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Ronan PJ, Korzan WJ, Johnson PL, Lowry CA, Renner KJ, Summers CH. Prior stress and vasopressin promote corticotropin-releasing factor inhibition of serotonin release in the central nucleus of the amygdala. Front Behav Neurosci 2023; 17:1148292. [PMID: 37064300 PMCID: PMC10098171 DOI: 10.3389/fnbeh.2023.1148292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 03/15/2023] [Indexed: 04/18/2023] Open
Abstract
Corticotropin-releasing factor (CRF) is essential for coordinating endocrine and neural responses to stress, frequently facilitated by vasopressin (AVP). Previous work has linked CRF hypersecretion, binding site changes, and dysfunctional serotonergic transmission with anxiety and affective disorders, including clinical depression. Crucially, CRF can alter serotonergic activity. In the dorsal raphé nucleus and serotonin (5-HT) terminal regions, CRF effects can be stimulatory or inhibitory, depending on the dose, site, and receptor type activated. Prior stress alters CRF neurotransmission and CRF-mediated behaviors. Lateral, medial, and ventral subdivisions of the central nucleus of the amygdala (CeA) produce CRF and coordinate stress responsiveness. The purpose of these experiments was to determine the effect of intracerebroventricular (icv) administration of CRF and AVP on extracellular 5-HT as an index of 5-HT release in the CeA, using in vivo microdialysis in freely moving rats and high performance liquid chromatography (HPLC) analysis. We also examined the effect of prior stress (1 h restraint, 24 h prior) on CRF- and AVP-mediated release of 5-HT within the CeA. Our results show that icv CRF infusion in unstressed animals had no effect on 5-HT release in the CeA. Conversely, in rats with prior stress, CRF caused a profound dose-dependent decrease in 5-HT release within the CeA. This effect was long-lasting (240 min) and was mimicked by CRF plus AVP infusion without stress. Thus, prior stress and AVP functionally alter CRF-mediated neurotransmission and sensitize CRF-induced inhibition of 5-HT release, suggesting that this is a potential mechanism underlying stress-induced affective reactivity in humans.
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Affiliation(s)
- Patrick J. Ronan
- Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD, United States
- Department of Psychiatry, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, United States
- Laboratory for Clinical and Translational Research in Psychiatry, Department of Veterans Affairs Medical Center, Denver, CO, United States
- Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States
- Kenneth J. Renner,
| | - Wayne J. Korzan
- Department of Biological and Environmental Sciences, The University of West Alabama, Livingston, AL, United States
| | - Philip L. Johnson
- Department of Biology, University of South Dakota, Vermillion, SD, United States
| | - Christopher A. Lowry
- Department of Integrative Physiology, University of Colorado, Boulder, Boulder, CO, United States
| | - Kenneth J. Renner
- Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States
- Department of Biology, University of South Dakota, Vermillion, SD, United States
- Patrick J. Ronan,
| | - Cliff H. Summers
- Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD, United States
- Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States
- Department of Biology, University of South Dakota, Vermillion, SD, United States
- *Correspondence: Cliff H. Summers,
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Collins AL, Aitken TJ, Huang IW, Shieh C, Greenfield VY, Monbouquette HG, Ostlund SB, Wassum KM. Nucleus Accumbens Cholinergic Interneurons Oppose Cue-Motivated Behavior. Biol Psychiatry 2019; 86:388-396. [PMID: 30955842 PMCID: PMC7003647 DOI: 10.1016/j.biopsych.2019.02.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/13/2019] [Accepted: 02/13/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND Environmental reward-predictive stimuli provide a major source of motivation for adaptive reward pursuit behavior. This cue-motivated behavior is known to be mediated by the nucleus accumbens (NAc) core. The cholinergic interneurons in the NAc are tonically active and densely arborized and thus well suited to modulate NAc function. However, their causal contribution to adaptive behavior remains unknown. Here we investigated the function of NAc cholinergic interneurons in cue-motivated behavior. METHODS We used chemogenetics, optogenetics, pharmacology, and a translationally analogous Pavlovian-to-instrumental transfer behavioral task designed to assess the motivating influence of a reward-predictive cue over reward-seeking actions in male and female rats. RESULTS The data show that NAc cholinergic interneuron activity critically opposes the motivating influence of appetitive cues. Chemogenetic inhibition of NAc cholinergic interneurons augmented cue-motivated behavior. Optical stimulation of acetylcholine release from NAc cholinergic interneurons prevented cues from invigorating reward-seeking behavior, an effect that was mediated by activation of β2-containing nicotinic acetylcholine receptors. CONCLUSIONS NAc cholinergic interneurons provide a critical regulatory influence over adaptive cue-motivated behavior and therefore are a potential therapeutic target for the maladaptive cue-motivated behavior that marks many psychiatric conditions, including addiction and depression.
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Affiliation(s)
- Anne L Collins
- Department of Psychology, University of California, Los Angeles, Los Angeles, California
| | - Tara J Aitken
- Department of Psychology, University of California, Los Angeles, Los Angeles, California
| | - I-Wen Huang
- Department of Chemical Engineering, University of California, Los Angeles, Los Angeles, California
| | - Christine Shieh
- Department of Psychology, University of California, Los Angeles, Los Angeles, California
| | - Venuz Y Greenfield
- Department of Psychology, University of California, Los Angeles, Los Angeles, California
| | - Harold G Monbouquette
- Department of Chemical Engineering, University of California, Los Angeles, Los Angeles, California
| | - Sean B Ostlund
- Department of Anesthesiology and Perioperative Care, University of California, Irvine, Irvine, California
| | - Kate M Wassum
- Department of Psychology, University of California, Los Angeles, Los Angeles, California; Brain Research Institute, University of California, Los Angeles, Los Angeles, California.
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Viltart O, Duriez P, Tolle V. Metabolic and neuroendocrine adaptations to undernutrition in anorexia nervosa: from a clinical to a basic research point of view. Horm Mol Biol Clin Investig 2018; 36:hmbci-2018-0010. [PMID: 29804101 DOI: 10.1515/hmbci-2018-0010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 03/13/2018] [Indexed: 02/07/2023]
Abstract
The exact mechanisms linking metabolic and neuroendocrine adaptations to undernutrition and the pathophysiology of anorexia nervosa (AN) are not fully understood. AN is a psychiatric disorder of complex etiology characterized by extreme starvation while the disease is progressing into a chronic state. Metabolic and endocrine alterations associated to this disorder are part of a powerful response to maintain whole body energy homeostasis. But these modifications may also contribute to associated neuropsychiatric symptoms (reward abnormalities, anxiety, depression) and thus participate to sustain the disease. The current review presents data with both a clinical and basic research point of view on the role of nutritional and energy sensors with neuroendocrine actions in the pathophysiology of the disease, as they modulate metabolic responses, reproductive functions, stress responses as well as physical activity. While clinical data present a full description of changes occurring in AN, animal models that integrate either spontaneous genetic mutations or experimentally-induced food restriction with hyperactivity and/or social stress recapitulate the main metabolic and endocrine alterations of AN and provide mechanistic information between undernutrition state and symptoms of the disease. Further progress on the central and peripheral mechanism involved in the pathophysiology of eating disorders partly relies on the development and/or refinement of existing animal models to include recently identified genetic traits and better mimic the complex and multifactorial dimensions of the disease.
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Affiliation(s)
- Odile Viltart
- Centre de Psychiatrie et Neurosciences, INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Université de Lille (Sciences et technologies), Lille, France
| | - Philibert Duriez
- Centre de Psychiatrie et Neurosciences, INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Clinique des Maladies Mentales et de l'Encéphale (CMME), Hôpital Sainte-Anne, Paris, France
| | - Virginie Tolle
- Centre de Psychiatrie et Neurosciences, INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
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4
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Modeling hypohedonia following repeated social defeat: Individual vulnerability and dopaminergic involvement. Physiol Behav 2017; 177:99-106. [PMID: 28433467 DOI: 10.1016/j.physbeh.2017.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 03/17/2017] [Accepted: 04/18/2017] [Indexed: 11/20/2022]
Abstract
Social defeat in rodents putatively can model hypohedonia. The present studies examined models for assessing hypohedonia-like behavior and tested the hypotheses that 1) individual differences in baseline reward sensitivity predict vulnerability, and 2) defeat elicits changes in pharmacological measures of striatal dopaminergic function. Male Wistar rats (n=142) received repeated defeat (3 "triad" blocks of 3 defeats) or control handling. To determine whether defeat influenced consumption of SuperSac (glucose-saccharin) over an isocaloric, less preferred, glucose solution, a 2-choice paradigm was used. To determine repeated defeat effects on the reinforcing efficacy of SuperSac, a progressive-ratio schedule of reinforcement was used. Amphetamine-induced locomotor activity (0.08mg/kg, s.c.) was determined as a measure sensitive to striatal dopaminergic function. Defeat reduced SuperSac consumption during the first two triads-an effect seen in the third triad only in defeated rats with High vs. Low baseline SuperSac intake. The characteristic escalation in PR breakpoint for SuperSac normally seen in controls was absent in defeated rats, leading to a significant difference by the third triad. Defeat-induced blunting of the escalation in PR performance was greater in rats with High antecedent PR breakpoints and persisted 2.5weeks post-defeat. Repeated defeat also blunted amphetamine-induced locomotion 13days post-defeat. Thus, hypohedonic-like effects of social defeat were detected and accompanied by persistently attenuated striatal dopamine function. Early effects were seen for consumption of differentially-palatable solutions, and persistent effects were seen for the "breakpoint" motivational measure. The results implicate initial reward sensitivity as a risk factor for stress-induced hypohedonia.
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Heit S, Owens MJ, Plotsky P, Nemeroff CB. ■ REVIEW : Corticotropin-releasing Factor, Stress, and Depression. Neuroscientist 2016. [DOI: 10.1177/107385849700300312] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Corticotropin-releasing factor (CRF), a 41 amino acid-containing neuropeptide, acts both as a hypothalamic releasing factor, controlling ACTH and corticosteroid secretion, and at extrahypothalamic CNS sites to mod ulate mammalian organisms' responses to stress. In this article, the evidence that CRF-containing neurons within the CNS are hyperactive in patients with depression is reviewed. The evidence, taken together, suggests that during depressive episodes, CRF is hypersecreted, resulting in both pituitary-adrenal axis hyperactivity and certain of the signs and symptoms of depression, including decreased appetite, decreased libido and disturbed sleep. There is also evidence that treatments for depression, including antidepressant medications and electroconvulsive therapy, reduce CRF hypersecretion within the CNS. Finally, evidence suggests that alterations in CRF-containing neurons and receptors are responsible for the widely held ob servation that early untoward life events increase an individual's vulnerability for affective disorders. These findings have a number of implications for treatment of the mood disorders, including the suggestion that the pharmacological manipulation of CRF receptors may provide a novel avenue for the treatment of de pression. NEUROSCIENTIST 3:186-194, 1997
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Affiliation(s)
- Stacey Heit
- Department of Psychiatry and Behavioral Sciences
| | | | - Paul Plotsky
- Department of Psychiatry and Behavioral Sciences, Department of Anatomy and Cell Biology Emory University
School of Medicine Atlanta, Georgia
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Waters RP, Rivalan M, Bangasser DA, Deussing JM, Ising M, Wood SK, Holsboer F, Summers CH. Evidence for the role of corticotropin-releasing factor in major depressive disorder. Neurosci Biobehav Rev 2015; 58:63-78. [PMID: 26271720 DOI: 10.1016/j.neubiorev.2015.07.011] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 06/24/2015] [Accepted: 07/24/2015] [Indexed: 01/05/2023]
Abstract
Major depressive disorder (MDD) is a devastating disease affecting over 300 million people worldwide, and costing an estimated 380 billion Euros in lost productivity and health care in the European Union alone. Although a wealth of research has been directed toward understanding and treating MDD, still no therapy has proved to be consistently and reliably effective in interrupting the symptoms of this disease. Recent clinical and preclinical studies, using genetic screening and transgenic rodents, respectively, suggest a major role of the CRF1 gene, and the central expression of CRF1 receptor protein in determining an individual's risk of developing MDD. This gene is widely expressed in brain tissue, and regulates an organism's immediate and long-term responses to social and environmental stressors, which are primary contributors to MDD. This review presents the current state of knowledge on CRF physiology, and how it may influence the occurrence of symptoms associated with MDD. Additionally, this review presents findings from multiple laboratories that were presented as part of a symposium on this topic at the annual 2014 meeting of the International Behavioral Neuroscience Society (IBNS). The ideas and data presented in this review demonstrate the great progress that has been made over the past few decades in our understanding of MDD, and provide a pathway forward toward developing novel treatments and detection methods for this disorder.
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Affiliation(s)
| | | | | | - J M Deussing
- Max Planck Institute of Psychiatry, Munich, Germany
| | - M Ising
- Max Planck Institute of Psychiatry, Munich, Germany
| | - S K Wood
- University of South Carolina School of Medicine, Columbia, SC, USA
| | - F Holsboer
- Max Planck Institute of Psychiatry, Munich, Germany; HMNC GmbH, Munich, Germany
| | - Cliff H Summers
- University of South Dakota, Vermillion, SD, USA; Sanford School of Medicine, Vermillion, SD, USA.
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7
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Liu X. Enhanced motivation for food reward induced by stress and attenuation by corticotrophin-releasing factor receptor antagonism in rats: implications for overeating and obesity. Psychopharmacology (Berl) 2015; 232:2049-60. [PMID: 25510859 PMCID: PMC4433618 DOI: 10.1007/s00213-014-3838-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 12/02/2014] [Indexed: 12/17/2022]
Abstract
RATIONALE Overeating beyond individuals' homeostatic needs critically contributes to obesity. The neurobehavioral mechanisms underlying the motivation to consume excessive foods with high calories are not fully understood. OBJECTIVE The present study examined whether a pharmacological stressor, yohimbine, enhances the motivation to procure food reward with an emphasis on comparisons between standard lab chow and high-fat foods. The effects of corticotropin-releasing factor (CRF) receptor blockade by a CRF1-selective antagonist NBI on the stress-enhanced motivation for food reward were also assessed. METHODS Male Sprague-Dawley rats with chow available ad libitum in their home cages were trained to press a lever under a progressive ratio schedule for deliveries of either standard or high-fat food pellets. For testing yohimbine stress effects, rats received an intraperitoneal administration of yohimbine 10 min before start of the test sessions. For testing effects of CRF1 receptor blockade on stress responses, NBI was administered 20 min prior to yohimbine challenge. RESULTS The rats emitted higher levels of lever responses to procure the high-fat food pellets compared with their counterparts on standard food pellets. Yohimbine challenge facilitated lever responses for the reward in all of the rats, whereas the effect was more robust in the rats on high-fat food pellets compared with their counterparts on standard food pellets. An inhibitory effect of pretreatment with NBI was observed on the enhancing effect of yohimbine challenge but not on the responses under baseline condition without yohimbine administration. CONCLUSIONS Stress challenge significantly enhanced the motivation of satiated rats to procure extra food reward, especially the high-fat food pellets. Activation of CRF1 receptors is required for the stress-enhanced motivation for food reward. These results may have implications for our better understanding of the biobehavioral mechanisms of overeating and obesity.
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Affiliation(s)
- Xiu Liu
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA,
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8
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Kawasaki T, Ohta M, Kawano Y, Masuda T, Gotoh K, Inomata M, Kitano S. Effects of sleeve gastrectomy and gastric banding on the hypothalamic feeding center in an obese rat model. Surg Today 2015; 45:1560-6. [PMID: 25724939 DOI: 10.1007/s00595-015-1135-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 01/27/2015] [Indexed: 12/19/2022]
Abstract
PURPOSE Laparoscopic sleeve gastrectomy (SG) and gastric banding (GB) are popular bariatric procedures for treating morbid obesity. This study aimed to investigate changes in the hypothalamic feeding center after these surgeries in a diet-induced obese rat model. METHODS Obesity was induced in 60 Sprague-Dawley rats using a high-energy diet for 6 weeks. These rats were divided into four groups: the sham-operated (SO) control, pair-fed (PF) control, SG and GB groups. Six weeks after the surgery, metabolic parameters, the plasma levels of leptin, ghrelin, peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) and the hypothalamic mRNA expressions of neuropeptide Y (NPY) and pro-opiomelanocortin (POMC) were measured. RESULTS Compared with those observed in the SO group, the body and fat tissue weights were significantly decreased and the metabolic parameters were significantly improved in the PF, SG and GB groups 6 weeks after surgery. The plasma ghrelin levels were significantly lower and the PYY and GLP-1 levels were significantly higher in the SG group than in the PF, GB and SO groups. Compared with that seen in the PF and GB groups, the hypothalamic mRNA expression of NPY was significantly lower and the expression of POMC was significantly higher in the SG group. CONCLUSIONS SG may affect the neurological pathway associated with appetite in the hypothalamus and thereby control ingestive behavior.
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Affiliation(s)
- Takahide Kawasaki
- Department of Gastroenterological and Pediatric Surgery, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan.
| | - Masayuki Ohta
- Department of Gastroenterological and Pediatric Surgery, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan
| | - Yuichiro Kawano
- Department of Gastroenterological and Pediatric Surgery, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan
| | - Takashi Masuda
- Department of Gastroenterological and Pediatric Surgery, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan
| | - Koro Gotoh
- Department of Endocrinology, Metabolism, and Rheumatology, Oita University Faculty of Medicine, Oita, Japan
| | - Masafumi Inomata
- Department of Gastroenterological and Pediatric Surgery, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, 879-5593, Japan
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Jackson KJ, Muldoon PP, De Biasi M, Damaj MI. New mechanisms and perspectives in nicotine withdrawal. Neuropharmacology 2014; 96:223-34. [PMID: 25433149 DOI: 10.1016/j.neuropharm.2014.11.009] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/21/2014] [Accepted: 11/17/2014] [Indexed: 02/08/2023]
Abstract
Diseases associated with tobacco use constitute a major health problem worldwide. Upon cessation of tobacco use, an unpleasant withdrawal syndrome occurs in dependent individuals. Avoidance of the negative state produced by nicotine withdrawal represents a motivational component that promotes continued tobacco use and relapse after smoking cessation. With the modest success rate of currently available smoking cessation therapies, understanding mechanisms involved in the nicotine withdrawal syndrome are crucial for developing successful treatments. Animal models provide a useful tool for examining neuroadaptative mechanisms and factors influencing nicotine withdrawal, including sex, age, and genetic factors. Such research has also identified an important role for nicotinic receptor subtypes in different aspects of the nicotine withdrawal syndrome (e.g., physical vs. affective signs). In addition to nicotinic receptors, the opioid and endocannabinoid systems, various signal transduction pathways, neurotransmitters, and neuropeptides have been implicated in the nicotine withdrawal syndrome. Animal studies have informed human studies of genetic variants and potential targets for smoking cessation therapies. Overall, the available literature indicates that the nicotine withdrawal syndrome is complex, and involves a range of neurobiological mechanisms. As research in nicotine withdrawal progresses, new pharmacological options for smokers attempting to quit can be identified, and treatments with fewer side effects that are better tailored to the unique characteristics of patients may become available. This article is part of the Special Issue entitled 'The Nicotinic Acetylcholine Receptor: From Molecular Biology to Cognition'.
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Affiliation(s)
- K J Jackson
- Department of Psychiatry, Virginia Commonwealth University, 800 E. Leigh St., Richmond, VA 23219, USA
| | - P P Muldoon
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1220 E. Marshall St., Richmond, VA 23219, USA
| | - M De Biasi
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - M I Damaj
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 1220 E. Marshall St., Richmond, VA 23219, USA.
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Sharma N, Awasthi S, Phadke SR. A novel genotyping method for detection of the CRHR1 (rs1396862: C>T) gene variation among North Indian population. Mol Biol Rep 2014; 41:2809-13. [PMID: 24452719 DOI: 10.1007/s11033-014-3135-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Accepted: 01/11/2014] [Indexed: 11/29/2022]
Abstract
Today, the genomic revolution in epidemiology, medicine and population based genetic association studies are results of on-going refocusing efforts toward development of inexpensive and accurate techniques for SNP genotyping. Despite this considerable gain, high throughput and routinely applicable newer SNP detection techniques are still needed. Therefore, aim of this study was to develop and validate a simple, rapid and inexpensive restriction enzyme based method for genotyping of corticotrophin-releasing hormone receptor1 (CRHR1; rs1396862: C>T) gene variant. This polymorphism has been investigated in a variety of psychiatric and association studies of asthma. A total of 250 healthy volunteers were recruited from same ethnicity and their blood DNA samples were employed for genotyping. Primers were designed using Batch primer3 Software. Specificity and functionality of primers were tested with BLAST database and UCSC In-silco PCR respectively. The lake of a PstI recognition site was seen with T allele. The allele frequencies for rs1396862: C>T were 0.88 (C allele) and 0.12 (T allele). We get 100% concordant genotyping results for sequencing and PCR-RFLP. This newer genotyping approach lowers the cost and increased the speed. It is particularly useful for small basic research studies of complex genetic disorder.
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Affiliation(s)
- Neeraj Sharma
- Department of Paediatrics & Translational Medicine Unit, King George's Medical University, Lucknow, 226003, UP, India,
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Sasse SK, Nyhuis TJ, Masini CV, Day HEW, Campeau S. Central gene expression changes associated with enhanced neuroendocrine and autonomic response habituation to repeated noise stress after voluntary wheel running in rats. Front Physiol 2013; 4:341. [PMID: 24324441 PMCID: PMC3839297 DOI: 10.3389/fphys.2013.00341] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 11/05/2013] [Indexed: 01/15/2023] Open
Abstract
Accumulating evidence indicates that regular physical exercise benefits health in part by counteracting some of the negative physiological impacts of stress. While some studies identified reductions in some measures of acute stress responses with prior exercise, limited data were available concerning effects on cardiovascular function, and reported effects on hypothalamic-pituitary-adrenocortical (HPA) axis responses were largely inconsistent. Given that exposure to repeated or prolonged stress is strongly implicated in the precipitation and exacerbation of illness, we proposed the novel hypothesis that physical exercise might facilitate adaptation to repeated stress, and subsequently demonstrated significant enhancement of both HPA axis (glucocorticoid) and cardiovascular (tachycardia) response habituation to repeated noise stress in rats with long-term access to running wheels compared to sedentary controls. Stress habituation has been attributed to modifications of brain circuits, but the specific sites of adaptation and the molecular changes driving its expression remain unclear. Here, in situ hybridization histochemistry was used to examine regulation of select stress-associated signaling systems in brain regions representing likely candidates to underlie exercise-enhanced stress habituation. Analyzed brains were collected from active (6 weeks of wheel running) and sedentary rats following control, acute, or repeated noise exposures that induced a significantly faster rate of glucocorticoid response habituation in active animals but preserved acute noise responsiveness. Nearly identical experimental manipulations also induce a faster rate of cardiovascular response habituation in exercised, repeatedly stressed rats. The observed regulation of the corticotropin-releasing factor and brain-derived neurotrophic factor systems across several brain regions suggests widespread effects of voluntary exercise on central functions and related adaptations to stress across multiple response modalities.
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Affiliation(s)
- Sarah K Sasse
- Department of Psychology and Neuroscience, University of Colorado Boulder, CO, USA
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12
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Illa M, Eixarch E, Batalle D, Arbat-Plana A, Muñoz-Moreno E, Figueras F, Gratacos E. Long-term functional outcomes and correlation with regional brain connectivity by MRI diffusion tractography metrics in a near-term rabbit model of intrauterine growth restriction. PLoS One 2013; 8:e76453. [PMID: 24143189 PMCID: PMC3797044 DOI: 10.1371/journal.pone.0076453] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 08/27/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Intrauterine growth restriction (IUGR) affects 5-10% of all newborns and is associated with increased risk of memory, attention and anxiety problems in late childhood and adolescence. The neurostructural correlates of long-term abnormal neurodevelopment associated with IUGR are unknown. Thus, the aim of this study was to provide a comprehensive description of the long-term functional and neurostructural correlates of abnormal neurodevelopment associated with IUGR in a near-term rabbit model (delivered at 30 days of gestation) and evaluate the development of quantitative imaging biomarkers of abnormal neurodevelopment based on diffusion magnetic resonance imaging (MRI) parameters and connectivity. METHODOLOGY At +70 postnatal days, 10 cases and 11 controls were functionally evaluated with the Open Field Behavioral Test which evaluates anxiety and attention and the Object Recognition Task that evaluates short-term memory and attention. Subsequently, brains were collected, fixed and a high resolution MRI was performed. Differences in diffusion parameters were analyzed by means of voxel-based and connectivity analysis measuring the number of fibers reconstructed within anxiety, attention and short-term memory networks over the total fibers. PRINCIPAL FINDINGS The results of the neurobehavioral and cognitive assessment showed a significant higher degree of anxiety, attention and memory problems in cases compared to controls in most of the variables explored. Voxel-based analysis (VBA) revealed significant differences between groups in multiple brain regions mainly in grey matter structures, whereas connectivity analysis demonstrated lower ratios of fibers within the networks in cases, reaching the statistical significance only in the left hemisphere for both networks. Finally, VBA and connectivity results were also correlated with functional outcome. CONCLUSIONS The rabbit model used reproduced long-term functional impairments and their neurostructural correlates of abnormal neurodevelopment associated with IUGR. The description of the pattern of microstructural changes underlying functional defects may help to develop biomarkers based in diffusion MRI and connectivity analysis.
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Affiliation(s)
- Miriam Illa
- Department of Maternal-Fetal Medicine, Institut Clinic de Ginecologia, Obstetricia i Neonatologia (ICGON), Hospital Clinic, Barcelona, Spain
- Fetal and Perinatal Medicine Research Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Elisenda Eixarch
- Department of Maternal-Fetal Medicine, Institut Clinic de Ginecologia, Obstetricia i Neonatologia (ICGON), Hospital Clinic, Barcelona, Spain
- Fetal and Perinatal Medicine Research Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
| | - Dafnis Batalle
- Fetal and Perinatal Medicine Research Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Ariadna Arbat-Plana
- Fetal and Perinatal Medicine Research Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Emma Muñoz-Moreno
- Fetal and Perinatal Medicine Research Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Francesc Figueras
- Department of Maternal-Fetal Medicine, Institut Clinic de Ginecologia, Obstetricia i Neonatologia (ICGON), Hospital Clinic, Barcelona, Spain
- Fetal and Perinatal Medicine Research Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
| | - Eduard Gratacos
- Department of Maternal-Fetal Medicine, Institut Clinic de Ginecologia, Obstetricia i Neonatologia (ICGON), Hospital Clinic, Barcelona, Spain
- Fetal and Perinatal Medicine Research Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
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13
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Van't Veer A, Carlezon WA. Role of kappa-opioid receptors in stress and anxiety-related behavior. Psychopharmacology (Berl) 2013; 229:435-52. [PMID: 23836029 PMCID: PMC3770816 DOI: 10.1007/s00213-013-3195-5] [Citation(s) in RCA: 199] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 06/17/2013] [Indexed: 12/15/2022]
Abstract
RATIONALE Accumulating evidence indicates that brain kappa-opioid receptors (KORs) and dynorphin, the endogenous ligand that binds at these receptors, are involved in regulating states of motivation and emotion. These findings have stimulated interest in the development of KOR-targeted ligands as therapeutic agents. As one example, it has been suggested that KOR antagonists might have a wide range of indications, including the treatment of depressive, anxiety, and addictive disorders, as well as conditions characterized by co-morbidity of these disorders (e.g., post-traumatic stress disorder) A general effect of reducing the impact of stress may explain how KOR antagonists can have efficacy in such a variety of animal models that would appear to represent different disease states. OBJECTIVE Here, we review evidence that disruption of KOR function attenuates prominent effects of stress. We will describe behavioral and molecular endpoints including those from studies that characterize the effects of KOR antagonists and KOR ablation on the effects of stress itself, as well as on the effects of exogenously delivered corticotropin-releasing factor, a brain peptide that mediates key effects of stress. CONCLUSION Collectively, available data suggest that KOR disruption produces anti-stress effects and under some conditions can prevent the development of stress-induced adaptations. As such, KOR antagonists may have unique potential as therapeutic agents for the treatment and even prevention of stress-related psychiatric illness, a therapeutic niche that is currently unfilled.
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MESH Headings
- Animals
- Anti-Anxiety Agents/pharmacology
- Anti-Anxiety Agents/therapeutic use
- Anxiety Disorders/drug therapy
- Anxiety Disorders/metabolism
- Anxiety Disorders/psychology
- Behavior, Animal/drug effects
- Brain/drug effects
- Brain/metabolism
- Brain/physiopathology
- Corticotropin-Releasing Hormone/metabolism
- Dynorphins/genetics
- Dynorphins/metabolism
- Humans
- Ligands
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/genetics
- Receptors, Opioid, kappa/metabolism
- Stress, Psychological/drug therapy
- Stress, Psychological/metabolism
- Stress, Psychological/psychology
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Affiliation(s)
- Ashlee Van't Veer
- Department of Psychiatry, Harvard Medical School, McLean Hospital, MRC 217, 115 Mill Street, Belmont, MA, 02478, USA
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14
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Cohen A, George O. Animal models of nicotine exposure: relevance to second-hand smoking, electronic cigarette use, and compulsive smoking. Front Psychiatry 2013; 4:41. [PMID: 23761766 PMCID: PMC3671664 DOI: 10.3389/fpsyt.2013.00041] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 05/13/2013] [Indexed: 12/23/2022] Open
Abstract
Much evidence indicates that individuals use tobacco primarily to experience the psychopharmacological properties of nicotine and that a large proportion of smokers eventually become dependent on nicotine. In humans, nicotine acutely produces positive reinforcing effects, including mild euphoria, whereas a nicotine abstinence syndrome with both somatic and affective components is observed after chronic nicotine exposure. Animal models of nicotine self-administration and chronic exposure to nicotine have been critical in unveiling the neurobiological substrates that mediate the acute reinforcing effects of nicotine and emergence of a withdrawal syndrome during abstinence. However, important aspects of the transition from nicotine abuse to nicotine dependence, such as the emergence of increased motivation and compulsive nicotine intake following repeated exposure to the drug, have only recently begun to be modeled in animals. Thus, the neurobiological mechanisms that are involved in these important aspects of nicotine addiction remain largely unknown. In this review, we describe the different animal models available to date and discuss recent advances in animal models of nicotine exposure and nicotine dependence. This review demonstrates that novel animal models of nicotine vapor exposure and escalation of nicotine intake provide a unique opportunity to investigate the neurobiological effects of second-hand nicotine exposure, electronic cigarette use, and the mechanisms that underlie the transition from nicotine use to compulsive nicotine intake.
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Affiliation(s)
- Ami Cohen
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA
| | - Olivier George
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA
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15
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Alcohol in excess: CRF₁ receptors in the rat and mouse VTA and DRN. Psychopharmacology (Berl) 2013; 225:313-27. [PMID: 22885872 PMCID: PMC3518642 DOI: 10.1007/s00213-012-2820-z] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 07/16/2012] [Indexed: 12/29/2022]
Abstract
RATIONALE Manipulation of the stress neuropeptide corticotropin-releasing factor (CRF), specifically central antagonism of the type 1 receptors (CRF-R1), effectively reduces alcoholic-like ethanol drinking in rodents. Escalated consumption is largely controlled by neurocircuitry that is important for reward and affect, such as the ventral tegmental area (VTA) and the dorsal raphé nucleus (DRN). OBJECTIVE The current studies investigated the role of CRF-R1 within the VTA and DRN and their relation to escalated ethanol drinking in two species. An additional goal was to explore whether high alcohol-drinking individuals would be more affected by CRF-R1 antagonism than low alcohol-drinking individuals. METHODS With a two-bottle choice drinking procedure, adult male C57BL/6J mice and Long-Evans rats were given 24-h access to 20 % ethanol and water on an intermittent schedule. Rats and mice were implanted with cannulae targeting the VTA or DRN. Doses of the CRF-R1 antagonist CP-154,526 (butyl-[2,4,6-trimethylphenyl)-7H-pyrrolo[2,3-d]pyrimidin-4-yl]ethylamine)) were microinfused to modulate drinking of ethanol and water over the course of 24 h. RESULTS In both mice and rats, intra-VTA CP-154,526 selectively decreased ethanol intake, while identical doses (0.3 and 0.6 μg) infused intra-DRN reduced both ethanol and water drinking. Long-Evans rats displayed a range of individual differences for ethanol preference, and CP-154,526 suppressed ethanol drinking in the high-preferring animals regardless of brain site manipulation. CONCLUSIONS The current findings confirm previous studies that blockade of CRF-R1 efficaciously reduces escalated drinking while also suggesting that the effects of intermittent access on alcohol consumption may require CRF interaction with dopamine in the VTA.
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16
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Jackson KJ, Sanjakdar SS, Chen X, Damaj MI. Nicotine reward and affective nicotine withdrawal signs are attenuated in calcium/calmodulin-dependent protein kinase IV knockout mice. PLoS One 2012; 7:e51154. [PMID: 23226481 PMCID: PMC3511389 DOI: 10.1371/journal.pone.0051154] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 10/29/2012] [Indexed: 11/19/2022] Open
Abstract
The influx of Ca(2+) through calcium-permeable nicotinic acetylcholine receptors (nAChRs) leads to activation of various downstream processes that may be relevant to nicotine-mediated behaviors. The calcium activated protein, calcium/calmodulin-dependent protein kinase IV (CaMKIV) phosphorylates the downstream transcription factor cyclic AMP response element binding protein (CREB), which mediates nicotine responses; however the role of CaMKIV in nicotine dependence is unknown. Given the proposed role of CaMKIV in CREB activation, we hypothesized that CaMKIV might be a crucial molecular component in the development of nicotine dependence. Using male CaMKIV genetically modified mice, we found that nicotine reward is attenuated in CaMKIV knockout (-/-) mice, but cocaine reward is enhanced in these mice. CaMKIV protein levels were also increased in the nucleus accumbens of C57Bl/6 mice after nicotine reward. In a nicotine withdrawal assessment, anxiety-related behavior, but not somatic signs or the hyperalgesia response are attenuated in CaMKIV -/- mice. To complement our animal studies, we also conducted a human genetic association analysis and found that variants in the CaMKIV gene are associated with a protective effect against nicotine dependence. Taken together, our results support an important role for CaMKIV in nicotine reward, and suggest that CaMKIV has opposing roles in nicotine and cocaine reward. Further, CaMKIV mediates affective, but not physical nicotine withdrawal signs, and has a protective effect against nicotine dependence in human genetic association studies. These findings further indicate the importance of calcium-dependent mechanisms in mediating behaviors associated with drugs of abuse.
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Affiliation(s)
- Kia J. Jackson
- Department of Psychiatry, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Sarah S. Sanjakdar
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Xiangning Chen
- Department of Psychiatry, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - M. Imad Damaj
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, United States of America
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17
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E Vollmer L, Ghosal S, A Rush J, R Sallee F, P Herman J, Weinert M, Sah R. Attenuated stress-evoked anxiety, increased sucrose preference and delayed spatial learning in glucocorticoid-induced receptor-deficient mice. GENES BRAIN AND BEHAVIOR 2012; 12:241-9. [PMID: 23088626 DOI: 10.1111/j.1601-183x.2012.00867.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 09/03/2012] [Accepted: 10/09/2012] [Indexed: 12/27/2022]
Abstract
The glucocorticoid-induced receptor (GIR) is a stress-responsive gene that is abundantly expressed in forebrain limbic regions. Glucocorticoid-induced receptor has been classified as a Neuropeptide Y-like receptor, however, physiological attributes have not been investigated. In this study, mice lacking GIR (-/-) were screened in various paradigms related to stress, anxiety, activity, memory, fear and reward. GIR -/- mice elicited behavioral insensitivity to the anxiogenic effects of restraint stress. However, hypothalamic pituitary adrenal axis response to stress was not impacted by GIR deficiency. Increased preference for sucrose was observed in GIR -/- mice suggestive of modulation of reward-associated behaviors by the receptor. A delayed acquisition of spatial learning was also observed in GIR -/- mice. There were no effects of genotype on the modulation of anxiety-like behavior, activity, fear-conditioning and extinction. Our data extend previous studies on GIR regulation by glucocorticoids and provide novel evidence for a role of GIR in reward, learning and the behavioral outcomes of stress.
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Affiliation(s)
- L E Vollmer
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH 45237, USA
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18
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Butler RK, White LC, Frederick-Duus D, Kaigler KF, Fadel JR, Wilson MA. Comparison of the activation of somatostatin- and neuropeptide Y-containing neuronal populations of the rat amygdala following two different anxiogenic stressors. Exp Neurol 2012; 238:52-63. [PMID: 22917777 DOI: 10.1016/j.expneurol.2012.08.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 07/02/2012] [Accepted: 08/01/2012] [Indexed: 01/29/2023]
Abstract
Rats exposed to the odor of a predator or to the elevated plus maze express fear behaviors without a prior exposure to either stimulus. The expression of innate fear provides for an ideal model of anxiety which can aid in the elucidation of brain circuits involved in anxiety-related behaviors. The current experiments compared activation of neuropeptide-containing neuronal populations in the amygdala of rats exposed to either the elevated plus maze (EPM; 5 min) versus home cage controls, or predator ferret odor versus butyric acid, or no odor (30 min). Sections of the brains were prepared for dual-labeled immunohistochemistry and counts of c-Fos co-localized with somatostatin (SOM) or neuropeptide Y (NPY) were made in the basolateral (BLA), central (CEA), medial (MEA) nuclei of the amygdala. Ferret odor and butyric acid exposure significantly decreased the percentage of SOM-positive neurons also immunoreactive for c-Fos in the anterior BLA compared to controls, whereas EPM exposure yielded a significant increase in the activation of SOM-positive neurons versus home cage controls. In the CEA, ferret odor and butyric exposure significantly decreased the percentage of SOM-positive neurons also immunoreactive for c-Fos compared to no-odor controls whereas EPM exposure yielded no change versus controls. In the MEA, both ferret odor exposure and EPM exposure resulted in increased SOM co-localized with c-Fos compared to control groups whereas NPY co-localized with c-Fos occurred following ferret odor exposure, but not EPM exposure. These results indicate that phenotypically distinct neuronal populations of the amygdala are differentially activated following exposure to different anxiogenic stimuli. These studies further elucidate the fundamental neurocircuitry of anxiety and could possibly explain the differential behavioral effects of predator versus novelty-induced stress.
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Affiliation(s)
- Ryan K Butler
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208, USA.
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19
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Gold AB, Lerman C. Pharmacogenetics of smoking cessation: role of nicotine target and metabolism genes. Hum Genet 2012; 131:10.1007/s00439-012-1143-9. [PMID: 22290489 PMCID: PMC3864572 DOI: 10.1007/s00439-012-1143-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 01/19/2012] [Indexed: 11/24/2022]
Abstract
Many smokers attempt to quit smoking but few are successful in the long term. The heritability of nicotine addiction and smoking relapse have been documented, and research is focused on identifying specific genetic influences on the ability to quit smoking and response to specific medications. Research in genetically modified cell lines and mice has identified nicotine acetylcholine receptor subtypes that mediate the pharmacological and behavioral effects of nicotine sensitivity and withdrawal. Human genetic association studies have identified single nucleotide polymorphisms (SNPs) in genes encoding nicotine acetylcholine receptor subunits and nicotine metabolizing enzymes that influence smoking cessation phenotypes. There is initial promising evidence for a role in smoking cessation for SNPs in the β2 and α5/α3/β4 nAChR subunit genes; however, effects are small and not consistently replicated. There are reproducible and clinically significant associations of genotypic and phenotypic measures of CYP2A6 enzyme activity and nicotine metabolic rate with smoking cessation as well as response to nicotine replacement therapies and bupropion. Prospective clinical trials to identify associations of genetic variants and gene-gene interactions on smoking cessation are needed to generate the evidence base for both medication development and targeted therapy approaches based on genotype.
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Affiliation(s)
- Allison B. Gold
- Center for Interdisciplinary Research on Nicotine Addiction, University of Pennsylvania, 3535 Market Street, Suite 4100, Philadelphia, PA 19104, USA
| | - Caryn Lerman
- Center for Interdisciplinary Research on Nicotine Addiction, University of Pennsylvania, 3535 Market Street, Suite 4100, Philadelphia, PA 19104, USA
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20
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Blood-borne angiotensin II acts in the brain to influence behavioral and endocrine responses to psychogenic stress. J Neurosci 2011; 31:15009-15. [PMID: 22016534 DOI: 10.1523/jneurosci.0892-11.2011] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This study elucidates the neural circuits by which circulating angiotensin II (ANGII) acts in the brain to influence humoral and behavioral responses to psychological stressors. To test the hypothesis that systemic ANGII mediates stress responding via the subfornical organ (SFO), we first found that the timing of increased systemic ANGII in response to 60 min restraint coincides with increased c-fos mRNA expression in the SFO. Next, we administered an anterograde neuronal tract tracer into the SFO and found that fibers originating there make appositions onto neurons in the paraventricular nucleus of the hypothalamus that are also c-fos positive following restraint stress. To determine whether circulating ANGII stimulates the release of stress hormones via activation of angiotensin type 1 receptors (AT1R) within the SFO, we delivered lentivirus to knockdown AT1R expression locally in the SFO. Inhibition of AT1R specifically within the SFO blunted the release of adrenocorticotrophin-releasing hormone and corticosterone in response to restraint stress and caused rats to spend more time in the open arms of an elevated-plus maze than controls, indicating that inhibition of AT1R within the SFO is anxiolytic. Collectively, these results suggest that circulating ANGII acts on AT1R in the SFO to influence responding to psychological stressors.
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21
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Hwa LS, Chu A, Levinson SA, Kayyali TM, DeBold JF, Miczek KA. Persistent escalation of alcohol drinking in C57BL/6J mice with intermittent access to 20% ethanol. Alcohol Clin Exp Res 2011; 35:1938-47. [PMID: 21631540 DOI: 10.1111/j.1530-0277.2011.01545.x] [Citation(s) in RCA: 232] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Intermittent access (IA) to drugs of abuse, as opposed to continuous access, is hypothesized to induce a kindling-type transition from moderate to escalated use, leading to dependence. Intermittent 24-hour cycles of ethanol access and deprivation can generate high levels of voluntary ethanol drinking in rats. METHODS The current study uses C57BL/6J mice (B6) in an IA to 20% ethanol protocol to escalate ethanol drinking levels. Adult male and female B6 mice were given IA to 20% ethanol on alternating days of the week with water available ad libitum. Ethanol consumption during the initial 2 hours of access was compared with a short-term, limited access "binge" drinking procedure, similar to drinking-in-the-dark (DID). B6 mice were also assessed for ethanol dependence with handling-induced convulsion, a reliable measure of withdrawal severity. RESULTS After 3 weeks, male mice given IA to ethanol achieved high stable levels of ethanol drinking in excess of 20 g/kg/24 h, reaching above 100 mg/dl blood ethanol concentrations, and showed a significantly higher ethanol preference than mice given continuous access to ethanol. Also, mice given IA drank about twice as much as DID mice in the initial 2-hour access period. B6 mice that underwent the IA protocol for longer periods of time displayed more severe signs of alcohol withdrawal. Additionally, female B6 mice were given IA to ethanol and drank significantly more than males (ca. 30 g/kg/24 h). DISCUSSION The IA method in B6 mice is advantageous because it induces escalated, voluntary, and preferential per os ethanol intake, behavior that may mimic a cardinal feature of human alcohol dependence, though the exact nature and site of ethanol acting in the brain and blood as a result of IA has yet to be determined.
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Affiliation(s)
- Lara S Hwa
- Psychology Department, Tufts University, Medford, Massachusetts 02155, USA.
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22
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Criado JR, Liu T, Ehlers CL, Mathé AA. Prolonged chronic ethanol exposure alters neuropeptide Y and corticotropin-releasing factor levels in the brain of adult Wistar rats. Pharmacol Biochem Behav 2011; 99:104-11. [PMID: 21527271 DOI: 10.1016/j.pbb.2011.04.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 04/06/2011] [Accepted: 04/09/2011] [Indexed: 12/26/2022]
Abstract
There is evidence to suggest that alterations in neuropeptide Y (NPY) and corticotropin-releasing factor (CRF) contribute to the escalated voluntary ethanol intake seen following long term chronic ethanol exposure. The present study assessed whether the duration of chronic ethanol exposure and abstinence alters brain levels of NPY and CRF in adult Wistar rats. NPY-like immunoreactivity (NPY-LI) and CRF-LI were determined in the amygdala (AMYG), frontal cortex (FCTX), hippocampus (HPC) and parietal cortex (PCTX) of adult Wistar rats after chronic ethanol exposure, and 24-h and 2-weeks following withdrawal (WD). Chronic ethanol exposure consisted of either a 2-week or an 8-week ethanol vapor regimen. No change in brain levels of NPY-LI, CRF-LI and the NPY-LI/CRF-LI ratio was observed 2-weeks following ethanol exposure, whereas, 8-weeks of ethanol exposure produced a significant effect on NPY-LI expression in the AMYG and FCTX. Moreover, an 8-week ethanol vapor regimen significantly increased CRF-LI levels in the HPC and PCTX. Findings from the present study suggest that a longer duration of ethanol vapor, similar to what is required to enhance voluntary drinking, is required to produce changes in NPY-LI and CRF-LI expression in the adult rat brain.
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Affiliation(s)
- José R Criado
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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23
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Hasan TF, Hasan H. Anorexia nervosa: a unified neurological perspective. Int J Med Sci 2011; 8:679-703. [PMID: 22135615 PMCID: PMC3204438 DOI: 10.7150/ijms.8.679] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Accepted: 09/19/2011] [Indexed: 12/20/2022] Open
Abstract
The roles of corticotrophin-releasing factor (CRF), opioid peptides, leptin and ghrelin in anorexia nervosa (AN) were discussed in this paper. CRF is the key mediator of the hypothalamo-pituitary-adrenal (HPA) axis and also acts at various other parts of the brain, such as the limbic system and the peripheral nervous system. CRF action is mediated through the CRF1 and CRF2 receptors, with both HPA axis-dependent and HPA axis-independent actions, where the latter shows nil involvement of the autonomic nervous system. CRF1 receptors mediate both the HPA axis-dependent and independent pathways through CRF, while the CRF2 receptors exclusively mediate the HPA axis-independent pathways through urocortin. Opioid peptides are involved in the adaptation and regulation of energy intake and utilization through reward-related behavior. Opioids play a role in the addictive component of AN, as described by the "auto-addiction opioids theory". Their interactions have demonstrated the psychological aspect of AN and have shown to prevent the functioning of the physiological homeostasis. Important opioids involved are β-lipotropin, β-endorphin and dynorphin, which interact with both µ and κ opioids receptors to regulate reward-mediated behavior and describe the higher incidence of AN seen in females. Moreover, ghrelin is known as the "hunger" hormone and helps stimulate growth hormone (GH) and hepatic insulin-like-growth-factor-1(IGF-1), maintaining anabolism and preserving a lean body mass. In AN, high levels of GH due to GH resistance along with low levels of IGF-1 are observed. Leptin plays a role in suppressing appetite through the inhibition of neuropeptide Y gene. Moreover, the CRF, opioid, leptin and ghrelin mechanisms operate collectively at the HPA axis and express the physiological and psychological components of AN. Fear conditioning is an intricate learning process occurring at the level of the hippocampus, amygdala, lateral septum and the dorsal raphe by involving three distinct pathways, the HPA axis-independent pathway, hypercortisolemia and ghrelin. Opioids mediate CRF through noradrenergic stimulation in association with the locus coeruleus. Furthermore, CRF's inhibitory effect on gonadotropin releasing hormone can be further explained by the direct relationship seen between CRF and opioids. Low levels of gonadotropin have been demonstrated in AN where only estrogen has shown to mediate energy intake. In addition, estrogen is involved in regulating µ receptor concentrations, but in turn both CRF and opioids regulate estrogen. Moreover, opioids and leptin are both an effect of AN, while many studies have demonstrated a causal relationship between CRF and anorexic behavior. Moreover, leptin, estrogen and ghrelin play a role as predictors of survival in starvation. Since both leptin and estrogen are associated with higher levels of bone marrow fat they represent a longer survival than those who favor the ghrelin pathway. Future studies should consider cohort studies involving prepubertal males and females with high CRF. This would help prevent the extrapolation of results from studies on mice and draw more meaningful conclusions in humans. Studies should also consider these mechanisms in post-AN patients, as well as look into what predisposes certain individuals to develop AN. Finally, due to its complex pathogenesis the treatment of AN should focus on both the pharmacological and behavioral perspectives.
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The role of the dynorphin-kappa opioid system in the reinforcing effects of drugs of abuse. Psychopharmacology (Berl) 2010; 210:121-35. [PMID: 20352414 PMCID: PMC2879894 DOI: 10.1007/s00213-010-1825-8] [Citation(s) in RCA: 297] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 03/06/2010] [Indexed: 10/19/2022]
Abstract
BACKGROUND Initial hypotheses regarding the role of the kappa opioid system in drug addiction suggested that kappa receptor stimulation had anti-addictive effects. However, recent research suggests that kappa receptor antagonists may reverse motivational aspects of dependence. In the present review, we revisit the studies that measured the effects of kappa receptor ligands on the reinforcing and rewarding effects of drugs and postulate underlying neurobiological mechanisms for these effects to elaborate a more complex view of the role of kappa receptor ligands in drug addiction. RESULTS The review of studies indicates that kappa receptor stimulation generally antagonizes the acute reinforcing/rewarding effects of drugs whereas kappa receptor blockade has no consistent effect. However, in a drug dependent-like state, kappa receptor blockade was effective in reducing increased drug intake. In animal models of reinstatement, kappa receptor stimulation can induce reinstatement via a stress-like mechanism. Results in conditioned place preference/aversion and intracranial self-stimulation indicate that kappa receptor agonists produce, respectively, aversive-like and dysphoric-like effects. Additionally, preclinical and postmortem studies show that administration or self-administration of cocaine, ethanol, and heroin activate the kappa opioid system. CONCLUSION kappa receptor agonists antagonize the reinforcing/rewarding effects of drugs possibly through punishing/aversive-like effects and reinstate drug seeking through stress-like effects. Evidence suggests that abused drugs activate the kappa opioid system, which may play a key role in motivational aspects of dependence. Kappa opioid systems may have an important role in driving compulsive drug intake.
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Hammack SE, Guo J, Hazra R, Dabrowska J, Myers KM, Rainnie DG. The response of neurons in the bed nucleus of the stria terminalis to serotonin: implications for anxiety. Prog Neuropsychopharmacol Biol Psychiatry 2009; 33:1309-20. [PMID: 19467288 PMCID: PMC2793530 DOI: 10.1016/j.pnpbp.2009.05.013] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 05/13/2009] [Accepted: 05/14/2009] [Indexed: 11/30/2022]
Abstract
Substantial evidence has suggested that the activity of the bed nucleus of the stria terminalis (BNST) mediates many forms of anxiety-like behavior in human and non-human animals. These data have led many investigators to suggest that abnormal processing within this nucleus may underlie anxiety disorders in humans, and effective anxiety treatments may restore normal BNST functioning. Currently some of the most effective treatments for anxiety disorders are drugs that modulate serotonin (5-HT) systems, and several decades of research have suggested that the activation of 5-HT can modulate anxiety-like behavior. Despite these facts, relatively few studies have examined how activity within the BNST is modulated by 5-HT. Here we review our own investigations using in vitro whole-cell patch-clamp electrophysiological methods on brain sections containing the BNST to determine the response of BNST neurons to exogenous 5-HT application. Our data suggest that the response of BNST neurons to 5-HT is complex, displaying both inhibitory and excitatory components, which are mediated by 5-HT(1A), 5-HT(2A), 5-HT(2C) and 5-HT(7) receptors. Moreover, we have shown that the selective activation of the inhibitory response to 5-HT reduces anxiety-like behavior, and we describe data suggesting that the activation of the excitatory response to 5-HT may be anxiogenic. We propose that in the normal state, the function of 5-HT is to dampen activity within the BNST (and consequent anxiety-like behavior) during exposure to threatening stimuli; however, we suggest that changes in the balance of the function of BNST 5-HT receptor subtypes could alter the response of BNST neurons to favor excitation and produce a pathological state of increased anxiety.
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Affiliation(s)
| | - JiDong Guo
- Departments of Psychiatry and Behavioral Sciences, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | - Rimi Hazra
- Departments of Psychiatry and Behavioral Sciences, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | - Joanna Dabrowska
- Departments of Psychiatry and Behavioral Sciences, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | - Karyn M. Myers
- Department of Psychiatry, Harvard Medical School, McClean Hospital, Boston, MA, USA
| | - Donald G. Rainnie
- Departments of Psychiatry and Behavioral Sciences, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
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26
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Schiml-Webb PA, Miller E, Deak T, Hennessy MB. Alpha-melanocyte-stimulating hormone attenuates behavioral effects of corticotropin-releasing factor in isolated guinea pig pups. Dev Psychobiol 2009; 51:399-407. [PMID: 19492314 DOI: 10.1002/dev.20379] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
During a 3-hr period of social isolation in a novel environment, guinea pig pups exhibit an initial active phase of behavioral responsiveness, characterized primarily by vocalizing, which is then followed by a stage of passive responsiveness in which pups display a distinctive crouch, eye-closing, and extensive piloerection. Prior treatment of pups with alpha-melanocyte-stimulating hormone (alpha-MSH) reduces each of the passive behaviors. The onset of passive responding during separation can be accelerated with peripheral injection of corticotropin-releasing factor (CRF). To examine whether CRF produces its effects through a mechanism similar to that of prolonged separation, we examined the effect of administering alpha-MSH to pups injected with CRF. As expected, CRF markedly enhanced passive responding during a 60-min period of separation. alpha-MSH delivered by either intracerebroventricular infusion or intraperitoneal injection significantly reduced each of the passive behavioral responses without significantly affecting active behavior. These findings, together with previous results indicating that it is the anti-inflammatory property of alpha-MSH that is responsible for its behavioral effects during prolonged separation, suggest that peripheral CRF speeds the induction of passive responding through a mechanism involving enhanced proinflammatory activity.
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Affiliation(s)
- Patricia A Schiml-Webb
- Department of Psychology, Wright State University, 335 Fawcett Hall, Dayton, OH 45435, USA.
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27
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Paulus MP, Potterat EG, Taylor MK, Van Orden KF, Bauman J, Momen N, Padilla GA, Swain JL. A neuroscience approach to optimizing brain resources for human performance in extreme environments. Neurosci Biobehav Rev 2009; 33:1080-8. [PMID: 19447132 DOI: 10.1016/j.neubiorev.2009.05.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 05/05/2009] [Accepted: 05/05/2009] [Indexed: 11/18/2022]
Abstract
Extreme environments requiring optimal cognitive and behavioral performance occur in a wide variety of situations ranging from complex combat operations to elite athletic competitions. Although a large literature characterizes psychological and other aspects of individual differences in performances in extreme environments, virtually nothing is known about the underlying neural basis for these differences. This review summarizes the cognitive, emotional, and behavioral consequences of exposure to extreme environments, discusses predictors of performance, and builds a case for the use of neuroscience approaches to quantify and understand optimal cognitive and behavioral performance. Extreme environments are defined as an external context that exposes individuals to demanding psychological and/or physical conditions, and which may have profound effects on cognitive and behavioral performance. Examples of these types of environments include combat situations, Olympic-level competition, and expeditions in extreme cold, at high altitudes, or in space. Optimal performance is defined as the degree to which individuals achieve a desired outcome when completing goal-oriented tasks. It is hypothesized that individual variability with respect to optimal performance in extreme environments depends on a well "contextualized" internal body state that is associated with an appropriate potential to act. This hypothesis can be translated into an experimental approach that may be useful for quantifying the degree to which individuals are particularly suited to performing optimally in demanding environments.
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28
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Greenwell TN, Funk CK, Cottone P, Richardson HN, Chen SA, Rice KC, Zorrilla EP, Koob GF. Corticotropin-releasing factor-1 receptor antagonists decrease heroin self-administration in long- but not short-access rats. Addict Biol 2009; 14:130-43. [PMID: 19291009 DOI: 10.1111/j.1369-1600.2008.00142.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Dysregulation of the stress-related corticotropin-releasing factor (CRF) system has been implicated in the development of drug dependence. The present study examined the effects of administering CRF type 1 (CRF(1)) receptor antagonists on heroin self-administration in animals allowed short (1 hour) or long (8-12 hours) access to intravenous heroin self-administration sessions. The nonpeptide CRF(1) antagonists MJL-1-109-2 (1 hour versus 8 hours access) or R121919 (1 hour versus 12 hours access) were systemically injected in both short- and long-access rats. MJL-1-109-2 (10 mg/kg) and R121919 (10 and 20 mg/kg) reduced heroin self-administration in long-access animals without altering heroin intake in short-access animals. Both MJL-1-109-2 and R121919 decreased first-hour intravenous heroin self-administration selectively in long-access rats, with R121919 decreasing cumulative heroin intake across the 12-hour session. The results demonstrate that blockade of the CRF-CRF(1) receptor system attenuates the increased heroin intake of rats with extended access to the drug.
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Affiliation(s)
- Thomas N Greenwell
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, USA
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29
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Jackson KJ, Damaj MI. L-type calcium channels and calcium/calmodulin-dependent kinase II differentially mediate behaviors associated with nicotine withdrawal in mice. J Pharmacol Exp Ther 2009; 330:152-61. [PMID: 19336664 DOI: 10.1124/jpet.109.151530] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Smoking is a widespread health problem. Because the nicotine withdrawal syndrome is a major contributor to continued smoking and relapse, it is important to understand the molecular and behavioral mechanisms of nicotine withdrawal to generate more effective smoking cessation therapies. Studies suggest a role for calcium-dependent mechanisms, such as L-type calcium channels and calcium/calmodulin-dependent protein kinase II (CaMKII), in the effects of nicotine dependence; however, the role of these mechanisms in nicotine-mediated behaviors is unclear. Thus, the goal of this study was to elucidate the role of L-type calcium channels and CaMKII in nicotine withdrawal behaviors. Using both pharmacological and genetic methods, our results show that L-type calcium channels are involved in physical, but not affective, nicotine withdrawal behaviors. Although our data do provide evidence of a role for CaMKII in nicotine withdrawal behaviors, our pharmacological and genetic assessments yielded different results concerning the specific role of the kinase. Pharmacological data suggest that CaMKII is involved in somatic signs and affective nicotine withdrawal, and activity level is decreased after nicotine withdrawal, whereas the genetic assessments yielded results suggesting that CaMKII is involved only in the anxiety-related response, yet the kinase activity may be increased after nicotine withdrawal; thus, future studies are necessary to clarify the precise behavioral specifics of the relevance of CaMKII in nicotine withdrawal behaviors. Overall, our data show that L-type calcium channels and CaMKII are relevant in nicotine withdrawal and differentially mediate nicotine withdrawal behaviors.
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Affiliation(s)
- K J Jackson
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Box 980613, Richmond, VA 23298-0613, USA.
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30
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Lee S, Choi I, Kang S, Rivier C. Role of various neurotransmitters in mediating the long-term endocrine consequences of prenatal alcohol exposure. Ann N Y Acad Sci 2009; 1144:176-88. [PMID: 19076376 DOI: 10.1196/annals.1418.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Adult rats and mice born to dams exposed to alcohol (fetal alcohol-exposed [FAE]) exhibit enhanced activity of their hypothalamic-pituitary-adrenal (HPA) axis when exposed to stressors. However, the mechanisms responsible for this phenomenon remain incompletely understood. Here two possibilities are reviewed: one that pertains to nitric oxide (NO), an unstable gas that stimulates the HPA axis; and one that focuses on catecholamines, which also stimulate this axis. Significant alterations were not observed in levels of NO synthase, the enzyme responsible for NO formation, in the paraventricula nucleus (PVN) of FAE rats. However, the stimulatory influence of this gas on the hypothalamic-pituitary-adrenal (HPA) axis was enhanced in these animals, thereby providing a mechanism likely to participate in the neuroendocrine hyperactivity that is the hallmark of this model. It was also recently shown that, while the ability of catecholamines to release adrenocorticotropic hormone (ACTH) was comparable in control rats and rats exposed to alcohol during embryonic development, there was a significant upregulation of the C1 brain-stem region when these latter animals were exposed to mild footshocks. Since this region sends prominent projections to the PVN, its increased activity may participate in the HPA axis hyperactivity observed in FAE offspring. Finally, microarray technology was used to search for potential differences in genes present in the brains of control and FAE mice. When these brains were collected on day 17.5 of embryonic development, several genes were upregulated, while others were downregulated, which may provide potential new candidates that mediate the influence of prenatal alcohol on the HPA axis of adult offspring.
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Affiliation(s)
- Soon Lee
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, La Jolla, CA 92037, USA
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31
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Jackson KJ, Kota DH, Martin BR, Damaj MI. The role of various nicotinic receptor subunits and factors influencing nicotine conditioned place aversion. Neuropharmacology 2009; 56:970-4. [PMID: 19371584 DOI: 10.1016/j.neuropharm.2009.01.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 01/26/2009] [Accepted: 01/28/2009] [Indexed: 11/16/2022]
Abstract
Affective nicotine withdrawal symptoms are of major motivational significance in contributing to relapse and continued tobacco use; thus, it is important to understand the molecular and receptor-mediated mechanisms that mediate affective withdrawal behaviors. Previous work using the conditioned place aversion (CPA) model has shown that nicotine withdrawal is associated with a negative affective state, and place aversion to previously neutral environmental stimuli represents a motivational component in the maintenance of drug use. Thus, the purpose of this study was to evaluate the role of genotype, sex, and age and to extend previous studies examining the role of various nicotinic receptor subtypes in the development of nicotine withdrawal aversion using the CPA model. Mice were chronically treated with nicotine and conditioned for two days with various nicotinic receptor antagonists. The major findings showed that mecamylamine and dihydro-beta-erythroidine (DHbetaE), but not hexamethonium or methyllycaconitine citrate (MLA), precipitated significant aversion in the CPA model. This pharmacological data support our previous knockout mouse data suggesting that nicotine CPA is mediated by central beta2-containing nicotinic receptors, but not alpha7 nicotinic receptors. Further, we show that sex and age are contributing factors to the development of nicotine CPA. Overall, the results of our study provide some insight into pharmacological and behavioral factors involved in the development of an aversive motivational component associated with nicotine withdrawal.
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Affiliation(s)
- K J Jackson
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 410 N. 12th Street, P.O. Box 980613, Richmond, VA 23298, USA.
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32
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Keen-Rhinehart E, Michopoulos V, Toufexis DJ, Martin EI, Nair H, Ressler KJ, Davis M, Owens MJ, Nemeroff CB, Wilson ME. Continuous expression of corticotropin-releasing factor in the central nucleus of the amygdala emulates the dysregulation of the stress and reproductive axes. Mol Psychiatry 2009; 14:37-50. [PMID: 18698320 PMCID: PMC2652696 DOI: 10.1038/mp.2008.91] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
An increase in corticotropin-releasing factor (CRF) is a putative factor in the pathophysiology of stress-related disorders. As CRF expression in the central nucleus of the amygdala (CeA) is important in adaptation to chronic stress, we hypothesized that unrestrained synthesis of CRF in CeA would mimic the consequences of chronic stress exposure and cause dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, increase emotionality and disrupt reproduction. To test this hypothesis, we used a lentiviral vector to increase CRF-expression site specifically in CeA of female rats. Increased synthesis of CRF in CeA amplified CRF and arginine vasopressin peptide concentration in the paraventricular nucleus of the hypothalamus, and decreased glucocorticoid negative feedback, both markers associated with the pathophysiology of depression. In addition, continuous expression of CRF in CeA also increased the acoustic startle response and depressive-like behavior in the forced swim test. Protein levels of gonadotropin-releasing hormone in the medial preoptic area were significantly reduced by continuous expression of CRF in CeA and this was associated with a lengthening of estrous cycles. Finally, sexual motivation but not sexual receptivity was significantly attenuated by continuous CRF synthesis in ovariectomized estradiol-progesterone-primed females. These data indicate that unrestrained CRF synthesis in CeA produces a dysregulation of the HPA axis, as well as many of the behavioral, physiological and reproductive consequences associated with stress-related disorders.Molecular Psychiatry (2009) 14, 37-50; doi:10.1038/mp.2008.91; published online 12 August 2008.
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Affiliation(s)
- E Keen-Rhinehart
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA,Center for Behavioral Neuroscience, Emory University, Atlanta, GA, USA
| | - V Michopoulos
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA,Center for Behavioral Neuroscience, Emory University, Atlanta, GA, USA
| | - DJ Toufexis
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA,Center for Behavioral Neuroscience, Emory University, Atlanta, GA, USA,School of Medicine, Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
| | - EI Martin
- School of Medicine, Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
| | - H Nair
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA,Center for Behavioral Neuroscience, Emory University, Atlanta, GA, USA
| | - KJ Ressler
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA,Center for Behavioral Neuroscience, Emory University, Atlanta, GA, USA,School of Medicine, Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
| | - M Davis
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA,Center for Behavioral Neuroscience, Emory University, Atlanta, GA, USA,School of Medicine, Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
| | - MJ Owens
- School of Medicine, Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
| | - CB Nemeroff
- School of Medicine, Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
| | - ME Wilson
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA,Center for Behavioral Neuroscience, Emory University, Atlanta, GA, USA
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33
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Long-term behavioral consequences of prenatal MDMA exposure. Physiol Behav 2008; 96:593-601. [PMID: 19162054 DOI: 10.1016/j.physbeh.2008.12.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 12/15/2008] [Accepted: 12/17/2008] [Indexed: 11/24/2022]
Abstract
The current study sought to determine whether prenatal 3,4-methylenedioxy-N-methamphetamine (MDMA) exposure from E14-20 in the rat resulted in behavioral sequelae in adult offspring. Prenatal MDMA exposure results in increased dopaminergic fiber density in the prefrontal cortex, striatum and nucleus accumbens of young rats. Since these areas are critical in response to novelty, reward, attention and locomotor activity, we hypothesized that prenatal MDMA exposure would produce significant changes in the performance of tasks that examine such behaviors in adult rats. Adult rats prenatally exposed to MDMA exhibited greater activity and spent more time in the center during a novel open field test as compared to controls. This increased activity was not reflected in normal home cage activity. Prenatal exposure to MDMA did not affect feeding or food reward. It did not alter cocaine self-administration behaviors, nor did it have an effect on the locomotor response to amphetamine challenge. Finally, while prenatal MDMA did not affect performance in the radial arm maze or the Morris water maze (MWM), these animals demonstrated altered performance in a cued MWM paradigm. Prenatal MDMA exposure resulted in perseverative attendance to a hanging cue when the platform in the MWM was removed as compared to controls. Together, these data demonstrate that prenatal exposure to MDMA results in a behavioral phenotype in adult rats characterized by reduced anxiety, a heightened response to novelty, and "hyperattentiveness" to environmental cues during spatial learning.
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Sparta DR, Ferraro FM, Fee JR, Knapp DJ, Breese GR, Thiele TE. The alcohol deprivation effect in C57BL/6J mice is observed using operant self-administration procedures and is modulated by CRF-1 receptor signaling. Alcohol Clin Exp Res 2008; 33:31-42. [PMID: 18945225 DOI: 10.1111/j.1530-0277.2008.00808.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The alcohol deprivation effect (ADE) is characterized by transient excessive alcohol consumption upon reinstatement of ethanol following a period of ethanol deprivation. While this phenomenon has been observed in rats using both bottle drinking (consummatory behavior) and operant self-administration (consummatory and appetitive "ethanol-seeking" behavior) procedures, ADE studies in mice have primarily relied on bottle drinking measures. Furthermore, the neurochemical pathways that modulate the ADE are not well understood. Therefore, we determined whether the ADE can be observed in C57BL/6J mice using operant self-administration procedures and if expression of the ADE is modulated by the corticotropin releasing factor-1 (CRF-1) receptor. METHODS C57BL/6J mice were trained in a 2-hour operant self-administration paradigm to lever press for 10% ethanol or water on separate response keys. Between operant sessions, mice had access to ethanol in their homecage. Once stable responding occurred, mice were deprived of ethanol for 4 days and were then retested with ethanol in the operant paradigm for 3 consecutive days. Next, to assess the role of the CRF-1 receptor, mice were given intraperitoneal (i.p.) injection (0, 10, or 20 mg/kg) of the CRF-1 receptor antagonist CP-154,526 30 minutes before ADE testing. Additional experiments assessed (i) ADE responding in which the alternate response lever was inactive, (ii) the effects of CP-154,526 on self-administration of a 1% sucrose solution following 4 days of deprivation, and (iii) ADE responding in which mice did not received i.p. injections throughout the experiment. RESULTS Mice exhibited a significant increase in postdeprivation lever responding for ethanol with either a water reinforced or inactive alternate lever. Interestingly, i.p. injection of a 10 mg/kg dose of CP-154,526 protected against the ADE while not affecting lever responding for a sucrose solution. Finally, baseline and deprivation-induced increases of ethanol reinforced lever responding were greater in mice not given i.p. injections. CONCLUSIONS The ADE in C57BL/6J mice can be modeled using the operant self-administration paradigm and increased ethanol self-administration associated with the ADE is modulated by CRF-1 receptor signaling.
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Affiliation(s)
- Dennis R Sparta
- Department of Psychology, University of North Carolina, Chapel Hill, NC 27599-3270, USA
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35
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Lastein S, Höglund E, Overli O, Døving KB. Effects of antalarmin, a CRF receptor 1 antagonist, on fright reaction and endocrine stress response in crucian carp (Carassius carassius). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2008; 194:1007-12. [PMID: 18830607 DOI: 10.1007/s00359-008-0372-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 09/04/2008] [Accepted: 09/05/2008] [Indexed: 11/24/2022]
Abstract
The corticotrophin-releasing factor (CRF) receptors show striking homogeneity throughout the vertebrate subphylum. In mammals, the CRF(1) receptor (CRFR(1)) plays an important role in mediating behavioral and endocrine responses to fear and stress. The specific roles of this receptor subtype in fear and stress reactions in non-mammalian vertebrates are largely unknown. Crucian carp displays the olfactory-mediated fright reaction, a stereotypic behavioral response to waterborne cues from damaged skin of conspecifics. This reaction shows several similarities to basic components of avoidance behavior in mammals. In the present study, we applied the non-peptide CRFR(1) antagonist, antalarmin, to crucian carp 1 h before exposure to conspecific skin extract. This treatment resulted in a suppression of the fright reaction. After skin extract exposure, antalarmin treatment also lead to lower plasma cortisol values, as compared to vehicle treatment. This suppression of the behavioral fright reaction and the stress induced rise in plasma cortisol in crucian carp suggests that the functions of the CRFR(1) are conserved by evolution.
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Affiliation(s)
- Stine Lastein
- Department of Molecular Biosciences, University of Oslo, Blindern, 0316, Oslo, Norway
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36
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Jackson KJ, Martin BR, Changeux JP, Damaj MI. Differential role of nicotinic acetylcholine receptor subunits in physical and affective nicotine withdrawal signs. J Pharmacol Exp Ther 2008; 325:302-12. [PMID: 18184829 DOI: 10.1124/jpet.107.132977] [Citation(s) in RCA: 168] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It has been suggested that the negative effects associated with nicotine withdrawal promote continued tobacco use and contribute to the high relapse rate of smoking behaviors. Thus, it is important to understand the receptor-mediated mechanisms underlying nicotine withdrawal to aid in the development of more successful smoking cessation therapies. The effects of nicotine withdrawal are mediated through nicotinic acetylcholine receptors (nAChRs); however, the role of nAChRs in nicotine withdrawal remains unclear. Therefore, we used mecamylamine-precipitated, spontaneous, and conditioned place aversion (CPA) withdrawal models to measure physical and affective signs of nicotine withdrawal in various nAChR knockout (KO) mice. beta2, alpha7, and alpha5 nAChR KO mice were chronically exposed to nicotine through surgically implanted osmotic minipumps. Our results show a loss of anxiety-related behavior and a loss of aversion in the CPA model in beta2 KO mice, whereas alpha7 and alpha5 KO mice displayed a loss of nicotine withdrawal-induced hyperalgesia and a reduction in somatic signs, respectively. These results suggest that beta2-containing nAChRs are involved in the affective signs of nicotine withdrawal, whereas non-beta2-containing nAChRs are more closely associated with physical signs of nicotine withdrawal; thus, the nAChR subtype composition may play an important role in the involvement of specific subtypes in nicotine withdrawal.
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Affiliation(s)
- K J Jackson
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Box 980613, Richmond, VA 23298-0613, USA
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37
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Bakshi VP, Newman SM, Smith-Roe S, Jochman KA, Kalin NH. Stimulation of lateral septum CRF2 receptors promotes anorexia and stress-like behaviors: functional homology to CRF1 receptors in basolateral amygdala. J Neurosci 2007; 27:10568-77. [PMID: 17898228 PMCID: PMC6673168 DOI: 10.1523/jneurosci.3044-06.2007] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 08/03/2007] [Accepted: 08/04/2007] [Indexed: 11/21/2022] Open
Abstract
The corticotropin-releasing factor (CRF) system is the primary central mediator of stress-like states, coordinating behavioral, endocrine, and autonomic responses to stress. Although induction of anorexia is a well documented effect of CRF receptor agonist administration, the central sites and behavioral processes underlying this phenomenon are poorly understood. The present studies addressed this question by examining the neuroanatomical, behavioral, and pharmacological mechanisms mediating decreases in feeding produced by the CRF1/CRF2 receptor agonist urocortin. Separate groups of food-restricted male Sprague Dawley rats were given infusions of urocortin (0, 50, 125, 250 ng/0.5 microl) into the lateral septum (LS) and immediately afterward were rated on a wide array of behaviors (locomotion, rearing, grooming, stereotypies) including a microstructural analysis of ingestive behavior. Intra-LS urocortin infusion dose-dependently reduced feeding and drinking while concomitantly increasing grooming, stereotypies, and ethological plus traditional measures of anxiety-like responses in the elevated plus-maze. Urocortin infusion into neighboring sites (lateral ventricle, medial caudate) had no effects. Coinfusion into the LS of the mixed CRF1/CRF2 receptor antagonist D-Phe-CRF(12-41) (0, 100, 1000 ng/0.5 microl) or the novel selective CRF2 receptor antagonist Astressin2B (0, 500, 1000 ng/0.5 microl) blocked urocortin-induced effects, but the CRF1-selective antagonist NBI27914 (0, 500, 1000 ng/0.5 microl) had no effect, although it completely reversed the behavioral sequelae of CRF when infused into the basolateral amygdala. These results indicate that one of the modes through which the CRF system promotes anorexia is the recruitment of stress-like states after stimulation of CRF2 receptors within the LS.
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Affiliation(s)
- Vaishali P Bakshi
- Department of Psychiatry, University of Wisconsin-Madison, Madison, Wisconsin 53719, USA.
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38
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Fee JR, Sparta DR, Picker MJ, Thiele TE. Corticotropin releasing factor-1 receptor antagonist, CP-154,526, blocks the expression of ethanol-induced behavioral sensitization in DBA/2J mice. Neuroscience 2007; 150:14-21. [PMID: 17919825 DOI: 10.1016/j.neuroscience.2007.08.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Revised: 08/01/2007] [Accepted: 09/02/2007] [Indexed: 10/22/2022]
Abstract
RATIONALE Manipulation of glucocorticoid receptor signaling has been shown to alter the acquisition and expression of ethanol-induced locomotor sensitization in mice. It is unknown if other components of the hypothalamic-pituitary-adrenal (HPA)-axis modulate locomotor sensitization resulting from repeated ethanol administration. In the present investigation, we determined if pretreatment with an i.p. injection of CP-154,526, a selective corticotropin releasing factor (CRF) type-1 receptor antagonist, would block the acquisition and/or expression of ethanol-induced locomotor sensitization in male DBA/2J mice. METHODS To assess the role of the CRF1 receptor in the acquisition of behavioral sensitization, mice were pretreated with an i.p. injection of CP-154,526 30 min before each of 10 sensitizing i.p. injections of ethanol. To determine the role of the CRF1 receptor in modulating the expression of ethanol-induced sensitization, mice that had previously been sensitized to the locomotor stimulant effects of ethanol were pretreated with CP-154,526 30 min before an i.p. injection of ethanol on the test day. In a third study, ethanol-naïve mice were pretreated with CP-154,526 30 min before an initial i.p. injection of ethanol to determine the combined effects of the CRF1 receptor antagonist and ethanol on locomotor activity. Blood ethanol concentrations were assessed at the termination of sensitization studies. RESULTS Pretreatment with CP-154,526 blocked the expression of ethanol-induced locomotor sensitization in DBA/2J mice but did not prevent the acquisition of sensitization. The ability of CP-154,526 to block the expression of ethanol-induced locomotor sensitization was not attributable to alterations in blood ethanol levels or possible sedative effects produced by the combined administration of CP-154,526 and ethanol. CONCLUSIONS These data provide novel evidence that CRF1 receptor signaling modulates the expression of ethanol-induced locomotor sensitization, and add to a growing literature suggesting a role for neurochemicals and hormones associated with the HPA-axis in behavioral sensitization resulting from repeated exposure to drugs of abuse.
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Affiliation(s)
- J R Fee
- Department of Psychology, University of North Carolina, Davie Hall, CB# 3270, Chapel Hill, NC 27599-3270, USA
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Kang JE, Cirrito JR, Dong H, Csernansky JG, Holtzman DM. Acute stress increases interstitial fluid amyloid-beta via corticotropin-releasing factor and neuronal activity. Proc Natl Acad Sci U S A 2007; 104:10673-8. [PMID: 17551018 PMCID: PMC1965571 DOI: 10.1073/pnas.0700148104] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Aggregation of the amyloid-beta (Abeta) peptide in the extracellular space of the brain is critical in the pathogenesis of Alzheimer's disease. Abeta is produced by neurons and released into the brain interstitial fluid (ISF), a process regulated by synaptic activity. To determine whether behavioral stressors can regulate ISF Abeta levels, we assessed the effects of chronic and acute stress paradigms in amyloid precursor protein transgenic mice. Isolation stress over 3 months increased Abeta levels by 84%. Similarly, acute restraint stress increased Abeta levels over hours. Exogenous corticotropin-releasing factor (CRF) but not corticosterone mimicked the effects of acute restraint stress. Inhibition of endogenous CRF receptors or neuronal activity blocked the effects of acute stress on Abeta. Thus, behavioral stressors can rapidly increase ISF Abeta through neuronal activity in a CRF-dependent manner, and the results suggest a mechanism by which behavioral stress may affect Alzheimer's disease pathogenesis.
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Affiliation(s)
| | | | | | | | - David M. Holtzman
- Departments of *Neurology
- Molecular Biology and Pharmacology
- Hope Center for Neurological Disorders, and
- Alzheimer's Disease Research Center, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110
- **To whom correspondence should be addressed. E-mail:
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Abstract
Fear is an adaptation to danger, but excessive fear underlies diverse forms of mental anguish and pathology. One neural site linked to a sense of adversity is the amygdala, and one neuropeptide, corticotropin-releasing hormone (CRH), is localized within the central nucleus of the amygdala. Glucocorticoids enhance the production of CRH in this region of the brain, resulting in increased attention to external events and, when sustained for longer periods of times, perhaps contributing to anxious depression.
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Affiliation(s)
- Jay Schulkin
- Department of Physiology and Biophysics, Georgetown University, School of Medicine, Washington, DC, USA.
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41
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Wilmouth CE, Spear LP. Withdrawal from chronic nicotine in adolescent and adult rats. Pharmacol Biochem Behav 2006; 85:648-57. [PMID: 17173961 PMCID: PMC1855282 DOI: 10.1016/j.pbb.2006.10.021] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Revised: 10/30/2006] [Accepted: 10/31/2006] [Indexed: 01/28/2023]
Abstract
The purpose of the present experiment is to assess potential differences in nicotine withdrawal in both adolescent and adult rats. Nicotine dependence was induced via osmotic minipump in adolescent rats (releasing 22.2 mg/kg/day on Postnatal Day 28) and adults (release rate of 18.4 mg/kg/day on Postnatal Day 60); differential initial release rates were used across age to compensate for the more rapid weight gain of adolescents. On Day 7 of nicotine exposure, withdrawal was induced via the administration of a nicotinic antagonist, mecamylamine (1.0 mg/kg i.p.), and withdrawal-induced anxiogenesis assessed on the elevated plus maze. On Days 1 and 4 after pump removal, animals were examined for startle responses and prepulse inhibition in an acoustic startle chamber. Adult animals exhibited a nicotine withdrawal-induced increase in anxiety, while adolescents did not. One day following the removal of minipumps, only nicotine dependent adolescent animals exhibited a disruption in prepulse inhibition. Nicotine withdrawal failed to produce an alteration in acoustic startle response in either group. Together these data suggest that ontogenic differences in nicotine withdrawal are dependent on the withdrawal measure examined, with adolescents being less sensitive than adults to anxiety-like symptoms, while being more sensitive to withdrawal-induced cognitive disruption.
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Affiliation(s)
- Carrie E Wilmouth
- Center for Developmental Psychobiology, Department of Psychology, Binghamton University, Binghamton, New York 13902-6000, USA
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42
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Schramm-Sapyta NL, Morris RW, Kuhn CM. Adolescent rats are protected from the conditioned aversive properties of cocaine and lithium chloride. Pharmacol Biochem Behav 2006; 84:344-52. [PMID: 16815539 PMCID: PMC3836192 DOI: 10.1016/j.pbb.2006.05.026] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Revised: 05/22/2006] [Accepted: 05/31/2006] [Indexed: 12/12/2022]
Abstract
In humans, most drug use is initiated during adolescence and adolescent users are more likely to become drug-dependent than adult users. Repeated, high levels of use are required for the transition from use to addiction. Individual levels of drug use are thought to result from a balance between the pleasant or rewarding and the unpleasant or aversive properties of the drug. Repeated high levels of drug use are required for the transition from drug use to dependence. We hypothesized that diminished aversive effects of drugs of abuse during adolescence might be one reason for higher rates of use and addiction during this phase. We therefore tested adolescent and adult CD rats in single-dose cocaine conditioned taste aversion (CTA) at a range of doses (10-40 mg/kg), and examined whether various behavioral markers of addiction vulnerability were correlated to outcome in cocaine CTA. We found that adolescents are indeed less susceptible to cocaine CTA. In fact, age was the predominant predictor of CTA outcome, predominating over measures of novelty-seeking, anxiety, and stress hormone levels, which are all known to be related to drug intake in other models. Furthermore, we found that adolescent rats are also less susceptible to conditioned taste aversion to a low dose of a non-addictive substance, lithium chloride. These results suggest that one explanation for elevated drug use and addiction among adolescents is reduced aversive or use-limiting effects of the drugs. This contributes to our understanding of why adolescence is a particularly vulnerable period for development of drug abuse.
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Affiliation(s)
| | | | - Cynthia M. Kuhn
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, USA
- Corresponding author. Room 100B, Research Park Bldg 2, Duke University Medical Center, PO Box 3813, Durham, NC 27710, USA. Tel.: +1 919 684 8828; fax: +1 919 681 8609
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43
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Fenoglio KA, Brunson KL, Baram TZ. Hippocampal neuroplasticity induced by early-life stress: functional and molecular aspects. Front Neuroendocrinol 2006; 27:180-92. [PMID: 16603235 PMCID: PMC2937188 DOI: 10.1016/j.yfrne.2006.02.001] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2005] [Revised: 02/11/2006] [Accepted: 02/13/2006] [Indexed: 12/16/2022]
Abstract
Whereas genetic factors contribute crucially to brain function, early-life events, including stress, exert long-lasting influence on neuronal function. Here, we focus on the hippocampus as the target of these early-life events because of its crucial role in learning and memory. Using a novel immature-rodent model, we describe the deleterious consequences of chronic early-life 'psychological' stress on hippocampus-dependent cognitive tasks. We review the cellular mechanisms involved and discuss the roles of stress-mediating molecules, including corticotropin releasing hormone, in the process by which stress impacts the structure and function of hippocampal neurons.
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Affiliation(s)
- Kristina A. Fenoglio
- Department of Anatomy/Neurobiology, University of California at Irvine, Irvine, CA 92697-4475, USA
| | - Kristen L. Brunson
- Department of Anatomy/Neurobiology, University of California at Irvine, Irvine, CA 92697-4475, USA
| | - Tallie Z. Baram
- Department of Anatomy/Neurobiology, University of California at Irvine, Irvine, CA 92697-4475, USA
- Department of Pediatrics, University of California at Irvine, Irvine, CA 92697-4475, USA
- Corresponding author. Fax: +1 949 824 1106. (T.Z. Baram)
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Kamprath K, Marsicano G, Tang J, Monory K, Bisogno T, Marzo VD, Lutz B, Wotjak CT. Cannabinoid CB1 receptor mediates fear extinction via habituation-like processes. J Neurosci 2006; 26:6677-86. [PMID: 16793875 PMCID: PMC6673838 DOI: 10.1523/jneurosci.0153-06.2006] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 04/05/2006] [Accepted: 04/25/2006] [Indexed: 11/21/2022] Open
Abstract
The interplay between fear expression and fear extinction provides an important prerequisite for adequate coping with aversive encounters. Current models propose that extinction of conditioned fear is mediated by associative safety learning. Here, we demonstrate that the cannabinoid CB1 receptor, which is crucially involved in fear extinction, is dispensable for associative safety learning. In fact, our results indicate that CB1 mediates fear extinction primarily via habituation-like processes. CB1 null-mutant mice were severely impaired not only in extinction of the fear response to a tone after fear conditioning but also in habituation of the fear response to a tone after sensitization with an inescapable footshock. Surprisingly, long-term habituation was generally affected even in situations with proper short-term adaptation, suggesting the existence of two separated CB1-dependent effector systems for short- and long-term fear adaptation. Our findings underscore the importance of habituation as a determinant of fear extinction in mice and characterize the cannabinoid CB1 receptor as an essential molecular correlate of this process.
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MESH Headings
- Acoustic Stimulation/methods
- Adaptation, Physiological/genetics
- Animals
- Behavior, Animal
- Conditioning, Psychological
- Evoked Potentials, Auditory/genetics
- Evoked Potentials, Auditory/physiology
- Extinction, Psychological/physiology
- Fear
- Habituation, Psychophysiologic/genetics
- Habituation, Psychophysiologic/physiology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Receptor, Cannabinoid, CB1/deficiency
- Receptor, Cannabinoid, CB1/physiology
- Time Factors
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Swain MG. Fatigue in liver disease: pathophysiology and clinical management. CANADIAN JOURNAL OF GASTROENTEROLOGY = JOURNAL CANADIEN DE GASTROENTEROLOGIE 2006; 20:181-8. [PMID: 16550262 PMCID: PMC2582971 DOI: 10.1155/2006/624832] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Accepted: 10/12/2005] [Indexed: 11/18/2022]
Abstract
Fatigue is the most commonly encountered symptom in patients with liver disease, and it has a significant impact on their quality of life. However, although some progress has been made with regard to the understanding of the processes which may generate fatigue in general, the underlying cause(s) of liver disease-associated fatigue remain incompletely understood. The present review describes recent advances which have been made in our ability to measure fatigue in patients with liver disease in the clinical setting, as well as in our understanding of potential pathways which are likely important in the pathogenesis of fatigue associated with liver disease. Specifically, experimental findings suggest that fatigue associated with liver disease likely occurs as a result of changes in neurotransmission within the brain. In conclusion, a reasonable approach to help guide in the management of the fatigued patient with liver disease is presented.
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Affiliation(s)
- Mark G Swain
- University of Calgary, Liver Unit, Health Sciences Centre, Alberta.
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46
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Amat J, Tamblyn JP, Paul ED, Bland ST, Amat P, Foster AC, Watkins LR, Maier SF. Microinjection of urocortin 2 into the dorsal raphe nucleus activates serotonergic neurons and increases extracellular serotonin in the basolateral amygdala. Neuroscience 2005; 129:509-19. [PMID: 15541873 DOI: 10.1016/j.neuroscience.2004.07.052] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/25/2004] [Indexed: 10/26/2022]
Abstract
The intra dorsal raphe nucleus (DRN) administration of corticotropin releasing hormone (CRF) inhibits serotonergic (5-HT) activity in this structure, an effect blocked by antagonists selective for the type 1 CRF receptor (CRF1). The DRN has a high density of the type 2 receptor (CRF2), and so the present experiments explored the impact of CRF2 activation within the DRN on 5-HT function. The intra-DRN administration of the selective CRF2 agonist urocortin 2 (Ucn 2) dose dependently increased 5-HT efflux in the basolateral amygdala, a projection region of the DRN. Intra-DRN Ucn 2 also increased c-fos expression in labeled 5-HT neurons. Both of these effects of Ucn 2 were completely blocked by intra-DRN antisauvagine-30 (ASV-30), a relatively selective CRF2 antagonist. These data suggest that CRF1 and CRF2 activation within the DRN affect 5-HT neurons in opponent fashion. Implications of these results for understanding the behavioral effects of CRF and other CRF-like ligands are discussed.
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Affiliation(s)
- J Amat
- Department of Psychology and Center for Neuroscience, University of Colorado at Boulder, Boulder, CO 80309-0345, USA.
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47
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Kawaguchi M, Scott KA, Moran TH, Bi S. Dorsomedial hypothalamic corticotropin-releasing factor mediation of exercise-induced anorexia. Am J Physiol Regul Integr Comp Physiol 2005; 288:R1800-5. [PMID: 15677523 DOI: 10.1152/ajpregu.00805.2004] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Running wheel access and resulting voluntary exercise alter food intake and reduce body weight. The neural mechanisms underlying these effects are unclear. In this study, we first assessed the effects of 7 days of running wheel access on food intake, body weight, and hypothalamic gene expression. We demonstrate that running wheel access significantly decreases food intake and body weight and results in a significant elevation of CRF mRNA expression in the dorsomedial hypothalamus (DMH) but not the paraventricular nucleus. Seven-day running wheel access also results in elevated arcuate nucleus and DMH neuropeptide Y gene expression. To assess a potential role for elevated DMH CRF activity in the activity-induced changes in food intake and body weight, we compared changes in food intake, body weight, and hypothalamic gene expression in rats receiving intracerebroventricular (ICV) CRF antagonist alpha-helical CRF or vehicle with or without access to running wheels. During a 4-day period of running wheel access, we found that exercise-induced reductions of food intake and body weight were significantly attenuated by ICV injection of the CRF antagonist. The effect on food intake was specific to a blockade of activity-induced changes in meal size. Central CRF antagonist injection further increased DMH CRF mRNA expression in exercised rats. Together, these data suggest that DMH CRF play a critical role in the anorexia resulting from increased voluntary exercise.
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Affiliation(s)
- Maiko Kawaguchi
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 720 Rutland Ave., Ross 618, Baltimore, MD 21205, USA
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48
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Liu J, Yu B, Neugebauer V, Grigoriadis DE, Rivier J, Vale WW, Shinnick-Gallagher P, Gallagher JP. Corticotropin-releasing factor and Urocortin I modulate excitatory glutamatergic synaptic transmission. J Neurosci 2004; 24:4020-9. [PMID: 15102917 PMCID: PMC6729414 DOI: 10.1523/jneurosci.5531-03.2004] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Corticotropin-releasing factor (CRF)-related peptides serve as hormones and neuromodulators of the stress response and play a role in affective disorders. These peptides are known to alter complex behaviors and neuronal properties, but their receptor-mediated effects at CNS synapses are not well described. Here we show that excitatory glutamatergic transmission is modulated by two endogenous CRF-related peptide ligands, corticotropin-releasing factor [CRF rat/human (r/h)] and Urocortin I (Ucn I), within the central nucleus of the amygdala (CeA) and the lateral septum mediolateral nucleus (LSMLN). These limbic nuclei are reciprocally innervated, are involved in stress and affective disorders, and have high densities of the CRF receptors CRF1 and CRF2. Activation of these receptors exerts diametrically opposed actions on glutamatergic transmission in these nuclei. In the CeA, CRF(r/h) depressed excitatory glutamatergic transmission through a CRF1-mediated postsynaptic action, whereas Ucn I facilitated synaptic responses through presynaptic and postsynaptic CRF2-mediated mechanisms. Conversely, in the LSMLN, CRF caused a CRF1-mediated facilitation of glutamatergic transmission via postsynaptic mechanisms, whereas Ucn I depressed EPSCs by postsynaptic and presynaptic CRF2-mediated actions. Furthermore, antagonists of these receptors also affected glutamatergic neurotransmission, indicating that endogenous ligands tonically modulated synoptic activity at these synapses. These data show that CRF receptors in CeA and LSMLN synapses exert and maintain a significant synaptic tone and thereby regulate excitatory glutamatergic transmission. The results also suggest that CRF receptors may provide novel targets in affective disorders and stress.
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Affiliation(s)
- Jie Liu
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555-1031, USA
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Rivier C. Role of nitric oxide in regulating the rat hypothalamic-pituitary-adrenal axis response to endotoxemia. Ann N Y Acad Sci 2003; 992:72-85. [PMID: 12794048 DOI: 10.1111/j.1749-6632.2003.tb03139.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This work examines the role of nitric oxide (NO) in the periphery (i.e., on the pituitary) and the brain (particularly on corticotropin-releasing factor [CRF] and vasopressin [VP] neurons in the paraventricular nucleus [PVN] of the hypothalamus) as a modulator of the ACTH response to lipopolysaccharide. We previously showed that NO restricted the pituitary response to VP while it facilitated the synthesis of PVN CRF and VP. In our experience, only relatively high doses of lipopolysaccharide (>50 microg/kg, injected intravenously [i.v.]) cause detectable increases in PVN neuronal activation. Our hypothesis, therefore, was that pituitary NO-VP interactions would predominate in rats injected with a low dose of lipopolysaccharide (0.5 microg/kg, i.v.) while the stimulatory influence of the gas on PVN neuronal activity would play an important role following i.v. injection of a large dose of lipopolysaccharide (50 microg/kg, i.v.). We observed that the ability of 0.5 microg/kg lipopolysaccharide to release ACTH was significantly enhanced by the subcutaneous (s.c.), but not the intracerebroventricular (i.c.v.) injection of L-NAME, an arginine derivative that blocks NO synthesis. The effect of s.c. L-NAME was reversed by immunoneutralization of endogenous VP, which indicated that in this model, the ability of lipopolysaccharide to release ACTH depended, at least in part, on the influence exerted by NO on the pituitary response to VP. In rats injected with the high lipopolysaccharide dose, the s.c. injection of L-NAME decreased plasma ACTH levels compared to those in rats pretreated with the vehicle. The effect of s.c. L-NAME was not significantly altered by VP antibodies. These results indicate that in this model, the primary influence of NO was exerted in the PVN and/or its afferents and that it did not depend on a peripheral, VP-mediated effect of the gas. On the one hand, these data are at odds with our finding that the i.c.v. injection of L-NAME only marginally altered the ACTH response to the large dose of lipopolysaccharide. As i.c.v. injected L-NAME should have primarily decreased hypothalamic, but not pituitary NOS, its only modest influence on ACTH release may have been due to a balance between stimulating and inhibiting effects of NO within the brain. As high doses of lipopolysaccharide increase brain levels of prostaglandin, monoamine, and proinflammatory cytokines, it will be important to investigate the influence exerted by NO on these secretagogues and on their interactions with PVN CRF and VP neurons, which may help us resolve the issues raised by our results. Collectively, these data support our hypothesis that the mechanisms mediating the ACTH response to a low lipopolysaccharide concentration involve the inhibitory VP-mediated influence of NO on pituitary activity. By contrast, the stimulatory effect of high doses of lipopolysaccharide on ACTH release depends, at least in part, on the ability of NO to upregulate PVN neuronal activity.
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Affiliation(s)
- Catherine Rivier
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, La Jolla, California 92037, USA.
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50
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Corticotropin releasing hormone type 2 receptors in the dorsal raphe nucleus mediate the behavioral consequences of uncontrollable stress. J Neurosci 2003. [PMID: 12574432 DOI: 10.1523/jneurosci.23-03-01019.2003] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Uncontrollable shock produces a constellation of behavioral changes that are not observed after equivalent escapable shock. These include interference with escape and potentiation of fear conditioning. The activation of corticotropin-releasing hormone (CRH) receptors within the caudal dorsal raphe nucleus (DRN) during inescapable tailshock (IS) has been shown to be critical for the development of these behavioral changes. CRH binds to two receptor subtypes, both of which are found in the DRN. The present set of studies examined which CRH receptor subtype mediates the effects of IS. Intra-DRN administration of the CRH(2) receptor antagonist anti-sauvagine-30 before IS dose-dependently blocked IS-induced behavioral changes; the CRH(1) receptor antagonist 2-methyl-4-(N-propyl-N-cycloproanemethylamino)-5-chloro-6-(2,4,6-trichloranilino)pyrimidine (NBI27914), administered in the same manner, did not. Moreover, the highly selective CRH(2) receptor agonist urocortin II (Ucn II) dose-dependently caused behavioral changes associated with IS in the absence of shock. Ucn II was effective at doses 100-fold lower than those previously required for CRH. The relationship between CRH(2) receptors and DRN 5-HT is discussed.
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