1988 — 1996 |
Hillard, Cecilia J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. R29Activity Code Description: Undocumented code - click on the grant title for more information. |
Neurochemical Mechanisms of Nicotine Action @ Medical College of Wisconsin
There is convincing evidence that tobacco use, both as cigarettes and smokeless tobacco preparations, is highly dependence producing and that chronic use can result in tolerance. Although many behavioral factors are thought to be involved in the initiation and maintenance of tobacco use, there is also convincing evidence that nicotine is necessary for the dependence process to occur. Despite this evidence, little is known about the neurochemical effects of nicotine in the brain or about the neurochemical consequences of chronic nicotine exposure. Previous investigators have shown that chronic nicotine treatment has effects on the number of nicotinic cholinergic binding sites in the brain, but these results are somewhat contradictory. The aims of the studies outlined in this proposal are to use a comprehensive approach to describe the neurochemical effects of nicotine in the brain and to determine whether these effects are involved in nicotine tolerance. In specific, three aspects of the functioning of the CNS nicotinic receptor will be explored: (1) Nicotinic cholinergic receptor regulation of sodium flux across neuronal membranes will be studied by measuring 22Na influx into synaptosomes. (2) The influx of sodium through receptor operated channels is hypothesized to depolarize the membrane and open voltage-regulated calcium channels. Nicotine-induced changes in synaptosomal calcium flux will be studied using 45Ca. (3) Monoamines are known to be released by nicotinic agonists. The mechanism of this release will be studied, with particular attention to the involvement of sodium and calcium influxes as preceding events. In addition, experiments will be carried out to determine whether the effects of nicotine on sodium or calcium influx or neurotransmitter release are altered in animals chronically treated with nicotine. The hypothesis to be tested is that tolerance to nicotine is due to a functional "down regulation" of the nicotinic cholinergic receptor system. As these experiments are performed, the pattern of relationships among brain region, neurochemical changes and physiological and behavioral measures of tolerance will be studied in rats exposed to various doses of nicotine, carbachol and a cholinesterase inhibitor. It is hoped that a consistent pattern of changes will emerge that will increase our insight into the neurochemical actions of nicotine and will demonstrate whether long term nicotine use changes the functioning of the CNS nicotinic cholinergic receptor system.
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0.958 |
1997 |
Hillard, Cecilia J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Cannanbinoids and Second Messengers in the Brain @ Medical College of Wisconsin
DESCRIPTION: (Applicant's Abstract) Although the cannabinoids have been and continue to be abused by many individuals in our society, their cellular mechanisms of action are not well understood. This lack of understanding has several consequences. First, without information concerning the cellular effects of the cannabinoids, estimates of the potential risks of use of this drug by humans are very difficult to make. Second, the full therapeutic potential of these agents cannot be exploited. Third, the cannabinoids produce a completely unique spectrum of effects so a more thorough understanding of their mechanism of action will provide basic information about brain functioning. A cannabinoid binding site (CB1) that has many of the characteristics of a G protein-coupled receptor has been identified in brain. It is our hypothesis delta 9-tetrahydrocannabinol (THC) and other synthetic cannabimimetics act as inhibitory modulators of neurotransmission as a result of activating the CB1 receptor. In specific, we hypothesize that CB1 activation results in the closure of voltage operated calcium channels. We will use cerebellar granule neurons in primary culture to study this hypothesis. We have three aims in this proposal; first, we will characterize the CB1 receptors of the cerebellum in terms of the efficacy of a variety of CB1 ligands to induce the G coupled state of the receptor and to promote G protein guanine nucleotide exchange. Second, we will determine which G-protein(s) couple to the CB1 receptor in the granule cells. Our third aim is to explore the hypothesis that the cannabinoids, acting through CB1, inhibit voltage-regulated calcium channels in cerebellar granule cells. As part of this aim, we will determine the types of calcium channels or currents involved in the effects of the cannabinoids as well as determine whether this effect is pertussis-toxin sensitive. We will also determine whether the effect of the cannabinoids on calcium is due to inhibition of adenylyl cyclase. It is anticipated that the successful completion of these studies will enhance our understanding of the mechanism of action of the cannabinoids and the neurochemical processes with which they interact in the brain.
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0.958 |
1998 — 1999 |
Hillard, Cecilia J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Cannabinoids and Second Messengers in the Brain @ Medical College of Wisconsin
DESCRIPTION: (Applicant's Abstract) Although the cannabinoids have been and continue to be abused by many individuals in our society, their cellular mechanisms of action are not well understood. This lack of understanding has several consequences. First, without information concerning the cellular effects of the cannabinoids, estimates of the potential risks of use of this drug by humans are very difficult to make. Second, the full therapeutic potential of these agents cannot be exploited. Third, the cannabinoids produce a completely unique spectrum of effects so a more thorough understanding of their mechanism of action will provide basic information about brain functioning. A cannabinoid binding site (CB1) that has many of the characteristics of a G protein-coupled receptor has been identified in brain. It is our hypothesis delta 9-tetrahydrocannabinol (THC) and other synthetic cannabimimetics act as inhibitory modulators of neurotransmission as a result of activating the CB1 receptor. In specific, we hypothesize that CB1 activation results in the closure of voltage operated calcium channels. We will use cerebellar granule neurons in primary culture to study this hypothesis. We have three aims in this proposal; first, we will characterize the CB1 receptors of the cerebellum in terms of the efficacy of a variety of CB1 ligands to induce the G coupled state of the receptor and to promote G protein guanine nucleotide exchange. Second, we will determine which G-protein(s) couple to the CB1 receptor in the granule cells. Our third aim is to explore the hypothesis that the cannabinoids, acting through CB1, inhibit voltage-regulated calcium channels in cerebellar granule cells. As part of this aim, we will determine the types of calcium channels or currents involved in the effects of the cannabinoids as well as determine whether this effect is pertussis-toxin sensitive. We will also determine whether the effect of the cannabinoids on calcium is due to inhibition of adenylyl cyclase. It is anticipated that the successful completion of these studies will enhance our understanding of the mechanism of action of the cannabinoids and the neurochemical processes with which they interact in the brain.
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0.958 |
2003 — 2005 |
Hillard, Cecilia J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Brain Endocannabinoids and Chronic Stress @ Medical College of Wisconsin
DESCRIPTION (provided by applicant): Stress is a risk factor for drug relapse in humans and it has been suggested that stress-induced neural adaptations alter the threshold for reward. Recent work indicates that the endocannabinoids (ECs), acting via the CB1 cannabinoid receptor, also sensitize the brain to reward; while the CB1 receptor antagonist, SR141716, produces the opposite effect, i.e. reduces the sensitivity of the brain to reward. Our preliminary data show that the concentrations of the EC, N-arachidonylethanolamine (AEA) is reduced in the limbic forebrain both by the dopamine uptake inhibitor GBR129092 and by acute restraint stress. Based upon these data, we hypothesize that the elevation of mesolimbic (ML) dopamine that occurs during stress results in a decrease in the concentration of mesolimbic AEA and that the resulting underactivity of CB1 receptors results in a counterbalancing reduction in the sensitivity of the reward pathway. We predict that manipulations that increase EC concentrations or CB1 receptor activity would enhance the stress-induced sensitization of the reward pathway while removal of CB1 receptors or their inhibition would reduce the sensitization. Mouse models will be used to complete the following specific aims: (1) To determine the relationship between mesolimbic dopamine and mesolimbic AEA; (2) To determine the effects of acute and chronic (predictable and unpredictable) stress on regional EC concentrations, CB1 receptor number and transduction, and FAAH activity; and (3) To determine the role of endogenous activation of the CB1 receptor in the adaptation of the reward circuit to chronic stress. In summary, we will use a combination of techniques to explore the relationships between cannabinergic tone and chronic stress with a focus on the possible role of the CB1 receptor in the modulation of reward sensitivity. The successful completion of these studies will enhance our understanding of the processes involved in the adaptation of the brain to chronic stress.
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0.958 |
2003 — 2006 |
Hillard, Cecilia J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Cannabinoid Receptors and Cerebrovascular Function @ Medical College of Wisconsin
DESCRIPTION (provided by applicant): Many factors regulate normal cerebral blood flow (CBF), including signaling molecules that are synthesized and released from cells in the vicinity of cerebral blood vessels. Pathological changes in the brain also affect CBF; for example, CNS inflammation can be accompanied by abnormalities in CBF that lead to life-threatening edema. The hypothesis to be tested by the experiments in this proposal is that endocannabinoids are synthesized by both perivascular microglia (resident immune cells of the brain) and cerebral endothelial cells and m CBF under both normal and pathological conditions. In addition, we hypothesize that endocannabinoids produce vasodilation via vascular smooth muscle (VSM) CB1 cannabinoid receptor activation. Support for this hypothesis includes our findings that: the CB1 cannabinoid receptor is expressed by cerebral arterial and arteriolar VSM cells; activation of the VSM CB1 receptorand results in inhibition of L-type calcium channels; cannabinoids vasodilate isolated cerebral vessels and increase CBF in vivo. Intact cerebral arteries synthesize endocannabinoids in response to microglial and endothelial activators, supporting the hypothesis that cells in the immediate vicinity of the VSM make endocannabinoids. In addition, microglial cells synthesize endocannabinoids in response to an activating stimulus, lipopolysaccharide (LPS). The primary model that we will use to approach this hypothesis is the isolated, middle cerebral artery from rat. We will also use atmospheric liquid chromatography-mass spectrometry to measure endocannabinoids and the in vivo significance of these findings will be explored using laser Doppler flowmetry. The specific aims of this proposal are: (1) to characterize the role of the CB1 receptor in cerebral arterial vasomotor tone and responsiveness; (2) to determine the distribution of the CB1 receptor throughout the cerebral vasculature; (3) to determine the cellular sources and regulation of endocannabinoid production in isolated cerebral arteries; (4) to determine whether activated microglial cells induce CB1 receptor-dependent vasodilation cerebral arteries; and (5) to determine the contribution of VSM CB1 receptors in the regulation of cerebral blood flow in vivo. Activated microglial cells contribute to many neurodegenerative diseases and to the worsening of stroke and trauma. Increased understanding of the mediators that are released by activated microglia and their targets may provide new therapeutic approaches to CNS diseases with an inflammatory component.
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0.958 |
2007 — 2008 |
Hillard, Cecilia J |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
Gender Differences in the Interactions Between Endocannabinoids and Stress @ Medical College of Wisconsin
[unreadable] DESCRIPTION (provided by applicant): Long-term objectives: This is a collaborative research effort between the laboratories of Dr. Cecilia Hillard, a basic scientist studying cannabinoid receptor function using animal and cellular models; and Dr. Harriet de Wit, a psychologist studying the effects of gender on stress responsivity and susceptibility to substance abuse in humans. One long term objective of this project is to solidify this collaborative relationship which will enhance both individual research projects through the addition of translational aims that bridge them. We will develop this collaboration through an Exploratory/Developmental project that will begin to test the hypothesis that gender differences in the effects of stress on endocannabinoid (eCB) signaling contribute to the gender differences in susceptibility to psychiatric disorders, including substance abuse. It is well established that depression and anxiety occur more frequently in women than in men, which suggests a gender difference in reactivity to stressful or threatening situations. Therefore, studies of gender differences in response to stress will clarify the differential vulnerability of women and men to these and other stress-related disorders, particularly substance abuse. The Specific Aims of the project are to determine the effects of gender and estrous stage in mice on: (1) the role of eCB/CB1 receptor signaling in the regulation of basal and stress-induced hypothalamic-pituitary-adrenal axis activation; and (2) expression of CB1 receptors, CB1 receptor function and the expression of eCB synthetic and catabolic proteins in brain regions known to be involved in the stress response. A second goal of this proposal is to explore the relationship between serum eCBs and gender differences in the human stress response. In particular, we will compare the responses to stress and serum eCBs in men and women in both the follicular and luteal phases. We will: (1) measure serum eCB contents in blood collected during two sessions: one that is a control visit to the research area, and the second during and after the administration of the Trier Social Stress Test; and (2) examine the relationships among serum eCB contents, gender/sex hormone status and indicators of the stress response, including ratings of anxiety, heart rate and salivary cortisol levels. These pilot studies will guide the development of hypothesis-driven translational research projects that will further explore the interactions among stress, gender, the risks of developing substance abuse and a novel and important signaling system in the brain, the endocannabinoids and their receptor, CB1. Stress is increasingly recognized as a significant risk factor for the development of many diseases in humans, including cardiovascular disease, depression, anxiety disorders and substance abuse disorders. Men and women differ in their responses to stressful life situations and differ in the stress-related diseases that they develop. Data collected in animals demonstrate that endocannabinoid signaling is "stress-protective". In addition, limited data suggest that endocannabinoid signaling differs between male and female rodents. The goal of the studies in this proposal are to expand the animal studies and to add human studies to determine whether gender differences in endocannabinoid signaling underlie or contribute to gender differences in stress responses. [unreadable] [unreadable] [unreadable] [unreadable]
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0.958 |
2009 — 2011 |
Hillard, Cecilia J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Biochemistry of Anandamide, An Endogenous Cannabinoid @ Medical College of Wisconsin
DESCRIPTION (provided by applicant): Long term goals. Our goals are to understand the mechanisms that regulate the concentrations of the endogenous ligands of the brain cannabinoid receptor (CB1) available to activate the receptor. This is important because of the importance of CB1 receptor activation in the regulation of signaling in the brain. Hypothesis: We hypothesize that changes in neuronal activity induce a rapid redistribution of the endocannabinoids (eCBs) from intracellular to extracellular domains. We further hypothesize that this redistribution occurs as a result of a combination of the mobilization of the eCBs from intracellular sequestration sites, increased synthesis and reduced catabolism. We also hypothesize that the primary sites of eCB catabolism are presynaptic, CB1 receptor expressing neurons. Aims: Our first aim is to determine regulation of eCB release in response to increased synaptic activity;the second is to study the mechanisms of inactivation of 2-AG;the third aim is to determine whether sterol carrier protein 2 is involved in the accumulation or sequestration of the eCBs by neurons. Methods: We will carry out these studies using cells in culture and cerebellar slices. We will use liquid chromatography:mass spectrometry to measure the effects of neuronal activation on the redistribution of the eCBs between tissue and buffer. Significance: It is becoming increasingly clear that the eCB/CB1 signaling pair plays important roles in many behavioral and neuropsychiatric disorders. In particular, several studies in both animals and humans suggest that altered eCB production could enhance the addictive liability of drugs of abuse. A CB1 receptor antagonist is being considered as a therapy for smoking cessation, for example. Therefore, increased understanding of the processes involved in the endogenous activation of the CB1 receptor will aid in our understanding of the potential for this drug to treat addiction. Novelty: Our laboratory has focused on the use of liquid chromatography mass spectrometry to assay endocannabinoids. We have coupled this technique with our ability to culture cells from the cerebellum as a unique approach to these goals.
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0.958 |
2010 — 2014 |
Hillard, Cecilia J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Cannabinoid Regulation of Glycogen Synthase Kinase-3 @ Medical College of Wisconsin
Cannabis sativa is currently the most commonly-used, illicit drug in the United States. Cannabis use, particularly by adolescents, increases the risk of developing schizophrenia-like psychoses in later life. In addition, people with bipolar disorder have a 20-40% lifetime prevalence of cannabis use, compared to 6% in the general population. These and other epidemiological data demonstrate that cannabis use predisposes susceptible individuals to the development of psychiatric disorders. Glycogen synthase kinase 3 (GSK-3) is emerging as an important regulatory kinase in the limbic brain; over-activity of GSK-3 has been linked to both bipolar disorder and schizophrenia. GSK-3 is phosphorylated and inactivated by protein kinases, including Akt and is a down-stream component of several neurotransmitters involved in mood regulation and psychosis. Data presented in this proposal demonstrate that prolonged cannabinoid-1 receptor (CB1R) activation by the cannabis constituent, 9-tetrahydrocannabinol (THC), significantly decreases GSK-3 phosphorylation in neurons. Since GSK-3 activity is reduced by phosphorylation, these data are consistent with enhanced GSK-3 activity following THC exposure. A second CB1R agonist, CP55940 shared these effects of THC. These preliminary data, together with data in the literature regarding D2 dopamine receptor signaling, were used to formulate the hypothesis that prolonged CB1R activation results in recruitment of ss-arrestin; ss-arrestin functions as a scaffold protein, bringing Akt in proximity with the protein phosphatase, PP2A. Akt is dephosphorylated and inactivated, resulting in dysinhibition of GSK-3 activity. Since GSK-3 over-activity is associated with mood dysregulation and psychosis, these data lead to the hypothesis that THC-mediated increase in GSK-3 activity contributes to the relationship between cannabis use and psychiatric disorders. The objective of the current project is to test the specific hypothesis that CB1R-mediated activation of GSK-3 occurs through ss-arrestin-mediated inhibition of Akt; is brain region specific and contributes to the anxiogenic and stress-enhancing effects of THC and other cannabinoid agonists. The specific aims of this project are: (1) to determine the mechanism by which CB1R agonists alter the phosphorylation state of GSK-3 in primary neurons in culture; (2) the determine the effects of acute and chronic exposure of mice to CB1R agonists and antagonists on the phosphorylation and activities of Akt and GSK-3 in brain regions, particularly those of the limbic system: (3) to determine the role of ss-arrestin in the effects of CB1R agonists and antagonists in behavioral assays of anxiety and stress by comparing their effects in wild type and ss-arrestin-2 null mice. Successful completion of the studies outlined in this proposal will advance our long-term objective to determine the mechanisms by which cannabis exposure predisposes individuals to the development of psychiatric illness.
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0.958 |
2014 — 2015 |
Deroon-Cassini, Terri A. [⬀] Hillard, Cecilia J |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
Role of Ecs in Resilience & Psychopathology After Trauma @ Medical College of Wisconsin
DESCRIPTION (provided by applicant): Predicting who develops Posttraumatic Stress Disorder (PTSD) after a traumatic injury has remained elusive. The long-term research goal is to identify the biological mechanisms involved in maintenance of or protection against the development of chronic PTSD. Emerging research suggests that the endocannabinoid signaling system (ECSS) modulates the stress response to reduce anxiety. The ECSS consists of the CB1 cannabinoid receptor (CB1R) and two endogenous ligands (N- arachidonylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG). The objective of this proposal is to determine the involvement of the ECSS in acute and long-term psychological distress following traumatic injury. The central hypothesis is that high endocannabinoid signaling increases the likelihood of resilience following trauma. The specific aims of the proposed project are to: 1) Characterize the circulating endocannabinoid signaling response (AEA, 2-AG) specific to traumatic injury (acute stressor) for chronic PTSD and resilience trajectories; 2) Determine the genotype variants of CNR1 and fatty acid amide hydrolase (FAAH) across chronic and resilient trajectories of PTSD symptom levels after traumatic injury. The ECSS engages the central (brain) nervous systems potentially impacting the fear conditioned response that occurs during a trauma that leads to the development of PTSD. Based on basic science research, greater activation of the ECSS after a traumatic effect may prove to be protective, leading to greater resilience after trauma, and ultimately helping to reduce the significant burden of PTSD. This study proposes a longitudinal prospective cohort study of single incident assaultive trauma survivors admitted to a level 1 trauma center for medical care. Participants will receive two blood draws in the hospital, a structured clinical interview to assess PTSD symptom severity, and a cheek swab for analysis of genetic material. At six months posttrauma, participants will return for an additional lab draw and the same structured clinical interview to assess for PTSD. Standardized laboratory techniques will be used to assess the serum for 2-AG and AEA, and standard techniques will evaluate the genotype variants of CNR1 and FAAH. Statistical analysis will compare endocannabinoid content for resilience and chronic PTSD, and will assess the genotype variants of CNR1 and FAAH for these two groups.
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0.958 |
2016 — 2017 |
Hillard, Cecilia J Olsen, Christopher M (co-PI) [⬀] |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
Cb2 Cannabinoid Receptors and Cocaine Action: Studies With Conditional Knock Outs @ Medical College of Wisconsin
? DESCRIPTION (provided by applicant): Substance use disorder (SUD) is a devastating psychopathology that is without FDA-approved drug therapies. One promising target for pharmacological intervention are CB2 cannabinoid receptors (CB2R). Previous studies have demonstrated that CB2R agonists reduce intravenous self-administration (SA) of cocaine and inhibit cocaine-induced hyperlocomotion. Since CB2R agonists have very few overt behavioral effects, they represent a promising new avenue for the treatment of SUD. Unfortunately, a lack of good experimental tools for their study inhibits further progress in uncovering the potential fo manipulation of CB2R signaling to treat SUDs. We have recently developed a transgenic mouse in which CB2R expression is coupled to eGFP expression and the CB2R gene is floxed, thus can be conditionally deleted (CB2Rtg). This mouse model allows for enhanced detection and enables conditional deletion of the CB2R. Exposure to cocaine is accompanied by microglial activation and reduced microglial activation is associated with reduced cocaine seeking. Microglia express CB2R, which is increased upon microglial activation. Microglial CB2R promote a neuroprotective phenotype, including suppressed release of pro-inflammatory cytokines. Recent studies also demonstrate that CB2R are expressed in DA neurons and function to inhibit DA release. We will test two hypotheses with the experiments in this proposal: that chronic cocaine exposure increases expression of microglial CB2R and that CB2R agonists act via microglial and DA neuronal CB2R to reduce cocaine SA. We will test these hypotheses with two aims. In aim one, we will use the eGFP reporter feature of the CB2Rtg to determine the effects of cocaine on CB2R expression. In aim two, we will use the floxed feature of the CB2Rtg to specifically delete CB2R from microglia and DA neurons; then apply a subtraction approach to explore the cellular site of action of CB2R agonists to reduce locomotor activity and cocaine SA. Successful completion of these studies will impact understanding of the effects of cocaine on neuroinflammation and CB2R expression; and the roles of CB2R in regulating cocaine intake through clarification of the cell types(s) that are involved in the inhibitory actions of CB2R agonists. We will also establish conditional CB2R-/- mouse lines for further studies of the role of this very interesting receptor in brain function. Thus, these studies will impact mechanistic examination of cocaine effects on the brain and provide important new tools for the study of the CB2R in the brain.
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0.958 |
2016 — 2017 |
Hillard, Cecilia J |
R03Activity Code Description: To provide research support specifically limited in time and amount for studies in categorical program areas. Small grants provide flexibility for initiating studies which are generally for preliminary short-term projects and are non-renewable. |
Circulating Endocannabinoids in Rats: Assay Development and Validation @ Medical College of Wisconsin
The mechanisms that regulate the intake of food are vital for survival and health. While too little food consumption can lead to death, an equal or greater problem in 21st century America is the over-consumption of calorie-dense and inadequate consumption of vitamin-rich foods, resulting in obesity and poor nutrition. CB1 cannabinoid receptors (CB1R) in the brain play a vital role in the regulation of food intake, while activation of CB1R in peripheral tissues results in increased fat and glycogen storage; reduced glucose utilization by muscles; and reduced thermogenesis in brown adipose. Endocannabinoids are present in the human circulation and their concentrations are regulated by metabolic state and exhibit a circadian pattern. These previous findings lead us to the overall hypotheses that endocannabinoids in the circulation convey information about the need for additional caloric intake and that sustained, high endocannabinoid concentrations contribute to overeating. The objectives of this proposal are to establish and characterize an assay system in which endocannabinoid concentrations in the circulation of awake, freely behaving rats are determined. We will examine changes in endocannabinoid concentrations across the daily cycle; and following acute food restriction and stress, as these have all been shown to impact circulating endocannabinoid concentrations in humans. We will carry out three specific aims. The first aim is to optimize the endocannabinoid measurement in rat plasma; determining the limits of detection and quantification, and robustness. The second aim is to apply the assay to measure the circadian changes in circulating endocannabinoid concentrations in relationship to other metabolic signaling molecules; and to examine the effects of a brief period of food deprivation. The third aim will examine the time course of the effects of fear-evoking odor presentation on circulating endocannabinoids. Successful completion of these studies will provide the basis for future studies, including exploration of the mechanisms by which changes in energy status affect endocannabinoids in the circulation; the tissue source of the endocannabinoids in the circulation; and, most importantly, whether the endocannabinoids entering the brain from the circulation convey information about metabolic status to brain reward circuit activity. These studies are highly translatable to humans because endocannabinoid concentrations are easily measured in human blood. Indeed, the innovation of this project lies in its beside to bench translation of human observations to an animal model that is amenable to mechanistic studies. The studies in this project will increase our understanding of several processes important in the regulation of circulating endocannabinoid concentrations and will set the stage for future human and animal studies of their role in eating disorders, drug addiction and mood disorders.
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0.958 |
2017 — 2018 |
Goveas, Joseph S Hillard, Cecilia J |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
Endocannabinoid System and Brain Network Function in Late-Life Depression @ Medical College of Wisconsin
TITLE: Endocannabinoid System and Brain Network Function in Late-Life Depression PROJECT SUMMARY/ABSTRACT During the past two decades, multiple pathophysiological mechanisms have been hypothesized to alter brain circuitry and explain the clinical heterogeneity of late-life major depression (LLD). Despite the diverse etiology of LLD, primary treatments have focused on modifying monoamine systems with limited effectiveness. Novel therapeutic targets are therefore clearly needed. Mounting evidence implicates the endocannabinoid signaling (ECS) system in the pathophysiology of major depression. However, its role in the neurobiologic underpinnings of depression in the elderly is currently unknown; this critical gap in knowledge is addressed in this study. This proposal's overall objective is to determine components of the ECS system and functional brain network features associated with LLD occurrence, and with two common symptom dimensions of LLD (low mood and anhedonia). Task-dependent functional MRI (T-fMRI) and resting-state functional connectivity MRI [R-fcMRI]) will be used to probe the emotional reactivity and ventral striatal brain network functioning, and peripheral endocannabinoid measures will be obtained to determine the functioning of the ECS system. Our central hypothesis is that reduced ECS in older adults with depression is associated with hyperactive amygdala and hypoactive ventral striatal functional activity, and disrupted functional connectivity in these brain networks. To achieve our objective, a total of 80 older adults (>60 years of age) will enrolled into the following groups that are equated for age and gender: (1) LLD (n = 50) and (2) healthy comparison (HC) (n = 30) subjects. This study employs a cross-sectional study design wherein the following aims will be completed: Aim 1. To determine the relationships between measures of brain network function and markers of the ECS system in subjects with LLD. Extensive clinical assessments will be conducted in antidepressant-free patients with LLD and in HC participants. These biologic measures will also be obtained: Brain network function (using task functional MRI paradigms and resting-state functional connectivity MRI) and peripheral ECS measures. Aim 2. To determine the relationships between brain network function and ECS measures and symptom dimensions in subjects with LLD. LLD and HC participants will also complete behavioral and self-report clinical measures of depressed mood and hedonic capacity. The stage will be set for future seminal research that uses ECS and brain network function measures as biomarkers to aid diagnosis by parsing LLD patients into more homogeneous subtypes, to predict and monitor outcomes to specific treatment interventions, and to guide selection of optimal treatment for individual patients prior to initiation.
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0.958 |
2017 — 2020 |
Drobyski, William R. [⬀] Hillard, Cecilia J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Cannabinoid-Mediated Mitigation of Graft Versus Host Disease: Roles of Cb2 Receptors and Adenosine Signaling @ Medical College of Wisconsin
Graft versus host disease (GVHD) is the major complication associated with allogeneic hematopoietic stem cell transplantation, and is characterized by both acute and chronic phases which have different pathophysiological mechanisms. Despite the use of pharmacological strategies which are primarily based on the administration of calcineurin-based agents, both acute and chronic GVHD remain major clinical problems. In preliminary studies, we have identified that signaling through the cannabinoid type 2 receptor (CB2R) mitigates the severity of both acute GVHD and also plays a pivotal role in reducing fibrosis in chronic GVHD. Moreover, we have discovered that that the nonpsychoactive, phytocannabinoid, cannabidiol (CBD) also inhibits GVH reactivity and potentiates adenosine signaling. Based on these studies, our overall hypothesis is that cannabinoids mitigate the severity of both acute and chronic GVHD, and that these anti-inflammatory effects are mechanistically mediated through the CB2R and the adenosine receptor signaling pathways. Studies in Specific Aim 1 will utilize a novel CB2R reporter mouse model that has flanking lox P sites that will allow us to both identify the critical immune cell populations that express the CB2R, and then eliminate these identified cells to formally test a functional role for these cells in acute GVHD biology. We will also employ several clinically relevant pharmacological approaches to determine whether administration of direct and selective CB2R agonists or, alternatively agents that inhibit the degradation of 2-arachidonyl glycerol (2-AG) which is the major endogenous ligand for the CB2R, can reduce the severity of this disease. Studies in Specific Aim 2 will define the role of CBD in mitigating the severity of acute GVHD by using selective pharmacological antagonists and genetic strategies to test the hypothesis that CBD regulates GVHD through the adenosine 2A receptor (A2AR) signaling pathway. We will also examine whether CBD augments the reconstitution of regulatory T cells and stabilizes Foxp3 expression in these cells through adenosine signaling. Experiments in Specific Aim 3 will determine whether cannabinoid signaling prevents the development of chronic GVHD-associated fibrosis which is a hallmark of this disease. Specifically, we will define the critical CB2R expressing immune cell populations which are present during the fibrotic phase of chronic GVHD and use cell-specific Cre-lox deletion approaches to define the functional significance of CB2R expression in identified cells. We will also assess whether either pharmacological administration of direct CB2R agonists, agents that inhibit the degradation of 2-AG, and CBD can prevent chronic GVHD-associated fibrosis. The overall goal of these studies is to define the mechanisms by which cannabinoids modulate both acute and chronic GVHD, and to test clinically relevant strategies that are designed to mitigate these complications in allogeneic hematopoietic stem cell transplant recipients.
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0.958 |
2019 — 2021 |
Hillard, Cecilia J Liu, Qing-Song |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Circuit-Specific Actions of Endocannabinoids in Stress and Mood Disorders @ Medical College of Wisconsin
Project Summary/Abstract The brain endocannabinoid (eCB) system can dampen behavioral and physiological responses to stress via activation of cannabinoid receptor 1 (CB1), one of the most abundant G protein-coupled receptors in the brain. However, the distinct neural circuits which underlie eCB-mediated effects remain incompletely identified and understood. Recent studies have identified the habenula, an epithalamic structure conserved across vertebrate evolution, to play a central role in encoding stress reactivity, avoidance behavior, and aversion in rodents and non-human primates, and its hyperactivity has been linked to anxiety-like behavior and mood dysregulation. Human studies have shown that habenula volumes and cell numbers are reduced in patients with depressive disorders, and deep brain stimulation of the habenula led to remission in an individual with treatment-resistant depression. Thus, both human and animal studies point to a critical role for the habenula in regulating behaviors relevant to stress responsivity and mood. In this study, we provide first evidence that neurons of the medial habenula (MHb) synthesize and release eCBs to suppress synaptic input from the medial septum and nucleus of the diagonal band (MSDB). Further, we show that this eCB/CB1 signaling is blunted in association with stress-induced anxiety-like behavior, and that knockdown of CB1 receptors in the MSDB is sufficient to mimic the stress-induced behavioral phenotype. Thus, these results, together with previous literature linking the MHb and the MSDB to anxiety-like behavior, led us to hypothesize that eCB/CB1 signaling in the MSDB- MHb pathway is a novel mechanism whereby eCBs attenuate stress-induced anxiety-like behavior, and that dysregulation of this signaling can contribute to this behavioral state. Three Specific Aims are proposed to test these hypotheses. Our first goal in Aim I will be to carry out a detailed assessment of the cell type-specific connectivity of the MSDB-MHb pathway, as very little is known regarding its anatomy and physiology. In Aim II, we will determine how eCBs regulate this circuit and how this regulation is affected by stress exposure. In Aim III, we will test the hypothesis that eCB signaling in this pathway regulates behavioral responses to stress. Successful completion of the outlined studies will advance our long-term objectives to understand the neural circuits underlying anxiety-like behavior, the specific mechanisms whereby eCBs exert behavior effects, and how dysregulation of eCB signaling may contribute to anxiety and mood-related disorders.
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0.958 |
2019 |
Deroon-Cassini, Terri A. [⬀] Hillard, Cecilia J |
R56Activity Code Description: To provide limited interim research support based on the merit of a pending R01 application while applicant gathers additional data to revise a new or competing renewal application. This grant will underwrite highly meritorious applications that if given the opportunity to revise their application could meet IC recommended standards and would be missed opportunities if not funded. Interim funded ends when the applicant succeeds in obtaining an R01 or other competing award built on the R56 grant. These awards are not renewable. |
Acute Endocannabinoid Activity Involved in Hyperarousal, Memory Formation, and Non-Remitting Ptsd: a Dense Sampling Approach @ Medical College of Wisconsin
Predicting who develops posttraumatic stress disorder has remained elusive, as acute neurobiological mechanisms of posttraumatic stress pathology are not well understood. The endocannabinoid signaling system (ECSS) is: involved in the stress response, connected with the limbic and neuroendocrine systems, and has been linked with behavioral responses consistent with anxiety in preclinical studies. The ECSS consists of the cannabinoid receptor (CB1R) and two endogenous ligands (endocannabinoids, eCBs), N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG). For those with non-remitting posttraumatic stress disorder (PTSD), there is evidence of endocannabinoid signaling dysregulation. Less well understood is the ECSS role in risk for PTSD in the acute period after trauma. The objective of this proposal is to characterize ECSS functioning early after trauma and to investigate its link to stress regulation circuitry, HPA axis functioning, affective memory formation and risk for non- remitting PTSD. The specific aims of the proposal are to: 1) Determine trajectories of circulating eCBs following trauma and their relationships with cortisol, arousal symptoms, neural circuits supporting and regulating arousal, and PTSD outcome; 2) Characterize challenge-elicited 2-AG & AEA response as a predictor of PTSD outcome; and 3) Explore the link between AEA with fear memory formation, neural activity in the hippocampal affective memory circuit, and PTSD. This study proposes a longitudinal prospective cohort study of traumatic injury survivors (ie, motor vehicle crash, gunshot and stab wound) evaluated at a level 1 trauma center. Participants will receive a risk screen for PTSD and if risk positive, an initial blood draw in the hospital (2-AG, AEA, cortisol). Acute blood draws and symptom assessments will occur at 1 and 2 weeks, amygdala and medial prefrontal cortex (mPFC) functioning utilizing functional magnetic resonance imaging (fMRI) and structured clinical interview to assess PTSD, depression, and other psychological disorders, along with a challenge task to evaluate eCB responding will occur at 1 month, with additional blood draws and structured clinical interviews occurring at 3, 6, and 12 months. Standardized laboratory techniques will be used to assess the serum for 2-AG, AEA, and cortisol. Statistical analysis will evaluate trajectories of eCBs, their relationships with cortisol, fear and affective memory circuitry, and collectively the capacity of these measurements to predict non-remitting PTSD.
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0.958 |
2020 |
Hillard, Cecilia J Lisdahl, Krista Maurine |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
Examining the Impact of Circulating Endocannabinoid Levels On Neurocognition, Mood, and Early Cannabis Use in Youth Enrolled in the Abcd Study @ University of Wisconsin Milwaukee
PROJECT SUMMARY The endogenous endocannabinoid (eCB) system includes cannabinoid receptor 1 (CB1R), CB2R, and two endogenous ligands (N-arachidonoylethanolamine;? AEA and 2-arachidonoylglycerol, 2AG). Animal findings demonstrate that the eCB system undergoes dynamic changes during adolescence and suggest a significant role in neurodevelopment, especially in CB1R-dense prefrontal, parietal, striatal and limbic brain regions. Research in adults have found that eCB system signaling modulates executive functioning, reward response, and stress and affective processing. Thus, there is strong preclinical evidence that the eCB system plays a substantial role in neuronal activity and neurodevelopment and disruption of or reduced eCB signaling during adolescence may result in abnormal neurocognitive development, risk for psychopathology, and increased risk for substance use, especially cannabis (CAN) use. Despite this evidence, no study to date has examined the role of the eCB system on neurocognition, mood, or early onset cannabis use and early cannabis subjective effects ex vivo in human youth due to the inherent challenges in employing invasive techniques [i.e., PET studies or collecting CSF]. However, there is now an available bioassay to measure circulating AEA and 2AG in serum collected from blood, that can be measured ex vivo in humans. Serum AEA and 2AG levels reflect both peripheral system synthesis and overflow from the brain and animal evidence has shown that circulating and brain eCB concentrations are robustly and significantly correlated. Further, adult studies have found significant associations between circulating serum eCBs and executive functioning, stress response, reward signaling, affective processing, mood and anxiety symptoms and regular CAN use. Notably, studies relating serum eCB levels and neurocognitive, psychopathology, and CAN use outcomes have not yet been conducted in youth- despite convincing preclinical evidence that the impact may be greater during these critical neurodevelopmental years. Thus, this R21 project will be the first to establish the link between circulating eCB levels and neurocognitive, psychopathology, and early CAN use outcomes in a subset of 2000 youth aged 11- 14 who are already enrolled in the longitudinal Adolescent Brain Cognitive Development (ABCD) Study (at 8 geographically-diverse research sites). We will also examine sex differences in these effects. Ultimately, this project will inform policy and health campaigns regarding the role of the eCB system in adolescent development and provide mechanistic information regarding the long-term impact of CAN exposure in youth.
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0.901 |
2020 — 2021 |
Drobyski, William R. [⬀] Hillard, Cecilia J |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Mechanistic Inflammatory Pathways in Graft Versus Host Disease @ Medical College of Wisconsin
PROJECT SUMMARY Graft versus host disease (GVHD) is the major complication associated with allogeneic hematopoietic stem cell transplantation (HSCT). Pathological damage to the skin, gastrointestinal tract, and liver are hallmarks of this disease; however, GVHD can also induce inflammation in the central nervous system (CNS) as well as cognitive and behavioral alterations in patients. We previously observed that host interleukin 6 (IL-6) production and the associated expansion of CNS resident macrophages (microglia) appear to have critical roles in the induction of neuroinflammation, but that blockade of IL-6 signaling does not completely mitigate disease severity. In preliminary studies, we have now identified endocannabinoid signaling through the type 2 cannabinoid receptor (CB2R) and the kynurenine metabolic pathway as novel IL-6- independent mechanisms by which inflammation is propagated in the brain. The overall goal of this proposal is to validate and characterize these two putative mechanistic pathways by which GVHD induces inflammation in the brain and ascertain how they modulate systemic manifestations of this disease. Our overall hypothesis is that inflammation during GVHD is attributable to CNS resident macrophages which induce inflammation and behavioral dysfunction through both the endocannabinoid signaling and kynurenine metabolic pathways. Studies in Specific Aim 1 will define the effect of CB2R signaling blockade on CNS and systemic manifestations of GVHD. We will employ pharmacological and genetic approaches that directly antagonize CB2R receptor signaling or inhibit the synthesis of 2-AG, the natural endocannabinoid ligand of the CB2R, to address this question. Experiments in Specific Aim 2 will determine whether expression of the CB2R on CNS resident macrophages is critical for mediating GVHD-induced inflammation. We will utilize novel CB2Rfl/fl mice which have flanking lox p sites which will allow for cell-specific deletion when bred with appropriate lineage-specific Cre animals. Studies in Specific Aim 3 will define the role of the kynurenine pathway in the pathophysiology of CNS and systemic inflammation that occur during GVHD. We will determine whether CNS resident macrophages are the dominant source of neurotoxic kynurenine metabolites, and define whether inhibition of this pathway using both genetic and pharmacological approaches prevents inflammation in the brain and periphery. The overall goal is to define relevant biochemical and immunological pathways that are responsible for GVHD-associated neuroinflammation in order to foster the development of clinically relevant strategies to mitigate this complication in allogeneic HSCT patients with blood cancers.
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0.958 |