Alexis C. Thompson - US grants

[unreadable] DESCRIPTION (provided by applicant): Cocaine use and dependence exact a considerable toll, not only to the individual user, but also to the community at large because the cocaine-driven behavior of the user causes a wide range of economic, biomedical and social problems, including crime, spread of infectious disease, and neonatal drug exposure. Currently there are no recommended drug therapies for cocaine dependence, although the need is great. Functional characteristics of the neurotransmitter neuropeptide Y (NPY) suggest that the development of medicinal drugs that target NPY neurotransmission will be effective in reducing cocaine craving and mood disturbances during periods of abstinence. Craving, anxiety, and depression during periods of cocaine abstinence underlie relapse. The research proposed here will test the effectiveness of NPY agonists (drugs that stimulate NPY activity) to reduce craving and heightened anxiety that occur during short (1 week) and long (3 week) periods of abstinence from cocaine in an animal model of cocaine dependence. To assess craving, rats will be tested in a place preference apparatus in which they will be trained to associate a particular place (a neutral environment) with a daily cocaine treatment. During periods of cocaine abstinence, the rat's preference to go to and remain in the place they previously received cocaine ("the neutral environment") will provide an indirect measure of cocaine seeking (craving). The effect of increasing NPY activity in the brain during periods of cocaine abstinence on place preference will be used to assess the effect of NPY on cue-induced cocaine seeking. Additionally, the interaction between NPY and a predator stress (exposure to a cat-scented cloth) on place preference, or the interaction between NPY and a subsequent exposure to cocaine on place preference, will be assessed to determine if NPY blocks stressand drug-induced increases in cocaine seeking. Finally, the impact of NPY on cocaine withdrawal will be assessed by evaluating the ability of NPY to suppress the heightened anxiety associated with the first 48 hrs of abstinence. The results will add to our understanding of the neurobiological substrates that underlie cocaine dependence and indicate whether or not the pursuit of medicinal compounds that target NPY neurotransmission is warranted for the purpose of managing cocaine dependence. [unreadable] [unreadable] [unreadable]

DESCRIPTION (provided by applicant): The goal of this application is to identify candidate biomarkers which, in combination, may constitute a lingering biosignature that is informative of cocaine abuse history over a protracted period of time. The neurochemical and behavioral manifestations of chronic cocaine abuse are known to endure for a considerable duration, and given the role of neuropeptides and other secreted proteins in compulsive behaviors, drug abuse, and addiction, we hypothesize that the proteome of biophases that can be obtained, by minimally-invasive means, may contain families of biomarkers that reflect the well-established neurochemical alterations and constitute a peripherally-accessable cocaine abuse biosignature. Our approach is to apply recent inter-related analytical advances in sample processing, nano-scale liquid chromatography (nano-LC), and mass spectrometry (MS) that enhance the suitability of nano-LC/MS approaches for the analysis of highly complex proteomic samples such as tissues or bodily fluids. These advances provide: (i) highly quantitative recovery of tissue or sample proteins, (ii) highly reproducible, selective, and sensitive expression profiling of proteins, (iii) quantification of significantly greater numbers of proteins, and (iv) highly sensitive, multiplexed quantification of specific proteins of interest and (v) their PTM status. In the context of a well-controlled and validated rat model of cocaine abuse and withdrawal, samples will be obtained from naive- and drug-withdrawn animals both before and during a relapse of cocaine administration. Proteomes of select neural centers and blood will be contrasted to assemble lists of abuse-selective biomarker candidates, and their importance will be ranked by the commonality among replicates, the magnitude of change, and bioinformatic criteria relating them plausibly as drug-abuse responsive. In the second phase, the top-prioritized candidates will be confirmed and absolute quantification will be performed;matched plasma samples will be interrogated for these candidate biomarkers to identify promising constituents of a biosignature. Finally, using a rat model of addiction involving self- administration, we will attempt to refine biosignature candidates in terms of use/abuse vs. dependence/addiction, to determinate the exclusivity of these markers for drug addiction. By employing these linked analytical technologies and a well-validated animal model, we aim to investigate, identify, and validate potential biosignatures of cocaine abuse and relapse, based upon differential comparison of proteins in peripheral blood samples, which could aid in diagnosis, evaluation of therapy, and monitoring of recovery. PUBLIC HEALTH RELEVANCE: Chronic use of drugs of abuse represents a scourge to users and society. The ability to obtain information about use patterns beyond the period of time in which drug or metabolites are detectable in blood would have broad applications in diagnosis, estimation of prognosis, personalization of treatment, evaluation of drug effects, and detection of relapse. We propose to combine novel analytical advances in liquid chromatography, mass spectrometry (LC/MS), and sample preparation, along with a series of validated animal models, to interrogate samples that are obtainable by minimally-invasive means, such as blood, to achieve the elusive goal of identifying families of persistent biomarkers, comprising a biosignature, of chronic cocaine abuse and addiction.