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Pan L, Xiao S, Xu Z, Li W, Zhao L, Zhang L, Qi R, Wang J, Cai Y. Orexin-A attenuated motion sickness through modulating neural activity in hypothalamus nuclei. Br J Pharmacol 2024; 181:1474-1493. [PMID: 38129941 DOI: 10.1111/bph.16307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 12/08/2023] [Accepted: 12/09/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND AND PURPOSE We evaluated the hypothesis that central orexin application could counteract motion sickness responses through regulating neural activity in target brain areas. EXPERIMENTAL APPROACH Thec effects of intracerebroventricular (i.c.v.) injection of orexin-A and SB-334867 (OX1 antagonist) on motion sickness-induced anorexia, nausea-like behaviour (conditioned gaping), hypoactivity and hypothermia were investigated in rats subjected to Ferris wheel-like rotation. Orexin-A responsive brain areas were identified using Fos immunolabelling and were verified via motion sickness responses after intranucleus injection of orexin-A, SB-334867 and TCS-OX2-29 (OX2 antagonist). The efficacy of intranasal application of orexin-A versus scopolamine on motion sickness symptoms in cats was also investigated. KEY RESULTS Orexin-A (i.c.v.) dose-dependently attenuated motion sickness-related behavioural responses and hypothermia. Fos expression was inhibited in the ventral part of the dorsomedial hypothalamus (DMV) and the paraventricular nucleus (PVN), but was enhanced in the ventral part of the premammillary nucleus ventral part (PMV) by orexin-A (20 μg) in rotated animals. Motion sickness responses were differentially inhibited by orexin-A injection into the DMV (anorexia and hypoactivity), the PVN (conditioned gaping) and the PMV (hypothermia). SB-334867 and TCS-OX2-29 (i.c.v. and intranucleus injection) inhibited behavioural and thermal effects of orexin-A. Orexin-A (60 μg·kg-1) and scopolamine inhibited rotation-induced emesis and non-retching/vomiting symptoms, while orexin-A also attenuated anorexia with mild salivation in motion sickness cats. CONCLUSION AND IMPLICATIONS Orexin-A might relieve motion sickness through acting on OX1 and OX2 receptors in various hypothalamus nuclei. Intranasal orexin-A could be a potential strategy against motion sickness.
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Affiliation(s)
- Leilei Pan
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Shuifeng Xiao
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Zichao Xu
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Wenping Li
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Long Zhao
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Ling Zhang
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Ruirui Qi
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Junqin Wang
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Yiling Cai
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
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Ma J, Yanase S, Udagawa L, Kuwaki T, Kusumoto-Yoshida I. Activation of neurons in the insular cortex and lateral hypothalamus during food anticipatory period caused by food restriction in mice. J Physiol Sci 2023; 73:34. [PMID: 38066417 PMCID: PMC10717706 DOI: 10.1186/s12576-023-00892-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 11/24/2023] [Indexed: 12/18/2023]
Abstract
Mice fed a single meal daily at a fixed time display food anticipatory activity (FAA). It has been reported that the insular cortex (IC) plays an essential role in food anticipation, and lateral hypothalamus (LH) regulates the expression of FAA. However, how these areas contribute to FAA production is still unclear. Thus, we examined the temporal and spatial activation pattern of neurons in the IC and LH during the food anticipation period to determine their role in FAA establishment. We observed an increase of c-Fos-positive neurons in the IC and LH, including orexin neurons of male adult C57BL/6 mice. These neurons were gradually activated from the 1st day to 15th day of restricted feeding. The activation of these brain regions, however, peaked at a distinct point in the food restriction procedure. These results suggest that the IC and LH are differently involved in the neural network for FAA production.
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Affiliation(s)
- Jihao Ma
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
| | - Sakurako Yanase
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
| | - Lisa Udagawa
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
| | - Tomoyuki Kuwaki
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
| | - Ikue Kusumoto-Yoshida
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan.
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Bonifazi A, Del Bello F, Giorgioni G, Piergentili A, Saab E, Botticelli L, Cifani C, Micioni Di Bonaventura E, Micioni Di Bonaventura MV, Quaglia W. Targeting orexin receptors: Recent advances in the development of subtype selective or dual ligands for the treatment of neuropsychiatric disorders. Med Res Rev 2023; 43:1607-1667. [PMID: 37036052 DOI: 10.1002/med.21959] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 03/08/2023] [Accepted: 03/28/2023] [Indexed: 04/11/2023]
Abstract
Orexin-A and orexin-B, also named hypocretin-1 and hypocretin-2, are two hypothalamic neuropeptides highly conserved across mammalian species. Their effects are mediated by two distinct G protein-coupled receptors, namely orexin receptor type 1 (OX1-R) and type 2 (OX2-R), which share 64% amino acid identity. Given the wide expression of OX-Rs in different central nervous system and peripheral areas and the several pathophysiological functions in which they are involved, including sleep-wake cycle regulation (mainly mediated by OX2-R), emotion, panic-like behaviors, anxiety/stress, food intake, and energy homeostasis (mainly mediated by OX1-R), both subtypes represent targets of interest for many structure-activity relationship (SAR) campaigns carried out by pharmaceutical companies and academies. However, before 2017 the research was predominantly directed towards dual-orexin ligands, and limited chemotypes were investigated. Analytical characterizations, including resolved structures for both OX1-R and OX2-R in complex with agonists and antagonists, have improved the understanding of the molecular basis of receptor recognition and are assets for medicinal chemists in the design of subtype-selective ligands. This review is focused on the medicinal chemistry aspects of small molecules acting as dual or subtype selective OX1-R/OX2-R agonists and antagonists belonging to different chemotypes and developed in the last years, including radiolabeled OX-R ligands for molecular imaging. Moreover, the pharmacological effects of the most studied ligands in different neuropsychiatric diseases, such as sleep, mood, substance use, and eating disorders, as well as pain, have been discussed. Poly-pharmacology applications and multitarget ligands have also been considered.
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Affiliation(s)
- Alessandro Bonifazi
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, Baltimore, Maryland, United States
| | - Fabio Del Bello
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| | - Gianfabio Giorgioni
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| | | | - Elizabeth Saab
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, Baltimore, Maryland, United States
| | - Luca Botticelli
- School of Pharmacy, Pharmacology Unit, University of Camerino, Camerino, Italy
| | - Carlo Cifani
- School of Pharmacy, Pharmacology Unit, University of Camerino, Camerino, Italy
| | | | | | - Wilma Quaglia
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
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Kennedy KER, Grandner MA. Sleep, rhythms, and food intake: Mechanistic insights. Sleep Med Rev 2023; 69:101791. [PMID: 37236066 DOI: 10.1016/j.smrv.2023.101791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023]
Affiliation(s)
- Kathryn E R Kennedy
- Sleep and Health Research Program, Department of Psychiatry, University of Arizona, Tucson, AZ, USA.
| | - Michael A Grandner
- Sleep and Health Research Program, Department of Psychiatry, University of Arizona, Tucson, AZ, USA
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Subramanian KS, Lauer LT, Hayes AMR, Décarie-Spain L, McBurnett K, Nourbash AC, Donohue KN, Kao AE, Bashaw AG, Burdakov D, Noble EE, Schier LA, Kanoski SE. Hypothalamic melanin-concentrating hormone neurons integrate food-motivated appetitive and consummatory processes in rats. Nat Commun 2023; 14:1755. [PMID: 36990984 PMCID: PMC10060386 DOI: 10.1038/s41467-023-37344-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/13/2023] [Indexed: 03/31/2023] Open
Abstract
The lateral hypothalamic area (LHA) integrates homeostatic processes and reward-motivated behaviors. Here we show that LHA neurons that produce melanin-concentrating hormone (MCH) are dynamically responsive to both food-directed appetitive and consummatory processes in male rats. Specifically, results reveal that MCH neuron Ca2+ activity increases in response to both discrete and contextual food-predictive cues and is correlated with food-motivated responses. MCH neuron activity also increases during eating, and this response is highly predictive of caloric consumption and declines throughout a meal, thus supporting a role for MCH neurons in the positive feedback consummatory process known as appetition. These physiological MCH neural responses are functionally relevant as chemogenetic MCH neuron activation promotes appetitive behavioral responses to food-predictive cues and increases meal size. Finally, MCH neuron activation enhances preference for a noncaloric flavor paired with intragastric glucose. Collectively, these data identify a hypothalamic neural population that orchestrates both food-motivated appetitive and intake-promoting consummatory processes.
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Affiliation(s)
- Keshav S Subramanian
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA
| | - Logan Tierno Lauer
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
| | - Anna M R Hayes
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
| | - Léa Décarie-Spain
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
| | - Kara McBurnett
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
| | - Anna C Nourbash
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
| | - Kristen N Donohue
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
| | - Alicia E Kao
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
| | - Alexander G Bashaw
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA
| | - Denis Burdakov
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Emily E Noble
- Department of Nutritional Sciences, University of Georgia, Athens, USA
| | - Lindsey A Schier
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA
| | - Scott E Kanoski
- Human and Evolutionary Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California, USA.
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA.
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Schéle E, Stoltenborg I, Xie A, Peris-Sampedro F, Adan RAH, Dickson SL. Engagement of the brain orexin system in activity-based anorexia behaviour in mice. Eur Neuropsychopharmacol 2023; 70:63-71. [PMID: 36889178 DOI: 10.1016/j.euroneuro.2023.02.014] [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: 09/20/2022] [Revised: 01/24/2023] [Accepted: 02/15/2023] [Indexed: 03/08/2023]
Abstract
While excessive physical activity is common amongst anorexia nervosa (AN) patients, contributing to their low body weight, little is known about the underlying biology and effective treatments targeting the hyperactivity are lacking. Given the role of orexin in arousal, physical activity and energy expenditure, we sought to investigate i) the extent to which orexin neurons are activated during severe anorectic state in the activity-based anorexia (ABA) mouse model, and ii) if the dual orexin receptor antagonist suvorexant can reduce physical activity during ABA. The Fos-TRAP2 technique enable us to visually capture active neurons (Fos expressing) during severe anorectic state in the ABA mouse model, and by immunohistochemistry, determine the extent to which these active neurons are orexin positive. In addition, suvorexant was administered peripherally to ABA mice and running activity was monitored. We found that a large population of orexin neurons in the hypothalamus are activated by ABA and that peripheral administration of suvorexant decreases food anticipatory activity in these mice. We conclude that orexin may be a suitable target to treat hyperactivity in AN and recommend further studies to examine the efficacy of suvorexant in aiding AN patients to control their drive for hyperactivity.
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Affiliation(s)
- Erik Schéle
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, 405 30 Gothenburg, Sweden.
| | - Iris Stoltenborg
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Anders Xie
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Fiona Peris-Sampedro
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Roger A H Adan
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht and Utrecht University, 3584 CJ Utrecht, The Netherlands
| | - Suzanne L Dickson
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, 405 30 Gothenburg, Sweden
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Sex-dependent role of orexin deficiency in feeding behavior and affective state of mice following intermittent access to a Western diet - Implications for binge-like eating behavior. Physiol Behav 2023; 260:114069. [PMID: 36572152 DOI: 10.1016/j.physbeh.2022.114069] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/02/2022] [Accepted: 12/22/2022] [Indexed: 12/24/2022]
Abstract
Binge eating disorder is a debilitating disease characterized by recurrent episodes of excessive food consumption and associated with psychiatric comorbidities. Despite a growing body of research investigating the neurobiological underpinnings of eating disorders, specific treatments are lacking. Given its fundamental role in feeding behaviors, we investigated the role of the orexin (hypocretin) neuropeptide system in binge-like eating and associated phenotypes. Specifically, we submitted female and male orexin-deficient mice to a paradigm of intermittent access (once weekly for 24 h) to a Western diet (WD) to induce binge-like eating. Additionally, we measured their anxiety-like behavior and plasma corticosterone levels. All mice showed binge-like eating in response to the intermittent WD access, but females did so to a greater extent than males. While orexin deficiency did not affect binge-like eating in this paradigm, we found that female orexin-deficient mice generally weighed more, and they expressed increased hypophagia and stress levels compared to wild-type mice following binge-like eating episodes. These detrimental effects of orexin deficiency were marginal or absent in males. Moreover, male wild-type mice expressed post-binge anxiety, but orexin-deficient mice did not. In conclusion, these results extend our knowledge of orexin's role in dysregulated eating and associated negative affective states, and contribute to the growing body of evidence indicating a sexual dimorphism of the orexin system. Considering that many human disorders, and especially eating disorders, have a strong sex bias, our findings further emphasize the importance of testing both female and male subjects.
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Merlin S, Furlong TM. Habitual behaviour associated with exposure to high-calorie diet is prevented by an orexin-receptor-1 antagonist. ADDICTION NEUROSCIENCE 2022; 4:100036. [PMID: 37476304 PMCID: PMC10357952 DOI: 10.1016/j.addicn.2022.100036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Habitual actions, which are associated with addictive behaviours, contribute to the loss of control of food seeking seen following exposure to calorie-dense foods in rats. Antagonism of orexin-receptor-1 (ORX-R1) has been shown to reduce a range of stimulus-driven feeding behaviours, but have yet to be implicated in the regulation of habitual actions. In the current study, male Long-Evans rats were given 'binge-like' access to high-calorie diet (HCD) or standard chow diet, and were subsequently trained to press a lever for food outcome. When lever responses were tested following outcome devaluation, chow-fed rats displayed goal-directed actions, whereas HCD-exposed rats displayed habitual actions. In study 1, it was shown that systemic administration of the ORX-R1 antagonist, SB-334867, prior to test restored goal-directed behaviour in HCD-exposed rats. In study 2, intra-nigral administration of SB-334867 similarly restored goal-directed behaviour, thereby implicating the substantia nigra as an important site for this effect. This study demonstrates that targeting ORX-R1 reduces habitual food seeking in male rats which may be important for understanding and treating compulsive feeding, obesity and binge eating disorder. This study also implicates the lateral hypothalamus, where ORX is produced, in mediating the expression of habits for the first time, and thus extends on the neurocircuits known to regulate habitual actions. Further investigation is required to determine whether the same effects are also seen in female rats, given that there are recognised sexual dimorphisms in feeding behaviour and a higher incidence of disordered eating in female than male populations.
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Affiliation(s)
- Sam Merlin
- School of Science, Western Sydney University, Campbelltown, NSW 2560, Australia
| | - Teri M. Furlong
- School of Biomedical Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
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Dhafar HO, BaHammam AS. Body Weight and Metabolic Rate Changes in Narcolepsy: Current Knowledge and Future Directions. Metabolites 2022; 12:1120. [PMID: 36422261 PMCID: PMC9693066 DOI: 10.3390/metabo12111120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/13/2022] [Accepted: 11/15/2022] [Indexed: 08/26/2023] Open
Abstract
Narcolepsy is a known auto-immune disease that presents mainly in the teenage years with irresistible sleep attacks. Patients with narcolepsy, especially NT1, have been found to have a high prevalence of obesity and other metabolic derangements. This narrative review aimed to address the relationship between narcolepsy and changes in weight and metabolic rate, and discuss potential mechanisms for weight gain and metabolic changes and future research agendas on this topic. This article will provide a balanced, up-to-date critical review of the current literature, and delineate areas for future research, in order to understand the pathophysiological metabolic changes in narcolepsy. Articles using predefined keywords were searched for in PubMed and Google Scholar databases, with predefined inclusion and exclusion criteria. Compared to controls, patients with narcolepsy are more likely to be obese and have higher BMIs and waist circumferences. According to recent research, weight gain in narcolepsy patients may be higher during the disease's outset. The precise mechanisms causing this weight gain remains unknown. The available information, albeit limited, does not support differences in basal or resting metabolic rates between patients with narcolepsy and controls, other than during the time of disease onset. The evidence supporting the role of orexin in weight gain in humans with narcolepsy is still controversial, in the literature. Furthermore, the available data did not show any appreciable alterations in the levels of CSF melanin-concentrating hormone, plasma and CSF leptin, or serum growth hormone, in relation to weight gain. Other mechanisms have been proposed, including a reduction in sympathetic tone, hormonal changes, changes in eating behavior and physical activity, and genetic predisposition. The association between increased body mass index and narcolepsy is well-recognized; however, the relationship between narcolepsy and other metabolic measures, such as body fat/muscle distribution and metabolic rate independent of BMI, is not well documented, and the available evidence is inconsistent. Future longitudinal studies with larger sample sizes are needed to assess BMR in patients with narcolepsy under a standard protocol at the outset of narcolepsy, with regular follow-up.
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Affiliation(s)
- Hamza O. Dhafar
- The University Sleep Disorders Center, Department of Medicine, College of Medicine, King Saud University, Riyadh 11451, Saudi Arabia
- Department of Family Medicine, Prince Mansour Military Hospital, Taif 26526, Saudi Arabia
| | - Ahmed S. BaHammam
- The University Sleep Disorders Center, Department of Medicine, College of Medicine, King Saud University, Riyadh 11451, Saudi Arabia
- The Strategic Technologies Program of the National Plan for Sciences and Technology and Innovation in the Kingdom of Saudi Arabia, P.O. Box 2454, Riyadh 11324, Saudi Arabia
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Lan T, Li H, Yang S, Shi M, Han L, Sahu SK, Lu Y, Wang J, Zhou M, Liu H, Huang J, Wang Q, Zhu Y, Wang L, Xu Y, Lin C, Liu H, Hou Z. The chromosome-scale genome of the raccoon dog: Insights into its evolutionary characteristics. iScience 2022; 25:105117. [PMID: 36185367 PMCID: PMC9523411 DOI: 10.1016/j.isci.2022.105117] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/07/2022] [Accepted: 09/08/2022] [Indexed: 11/28/2022] Open
Affiliation(s)
- Tianming Lan
- BGI Life Science Joint Research Center, Northeast Forestry University, Harbin 150040, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen 518083, China
| | - Haimeng Li
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen 518083, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shangchen Yang
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Minhui Shi
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen 518083, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Han
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Sunil Kumar Sahu
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen 518083, China
| | - Yaxian Lu
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Jiangang Wang
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen 518083, China
| | - Mengchao Zhou
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Hui Liu
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Ministry of Education), College of Forestry, Hainan University, Haikou 570228, China
| | - Junxuan Huang
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen 518083, China
| | - Qing Wang
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen 518083, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yixin Zhu
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen 518083, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Wang
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yanchun Xu
- BGI Life Science Joint Research Center, Northeast Forestry University, Harbin 150040, China
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China
- Corresponding author
| | - Chuyu Lin
- Shenzhen Zhong Nong Jing Yue Biotech Company Limited, Shenzhen 518120, China
- Corresponding author
| | - Huan Liu
- BGI Life Science Joint Research Center, Northeast Forestry University, Harbin 150040, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen 518083, China
- Guangdong Provincial Key Laboratory of Genome Read and Write, BGI-Shenzhen, Shenzhen 518120, China
- Corresponding author
| | - Zhijun Hou
- BGI Life Science Joint Research Center, Northeast Forestry University, Harbin 150040, China
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China
- Corresponding author
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Lu Y, Zhang R, Lei H, Hang Y, Xue H, Cai X, Lu Y. Supplementation with Fermented Feedstuff Enhances Orexin Expression and Secretion Associated with Increased Feed Intake and Weight Gain in Weaned Pigs. Animals (Basel) 2022; 12:1329. [PMID: 35625175 PMCID: PMC9138051 DOI: 10.3390/ani12101329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 11/23/2022] Open
Abstract
The health status of weaned pigs is crucial for their subsequent growth performance. Supplementation with fermented feedstuff is able to improve the feed intake and growth of weaned pigs; however, the exact mechanism behind this is not clear. Hence, in the present study a total of 320 Duroc × Landrace × Yorkshire weaned pigs were selected and allocated to the following two groups: unfermented diet group (UFD) and fermented diet group (FD). The experimental period lasted 21 days. At the end of the experiment, feces, blood, and gastrointestinal tissue samples (including the stomach, jejunum, and ileum) were collected and used for further analysis. The results of growth performance suggested that the FD group had significantly increased (p < 0.05) average daily feed intake (ADFI) and average daily gain (ADG) during the first week, during the last two weeks, and over the entire three-week period compared with the UFD group. The results of the apparent nutrient digestibility of pigs showed that, compared with the UFD group, the FD group showed increased phosphorus (p < 0.05) and CP (p < 0.1) digestibility. There were no significant differences in the serum biochemical parameters between the UFD and FD groups. Moreover, our results showed that the FD group showed significantly increased gene expression of SGLT1 and PepT1 in the jejunum (p < 0.05). Compared with the UFD group, the FD group showed an increased (p < 0.05) serum orexin level and prepro-orexin (PPOX) expression in the gastric fundus, jejunum, and ileum mucosa and increased IGF-1 and IGFR expression in the jejunum. Collectively, these results indicated that supplementation with fermented feedstuff in the diet effectively enhanced the feed intake and growth of weaned pigs and that this may have been caused by the increased orexin, IGF-1, and IGFR serum levels.
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Affiliation(s)
- Yang Lu
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China; (H.L.); (Y.H.); (H.X.); (X.C.)
| | - Ruiyang Zhang
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110866, China;
| | - Hulong Lei
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China; (H.L.); (Y.H.); (H.X.); (X.C.)
| | - Yiqiong Hang
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China; (H.L.); (Y.H.); (H.X.); (X.C.)
| | - Huiqin Xue
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China; (H.L.); (Y.H.); (H.X.); (X.C.)
| | - Xuan Cai
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China; (H.L.); (Y.H.); (H.X.); (X.C.)
| | - Yonghong Lu
- Institute of Animal Husbandry and Veterinary Science, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China; (H.L.); (Y.H.); (H.X.); (X.C.)
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12
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Abstract
The hypocretins (Hcrts), also known as orexins, are two neuropeptides produced exclusively in the lateral hypothalamus. They act on two specific receptors that are widely distributed across the brain and involved in a myriad of neurophysiological functions that include sleep, arousal, feeding, reward, fear, anxiety and cognition. Hcrt cell loss in humans leads to narcolepsy with cataplexy (narcolepsy type 1), a disorder characterized by intrusions of sleep into wakefulness, demonstrating that the Hcrt system is nonredundant and essential for sleep/wake stability. The causal link between Hcrts and arousal/wakefulness stabilisation has led to the development of a new class of drugs, Hcrt receptor antagonists to treat insomnia, based on the assumption that blocking orexin-induced arousal will facilitate sleep. This has been clinically validated: currently, two Hcrt receptor antagonists are approved to treat insomnia (suvorexant and lemborexant), with a New Drug Application recently submitted to the US Food and Drug Administration for a third drug (daridorexant). Other therapeutic applications under investigation include reduction of cravings in substance-use disorders and prevention of neurodegenerative disorders such as Alzheimer's disease, given the apparent bidirectional relationship between poor sleep and worsening of the disease. Circuit neuroscience findings suggest that the Hcrt system is a hub that integrates diverse inputs modulating arousal (e.g., circadian rhythms, metabolic status, positive and negative emotions) and conveys this information to multiple output regions. This neuronal architecture explains the wealth of physiological functions associated with Hcrts and highlights the potential of the Hcrt system as a therapeutic target for a number of disorders. We discuss present and future possible applications of drugs targeting the Hcrt system for the treatment of circuit-related neuropsychiatric and neurodegenerative conditions.
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Affiliation(s)
- Laura H Jacobson
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia.,Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia.,Melbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Daniel Hoyer
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia.,Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia.,Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, USA
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13
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Pantazis CB, James MH, O’Connor S, Shin N, Aston-Jones G. Orexin-1 receptor signaling in ventral tegmental area mediates cue-driven demand for cocaine. Neuropsychopharmacology 2022; 47:741-751. [PMID: 34635803 PMCID: PMC8782853 DOI: 10.1038/s41386-021-01173-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 08/10/2021] [Accepted: 08/27/2021] [Indexed: 02/03/2023]
Abstract
Drug-associated sensory cues increase motivation for drug and the orexin system is importantly involved in this stimulus-enhanced motivation. Ventral tegmental area (VTA) is a major target by which orexin signaling modulates reward behaviors, but it is unknown whether this circuit is necessary for cue-driven motivation for cocaine. Here, we investigated the role of VTA orexin signaling in cue-driven motivation for cocaine using a behavioral economics (BE) paradigm. We found that infusion of the orexin-1 receptor (Ox1R) antagonist SB-334867 (SB) into VTA prior to BE testing reduced motivation when animals were trained to self-administer cocaine with discrete cues and tested on BE with those cues. SB had no effect when animals were trained to self-administer cocaine without cues or tested on BE without cues, indicating that learning to associate cues with drug delivery during self-administration training was necessary for cues to recruit orexin signaling in VTA. These effects were specific to VTA, as injections of SB immediately dorsal had no effect. Moreover, intra-VTA SB did not have an impact on locomotor activity, or low- or high-effort consumption of sucrose. Finally, we microinjected a novel retrograde adeno-associated virus (AAVretro) containing an orexin-specific short hairpin RNA (OxshRNA) into VTA to knock down orexin in the hypothalamus-VTA circuit. These injections significantly reduced orexin expression in lateral hypothalamus (LH) and decreased cue-driven motivation. These studies demonstrate a role for orexin signaling in VTA, specifically when cues predict drug reward.
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Affiliation(s)
- Caroline B. Pantazis
- grid.430387.b0000 0004 1936 8796Brain Health Institute, Rutgers University/Rutgers Biomedical and Health Sciences, Piscataway, NJ USA ,grid.94365.3d0000 0001 2297 5165Neurobiology of Addiction Section, Integrative Neuroscience Research Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD USA
| | - Morgan H. James
- grid.430387.b0000 0004 1936 8796Brain Health Institute, Rutgers University/Rutgers Biomedical and Health Sciences, Piscataway, NJ USA ,grid.430387.b0000 0004 1936 8796Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers Unviversity, Piscataway, NJ USA
| | - Shayna O’Connor
- grid.430387.b0000 0004 1936 8796Brain Health Institute, Rutgers University/Rutgers Biomedical and Health Sciences, Piscataway, NJ USA
| | - Noah Shin
- grid.430387.b0000 0004 1936 8796Brain Health Institute, Rutgers University/Rutgers Biomedical and Health Sciences, Piscataway, NJ USA ,grid.430387.b0000 0004 1936 8796Cell Biology and Neuroscience Department, Rutgers University-New Brunswick, Piscataway, NJ USA
| | - Gary Aston-Jones
- Brain Health Institute, Rutgers University/Rutgers Biomedical and Health Sciences, Piscataway, NJ, USA.
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14
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Knez R, Stevanovic D, Fernell E, Gillberg C. Orexin/Hypocretin System Dysfunction in ESSENCE (Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations). Neuropsychiatr Dis Treat 2022; 18:2683-2702. [PMID: 36411777 PMCID: PMC9675327 DOI: 10.2147/ndt.s358373] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 07/28/2022] [Indexed: 11/17/2022] Open
Abstract
Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations (ESSENCE) is an umbrella term covering a wide range of neurodevelopmental difficulties and disorders. Thus, ESSENCE includes attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and other neurodevelopmental disorders (NDDs) and difficulties, with a variety of symptoms in cognitive, motor, sensory, social, arousal, regulatory, emotional, and behavioral developmental domains, frequently co-occurring and likely having partly common neurobiological substrates. The ESSENCE concept is a clinical paradigm that promotes organizing NDDs in everyday clinical practice according to their coexistence, symptom dimensions overlapping, and treatment possibilities. Despite increased knowledge regarding NDDs, the neurobiological mechanisms that underlie them and other ESSENCE-related problems, are not well understood. With its wide range of neural circuits and interactions with numerous neurotransmitters, the orexin/hypocretin system (Orx-S) is possibly associated with a variety of neurocognitive, psychobiological, neuroendocrine, and physiological functions and behaviors. Dysfunction of Orx-S has been implicated in various psychiatric and neurological disorders. This article provides an overview of Orx-S dysfunctions' possible involvement in the development, presentation, and maintenance of ESSENCE. We provide a focused review of current research evidence linking orexin neuropeptides with specific clinical NDDs symptoms, mostly in ADHD and ASD, within the Research Domain Criteria (RDoC) framework. We propose that Orx-S dysfunction might have an important role in some of these neurodevelopmental symptom domains, such as arousal, wakefulness, sleep, motor and sensory processing, mood and emotional regulation, fear processing, reward, feeding, attention, executive functions, and sociability. Our perspective is presented from a clinical point of view. Further, more thorough systematic reviews are needed as well as planning of extensive new research into the Orx-S's role in ESSENCE, especially considering RDoC elements.
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Affiliation(s)
- Rajna Knez
- Gillberg Neuropsychiatry Centre, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Pediatrics, Skaraborg Hospital, Skövde, Sweden.,School of Health Sciences, University of Skövde, Skövde, Sweden
| | - Dejan Stevanovic
- Gillberg Neuropsychiatry Centre, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Elisabeth Fernell
- Gillberg Neuropsychiatry Centre, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Christopher Gillberg
- Gillberg Neuropsychiatry Centre, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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15
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Repetitive and Inflexible Active Coping and Addiction-like Neuroplasticity in Stressed Mice of a Helplessness-Resistant Inbred Strain. Behav Sci (Basel) 2021; 11:bs11120174. [PMID: 34940109 PMCID: PMC8698352 DOI: 10.3390/bs11120174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 11/23/2021] [Accepted: 11/30/2021] [Indexed: 01/02/2023] Open
Abstract
Dysfunctional coping styles are involved in the development, persistence, and relapse of psychiatric diseases. Passive coping with stress challenges (helplessness) is most commonly used in animal models of dysfunctional coping, although active coping strategies are associated with generalized anxiety disorder, social anxiety disorder, panic, and phobias as well as obsessive-compulsive and post-traumatic stress disorder. This paper analyzes the development of dysfunctional active coping strategies of mice of the helplessness–resistant DBA/2J (D2) inbred strain, submitted to temporary reduction in food availability in an uncontrollable and unavoidable condition. The results indicate that food-restricted D2 mice developed a stereotyped form of food anticipatory activity and dysfunctional reactive coping in novel aversive contexts and acquired inflexible and perseverant escape strategies in novel stressful situations. The evaluation of FosB/DeltaFosB immunostaining in different brain areas of food-restricted D2 mice revealed a pattern of expression typically associated with behavioral sensitization to addictive drugs and compulsivity. These results support the conclusion that an active coping style represents an endophenotype of mental disturbances characterized by perseverant and inflexible behavior.
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16
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Sleep dysregulation in binge eating disorder and "food addiction": the orexin (hypocretin) system as a potential neurobiological link. Neuropsychopharmacology 2021; 46:2051-2061. [PMID: 34145404 PMCID: PMC8505614 DOI: 10.1038/s41386-021-01052-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/26/2021] [Accepted: 05/28/2021] [Indexed: 12/12/2022]
Abstract
It has been proposed that binge eating reflects a pathological compulsion driven by the "addictive" properties of foods. Proponents of this argument highlight the large degree of phenomenological and diagnostic overlap between binge eating disorder (BED) and substance use disorders (SUDs), including loss of control over how much is consumed and repeated unsuccessful attempts to abstain from consumption, as well as commonalities in brain structures involved in food and drug craving. To date, very little attention has been given to an additional behavioral symptom that BED shares with SUDs-sleep dysregulation-and the extent to which this may contribute to the pathophysiology of BED. Here, we review studies examining sleep outcomes in patients with BED, which collectively point to a heightened incidence of sleep abnormalities in BED. We identify the orexin (hypocretin) system as a potential neurobiological link between compulsive eating and sleep dysregulation in BED, and provide a comprehensive update on the evidence linking this system to these processes. Finally, drawing on evidence from the SUD literature indicating that the orexin system exhibits significant plasticity in response to drugs of abuse, we hypothesize that chronic palatable food consumption likewise increases orexin system activity, resulting in dysregulated sleep/wake patterns. Poor sleep, in turn, is predicted to exacerbate binge eating, contributing to a cycle of uncontrolled food consumption. By extension, we suggest that pharmacotherapies normalizing orexin signaling, which are currently being trialed for the treatment of SUDs, might also have utility in the clinical management of BED.
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17
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Smith LL. The Central Role of Hypothermia and Hyperactivity in Anorexia Nervosa: A Hypothesis. Front Behav Neurosci 2021; 15:700645. [PMID: 34421554 PMCID: PMC8377352 DOI: 10.3389/fnbeh.2021.700645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/24/2021] [Indexed: 12/24/2022] Open
Abstract
Typically, the development of anorexia nervosa (AN) is attributed to psycho-social causes. Several researchers have recently challenged this view and suggested that hypothermia and hyperactivity (HyAc) are central to AN. The following hypothesis will attempt to clarify their role in AN. Anorexia nervosa patients (ANs) have significantly lower core temperatures (Tcore) compared to healthy controls (HCs). This reduced temperature represents a reset Tcore that needs to be maintained. However, ANs cannot maintain this Tcore due primarily to a reduced basal metabolic rate (BMR); BMR usually supplies heat to sustain Tcore. Therefore, to generate the requisite heat, ANs revert to the behavioral-thermoregulatory strategy of HyAc. The majority of ANs (~89%) are reportedly HyAc. Surprisingly, engagement in HyAc is not motivated by a conscious awareness of low Tcore, but rather by the innocuous sensation of "cold- hands" frequently reported by ANs. That is, local hand-thermoreceptors signal the brain to initiate HyAc, which boosts perfusion of the hands and alters the sensation of "cold-discomfort" to one of "comfort." This "rewarding" consequence encourages repetition/habit formation. Simultaneously, hyperactivity increases the availability of heat to assist with the preservation of Tcore. Additionally, HyAc induces the synthesis of specific brain neuromodulators that suppress food intake and further promote HyAc; this outcome helps preserve low weight and perpetuates this vicious cycle. Based on this hypothesis and supported by rodent research, external heat availability should reduce the compulsion to be HyAc to thermoregulate. A reduction in HyAc should decrease the production of brain neuromodulators that suppress appetite. If verified, hopefully, this hypothesis will assist with the development of novel treatments to aid in the resolution of this intractable condition.
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Affiliation(s)
- Lucille Lakier Smith
- Human Performance Laboratory, Department of Kinesiology, School of Health Sciences, East Carolina University, Greenville, NC, United States
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18
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Muthmainah M, Gogos A, Sumithran P, Brown RM. Orexins (hypocretins): The intersection between homeostatic and hedonic feeding. J Neurochem 2021; 157:1473-1494. [PMID: 33608877 DOI: 10.1111/jnc.15328] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/11/2021] [Accepted: 02/15/2021] [Indexed: 12/11/2022]
Abstract
Orexins are hypothalamic neuropeptides originally discovered to play a role in the regulation of feeding behaviour. The broad connections of orexin neurons to mesocorticolimbic circuitry suggest they may play a role in mediating reward-related behaviour beyond homeostatic feeding. Here, we review the role of orexin in a variety of eating-related behaviour, with a focus on reward and motivation, and the neural circuits driving these effects. One emerging finding is the involvement of orexins in hedonic and appetitive behaviour towards palatable food, in addition to their role in homeostatic feeding. This review discusses the brain circuitry and possible mechanisms underlying the role of orexins in these behaviours. Overall, there is a marked bias in the literature towards studies involving male subjects. As such, future work needs to be done to involve female subjects. In summary, orexins play an important role in driving motivation for high salient rewards such as highly palatable food and may serve as the intersection between homeostatic and hedonic feeding.
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Affiliation(s)
- Muthmainah Muthmainah
- The Florey Institute of Neuroscience and Mental Health, Mental Health Research Theme, Parkville, Melbourne, Vic., Australia.,The Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Vic., Australia.,Department of Anatomy, Faculty of Medicine, Universitas Sebelas Maret, Surakarta, Indonesia
| | - Andrea Gogos
- The Florey Institute of Neuroscience and Mental Health, Mental Health Research Theme, Parkville, Melbourne, Vic., Australia
| | - Priya Sumithran
- Department of Medicine (Austin), University of Melbourne, Heidelberg, Vic., Australia.,Department of Endocrinology, Austin Health, Heidelberg, Vic., Australia
| | - Robyn M Brown
- The Florey Institute of Neuroscience and Mental Health, Mental Health Research Theme, Parkville, Melbourne, Vic., Australia.,The Florey Department of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Vic., Australia
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19
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Boswell RG, Potenza MN, Grilo CM. The Neurobiology of Binge-eating Disorder Compared with Obesity: Implications for Differential Therapeutics. Clin Ther 2021; 43:50-69. [PMID: 33257092 PMCID: PMC7902428 DOI: 10.1016/j.clinthera.2020.10.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 10/30/2020] [Accepted: 10/30/2020] [Indexed: 12/13/2022]
Abstract
PURPOSE Emerging work indicates divergence in the neurobiologies of binge-eating disorder (BED) and obesity despite their frequent co-occurrence. This review highlights specific distinguishing aspects of BED, including elevated impulsivity and compulsivity possibly involving the mesocorticolimbic dopamine system, and discusses implications for differential therapeutics for BED. METHODS This narrative review describes epidemiologic, clinical, genetic, and preclinical differences between BED and obesity. Subsequently, this review discusses human neuroimaging work reporting differences in executive functioning, reward processing, and emotion reactivity in BED compared with obesity. Finally, on the basis of the neurobiology of BED, this review identifies existing and new therapeutic agents that may be most promising given their specific targets based on putative mechanisms of action relevant specifically to BED. FINDINGS BED is characterized by elevated impulsivity and compulsivity compared with obesity, which is reflected in divergent neurobiological characteristics and effective pharmacotherapies. Therapeutic agents that influence both reward and executive function systems may be especially effective for BED. IMPLICATIONS Greater attention to impulsivity/compulsivity-related, reward-related, and emotion reactivity-related processes may enhance conceptualization and treatment approaches for patients with BED. Consideration of these distinguishing characteristics and processes could have implications for more targeted pharmacologic treatment research and interventions.
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Affiliation(s)
- Rebecca G Boswell
- Yale School of Medicine, Department of Psychiatry, New Haven, CT, USA.
| | - Marc N Potenza
- Yale School of Medicine, Department of Psychiatry, New Haven, CT, USA; Connecticut Mental Health Center, New Haven, CT, USA; Connecticut Council on Problem Gambling, Wethersfield, CT, USA; Yale School of Medicine, Child Study Center, New Haven, CT, USA; Yale University, Department of Neuroscience, New Haven, CT, USA
| | - Carlos M Grilo
- Yale School of Medicine, Department of Psychiatry, New Haven, CT, USA; Yale University, Department of Psychology, New Haven, CT, USA
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20
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Williams DL, Coiduras II, Parise EM, Maske CB. Hindbrain orexin 1 receptors blunt intake suppression by gastrointestinal nutrients and cholecystokinin in male rats. Peptides 2020; 133:170351. [PMID: 32579900 PMCID: PMC7556705 DOI: 10.1016/j.peptides.2020.170351] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/19/2020] [Accepted: 06/19/2020] [Indexed: 01/06/2023]
Abstract
Hypothalamic orexin neurons project to many brain areas, including hindbrain structures such as the nucleus of the solitary tract (NTS) and area postrema (AP), where orexin 1 receptors (OX1Rs) are expressed. Hindbrain administration of orexin-A increases feeding and meal size, and blockade of hindbrain OX1Rs with the selective antagonist SB334867 has the opposite effect. Here we asked whether hindbrain OX1R stimulation or blockade alter rats' sensitivity to gastrointestinal satiety signals. Rats received 4th intracerebroventricular (icv) injections of vehicle or orexin-A, at a dose with no effect on its own, prior to an intragastric (IG) infusion of saline or a satiating volume of Ensure. IG Ensure suppressed subsequent chow intake, but orexin-A pretreatment significantly attenuated this IG nutrient-induced satiety at 2 h into the dark phase. In a second experiment, rats received NTS injections of vehicle or orexin-A before intraperitoneal (IP) injection of vehicle or the satiation hormone cholecystokinin (CCK). NTS orexin-A pretreatment completely blocked the intake-suppressive effect of CCK on dark-phase chow intake. Finally, we investigated the role of endogenous hindbrain OX1R activation by pretreating rats with 4th-icv injection of vehicle or SB334867 followed by IG infusion of saline or Ensure just before a chocolate Ensure licking test session. IG nutrient infusion suppressed Ensure intake, and blockade of hindbrain OX1Rs significantly prolonged that intake-suppressive effect. We conclude that hindbrain OX1Rs are a mechanism though which hypothalamic orexin neurons can reduce animals' sensitivity to gastrointestinal nutrient load, allowing them to consume more food.
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Affiliation(s)
- Diana L Williams
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL, 32306-4301 USA.
| | - Isabel I Coiduras
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL, 32306-4301 USA
| | - Eric M Parise
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL, 32306-4301 USA
| | - Calyn B Maske
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL, 32306-4301 USA
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21
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James MH, Fragale JE, O'Connor SL, Zimmer BA, Aston-Jones G. The orexin (hypocretin) neuropeptide system is a target for novel therapeutics to treat cocaine use disorder with alcohol coabuse. Neuropharmacology 2020; 183:108359. [PMID: 33091458 DOI: 10.1016/j.neuropharm.2020.108359] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/05/2020] [Accepted: 10/15/2020] [Indexed: 12/14/2022]
Abstract
An estimated 50-90% of individuals with cocaine use disorder (CUD) also report using alcohol. Cocaine users report coabusing alcohol to 'self-medicate' against the negative emotional side effects of the cocaine 'crash', including the onset of anxiety. Thus, pharmaceutical strategies to treat CUD would ideally reduce the motivational properties of cocaine, alcohol, and their combination, as well as reduce the onset of anxiety during drug withdrawal. The hypothalamic orexin (hypocretin) neuropeptide system offers a promising target, as orexin neurons are critically involved in activating behavioral and physiological states to respond to both positive and negative motivators. Here, we seek to describe studies demonstrating efficacy of orexin receptor antagonists in reducing cocaine, alcohol- and stress-related behaviors, but note that these studies have largely focused on each of these phenomena in isolation. For orexin-based compounds to be viable in the clinical setting, we argue that it is imperative that their efficacy be tested in animal models that account for polysubstance use patterns. To begin to examine this, we present new data showing that rats' preferred level of cocaine intake is significantly increased following chronic homecage access to alcohol. We also report that cocaine intake and motivation are reduced by a selective orexin-1 receptor antagonist when rats have a history of cocaine + alcohol, but not a limited history of cocaine alone. In light of these proof-of-principle data, we outline what we believe to be the key priorities going forward with respect to further examining the orexin system in models of polysubstance use. This article is part of the special issue on Neurocircuitry Modulating Drug and Alcohol Abuse.
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Affiliation(s)
- Morgan H James
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical Health Sciences, Piscataway, NJ, USA; Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, NJ, USA; Florey Institute of Neuroscience and Mental Health, University of Melbourne, VIC, Australia
| | - Jennifer E Fragale
- Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, NJ, USA
| | - Shayna L O'Connor
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical Health Sciences, Piscataway, NJ, USA; Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, NJ, USA
| | - Benjamin A Zimmer
- Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, NJ, USA
| | - Gary Aston-Jones
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical Health Sciences, Piscataway, NJ, USA; Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, NJ, USA.
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22
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Pulver A, Kiive E, Kanarik M, Harro J. Association of orexin/hypocretin receptor gene (HCRTR1) with reward sensitivity, and interaction with gender. Brain Res 2020; 1746:147013. [PMID: 32652147 DOI: 10.1016/j.brainres.2020.147013] [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] [Received: 04/13/2020] [Revised: 07/02/2020] [Accepted: 07/06/2020] [Indexed: 12/12/2022]
Abstract
Orexins/hypocretins maintain wakefulness, increase appetite and participate in the coordination of stress response. We have recently provided evidence on the role of orexins in aggression, showing the association of the HCRTR1 genotype. (rs2271933 G > A; leading to amino acid substitution Ile408Val) with aggressiveness or breach of law in four independent cohorts. Aggressive behaviour can be reward driven and hence we have examined the association of HCRTR1 rs2271933 genotype with different aspects of reward sensitivity in the birth cohort representative Estonian Children Personality Behaviour and Health Study. HCRTR1 genotype was associated with reward sensitivity in a gender dependent manner. Male HCRTR1 A/A homozygotes had higher Openness to Rewards and the overall reward sensitivity score while, in contrast, female A/A homozygotes scored lower than G-allele carriers in Openness to Rewards. In the total sample, aggressiveness correlated positively with reward sensitivity, but this was on account of Insatiability by Reward. In contrast, the HCRTR1 A/A homozygotes had a positive association of aggressiveness and Openness to Rewards. Experience of stressful life events had a small but significant increasing effect on both aspects of reward sensitivity, and correlated in an anomalous way with reward sensitivity in the HCRTR1 A/A homozygotes. Conclusively, the higher aggressiveness of HCRTR1 A/A homozygotes appears based on a qualitative difference in sensitivity to rewards, in the form that suggests their lower ability to prevent responses to challenges being converted into overt aggression.
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Affiliation(s)
- Aleksander Pulver
- School of Natural Sciences and Health, Tallinn University, Narva Road 29, Astra Building, 10120 Tallinn, Estonia
| | - Evelyn Kiive
- Division of Special Education, Department of Education, University of Tartu, Näituse 2, 50409 Tartu, Estonia
| | - Margus Kanarik
- Division of Neuropsychopharmacology, Department of Psychology, University of Tartu, Ravila 14A Chemicum, 50411 Tartu, Estonia
| | - Jaanus Harro
- School of Natural Sciences and Health, Tallinn University, Narva Road 29, Astra Building, 10120 Tallinn, Estonia; Division of Neuropsychopharmacology, Department of Psychology, University of Tartu, Ravila 14A Chemicum, 50411 Tartu, Estonia.
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23
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Freeman LR, Bentzley BS, James MH, Aston-Jones G. Sex Differences in Demand for Highly Palatable Foods: Role of the Orexin System. Int J Neuropsychopharmacol 2020; 24:54-63. [PMID: 32496559 PMCID: PMC7816693 DOI: 10.1093/ijnp/pyaa040] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/04/2020] [Accepted: 05/29/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The prevalence of eating disorders, including binge eating disorder, is significantly higher in women. These findings are mirrored by preclinical studies, which indicate that female rats have a higher preference for palatable food and show greater binge-like eating compared with male rats. METHODS Here, we describe a novel within-session behavioral-economic paradigm that allows for the simultaneous measurement of the intake at null cost (Q0) and normalized demand elasticity (α) of 3 types of palatable food (low fat, high fat, and chocolate sucrose pellets) via demand curve analysis. In light of evidence that the orexin (hypocretin) system is critically involved in reward and feeding behaviors, we also examined the role of orexin function in sex differences of economic demand for palatable foods. RESULTS The novel within-session behavioral-economic approach revealed that female rats have higher intake (demand) than males for all palatable foods at low cost (normalized to body weight) but no difference in intake at higher prices, indicating sex-dependent differences in the hedonic, but not motivational, aspects of palatable food. Immediately following behavioral-economic testing, we observed more orexin-expressing neurons and Fos expression (measure of recent neural activation) in these neurons in female rats compared with male rats. Moreover, the orexin-1 receptor antagonist SB334867 reduced both low- and high-cost intake for palatable food in both male and female rats. CONCLUSIONS These findings provide evidence of higher demand at low prices for palatable food in females and indicate that these behavioral differences may be associated with sexual dimorphism in orexin system function.
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Affiliation(s)
- Linnea R Freeman
- Department of Biology, Furman University, Greenville, South Carolina
| | - Brandon S Bentzley
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California
| | - Morgan H James
- Brain Health Institute, Rutgers University, Piscataway, New Jersey,Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Gary Aston-Jones
- Brain Health Institute, Rutgers University, Piscataway, New Jersey,Correspondence: Gary Aston-Jones, PhD, 683 Hoes Lane West, Piscataway, NJ 08854 ()
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24
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Buczek L, Migliaccio J, Petrovich GD. Hedonic Eating: Sex Differences and Characterization of Orexin Activation and Signaling. Neuroscience 2020; 436:34-45. [PMID: 32283183 DOI: 10.1016/j.neuroscience.2020.04.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 04/01/2020] [Accepted: 04/05/2020] [Indexed: 02/09/2023]
Abstract
Palatable taste can stimulate appetite in the absence of hunger, and individual differences in hedonic eating may be critical to overeating. Women are more prone to obesity and binge eating than men, which warrants comparisons of hedonic versus physiological consumption and the underlying neural substrates in both sexes. The current study examined palatable (high-sugar) food consumption in male and female rats under physiological hunger and satiety, and the role of the neuropeptide orexin/hypocretin (ORX). Across multiple tests, females consistently consumed similar amounts of palatable food regardless of whether they were hungry or sated prior to testing. In contrast, males typically adjusted their consumption according to their hunger/satiety state. This difference was specific to palatable food consumption, as both sexes ate standard chow according to their hunger state. ORX is important in food motivation and reward behaviors. Thus, to begin to determine the neuronal mechanisms of hedonic eating, we examined activation and signaling of ORX neurons. We systematically characterized Fos induction patterns of ORX neurons across the entire rostrocaudal extent of the lateral hypothalamus and found that they were activated by food and by fasting in both sexes. Then, we showed that systemic blockade of ORX receptor 1 signaling with SB-334867 decreased palatable food consumption in hungry and sated rats of both sexes. These results demonstrate sex differences in hedonic eating; increased susceptibility in females to overeat palatable food regardless of hunger state, and that ORX is a critical neuropeptide mechanism of hedonic eating in both sexes.
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Affiliation(s)
- Laura Buczek
- Department of Psychology, Boston College, Chestnut Hill, MA 02467, United States
| | - Jennifer Migliaccio
- Department of Psychology, Boston College, Chestnut Hill, MA 02467, United States
| | - Gorica D Petrovich
- Department of Psychology, Boston College, Chestnut Hill, MA 02467, United States.
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25
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Mohammadkhani A, James MH, Pantazis CB, Aston-Jones G. Persistent effects of the orexin-1 receptor antagonist SB-334867 on motivation for the fast acting opioid remifentanil. Brain Res 2020; 1731:146461. [PMID: 31526801 PMCID: PMC7069781 DOI: 10.1016/j.brainres.2019.146461] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 08/29/2019] [Accepted: 09/13/2019] [Indexed: 12/19/2022]
Abstract
The orexin (hypocretin) system is multifaceted, and regulates sleep-wake cycles, nociception, endocrine function and reward-seeking behavior. We have established an important role for this system in motivation for drugs of abuse. The orexin-1 receptor (Ox1R) antagonist SB334867 (SB) reduces seeking of drug reward under conditions of high motivation. There is some evidence that the effects of systemic SB on reward seeking persist beyond the pharmacological availability of the drug, however the time course of these effects is not well characterized, nor is it known whether similar persistent effects are observed following intraparenchymal injections. Here, we used a behavioral economics paradigm, which allows for repeated testing of drug motivation across consecutive days, to examine the persistent effects of acute systemic and local treatment with SB on motivation for the short-acting μ-opioid receptor agonistremifentanil. Systemic injections of SB immediately prior to behavioral testing reduced motivation for remifentanil; this effect was sustained on a subsequent test at 24 h, but not on a third test at 48 h. When injected into ventral pallidum (VP) the effects of SB were more persistent, with reduced motivation observed for up to 48 h. We next made SB injections into VP 24 h prior to behavioral testing; this produced effects that persisted for at least 72 h post-treatment. Cued reinstatement of extinguished remifentanil seeking was also attenuated by pretreatment with SB 24 h earlier. These data indicate that the effects of SB on opioid seeking behavior persist beyond the bioavailability of the compound. These observations have important ramifications for the future clinical use of orexin receptor antagonists for the treatment of addiction.
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Affiliation(s)
- Aida Mohammadkhani
- Brain Health Institute, Rutgers University, Piscataway, NJ 08854, United States; School of Cognitive Sciences (SCS), Institute for Research in Fundamental Sciences (IPM), PO Box 1954851167, Tehran, Iran; Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Morgan H James
- Brain Health Institute, Rutgers University, Piscataway, NJ 08854, United States; Florey Institute of Neuroscience and Mental Health, University of Melbourne, VIC, Australia
| | - Caroline B Pantazis
- Brain Health Institute, Rutgers University, Piscataway, NJ 08854, United States; Neurobiology of Addiction Section, Integrative Neuroscience Research Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - Gary Aston-Jones
- Brain Health Institute, Rutgers University, Piscataway, NJ 08854, United States.
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26
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Introduction to the Special Issue: "Making orexin-based therapies for addiction a reality: What are the steps from here?". Brain Res 2020; 1731:146665. [PMID: 31930996 DOI: 10.1016/j.brainres.2020.146665] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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27
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Ritter S, Li AJ, Wang Q. Hindbrain glucoregulatory mechanisms: Critical role of catecholamine neurons in the ventrolateral medulla. Physiol Behav 2019; 208:112568. [PMID: 31173784 PMCID: PMC7015674 DOI: 10.1016/j.physbeh.2019.112568] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 06/03/2019] [Accepted: 06/03/2019] [Indexed: 12/29/2022]
Abstract
Glucose is the required metabolic substrate for the brain. Yet the brain stores very little glucose. Therefore, the brain continuously monitors glucose availability to detect hypoglycemia and to mobilize system-wide responses to protect and restore euglycemia. Catecholamine (CA) neurons in the hindbrain are critical elements of the brain's glucoregulatory mechanisms. They project widely throughout the brain and spinal cord, innervating sites controlling behavioral, endocrine and visceral responses. Hence, CA neurons are capable of triggering a rapid, coordinated and multifaceted response to glucose challenge. This article reviews experimental data that has begun to elucidate the importance of CA neurons for glucoregulation, the functions of specific CA subpopulations in the ventrolateral medulla, and the extended circuitry through which they engage other levels of the nervous system to accomplish their essential glucoregulatory task. Hopefully, this review also suggests the vast amount of work yet to be done in this area and the justification for engaging in that effort.
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Affiliation(s)
- Sue Ritter
- Department of Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, United States of America.
| | - Ai-Jun Li
- Department of Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, United States of America
| | - Qing Wang
- Department of Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, United States of America
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28
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Wiskerke J, James MH, Aston-Jones G. The orexin-1 receptor antagonist SB-334867 reduces motivation, but not inhibitory control, in a rat stop signal task. Brain Res 2019; 1731:146222. [PMID: 31002819 DOI: 10.1016/j.brainres.2019.04.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 03/22/2019] [Accepted: 04/15/2019] [Indexed: 12/11/2022]
Abstract
There is considerable clinical interest in the neuropeptide orexin/hypocretin for its ability to regulate motivation and reward as well as arousal and wakefulness. For instance, antagonists for the orexin-1 receptor (OxR1) are thought to hold great promise for treating drug addiction and disorders associated with overeating, as these compounds repeatedly have been found to suppress seeking of various drugs of abuse as well as highly palatable foods in preclinical models. Given the hypothesized role of OxR1 signaling in cue-driven motivation, an outstanding question is whether pharmacologically blocking this receptor affects cognitive functioning. Response inhibition - the ability to cancel ongoing behavior - is one aspect of cognitive control that may be particularly relevant. Response inhibition deficits are commonly associated with a range of psychiatric disorders and neurological diseases, including substance use disorders and obesity. Moreover, OxR1 signaling recently has been implicated in waiting impulsivity, another aspect of inhibitory control. Here, we investigated the effects of the OxR1 antagonist SB-334867 on response inhibition in a rat version of the stop-signal reaction time task. Results show that acutely blocking OxR1 had minimal effects on response inhibition or attentional functioning. In contrast, this manipulation reduced motivation to perform the task and earn food rewards, consistent with other recent findings. These results add to the growing body of literature implicating OxR1 in the regulation of motivation and suggest that effects of pharmacological compounds such as SB-334867 on drug-seeking behavior are not related to effects on response inhibition.
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Affiliation(s)
- Joost Wiskerke
- Brain Health Institute, Rutgers University, Piscataway, NJ, USA; Present address: Center for Social and Affective Neuroscience, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
| | - Morgan H James
- Brain Health Institute, Rutgers University, Piscataway, NJ, USA; Florey Institute for Neuroscience and Mental Health, Parkville, VIC, Australia
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29
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Almeneessier AS, BaHammam AS. How does diurnal intermittent fasting impact sleep, daytime sleepiness, and markers of the biological clock? Current insights. Nat Sci Sleep 2018; 10:439-452. [PMID: 30573998 PMCID: PMC6292409 DOI: 10.2147/nss.s165637] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Mealtimes and feeding schedules may interfere with the circadian system and impact sleep. The practice of intermittent fasting (IF) in its different formats is increasing worldwide. However, most studies addressing the effect of IF on circadian rhythms, daytime sleepiness, and sleep architecture have been conducted during diurnal IF for Ramadan. In this article, we analyze the effect of diurnal IF on the circadian clock, sleep, and daytime sleepiness. In free-living, unconstrained environments that do not control for lifestyle changes such as sleep/wake schedules, sleep duration, and light exposure, studies have demonstrated sudden and significant delays in bedtime and wake time during diurnal intermittent fasting for Ramadan. However, subsequent studies that accounted for lifestyle factors and sleep/wake patterns have reported no changes in markers of the biological clock, daytime sleepiness, or sleep parameters. Nevertheless, several researchers have demonstrated a reduction in the proportion of rapid eye movement stage sleep as the significant alteration in sleep architecture during fasting.
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Affiliation(s)
- Aljohara S Almeneessier
- Department of Medicine, University Sleep Disorders Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia, .,Department of Family Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Ahmed S BaHammam
- Department of Medicine, University Sleep Disorders Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia,
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