxytocin action in the hindbrain reduces body recorded the activity of NAcSh cholinergic interneurons as weight gain and adiposity by reducing energy intake and in- well as acetylcholine activity in the dorsal and ventral NAc creasing BAT thermogenesis in female HFD-fed rats. shell. These recordings show that cholinergic neural activity as well as acetylcholine activity are reduced during reward consumption in the ventral, but not dorsal, NAcSh, reflecting the inhibition by the GABA neurons during this time. I also used the inhibitory photo-activatable chloride pump JAWS to inhibit GABAergic projections during reward consumption, finding that animals made reduced reward seeking events and consumed fewer rewards when JAWS is activated. Collec- tively, these results indicate GABAergic projections from the VTA to specifically the ventral NAcSh function in reward re- inforcement by inhibiting cholinergic activity during reward consumption. These results characterize a previously un- known neural circuit and help us better understand psychi- atric disorders like depression and addiction that impact these circuits.

Hindbrain Administration of Oxytocin Reduces Body Weight Gain, Adiposity and Energy Intake in Female High Fat Diet-Fed Rats. Ron Vered, Senior, Pre-Sciences Mentor: James Blevins, Medicine, VA Puget Sound Health Care System/University of Washington

Previous studies indicate that CNS administration of oxytocin (OT) reduces body weight in male high fat diet-induced obese (DIO) rodents by reducing food intake and increasing energy expenditure (EE). We recently demonstrated that hindbrain [fourth ventricular (4V)] administration of OT elicits weight loss and elevates interscapular brown adipose tissue tempera- ture (TIBAT; surrogate marker of increased EE) in male DIO rats. What remains unclear is whether chronic CNS OT can impact body weight in female high fat diet-fed (HFD) rats and whether this involves activation of hindbrain OT recep- tors. We hypothesized that OT-induced stimulation of hind- brain OT receptors reduces weight gain and adiposity, in part, by reducing energy intake and increasing BAT thermogenesis in female HFD-fed rats. To test this hypothesis, we measured the effects of chronic 4V OT (≈16.1 ug/day) or vehicle in- fusions over 28 days on body weight, adiposity and energy intake in female HFD-fed (60% kcal from fat) rats (N=7- 8/group). We found that chronic 4V OT reduced weight gain (P<0.05) and relative fat mass (P<0.05) in randomly cycling female HFD-fed rats. These effects were attributed, in part, to reduced energy intake evident during weeks 2 (P<0.05), 3 (P<0.05) and 4 (P<0.05). To assess if hindbrain OT ad- ministration also elevates BAT thermogenesis, we examined the effects of acute 4V OT (1, 5 ug) or vehicle on TIBAT in a separate group of female HFD-fed rats (N=8/group). We found that the low dose (1 ug) elevated TIBAT at 0.75, 1, 1.25, 1.5 and 2-h post-injection (P<0.05); the higher dose (5 ug) elevated TIBAT at 0.75, 1, 1.25, 1.5, 1.75 and 2-h post- injection (P<0.05). Together, these findings support the hy-

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