Tag: Human Physiology

Differences in Old and Young Patient-Derived Myotubes Response to Amino Acid Stimulation

Presenter(s): Jeanette Helgerson—Human Physiology

Faculty Mentor(s): Hans Dreyer, Doug Foote

Session 3: The Substance of Us

Human muscle cell growth is regulated through the protein complex mTOR, the mammalian target of rapamycin, which is activated by nutrients such as amino acids and growth factors such as insulin . We wanted to know if there were differences in how old and young patient derived muscle cells responded to amino acids, particularly how the mTOR cascade was affected . The mTOR response to amino acids has been studied in many types of cells, but this study’s approach using patient derived human skeletal muscle cells to analyze mTOR response has yet to be explored . Using purified samples of these patient derived cells, a mixture of amino acids (LRK) that are known to activate mTOR were given, and the cellular signaling of certain proteins were quantified to measure mTOR activation . Both young and old patient derived cells were given these conditions and the averages of the groups were compared . This research is currently ongoing, so not all of the data is available yet . Knowing the differences in how young and old patient derived cells respond to amino acids is important because it could help alleviate muscle loss . Muscle loss shortens lifespans and diminishes the quality of life for many people, so understanding the underlying mechanisms of how to gain muscle back after the aging process, injury, or surgery, is imperative .

Colorado’s Government and Public Health Response to COVID-19

Presenter(s): Amelia Hardeman—Human Physiology

Co-Presenter(s): Myriah Kunipo-Aguirre, Hannah Heskin, Angelique Wallman

Faculty Mentor(s): Kristin Yarris

Session 2: US Outbreak Breakout—COVID-19 Research

I am currently enrolled in the course titled Field Experience: Global Crisis with Dr . Kristin Yarris . This research project aims to track the response of the State of Colorado through the state’s government and local Public Health perspective . I will track and analyze the government’s response through
Gov . Jared Polis’ policies and the Colorado Department of Public Health and Environment’s data and recommendations, perspectives from frontline health care workers, and the public’s response to these policies and recommendations ultimately leading to the amount of cases and deaths . I will have direct conversations with front line health care workers discussing their perspectives on the state’s response as well as the public’s response . All data and interviews will be compiled into a Podcast to share the information and perspectives on Colorado’s response to COVID-19 as a whole .

Stem Cell Research

Presenter(s): Aryanna Entezari-Schweiger—Human Physiology

Session 5: The Bonds that Make Us

Imagine having the ability to transplant organs without rejection, create medications without requiring human trials and extend a humans life . Stem cells give researchers exactly that! These cells have proven their ability to cure the incurable, learn about the effects of drugs, and understand the developmental process of humans . Stem cells have already cured people with seemingly “incurable” medical conditions such as Alzeihmers, spinal cord injuries and diabetes so investment into stem cell research should be a research priority . Embryonic stem cells are harvested from undifferentiated embryos early in development and inserted into damaged tissues to differentiate into healthy, functioning cells . However, with the moral implications about embryonic stem cells, scientists have turned to reprogramming adult stem cells to further their research . Adult stem cells can be harvested and reprogrammed into pluripotent stem cells and used for therapeutic purposes or medical research . With over 50 years of stem cell research, society should be seeing greater medical advancements . Unfortunately, stem cell research is not commonly funded by wealthy private institutions but rather from limited federal funds . Stem cell research is one of the youngest fields of research that has great promise of treatment and cure for the most common diseases in the world . Through continued intensive research, findings become more and more conclusive and have proved to have a widespread use . Stem cell research should be a front runner in medical laboratories in hopes of enhancing medical treatment .

Comparison of Stop-Signal and Continuous Movement Reaction Stop Times to Measure Inhibitory Control

Presenter(s): Dominique Denning—Human Physiology

Faculty Mentor(s): Nicole Swann, Kelsey Schultz

Session: Prerecorded Poster Presentation

For the past few decades, a major tool used to study inhibitory control has been the Stop-Signal Task (SST) . This task gives an estimate of how well individuals can inhibit initiated movements . The speed of stopping can be estimated as the stop-signal reaction time, or SSRT . This task has proven useful, but there are limitations . For example, SSRT can only be estimated overall and not at the individual trial level . Additionally, the standard stop task involves stopping a planned movement, rather than stopping a movement which is already ongoing . To address these limitations, we have developed a new continuous movement stop task (CMST) . This task directly measures the termination of an ongoing movement, allowing measurement of stopping speed at the individual trial level . It is currently unknown how stopping measures with this new task relates to SSRT measured with the conventional stop signal task . Our research addresses this question . Thirty participants will complete both the standard stopping task and our new continuous movement stopping task . We will compare stopping speed derived from our novel task to conventional SSRTs estimated by the standard stop task . The results of our study will help us better understand the relationship between the two tasks and also help establish the generalizability of inhibitory control .

Association between a non-invasive assessment of frailty and vascular dysfunction in old mice

Presenter(s): Jazmin Cole—Human Physiology, Biology

Faculty Mentor(s): Ashley Walker

Session 6: Interact & React

Advancing age is characterized by not only an increased risk for cardiovascular diseases (CVDs), but also a decline in functional reserve and impaired adaptive capacity across multiple physiologic systems, also known as frailty . Impaired vascular function is a known contributor to CVDs and potentially has a role in increased frailty . In patients with overt disease, measures of frailty are related to vascular endothelial cell dysfunction . However, the relation between vascular endothelial function and frailty in a non-disease population is unknown .

To examine the relation between vascular function and frailty in the context of similar genetics and environment, we studied wildtype C57BL/6 mice . In young (9 mo, n=7) and old (23-30 mo, n=27) male and female mice, we assessed endothelial-dependent dilation (EDD) ex vivo in isolated, pressurized mesentery arteries and middle cerebral arteries (MCA) . Mouse frailty was assessed using a previously established non-invasive 31-item frailty index based on clinical signs of deterioration . The severity of each deficit was assessed by two independent observers and assigned a value between 0-1, with a higher score indicating more severe frailty .

Frailty index was ~6 fold greater in old compared with young mice (p<0 .001) . Among the old mice, frailty index was correlated with mesentery artery maximal EDD (r=-0 .53 p=0 .002), and remained significant after controlling for age (partial correlation: r=-0 .38, p=0 .03) .

This study demonstrates that frailty, independent of age, is associated with mesentery artery endothelial dysfunction in wildtype, non-diseased mice . However, it remains unknown whether the mesentery artery dysfunction is a cause or consequence of the greater frailty . Interestingly, we found a lack of association between frailty and cerebral artery endothelial function . Future research is needed to determine the mechanisms linking frailty and mesentery artery dysfunction .

Cardiopulmonary Differences in Apnea Divers Breathing Isocapnic Normobaric Hypoxia

Presenter(s): Mohini Bryant-Ekstrand—Human Physiology

Faculty Mentor(s): Andrew Lovering, Tyler Kelly

Session: Prerecorded Poster Presentation

Hypoxia (low oxygen), induces a reversible form of pulmonary hypertension which can be studied to elucidate the etiology of pulmonary hypertension and right heart dysfunction . Breath hold divers (BHD) routinely place themselves into extremely hypoxemic (low blood oxygen) conditions and therefore may repeatedly expose themselves to acute bouts of pulmonary hypertension and increased right heart work . A patent foramen ovale is a tunnel between the top chambers (atria) of the heart present in 35% of the populations that may exacerbate hypoxemia thereby worsening pulmonary hypertension . The purpose of this study was to 1) determine if pulmonary arterial pressure and right heart dysfunction in hypoxia was greater in BHD compared to controls, 2) determine if the presence of a PFO contributed to the responses measured and 3) determine the role of a pulmonary vasodilator in ameliorating the increased pulmonary pressure in response to hypoxia . Subjects (n=26, 13 BHD, 13 Control) completed two 30-minute hypoxic breathing challenges, after receiving either 50mg sildenafil or placebo, with a 48-hour minimum washout period between visits . Saline contrast echocardiography was used to detect PFO . Pulmonary pressure and right heart function measures were made using Doppler ultrasound . Compared to placebo, sildenafil produced vasodilation before hypoxia in BHD and after 30 minutes of hypoxia in controls . PFO had no effect . Our preliminary data suggests elite breath hold divers may have a chronic pulmonary vasoconstriction in room air that is prevented with administration of sildenafil, and these findings are independent of having a PFO .

Convergence of dyadic similarity ratings predicts similarity in neural representations of others within social networks

Presenter(s): Youri Benadjaoud—Human Physiology/Psychology

Faculty Mentor(s): Taylor Guthrie, Rob Chavez

Session: Prerecorded Poster Presentation

A history of classic research in social psychology has demonstrated that human social groups are highly homophilous- people tend to associate with others similar to themselves . More recently, researchers showed that the brain shows similar effects of homophily, with close individuals showing greater neural response similarity to naturalistic stimuli than unfamiliar individuals (Parkinson et al ., 2018) . It is an open question, however, whether a similar degree of neural homophily exists when close individuals think of other specific members of their social group . The current study investigated this question by recruiting multiple social network groups that consisted of several close-knit individuals . Using a round robin fMRI design, individuals completed a standard self/other trait judgement task in which each participant was both the perceiver and a target . Similarity among dyadic pairs were calculated within multivoxel response patterns to each other member of their group . Using the correlation distance between multivoxel pattern response vectors combined with euclidean distance calculations between perceiver ratings of similarity with the target, we fit a multilevel linear effects model that predicted neural similarity from the convergence of dyadic similarity ratings. Our results indicate that the degree of similarity between multivoxel response patterns while individuals were rating the same target were significantly predicted by the the degree to which the perceivers agreed on how similar they were with the target . These findings suggest that people who agree on how similar a person is to themselves tend to have greater similarity in neural representations of that particular other .

Researching with the Kesey and Le Guin Papers during the 2020 COVID-19 Crisis— Research Posters by Honors College 223 Students

Presenter(s): Lyla Balthazaar—Human Physiology

Co-Presenter(s): Max Braker, Zoey, Cynkin , Jake Heinonen, Rose, McNamee, Carmen Reddick, Garret, Smith , Xitlali Torres, Micah, Woods 

Faculty Mentor(s): Stephen Rust

Session: Prerecorded Poster Presentation

Students in Dr . Stephen Rust’s course “Researching Oregon Writers” examined a digitized mini-archive of materials prepared during the COVID-19 crisis by the Knight Library Special Collections with the goal of better understanding how archival materials can shape and reshape our thinking about an author’s life and literary works . Items include personal correspondence between Ken Kesey and friend Ken Babbs composed while Kesey was writing One Flew Over the Cuckoo’s Nest (1962), correspondence between Ursula K . Le Guin and literary agent Virginia Kidd while Le Guin was writing The Left Hand of Darkness (1969), and manuscript pages from each novel . Their posters will blend of select images from the digital mini-archive to and written elements of humanities research posters along with virtual audio presentations . We hope these poster presentations will inspire viewers to appreciate the value of archives for preserving literary and cultural history and open new perspectives into Le Guin and Kesey’s life and work . Xitali Torres, Carmen Reddick Bayley Burke, and Micah Woods are interested in how Kesey’s correspondence with Babbs can shed light on the development of particular characters in One Flew Over the Cuckoo’s Nest and Kesey’s relationship with the 1960s counterculture . Rose Kordahal, Elyria Kabasenche, and Jake Heinonen are researching Kesey’s correspondence and journal entries before and after the publication of Cuckoo’s Nest to explore his authorial intentions regarding the civil rights of patients in mental hospitals . Ethan Scott, Zoey Cantor, and Garret Simmer how Kesey’s personal view on conformity and freedom inform how those themes develop in his work and are particularly interested in archival materials that might shed light on his use of laughter as a metaphor for rebellion against social norms. Zoey Whittington, Jacob Smith, and Donovan Muniz hope to learn more about the impact of 1960s Sexual Revolution on Le Guin’s writing and her development of a genderless society in The Left Hand of Darkness . Lyla Balthazaar, Max Braker, and Eleanor Davis are studying Le Guin’s business correspondence with her agent Virginia Kidd to examine how they sought to position her work in the science fiction marketplace . Elliot Terner, Audra McNamee, and David Cynkin are curious to examine Le Guin’s writings about science and philosophy as well as her engagement with literary scholarship to consider how her personal beliefs and interests shaped the direction of her creative writing .

The Effect of Emotion on Associative Memory: Anger Versus Fear

Presenter(s): Melissa Adler—Human Physiology

Faculty Mentor(s): Dasa Zeithamova, Caitlin Bowman

Session: Prerecorded Poster Presentation

Studies show that emotion enhances memory for individual items but weakens memory for associations between items . One explanation for this associative memory impairment is that emotional stimuli capture attention, causing enhanced encoding of the emotional item but encoding of the surrounding environment . This hypothesis generates the prediction that emotional information always impairs associative memory . Alternatively, it may be that emotion orients attention towards threats in the environment, thus suggesting anger and fear have different effects on memory for associated information . To adjudicate between these hypotheses, subjects studied sets of three images, consisting of two objects and a face with either a neutral, angry, or fearful expression . Subjects were later tested on their memory for the associations between the three items . Supporting our the first hypothesis, memory for both angry and fearful associations was worse than memory for neutral associations . Contrary to our the second hypothesis, there were no differences in memory for angry versus fearful associations . Thus, emotional information itself seems to capture attention, weakening memory for related information . If we understand the mechanisms of how negative emotion influences associative memory, we may discover methods of counteracting the impairment via various memory-improving techniques . This could lead to increased memory accuracy for emotional events and thus increased accuracy and reliability of eyewitness testimonies .