Robert W. Gereau, IV - US grants

It is well-established that the amygdala, a forebrain multinuclear structure, plays a crucial role in emotional[unreadable] behaviors such as fear, anxiety, and stress. It has recently been proposed that the amygdala, in particular the[unreadable] central nucleus (CeA), is also involved in the modulation of pain sensation. Evidence from anatomical,[unreadable] behavioral, and physiological studies support the hypothesis that the amygdala serves as a neural pain center[unreadable] that integrates noxious sensory information and emotions. Preliminary results from our lab and others have[unreadable] demonstrated that electrophysiological changes occur in the central nucleus of the amygdala during periods of[unreadable] persistent pain. For this reason, we have been performing studies aimed at elucidating the signaling cascades[unreadable] involved in the modulation of pain sensation by the amygdala. Our preliminary studies indicate that[unreadable] inflammation of one hindpaw induces acute pain in the injected paw, and after a period of several hours, also[unreadable] in the uninjured contralateral paw. Interestingly, the timing of the onset of this contralateral hypersensitivity[unreadable] coincides with the activation of the extracellular signal regulated kinase (ERK) in the right amygdala,[unreadable] specifically in the laterocapsular subdivision of the central nucleus (CeC). Our preliminary data support the[unreadable] hypothesis that ERK activation in the right (but not left) CeC underlies the development of generalized pain[unreadable] hypersensitivity after inflammation. However, there are still a number of unanswered questions regarding the[unreadable] role of amygdala ERK activation in pain modulation. The present application will address some of these issues.[unreadable] In the first aim, we will test whether the right lateralized ERK activation in the CeC is physiologically relevant in[unreadable] multiple pain models. The second aim of the proposal utilizes patch clamp recordings from brain slices to test[unreadable] the hypothesis that ERK activation leads to acute modulation of neuronal excitability and/or synaptic[unreadable] transmission in the CeC. These studies will lay important groundwork for future investigations of the[unreadable] importance of amygdala ERK signaling in pain sensitization.

[unreadable] DESCRIPTION (provided by applicant): Our research addresses the cellular and molecular mechanisms that underlie pain hypersensitivity associated with injury and disease. We have been studying the role of the neurotransmitter glutamate (Glu) in the modulation of pain sensitivity in the periphery. Glu is a key inflammatory mediator that is released into peripheral tissues during inflammation, and we have found that G protein-coupled Glu receptors known as metabotropic Glu (mGlu) receptors are expressed in peripheral terminals of nociceptors. In the previous term of this grant, our studies showed that activation of peripheral mGluS in nociceptor terminals induces hypersensitivity to thermal and mechanical stimuli. The thermal hyperalgesia can be explained, at least in part, by PKA-dependent sensitization of the heat-sensing protein, TRPV1. We showed that PKA and PKC directly phosphorylate TRPV1, and identified phosphorylation sites critical for modulation of TRPV1 by PKA and PKC in heterologous systems. However, differences in the PKA and PKC modulation of TRPV1 in heterologous systems relative to natively expressed TRPV1 call into question whether the same phosphorylation sites are involved. While this TRPV1 modulation can account for regulation of thermal nociception by mGluS, it cannot explain the induction of mechanical hypersensitivity. Preliminary data show that mGluS enhances excitability of nociceptors, and we suggest that this may underlie the induction of mechanical sensitization by mGluS. Our work and the work of others points to an important role of mGluS is mediating pain hypersensitivity, and as a consequence mGluS antagonists are being pursued as a novel class of analgesics. However, recent work has called into question whether mGluS antagonists reduce pain by blocking mGluS or by an "off target" action. Studies in the present proposal will address the following open questions: 1) What phosphorylation sites mediate sensitization of TRPV1 in native DRG neurons? 2) What is the relative importance of central and peripheral mGluS in pain hypersensitivity? 3) What are the cellular mechanisms that underlie mechanical hypersensitivity induced by activation of peripheral mGluS? These studies will reveal the cellular and molecular mechanisms by which mGluS modulates thermal and mechanical pain sensation, and will clearly define the role of central and peripheral mGluS in the modulation of pain. They may also help promote the development of mGluS antagonists as analgesics. [unreadable] [unreadable] [unreadable]

[unreadable] DESCRIPTION (provided by applicant): The Midwest Pain Interest Group Meeting is an annual meeting of basic scientists, clinicians, and their trainees that work in the pain field. The meeting has as its core mission the exchange of knowledge about pain research and treatments and the development of young pain scientists. The meeting rotates between a number of Midwest institutions, and for 2007 the meeting is being hosted by Washington University School of Medicine in St. Louis on June 8 and 9. At this year's meeting, a main focus will be to increase basic science/clinical science interactions as part of an overall goal of promoting research translation. The meeting takes place over two days, with an afternoon poster session and reception incorporating both basic science and clinical research on day one. This is followed by a dinner and social event, which would not be supported by NIH funds. The following morning sees two concurrent sessions, the first is a continuing medical education session for clinicians; this will include multiple topics related to state of the art pain management, and the second morning session is oral presentations by trainees and junior faculty from the represented institutions. Presentations by women and members of underrepresented minorities are particularly encouraged. After these talks, both sessions come together for a luncheon with a plenary speaker that is of broad interest to clinicians and basic scientists. This year the plenary speaker will be Dr. Jeff Mogil from McGill, who has agreed to come and will be speaking on the general topic of genetic influences on pain and analgesia. This meeting provides an annual forum where we emphasize extensive informal interaction between basic scientists and clinicians working in the pain field. The emphasis is always on trainees. Having this meeting on an annual basis helps establish a consistent network of pain research peers in the region, and has been a real driver for new and innovative collaborations amongst member institutions. [unreadable] [unreadable] [unreadable]

2H-1,3,2-Oxazaphosphorin-2-amine, N,N-bis(2-chloroethyl)tetrahydro-, 2-oxide; 2H-1,3,2-oxazaphosphorin-2-amine, N,N-is(2-chloroethyl)tetrahydro-,2-oxide; Abdomen; Abdominal; Abdominal Muscles; Acute; Address; Allergy; Animal Model; Animal Models and Related Studies; Animals; Antimorphic mutation; Autonomic pain; Behavior; Behavioral; Biochemical; Bladder; Bladder Diseases; Bladder Disorder; CTX; CYCLO-cell; Carloxan; Cell Communication and Signaling; Cell Signaling; Central Nervous System; Characteristics; Chronic; Ciclofosfamida; Ciclofosfamide; Cicloxal; Clafen; Claphene; Cycloblastin; Cycloblastine; Cyclophospham; Cyclophosphamide; Cyclophosphamidum; Cyclophosphan; Cyclophosphane; Cyclophosphanum; Cyclostin; Cyclostine; Cytophosphan; Cytophosphane; Cytoxan; Dominant Negative; Dominant-Negative Mutant; Dominant-Negative Mutation; Dorsal Horn Cells; Dorsal Horn of the Spinal Cord; Dose; ERK 1; ERK1; ERK1 Kinase; ERK2; ERT1; Endoxan; Endoxana; Enduxan; Extracellular Signal-Regulated Kinase 1; Fosfaseron; Genoxal; Genuxal; Goals; Hyperalgesia; Hyperalgesic Sensations; Hypersensitivity; INFLM; Inflammation; Inflammatory; Injury; Interstitial Cystitis; Intracellular Communication and Signaling; Ion Channels, Potassium; Isoforms; K channel; Knock-out; Knockout; Knockout Mice; Laboratories; Ledoxina; Localized; MAP Kinase 3; MAP-ERK Kinase; MAPK ERK Kinases; MAPK1; MAPK1 gene; MAPK2; MAPK3; MAPK3 Mitogen-Activated Protein Kinase; MAPK3 gene; MEKs; Mammals, Mice; Measurement; Mediating; Medulla Spinalis; Meiosis-Activated Myelin Basic Protein Kinase p44(mpk); Methods; Methods and Techniques; Methods, Other; Mice; Mice, Knock-out; Mice, Knockout; Microtubule-Associated Protein-2 Kinase; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase 3 Gene; Mitoxan; Modeling; Molecular; Murine; Mus; Neosar; Nervous System, CNS; Neuraxis; Neurons, Dorsal Horn; Neurons, Posterior Horn; Nociception; Nociceptive Impulse; Nociceptive Stimulus; Null Mouse; P41MAPK; P42MAPK; P44ERK1; P44MAPK; PRKM1; PRKM2; PSTkinase p44mpk; Pain; Pain Disorder; Pain Research; Painful; Patients; Phosphorylation; Posterior Horn Cells; Potassium Channel; Process; Procytox; Protein Isoforms; Protein Phosphorylation; Protein-Serine-Threonine Kinase p44(mpk); Research; Role; Sendoxan; Signal Transduction; Signal Transduction Systems; Signaling; Spinal; Spinal Cord; Spinal cord posterior horn; Syklofosfamid; Syndrome; Techniques; Testing; Time; Transgenic Animals; Urinary System, Bladder; Visceral; Visceral pain; Zytoxan; allodynia; biological signal transduction; central pain; central sensitization; cortical pain; dorsal horn; experience; experiment; experimental research; experimental study; frontier; hyperalgia; inflammatory pain; model organism; mouse model; neuronal excitability; new therapeutics; next generation therapeutics; nociceptive; novel therapeutics; p44 (MAPK); p44 MAPK; research study; response; social role; urinary bladder; urinary bladder disorder

Abstract Interstitial cystitis/Bladder Pain Syndrome (IC/BPS) is a serious and painful condition of unknown etiology that affects 3-6% of women in the United States. The major clinical symptoms of IC/BPS are pain on bladder filling and increased urinary urgency and frequency. The majority of IC/BPS patients (90%) also suffer from comorbid anxiety and/or depression, contributing to a poor quality of life. The high rate of comorbid affective disorders in IC/BPS patients suggests that a common supraspinal neural circuit may be responsible for both enhanced pain and negative affect in patients with IC/BPS. Based on a large body of work in the neurosciences, we hypothesize that the central nucleus of the amygdala (CeA) is a crucial hub of neuronal activity that regulates both bladder pain and negative affect. In this project, we propose a series of studies that seeks to determine the necessity and sufficiency of neuronal subpopulations in the CeA in the induction of voiding dysfunction, pain sensitization, and comorbid anxiety and depression in models of cystitis. Does activation of this circuit lead only to hypersensitivity to stimulation, or is this also critical for ongoing or spontaneous pain? Does the same population of neurons mediate both pain sensitization and increased anxiety following injury? What are the critical inputs and projections from these neurons that lead to these debilitating consequences of cystitis? We employ a multidisciplinary approach including viral anatomical tract tracing, optogenetics, chemogenetics, and in vivo imaging of neural activity in awake, freely moving mice to address these questions. These studies will provide new insights into the critical role of the CeA in bladder pain and comorbid affective disorders in the context of bladder pain syndrome, and provide the basis for future studies building on this to gain insights into circuit, cellular and synaptic mechanisms of voiding dysfunction, chronic pain and comorbid anxiety and depression.

Abstract The current epidemic of opioid-related deaths ravaging the nation demands innovative new approaches to treat opioid use disorders and prevent deaths resulting from accidental overdose. Patients with a history of opioid use followed by a period of sobriety are at particularly high risk for overdose. This increased risk stems from the development of tolerance during prolonged periods of use. Tolerance can quickly fade during a period of abstinence, so if a patient relapses and takes the same dose used prior to the period of abstinence, the dose will be high enough to precipitate an acute respiratory crisis, leading to injury or death. Current treatment requires administration of naloxone by first responders. This treatment requires timely identification of the overdose and need for a rescue injection, as well as the immediate availability of the medication. The development of a fail- safe treatment that would provide a life-saving dose of naloxone without the need for intervention by another party could significantly reduce mortality. In the present application, we propose the development of a new medical device comprising an implantable, closed-loop system that senses the presence of an opioid overdose, and automatically administers a life-saving bolus injection of naloxone, and simultaneously alerts first responders. This proposal builds on technologies that the investigative team has developed over the past several years.