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Passeri A, Municchi D, Cavalieri G, Babicola L, Ventura R, Di Segni M. Linking drug and food addiction: an overview of the shared neural circuits and behavioral phenotype. Front Behav Neurosci 2023; 17:1240748. [PMID: 37767338 PMCID: PMC10520727 DOI: 10.3389/fnbeh.2023.1240748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 08/21/2023] [Indexed: 09/29/2023] Open
Abstract
Despite a lack of agreement on its definition and inclusion as a specific diagnosable disturbance, the food addiction construct is supported by several neurobiological and behavioral clinical and preclinical findings. Recognizing food addiction is critical to understanding how and why it manifests. In this overview, we focused on those as follows: 1. the hyperpalatable food effects in food addiction development; 2. specific brain regions involved in both food and drug addiction; and 3. animal models highlighting commonalities between substance use disorders and food addiction. Although results collected through animal studies emerged from protocols differing in several ways, they clearly highlight commonalities in behavioral manifestations and neurobiological alterations between substance use disorders and food addiction characteristics. To develop improved food addiction models, this heterogeneity should be acknowledged and embraced so that research can systematically investigate the role of specific variables in the development of the different behavioral features of addiction-like behavior in preclinical models.
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Affiliation(s)
- Alice Passeri
- IRCCS Fondazione Santa Lucia, Rome, Italy
- Department of Psychology and Center “Daniel Bovet”, Sapienza University, Rome, Italy
| | - Diana Municchi
- IRCCS Fondazione Santa Lucia, Rome, Italy
- Department of Psychology and Center “Daniel Bovet”, Sapienza University, Rome, Italy
| | - Giulia Cavalieri
- Department of Psychology and Center “Daniel Bovet”, Sapienza University, Rome, Italy
| | | | - Rossella Ventura
- Department of Psychology and Center “Daniel Bovet”, Sapienza University, Rome, Italy
- IRCCS San Raffaele, Rome, Italy
| | - Matteo Di Segni
- IRCCS Fondazione Santa Lucia, Rome, Italy
- Department of Psychology and Center “Daniel Bovet”, Sapienza University, Rome, Italy
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2
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Geisler CE, Hayes MR. Metabolic Hormone Action in the VTA: Reward-Directed Behavior and Mechanistic Insights. Physiol Behav 2023; 268:114236. [PMID: 37178855 DOI: 10.1016/j.physbeh.2023.114236] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 04/10/2023] [Accepted: 05/10/2023] [Indexed: 05/15/2023]
Abstract
Dysfunctional signaling in midbrain reward circuits perpetuates diseases characterized by compulsive overconsumption of rewarding substances such as substance abuse, binge eating disorder, and obesity. Ventral tegmental area (VTA) dopaminergic activity serves as an index for how rewarding stimuli are perceived and triggers behaviors necessary to obtain future rewards. The evolutionary linking of reward with seeking and consuming palatable foods ensured an organism's survival, and hormone systems that regulate appetite concomitantly developed to regulate motivated behaviors. Today, these same mechanisms serve to regulate reward-directed behavior around food, drugs, alcohol, and social interactions. Understanding how hormonal regulation of VTA dopaminergic output alters motivated behaviors is essential to leveraging therapeutics that target these hormone systems to treat addiction and disordered eating. This review will outline our current understanding of the mechanisms underlying VTA action of the metabolic hormones ghrelin, glucagon-like peptide-1, amylin, leptin, and insulin to regulate behavior around food and drugs of abuse, highlighting commonalities and differences in how these five hormones ultimately modulate VTA dopamine signaling.
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Affiliation(s)
- Caroline E Geisler
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Matthew R Hayes
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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3
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Borges C, Inigo F, Quteishat N, Charles J, Ah-Yen E, U S. Acute food deprivation-induced relapse to heroin seeking after short and long punishment-imposed abstinence in male rats. Psychopharmacology (Berl) 2023; 240:595-607. [PMID: 35951079 DOI: 10.1007/s00213-022-06207-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 07/28/2022] [Indexed: 11/24/2022]
Abstract
RATIONAL Stress is a major trigger for drug relapse in humans and animal models, even after prolonged abstinence. However, animal models for stress-induced relapse were criticized for the lack of predictive and face validity. OBJECTIVES Here we investigated the effect of acute food deprivation stress in a novel stress-induced relapse model using voluntary, punishment-imposed abstinence from heroin. We also performed a detailed characterization of the development of punishment-imposed abstinence. METHODS Male rats were trained to self-administered heroin (0.1 mg/kg/infusion) for 2 weeks, using the seeking-taking chained schedule. Pressing the 'seeking' lever led to the insertion of the 'taking' lever and pressing the take lever resulted in heroin infusion. Following self-administration training, rats were exposed to 8 or 21 days of heroin-seeking punishment. During punishment, 30% of the completed seek links resulted in a mild escalating footshock instead of take lever presentation. Next, rats were tested for heroin seeking under extinction conditions after 24 h of food deprivation and sated conditions. RESULTS Probabilistic punishment of seeking lever responses resulted in gradual suppression of heroin seeking and taking. Exposure to food-deprivation stress induced a robust relapse to heroin seeking after short and long punishment-imposed abstinence periods, without significant effects of time, i.e., no incubation of heroin seeking. Individual differences were observed in the development of punishment-induced abstinence and stress-induced relapse. CONCLUSIONS These results suggest that stress is a reliable trigger to relapse even after a prolonged period of punishment-induced, voluntary abstinence.
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Affiliation(s)
- C Borges
- Department of Psychology, Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, Quebec, Canada
| | - F Inigo
- Department of Psychology, Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, Quebec, Canada
| | - N Quteishat
- Department of Psychology, Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, Quebec, Canada
| | - J Charles
- Department of Psychology, Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, Quebec, Canada
| | - E Ah-Yen
- Department of Psychology, Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, Quebec, Canada
| | - Shalev U
- Department of Psychology, Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, Quebec, Canada.
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4
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Engel JA, Pålsson E, Vallöf D, Jerlhag E. Ghrelin activates the mesolimbic dopamine system via nitric oxide associated mechanisms in the ventral tegmental area. Nitric Oxide 2023; 131:1-7. [PMID: 36513266 DOI: 10.1016/j.niox.2022.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/08/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022]
Abstract
Besides enhanced feeding, the orexigenic peptide ghrelin activates the mesolimbic dopamine system to cause reward as measured by locomotor stimulation, dopamine release in nucleus accumbens shell (NAcS), and conditioned place preference. Although the ventral tegmental area (VTA) appears to be a central brain region for this ghrelin-reward, the underlying mechanisms within this area are unknown. The findings that the gaseous neurotransmitter nitric oxide (NO) modulate the ghrelin enhanced feeding, led us to hypothesize that ghrelin increases NO levels in the VTA, and thereby stimulates reward-related behaviors. We initially demonstrated that inhibition of NO synthesis blocked the ghrelin-induced activation of the mesolimbic dopamine system. We then established that antagonism of downstream signaling of NO in the VTA, namely sGC, prevents the ability of ghrelin to stimulate the mesolimbic dopamine system. The association of ghrelin to NO was further strengthened by in vivo electrochemical recordings showing that ghrelin enhances the NO release in the VTA. Besides a GABAB -receptor agonist, known to reduce NO and cGMP, blocks the stimulatory properties of ghrelin. The present series of experiments reveal that ablated NO signaling, through pharmacologically inhibiting the production of NO and/or cGMP, prevents the ability of ghrelin to induced reward-related behaviors.
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Affiliation(s)
- Jörgen A Engel
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Erik Pålsson
- Institute of Neuroscience and Physiology, Department of Neurochemistry and Psychiatry, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Daniel Vallöf
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Jerlhag
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
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5
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Involvement of the ghrelin system in the maintenance and reinstatement of cocaine-motivated behaviors: a role of adrenergic action at peripheral β1 receptors. Neuropsychopharmacology 2022; 47:1449-1460. [PMID: 34923576 PMCID: PMC9206024 DOI: 10.1038/s41386-021-01249-2] [Citation(s) in RCA: 4] [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: 08/17/2021] [Revised: 11/22/2021] [Accepted: 11/28/2021] [Indexed: 12/30/2022]
Abstract
Cocaine addiction is a significant medical and public concern. Despite decades of research effort, development of pharmacotherapy for cocaine use disorder remains largely unsuccessful. This may be partially due to insufficient understanding of the complex biological mechanisms involved in the pathophysiology of this disorder. In the present study, we show that: (1) elevation of ghrelin by cocaine plays a critical role in maintenance of cocaine self-administration and cocaine-seeking motivated by cocaine-conditioned stimuli; (2) acquisition of cocaine-taking behavior is associated with the acquisition of stimulatory effects of cocaine by cocaine-conditioned stimuli on ghrelin secretion, and with an upregulation of ghrelin receptor mRNA levels in the ventral tegmental area (VTA); (3) blockade of ghrelin signaling by pretreatment with JMV2959, a selective ghrelin receptor antagonist, dose-dependently inhibits reinstatement of cocaine-seeking triggered by either cocaine or yohimbine in behaviorally extinguished animals with a history of cocaine self-administration; (4) JMV2959 pretreatment also inhibits brain stimulation reward (BSR) and cocaine-potentiated BSR maintained by optogenetic stimulation of VTA dopamine neurons in DAT-Cre mice; (5) blockade of peripheral adrenergic β1 receptors by atenolol potently attenuates the elevation in circulating ghrelin induced by cocaine and inhibits cocaine self-administration and cocaine reinstatement triggered by cocaine. These findings demonstrate that the endogenous ghrelin system plays an important role in cocaine-related addictive behaviors and suggest that manipulating and targeting this system may be viable for mitigating cocaine use disorder.
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Involvement of the ghrelin system in the maintenance of oxycodone self-administration: converging evidence from endocrine, pharmacologic and transgenic approaches. Mol Psychiatry 2022; 27:2171-2181. [PMID: 35064236 PMCID: PMC9133122 DOI: 10.1038/s41380-022-01438-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/08/2021] [Accepted: 01/05/2022] [Indexed: 12/15/2022]
Abstract
Ghrelin, an orexigenic hormone, has emerged as a critical biological substrate implicated in drug reward. However, the response of the ghrelin system to opioid-motivated behaviors and the role of ghrelin in oxycodone self-administration remain to be studied. Here, we investigated the reciprocal interactions between the endogenous ghrelin system and oxycodone self-administration behaviors in rats and the role of the ghrelin system in brain stimulation reward (BSR) driven by optogenetic stimulation of midbrain reward circuits in mice. Oxycodone self-administration significantly elevated plasma ghrelin, des-acyl ghrelin and growth hormone and showed no effect on plasma LEAP2, a newly identified endogenous ghrelin receptor (GHS-R1a) antagonist. Oxycodone self-administration produced significant decreases in plasma gastric inhibitory polypeptide and insulin. Acquisition of oxycodone self-administration significantly upregulated GHS-R1a mRNA levels in dopamine neurons in the ventral tegmental area (VTA), a brain region critical in drug reward. Pretreatment with JMV2959, a selective GHS-R1a antagonist, dose-dependently reduced oxycodone self-administration and decreased the breakpoint for oxycodone under a progressive ratio reinforcement in Long-Evans rats. The inhibitory effects of JMV2959 on oxycodone self-administration is selectively mediated by GHS-R1a as JMV2959 showed a similar effect in Wistar wildtype but not in GHS-R knockout rats. JMV2959 pretreatment significantly inhibited BSR driven by selective stimulation of VTA dopamine neurons, but not by stimulation of striatal GABA neurons projecting to the VTA in mice. These findings suggest that elevation of ghrelin signaling by oxycodone or oxycodone-associated stimuli is a causal process by which oxycodone motivates oxycodone drug-taking and targeting the ghrelin system may be a viable treatment approach for opioid use disorders.
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Sustkova-Fiserova M, Charalambous C, Khryakova A, Certilina A, Lapka M, Šlamberová R. The Role of Ghrelin/GHS-R1A Signaling in Nonalcohol Drug Addictions. Int J Mol Sci 2022; 23:761. [PMID: 35054944 PMCID: PMC8776007 DOI: 10.3390/ijms23020761] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 01/27/2023] Open
Abstract
Drug addiction causes constant serious health, social, and economic burden within the human society. The current drug dependence pharmacotherapies, particularly relapse prevention, remain limited, unsatisfactory, unreliable for opioids and tobacco, and even symptomatic for stimulants and cannabinoids, thus, new more effective treatment strategies are researched. The antagonism of the growth hormone secretagogue receptor type A (GHS-R1A) has been recently proposed as a novel alcohol addiction treatment strategy, and it has been intensively studied in experimental models of other addictive drugs, such as nicotine, stimulants, opioids and cannabinoids. The role of ghrelin signaling in these drugs effects has also been investigated. The present review aims to provide a comprehensive overview of preclinical and clinical studies focused on ghrelin's/GHS-R1A possible involvement in these nonalcohol addictive drugs reinforcing effects and addiction. Although the investigation is still in its early stage, majority of the existing reviewed experimental results from rodents with the addition of few human studies, that searched correlations between the genetic variations of the ghrelin signaling or the ghrelin blood content with the addictive drugs effects, have indicated the importance of the ghrelin's/GHS-R1As involvement in the nonalcohol abused drugs pro-addictive effects. Further research is necessary to elucidate the exact involved mechanisms and to verify the future potential utilization and safety of the GHS-R1A antagonism use for these drug addiction therapies, particularly for reducing the risk of relapse.
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Affiliation(s)
- Magdalena Sustkova-Fiserova
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Chrysostomos Charalambous
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Anna Khryakova
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Alina Certilina
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Marek Lapka
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Romana Šlamberová
- Department of Physiology, Third Faculty of Medicine, Charles University, Ke Karlovu 4, 120 00 Prague, Czech Republic;
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Shevchouk OT, Tufvesson-Alm M, Jerlhag E. An Overview of Appetite-Regulatory Peptides in Addiction Processes; From Bench to Bed Side. Front Neurosci 2021; 15:774050. [PMID: 34955726 PMCID: PMC8695496 DOI: 10.3389/fnins.2021.774050] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/08/2021] [Indexed: 12/17/2022] Open
Abstract
There is a substantial need for new pharmacological treatments of addiction, and appetite-regulatory peptides are implied as possible candidates. Appetite regulation is complex and involves anorexigenic hormones such as glucagon-like peptide-1 (GLP-1) and amylin, and orexigenic peptides like ghrelin and all are well-known for their effects on feeding behaviors. This overview will summarize more recent physiological aspects of these peptides, demonstrating that they modulate various aspects of addiction processes. Findings from preclinical, genetic, and experimental clinical studies exploring the association between appetite-regulatory peptides and the acute or chronic effects of addictive drugs will be introduced. Short or long-acting GLP-1 receptor agonists independently attenuate the acute rewarding properties of addictive drugs or reduce the chronic aspects of drugs. Genetic variation of the GLP-1 system is associated with alcohol use disorder. Also, the amylin pathway modulates the acute and chronic behavioral responses to addictive drugs. Ghrelin has been shown to activate reward-related behaviors. Moreover, ghrelin enhances, whereas pharmacological or genetic suppression of the ghrelin receptor attenuates the responses to various addictive drugs. Genetic studies and experimental clinical studies further support the associations between ghrelin and addiction processes. Further studies should explore the mechanisms modulating the ability of appetite-regulatory peptides to reduce addiction, and the effects of combination therapies or different diets on substance use are warranted. In summary, these studies provide evidence that appetite-regulatory peptides modulate reward and addiction processes, and deserve to be investigated as potential treatment target for addiction.
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Affiliation(s)
- Olesya T Shevchouk
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Maximilian Tufvesson-Alm
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Jerlhag
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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9
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Micioni Di Bonaventura E, Botticelli L, Del Bello F, Giorgioni G, Piergentili A, Quaglia W, Cifani C, Micioni Di Bonaventura MV. Assessing the role of ghrelin and the enzyme ghrelin O-acyltransferase (GOAT) system in food reward, food motivation, and binge eating behavior. Pharmacol Res 2021; 172:105847. [PMID: 34438062 DOI: 10.1016/j.phrs.2021.105847] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 02/06/2023]
Abstract
The peripheral peptide hormone ghrelin is a powerful stimulator of food intake, which leads to body weight gain and adiposity in both rodents and humans. The hormone, thus, increases the vulnerability to obesity and binge eating behavior. Several studies have revealed that ghrelin's functions are due to its interaction with the growth hormone secretagogue receptor type 1a (GHSR1a) in the hypothalamic area; besides, ghrelin also promotes the reinforcing properties of hedonic food, acting at extra-hypothalamic sites and interacting with dopaminergic, cannabinoid, opioid, and orexin signaling. The hormone is primarily present in two forms in the plasma and the enzyme ghrelin O-acyltransferase (GOAT) allows the acylation reaction which causes the transformation of des-acyl-ghrelin (DAG) to the active form acyl-ghrelin (AG). DAG has been demonstrated to show antagonist properties; it is metabolically active, and counteracts the effects of AG on glucose metabolism and lipolysis, and reduces food consumption, body weight, and hedonic feeding response. Both peptides seem to influence the hypothalamic-pituitary-adrenal (HPA) axis and the corticosterone/cortisol level that drive the urge to eat under stressful conditions. These findings suggest that DAG and inhibition of GOAT may be targets for obesity and bingeing-related eating disorders and that AG/DAG ratio may be an important potential biomarker to assess the risk of developing maladaptive eating behaviors.
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Affiliation(s)
| | - Luca Botticelli
- School of Pharmacy, Pharmacology Unit, University of Camerino, via Madonna delle Carceri, 9, 62032 Camerino, Italy
| | - Fabio Del Bello
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, via S. Agostino, 1, 62032 Camerino, Italy
| | - Gianfabio Giorgioni
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, via S. Agostino, 1, 62032 Camerino, Italy
| | - Alessandro Piergentili
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, via S. Agostino, 1, 62032 Camerino, Italy
| | - Wilma Quaglia
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, via S. Agostino, 1, 62032 Camerino, Italy
| | - Carlo Cifani
- School of Pharmacy, Pharmacology Unit, University of Camerino, via Madonna delle Carceri, 9, 62032 Camerino, Italy.
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10
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Smith NK, Grueter BA. Hunger-driven adaptive prioritization of behavior. FEBS J 2021; 289:922-936. [PMID: 33630426 DOI: 10.1111/febs.15791] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/11/2021] [Accepted: 02/24/2021] [Indexed: 12/19/2022]
Abstract
In order to survive, an animal must adapt its behavioral priorities to accommodate changing internal and external conditions. Hunger, a universally recognized interoceptive signal, promotes food intake though increasingly well-understood neural circuits. Less understood, is how hunger is integrated into the neural computations that guide nonfeeding behaviors. Within the brain, agouti-related peptide neurons in the arcuate nucleus of the hypothalamus have been found to powerfully stimulate feeding in addition to mediating other hunger-driven behavioral phenotypes. In this review, we compile the behavioral plasticity downstream of hunger and present identified or potential molecular and neural circuit mechanisms. We catalogue hunger's ability to increase exploration, decrease anxiety, and alter social behavior, among other phenotypes. Finally, we suggest paths forward for understanding hunger-driven behavioral adaptation and discuss the benefits of understanding state-dependent modulation of neural circuits controlling behavior.
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Affiliation(s)
- Nicholas K Smith
- Neuroscience Graduate Program, Vanderbilt University, Nashville, TN, USA
| | - Brad A Grueter
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA.,Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA.,Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.,Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
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11
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Assessing the Role of Corticothalamic and Thalamo-Accumbens Projections in the Augmentation of Heroin Seeking in Chronically Food-Restricted Rats. J Neurosci 2020; 41:354-365. [PMID: 33219004 DOI: 10.1523/jneurosci.2103-20.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/09/2020] [Accepted: 11/15/2020] [Indexed: 02/06/2023] Open
Abstract
Drug addiction is a chronic disorder characterized by compulsive drug seeking, and involves repetitive cycles of compulsive drug use, abstinence, and relapse. In both human and animal models of addiction, chronic food restriction increases rates of relapse. Our laboratory has reported a robust increase in drug seeking following a period of withdrawal in chronically food-restricted rats compared with sated controls. Recently, we reported that activation of the paraventricular nucleus of the thalamus (PVT) abolished heroin seeking in chronically food-restricted rats. However, the precise inputs and outputs of the PVT that mediate this effect remain elusive. The goal of the current study was to determine the role of corticothalamic and thalamo-accumbens projections in the augmentation of heroin seeking induced by chronic food restriction. Male Long-Evans rats were trained to self-administer heroin for 10 d. Next, rats were removed from the self-administration chambers and were subjected to a 14 d withdrawal period while sated (unlimited access to food) or mildly food-restricted (FDR). On day 14, rats were returned to the self-administration context for a 3 h heroin-seeking test under extinction conditions during which corticothalamic and thalamo-accumbens neural activity was altered using chemogenetics. Surprisingly, chemogenetic activation or inhibition of corticothalamic projections did not alter heroin-seeking behavior. Chemogenetic activation of thalamo-accumbens shell, but not core, projectors attenuated heroin seeking in FDR rats. The results indicate an important role for the PVT to nucleus accumbens shell projections in the augmentation of heroin seeking induced by chronic food restriction.SIGNIFICANCE STATEMENT Relapse to heroin use is one of the major obstacles in the treatment of opiate addiction. Triggers for relapse are modulated by environmental challenges such as caloric restriction. Elucidating the brain mechanisms that underlie relapse is critical for evidence-based treatment development. Here we demonstrate a critical role for the input from the paraventricular thalamus (PVT), a hub for cortical, sensory, and limbic information, to the nucleus accumbens shell (an area known to be important for reward and motivation) in the augmentation of heroin seeking in food-restricted rats. Our findings highlight a previously unknown role for the PVT in heroin seeking following a period of abstinence.
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12
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Cornejo MP, Mustafá ER, Barrile F, Cassano D, De Francesco PN, Raingo J, Perello M. THE INTRIGUING LIGAND-DEPENDENT AND LIGAND-INDEPENDENT ACTIONS OF THE GROWTH HORMONE SECRETAGOGUE RECEPTOR ON REWARD-RELATED BEHAVIORS. Neurosci Biobehav Rev 2020; 120:401-416. [PMID: 33157147 DOI: 10.1016/j.neubiorev.2020.10.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/18/2020] [Accepted: 10/20/2020] [Indexed: 02/07/2023]
Abstract
The growth hormone secretagogue receptor (GHSR) is a G-protein-coupled receptor (GPCR) highly expressed in the brain, and also in some peripheral tissues. GHSR activity is evoked by the stomach-derived peptide hormone ghrelin and abrogated by the intestine-derived liver-expressed antimicrobial peptide 2 (LEAP2). In vitro, GHSR displays ligand-independent actions, including a high constitutive activity and an allosteric modulation of other GPCRs. Beyond its neuroendocrine and metabolic effects, cumulative evidence shows that GHSR regulates the activity of the mesocorticolimbic pathway and modulates complex reward-related behaviors towards different stimuli. Here, we review current evidence indicating that ligand-dependent and ligand-independent actions of GHSR enhance reward-related behaviors towards appetitive stimuli and drugs of abuse. We discuss putative neuronal networks and molecular mechanisms that GHSR would engage to modulate such reward-related behaviors. Finally, we briefly discuss imaging studies showing that ghrelin would also regulate reward processing in humans. Overall, we conclude that GHSR is a key regulator of the mesocorticolimbic pathway that influences its activity and, consequently, modulates reward-related behaviors via ligand-dependent and ligand-independent actions.
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Affiliation(s)
- María P Cornejo
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Emilio R Mustafá
- Laboratory of Electrophysiology of the IMBICE, 1900 La Plata, Buenos Aires, Argentina
| | - Franco Barrile
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Daniela Cassano
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Pablo N De Francesco
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Jesica Raingo
- Laboratory of Electrophysiology of the IMBICE, 1900 La Plata, Buenos Aires, Argentina
| | - Mario Perello
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina.
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Joshi DD, Puaud M, Fouyssac M, Belin‐Rauscent A, Everitt B, Belin D. The anterior insular cortex in the rat exerts an inhibitory influence over the loss of control of heroin intake and subsequent propensity to relapse. Eur J Neurosci 2020; 52:4115-4126. [DOI: 10.1111/ejn.14889] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/19/2020] [Accepted: 06/22/2020] [Indexed: 12/31/2022]
Affiliation(s)
- Dhaval D. Joshi
- Department of Psychology University of Cambridge Cambridge UK
| | - Mickaël Puaud
- Department of Psychology University of Cambridge Cambridge UK
| | - Maxime Fouyssac
- Department of Psychology University of Cambridge Cambridge UK
| | | | - Barry Everitt
- Department of Psychology University of Cambridge Cambridge UK
| | - David Belin
- Department of Psychology University of Cambridge Cambridge UK
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Moose JE, Leets KA, Mate NA, Chisholm JD, Hougland JL. An overview of ghrelin O-acyltransferase inhibitors: a literature and patent review for 2010-2019. Expert Opin Ther Pat 2020; 30:581-593. [PMID: 32564644 DOI: 10.1080/13543776.2020.1776263] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION The peptide hormone ghrelin regulates physiological processes associated with energy homeostasis such as appetite, insulin signaling, glucose metabolism, and adiposity. Ghrelin has also been implicated in a growing number of neurological pathways involved in stress response and addiction behavior. For ghrelin to bind the growth hormone secretagogue receptor 1a (GHS-R1a) and activate signaling, the hormone must first be octanoylated on a specific serine side chain. This key transformation is performed by the enzyme ghrelin O-acyltransferase (GOAT), and therefore GOAT inhibitors may be useful in treating disorders related to ghrelin signaling such as diabetes, obesity, and related metabolic syndromes. AREAS COVERED This report covers ghrelin and GOAT as potential therapeutic targets and summarizes work on GOAT inhibitors through the end of 2019, highlighting recent successes with both peptidomimetics and small molecule GOAT inhibitors as potent modulators of GOAT-catalyzed ghrelin octanoylation. EXPERT OPINION A growing body of biochemical and structural knowledge regarding the ghrelin/GOAT system now enables multiple avenues for identifying and optimizing GOAT inhibitors. We are at the beginning of a new era with increased opportunities for leveraging ghrelin and GOAT in the understanding and treatment of multiple health conditions including diabetes, obesity, and addiction.
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Affiliation(s)
- Jacob E Moose
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Katelyn A Leets
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Nilamber A Mate
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - John D Chisholm
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - James L Hougland
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
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