Life Sciences Commons^™

Genetic Determinants Of Primary Nociceptor Sensitivity In Drosophila Melanogaster, Christine Hale

Electronic Theses and Dissertations

Abnormal pain affects ~50 million adults nationwide. With many of the current treatment options for chronic pain, such as opioid analgesics, carrying side effects such as the threat for addiction, research into safer and more effective options for chronic pain relief is crucial. Abnormal alterations in nociceptive sensitivity, which is the sensitivity of peripheral sensory neurons that detect noxious stimuli, can underlie, and perpetuate chronic pain. However, much is still unknown about the mechanism of how these abnormal alterations in sensitivity occur. To help elucidate genetic components controlling nociceptive sensitivity, the Drosophila melanogaster larval nociception model has been used …

A Framework For Evaluating Evidence Of Pain In Animals, Matilda Gibbons, Lars Chittka

Animal Sentience

Crump et al. define eight criteria indicating sentience in animals, with a focus on pain. Here, we point out the risk of false negative or false positive diagnoses of pain. Criteria of different levels of inclusivity are useful for using the precautionary principle in animal welfare considerations, and for more formal scientific evidence of pain. We suggest tightening the criteria -- from more general evidence of sentience to pain alone -- because crucial evidence for animal welfare decisions might otherwise be missed for animals subjected to invasive and injurious procedures.

Opioid Use Disorder: The Timeline For Medication Assisted Therapy, Alexander Cristofori

Capstone Showcase

Opioid Use Disorder is patterns of opioid use leading to withdrawal, giving up important life events in order to use opioids, and excessive time spent using opioids, to name a few diagnostic criteria. The clinical progression of the disorder involves periods of acute exacerbation and remission that are cyclic in nature. Treatment is most effective when it includes both pharmacological and psychosocial modalities, referred to as medication assisted therapy (MAT). Three drugs used commonly in MAT-based treatment for OUD from oldest to newest include Methadone, Buprenorphine-naloxone, and Naltrexone. Treatment program models that prioritize total abstinence from the addictive substance attached …

Inhibition Of Pain Or Response To Injury In Invertebrates And Vertebrates, Matilda Gibbons, Sajedeh Sarlak

Animal Sentience

In certain situations, insects appear to lack a response to noxious stimuli that would cause pain in humans. For example, from the fact that male mantids continue to mate while being eaten by their partner it does not follow that insects do not feel pain; it could be the result of modulation of nociceptive inputs or behavioural outputs. When we try to infer the underlying mental state of an insect from its behaviour, it is important to consider the behavioural effects of the associated physiological and neurobiological mechanisms.

Characterization Of G-Protein Coupled Receptors In Pain, Depression And Anxiety, Neil Lax

Electronic Theses and Dissertations

Chronic pain and major depressive disorder are widespread conditions in the world. Interestingly, these conditions often occur comorbidly, with each individual disease amplifying the symptoms of the other. A significant amount of preclinical research in pain and depression focuses on G-protein coupled receptors (GPCRs), implying that GPCRs may be useful in treating this comorbidity. Our efforts have sought to characterize several poorly understood GPCRs, including the serotonin receptor subtypes 2C and 7 (5-HT2CR and 5-HT7R) and metabotropic glutamate receptor 5 (mGluR5), along with more well-known GPCRs such as the mu opioid receptor (MOR), and the role that they play in …

Complexities Of Chronic Opioid Exposure, Maciej Gonek

Theses and Dissertations

Studies on repeated exposure to opioids have been carried out for decades yet the mechanisms for certain phenomena such as tolerance are still not fully understood. Furthermore, different medications, such as frequently prescribed benzodiazepines, or different disease states, such as HIV, have their own effects and interactions with chronic opioid exposure that are not fully understood. The overall objective of this dissertation was to investigate the complexities of chronic opioid exposure and how different disease states and medications may modulate the effects of chronic opioids. Our findings demonstrate that the administration of diazepam, at doses that are not antinociceptive or …

Comparative Evolutionary Approach To Pain Perception In Fishes, Culum Brown

Animal Sentience

Arguments against the fact that fish feel pain repeatedly appear even in the face of growing evidence that they do. The standards used to judge pain perception keep moving as the hurdles are repeatedly cleared by novel research findings. There is undoubtedly a vested commercial interest in proving that fish do not feel pain, so the topic has a half-life well past its due date. Key (2016) reiterates previous perspectives on this topic characterised by a black-or-white view that is based on the proposed role of the human cortex in pain perception. I argue that this is incongruent with our …

Fighting Forms Of Expression, Paul J.B. Hart

Animal Sentience

Even though Key (2016) has done a very thorough job of assembling evidence showing that fish are unlikely to have the neurological capacity to be conscious and feel pain, there will still be a significant number of behavioural biologists who want to continue maintaining that fish do have consciousness and suffer from pain. In this commentary the reasons for people resisting the conclusions of the evidence are discussed. The reasons revolve around three aspects of the debate: the overblown respect humans have for the powers of consciousness in our day-to-day behaviour, the often used assumption that the possession of complex …

Chronic Pancreatitis, Pain, And Anxiety In An Alcohol And High Fat Mouse Model, Tiffanie Clinkinbeard

Theses and Dissertations--Gerontology

Homeodynamic space (HDS) shrinks as vulnerability increases with aging and repeated damage to the cells. HDS is lost in alcoholic pancreatitis patients due to overconsumption of alcohol, smoking, and high fat diets. Etiologically relevant animal models for study of chronic pancreatitis (CP) are needed. In order to begin filling this gap a central purpose of this dissertation research was to examine relationships between the alcohol and high fat diet (AHF) and pancreatitis with attention to hypersensitivity and anxiety-like behaviors. The AHF diet induced pancreatitis described here etiologically mimics human risk factors of AHF consumption for advancement to alcoholic CP.

In …

Injury Establishes Constitutive Μ-Opioid Receptor Activity Leading To Lasting Endogenous Analgesia And Dependence, Gregory F. Corder

Theses and Dissertations--Physiology

Injury causes increased pain sensation in humans and animals but the mechanisms underlying the emergence of persistent pathological pain states, which arise in the absence of on-going physical damage, are unclear. Therefore, elucidating the physiological regulation of such intractable pain is of exceptional biomedical importance. It is well known that endogenous activation of µ-opioid receptors (MORs) provides relief from acute pain but the consequences of prolonged endogenous opioidergic signaling have not been considered. Here we test the hypothesis that the intrinsic mechanisms of MOR signaling promote pathological sensitization of pain circuits in the spinal cord. We found that tissue inflammation …