An estimated 11% of women and 5% of men suffer from symptoms related to interstitial cystitis/painful bladder syndrome (IC/PBS), which generates a minimum $20 billion in direct medical costs annually in the United States. Approximately 17-40% of IC/PBS patients exhibit symptoms of a secondary chronic pelvic pain disorder and up to half suffer from depression and/or panic disorder. Comorbidity of syndromes has been associated with altered functioning of the hypothalamic-pituitary-adrenal (HPA) axis, which regulates stress response and influences the perception of pain. Corticotropin-releasing factor (CRF) is the principal initiator of the stress response and, along with the related urocortis (Ucn), mediates downstream stress responses, as well as influences both positive and negative feedback onto the HPA axis. CRF is also a potent stimulator of peripheral mast cell degranulation and functions as a neuropeptide involved in regulating the central micturition reflex. Early life stress or trauma is a significant risk factor for HPA axis disruption and significantly increases the likelihood of developing chronic pelvic pain and mood disorders during adolescence or adulthood. Rodent models of neonatal stress display disruption of proper feedback onto the HPA axis, resulting in anhedonia, anxiety-like behaviors, and hyperalgesia and neurogenic inflammation in the pelvic viscera. Voluntary exercise has been shown to reverse many abnormalities associated with early life stress, including symptoms associated with chronic pain and mood disorders. The goal of the current proposal is to understand how manipulation of the limbic regulation and downstream output of the HPA axis affects both behavior and urogenital sensitivity in mice that were exposed to early life stress. Our central hypothesis is that comorbid urogenital pain syndromes and mood disorders in NMS mice arise from increased output of the HPA axis, due to diminished negative regulatory input from the hippocampus, and can be differentially attenuated by peripherally- and centrally-mediated interventions. We have designed three specific aims (SAs) to test this hypothesis. SA1 will determine how NMS alters the expression patterns and downstream peripheral influences of CRF-responsive brain regions. SA2 will determine the impact of mast cell activation on urogenital sensitivity and micturition in NMS mice. SA3 will determine the impact of voluntary exercise on improving hippocampal regulatory input onto the HPA axis in NMS mice. At the completion of this project, we will have gained novel insight on the mechanisms underlying comorbid pelvic pain and mood disorders following early life stress. We will also have obtained preclinical evidence on the efficacy of exercise, an easily translatable intervention, as a potentil treatment strategy for these debilitating disorders.
Patients with interstitial cystitis/painful bladder syndrome commonly suffer from additional chronic pain conditions and/or depression, anxiety, and panic disorders. The goal of this proposal is to better understand how early life stress may contribute towards these disorders and determine the efficacy of exercise in preventing or reversing many of the associated side effects.
