1
|
Esmaili-Shahzade-Ali-Akbari P, Ghaderi A, Sadeghi A, Nejat F, Mehramiz A. The Role of Orexin Receptor Antagonists in Inhibiting Drug Addiction: A Review Article. ADDICTION & HEALTH 2024; 16:130-139. [PMID: 39051042 PMCID: PMC11264478 DOI: 10.34172/ahj.2024.1491] [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] [Received: 07/29/2023] [Accepted: 04/15/2024] [Indexed: 07/27/2024]
Abstract
The orexinergic system and its receptors are involved in many physiological processes. Their functions in energy homeostasis, arousal, cognition, stress processing, endocrine functions, and pain modulation have been investigated. Many studies have shown that the orexinergic system cooperates with the dopaminergic system in the addiction process. Emerging evidence suggests that the orexinergic system can be effective in the induction of drug dependence and tolerance. Therefore, several researches have been conducted on the effect of orexin receptor (OXR) antagonists on reducing tolerance and dependence caused by drug abuse. Due to the significant growth of the studies on the orexinergic system, the current literature was conducted to collect the findings of previous studies on orexin and its receptors in the induction of drug addiction. In addition, cellular and molecular mechanisms of the possible role of orexin in drug tolerance and dependence are discussed. The findings indicate that the administration of OXR antagonists reduces drug dependence. OXR blockers seem to counteract the addictive effects of drugs through multiple mechanisms, such as preventing neuronal adaptation. This review proposes the potential clinical use of OXR antagonists in the treatment of drug dependence.
Collapse
Affiliation(s)
- Peyman Esmaili-Shahzade-Ali-Akbari
- Department of Addiction Studies, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran
- Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Amir Ghaderi
- Department of Addiction Studies, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran
| | - Atena Sadeghi
- Department of Microbiology, Faculty of Medicine, Shahed University, Tehran, Iran
| | - Fatemeh Nejat
- Department of Biology and Health Sciences, Meredith College, Raleigh, North Carolina, USA
| | - Alireza Mehramiz
- Department of Physical Therapy, Faculty of Paramedical and Rehabilitation Science, Mashhad University of Medical Sciences, Mashhad, Iran
| |
Collapse
|
2
|
Ouaidat S, Amaral IM, Monteiro DG, Harati H, Hofer A, El Rawas R. Orexins/Hypocretins: Gatekeepers of Social Interaction and Motivation. Int J Mol Sci 2024; 25:2609. [PMID: 38473854 DOI: 10.3390/ijms25052609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/12/2024] [Accepted: 02/20/2024] [Indexed: 03/14/2024] Open
Abstract
Ever since the discovery of the brain's orexin/hypocretin system, most research was directed toward unveiling its contribution to the normal functioning of individuals. The investigation of reward-seeking behaviors then gained a lot of attention once the distribution of orexinergic neurons was revealed. Here, we discuss findings on the involvement of orexins in social interaction, a natural reward type. While some studies have succeeded in defining the relationship between orexin and social interaction, the controversy regarding its nature (direct or inverse relation) raises questions about what aspects have been overlooked until now. Upon examining the literature, we identified a research gap concerning conditions influencing the impact of orexins on social behavior expression. In this review, we introduce a number of factors (e.g., stress, orexin's source) that must be considered while studying the role of orexins in social interaction. Furthermore, we refer to published research to investigate the stage at which orexins affect social interaction and we highlight the nucleus accumbens (NAc) shell's role in social interaction and other rewarding behaviors. Finally, the underlying orexin molecular pathway influencing social motivation in particular illnesses is proposed. We conclude that orexin's impact on social interaction is multifactorial and depends on specific conditions available at a time.
Collapse
Affiliation(s)
- Sara Ouaidat
- Division of Psychiatry I, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, 6020 Innsbruck, Austria
- Neuroscience Research Center, Faculty of Medical Sciences, Lebanese University, Beirut P.O. Box 1533, Lebanon
| | - Inês M Amaral
- Division of Psychiatry I, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Diogo G Monteiro
- Division of Psychiatry I, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Hayat Harati
- Neuroscience Research Center, Faculty of Medical Sciences, Lebanese University, Beirut P.O. Box 1533, Lebanon
| | - Alex Hofer
- Division of Psychiatry I, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Rana El Rawas
- Division of Psychiatry I, Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, Medical University Innsbruck, 6020 Innsbruck, Austria
| |
Collapse
|
3
|
Bandarabadi M, Li S, Aeschlimann L, Colombo G, Tzanoulinou S, Tafti M, Becchetti A, Boutrel B, Vassalli A. Inactivation of hypocretin receptor-2 signaling in dopaminergic neurons induces hyperarousal and enhanced cognition but impaired inhibitory control. Mol Psychiatry 2024; 29:327-341. [PMID: 38123729 PMCID: PMC11116111 DOI: 10.1038/s41380-023-02329-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 11/09/2023] [Accepted: 11/15/2023] [Indexed: 12/23/2023]
Abstract
Hypocretin/Orexin (HCRT/OX) and dopamine (DA) are both key effectors of salience processing, reward and stress-related behaviors and motivational states, yet their respective roles and interactions are poorly delineated. We inactivated HCRT-to-DA connectivity by genetic disruption of Hypocretin receptor-1 (Hcrtr1), Hypocretin receptor-2 (Hcrtr2), or both receptors (Hcrtr1&2) in DA neurons and analyzed the consequences on vigilance states, brain oscillations and cognitive performance in freely behaving mice. Unexpectedly, loss of Hcrtr2, but not Hcrtr1 or Hcrtr1&2, induced a dramatic increase in theta (7-11 Hz) electroencephalographic (EEG) activity in both wakefulness and rapid-eye-movement sleep (REMS). DAHcrtr2-deficient mice spent more time in an active (or theta activity-enriched) substate of wakefulness, and exhibited prolonged REMS. Additionally, both wake and REMS displayed enhanced theta-gamma phase-amplitude coupling. The baseline waking EEG of DAHcrtr2-deficient mice exhibited diminished infra-theta, but increased theta power, two hallmarks of EEG hyperarousal, that were however uncoupled from locomotor activity. Upon exposure to novel, either rewarding or stress-inducing environments, DAHcrtr2-deficient mice featured more pronounced waking theta and fast-gamma (52-80 Hz) EEG activity surges compared to littermate controls, further suggesting increased alertness. Cognitive performance was evaluated in an operant conditioning paradigm, which revealed that DAHcrtr2-ablated mice manifest faster task acquisition and higher choice accuracy under increasingly demanding task contingencies. However, the mice concurrently displayed maladaptive patterns of reward-seeking, with behavioral indices of enhanced impulsivity and compulsivity. None of the EEG changes observed in DAHcrtr2-deficient mice were seen in DAHcrtr1-ablated mice, which tended to show opposite EEG phenotypes. Our findings establish a clear genetically-defined link between monosynaptic HCRT-to-DA neurotransmission and theta oscillations, with a differential and novel role of HCRTR2 in theta-gamma cross-frequency coupling, attentional processes, and executive functions, relevant to disorders including narcolepsy, attention-deficit/hyperactivity disorder, and Parkinson's disease.
Collapse
Affiliation(s)
- Mojtaba Bandarabadi
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| | - Sha Li
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| | - Lea Aeschlimann
- Centre for Psychiatric Neuroscience, Department of Psychiatry, The Lausanne University Hospital, Lausanne, Switzerland
| | - Giulia Colombo
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy
| | | | - Mehdi Tafti
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| | - Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy
| | - Benjamin Boutrel
- Centre for Psychiatric Neuroscience, Department of Psychiatry, The Lausanne University Hospital, Lausanne, Switzerland
| | - Anne Vassalli
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland.
| |
Collapse
|
4
|
Zamanirad F, Eskandari K, Mousavi Z, Haghparast A. Blockade of the orexin-2 receptors within the ventral tegmental area facilitates the extinction and prevents the reinstatement of methamphetamine-seeking behavior. Physiol Behav 2024; 273:114382. [PMID: 37866644 DOI: 10.1016/j.physbeh.2023.114382] [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: 04/22/2023] [Revised: 10/19/2023] [Accepted: 10/19/2023] [Indexed: 10/24/2023]
Abstract
Repeated use of methamphetamine (METH) causes severe effects on the central nervous system, associated with an increased relapse rate. The orexinergic system is highly implicated in the reward circuitry and may be a promising target for treating psychostimulant dependency. The present study aimed to investigate the involvement of the orexin system, mainly the orexin-2 receptors (OX2R) in the ventral tegmental area (VTA) in the extinction and reinstatement of METH-seeking behavior using a conditioned place preference (CPP) paradigm. To this end, animals received METH (1 mg/kg; sc) for a 5-day conditioning period. Then, in the first set of experiments, different groups of rats were given intra-VTA TCS OX2 29 (1, 3, 10, or 30 nmol/0.3 μl DMSO) as an OX2R antagonist over a 10-day extinction period. In another experiment, after the extinction period, a different set of animals received a single dose of TCS OX2 29 (1, 3, 10, or 30 nmol) before the priming dose of METH (0.25 mg/kg; sc) on the reinstatement day. The results revealed that TCS OX2 29 (10 and 30 nmol) remarkably facilitated the extinction of rewarding properties of METH (P < 0.001 for both doses). Furthermore, TCS OX2 29 (3, 10, or 30 nmol) significantly suppressed the METH-induced reinstatement (3 nmol; P < 0.05, 10 nmol; P < 0.01, and 30 nmol; P < 0.001). In conclusion, the current study revealed that the orexinergic system, specifically the VTA OX2R, is involved in METH-seeking behaviors and that manipulation of this system can be considered a potential therapeutics in treating METH dependency.
Collapse
Affiliation(s)
- Ferdos Zamanirad
- Pharmacology and Toxicology Department, Faculty of Pharmacy and Pharmaceutical Sciences, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Kiarash Eskandari
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zahra Mousavi
- Pharmacology and Toxicology Department, Faculty of Pharmacy and Pharmaceutical Sciences, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Abbas Haghparast
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; School of Cognitive Sciences, Institute for Research in Fundamental Sciences, Tehran, Iran; Department of Basic Sciences, Iranian Academy of Medical Sciences, Tehran, Iran.
| |
Collapse
|
5
|
Powell K, Lin K, Tambo W, Saavedra AP, Sciubba D, Al Abed Y, Li C. Trigeminal nerve stimulation: a current state-of-the-art review. Bioelectron Med 2023; 9:30. [PMID: 38087375 PMCID: PMC10717521 DOI: 10.1186/s42234-023-00128-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/04/2023] [Indexed: 09/26/2024] Open
Abstract
Nearly 5 decades ago, the effect of trigeminal nerve stimulation (TNS) on cerebral blood flow was observed for the first time. This implication directly led to further investigations and TNS' success as a therapeutic intervention. Possessing unique connections with key brain and brainstem regions, TNS has been observed to modulate cerebral vasodilation, brain metabolism, cerebral autoregulation, cerebral and systemic inflammation, and the autonomic nervous system. The unique range of effects make it a prime therapeutic modality and have led to its clinical usage in chronic conditions such as migraine, prolonged disorders of consciousness, and depression. This review aims to present a comprehensive overview of TNS research and its broader therapeutic potentialities. For the purpose of this review, PubMed and Google Scholar were searched from inception to August 28, 2023 to identify a total of 89 relevant studies, both clinical and pre-clinical. TNS harnesses the release of vasoactive neuropeptides, modulation of neurotransmission, and direct action upon the autonomic nervous system to generate a suite of powerful multitarget therapeutic effects. While TNS has been applied clinically to chronic pathological conditions, these powerful effects have recently shown great potential in a number of acute/traumatic pathologies. However, there are still key mechanistic and methodologic knowledge gaps to be solved to make TNS a viable therapeutic option in wider clinical settings. These include bimodal or paradoxical effects and mechanisms, questions regarding its safety in acute/traumatic conditions, the development of more selective stimulation methods to avoid potential maladaptive effects, and its connection to the diving reflex, a trigeminally-mediated protective endogenous reflex. The address of these questions could overcome the current limitations and allow TNS to be applied therapeutically to an innumerable number of pathologies, such that it now stands at the precipice of becoming a ground-breaking therapeutic modality.
Collapse
Affiliation(s)
- Keren Powell
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA
- Institute for Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Kanheng Lin
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA
- Institute for Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
- Emory University, Atlanta, GA, USA
| | - Willians Tambo
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA
- Institute for Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
- Elmezzi Graduate School of Molecular Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | | | - Daniel Sciubba
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
| | - Yousef Al Abed
- Institute for Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Chunyan Li
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA.
- Institute for Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA.
- Elmezzi Graduate School of Molecular Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA.
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA.
| |
Collapse
|
6
|
Black EM, Samels SB, Xu W, Barson JR, Bass CE, Kortagere S, España RA. Hypocretin / Orexin Receptor 1 Knockdown in GABA or Dopamine Neurons in the Ventral Tegmental Area Differentially Impact Mesolimbic Dopamine and Motivation for Cocaine. ADDICTION NEUROSCIENCE 2023; 7:100104. [PMID: 37854172 PMCID: PMC10583964 DOI: 10.1016/j.addicn.2023.100104] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
The hypocretins/orexins (HCRT) have been demonstrated to influence motivation for cocaine through actions on dopamine (DA) transmission. Pharmacological or genetic disruption of the hypocretin receptor 1 (Hcrtr1) reduces cocaine self-administration, blocks reinstatement of cocaine seeking, and decreases conditioned place preference for cocaine. These effects are likely mediated through actions in the ventral tegmental area (VTA) and resulting alterations in DA transmission. For example, HCRT drives VTA DA neuron activity and enhances the effects of cocaine on DA transmission, while disrupting Hcrtr1 attenuates DA responses to cocaine. These findings have led to the perspective that HCRT exerts its effects through Hcrtr1 actions in VTA DA neurons. However, this assumption is complicated by the observation that Hcrtr1 are present on both DA and GABA neurons in the VTA and HCRT drives the activity of both neuronal populations. To address this issue, we selectively knocked down Hcrtr1 on either DA or GABA neurons in the VTA and examined alterations in DA transmission and cocaine self-administration in female and male rats. We found that Hcrtr1 knockdown in DA neurons decreased DA responses to cocaine, increased days to acquire cocaine self-administration, and reduced motivation for cocaine. Although, Hcrtr1 knockdown in GABA neurons enhanced DA responses to cocaine, this manipulation did not affect cocaine self-administration. These observations indicate that while Hcrtr1 on DA versus GABA neurons exert opposing effects on DA transmission, only Hcrtr1 on DA neurons affected acquisition or motivation for cocaine - suggesting a complex interplay between DA transmission and behavior.
Collapse
Affiliation(s)
- Emily M. Black
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Shanna B. Samels
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Wei Xu
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Jessica R. Barson
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Caroline E. Bass
- Department of Pharmacology and Toxicology, Jacobs School of Medicine, State University of New York at Buffalo, Buffalo NY 14214
| | - Sandhya Kortagere
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Rodrigo A. España
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129
| |
Collapse
|
7
|
Malik JA, Agrewala JN. Future perspectives of emerging novel drug targets and immunotherapies to control drug addiction. Int Immunopharmacol 2023; 119:110210. [PMID: 37099943 DOI: 10.1016/j.intimp.2023.110210] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 04/14/2023] [Accepted: 04/15/2023] [Indexed: 04/28/2023]
Abstract
Substance Use Disorder (SUD) is one of the major mental illnesses that is terrifically intensifying worldwide. It is becoming overwhelming due to limited options for treatment. The complexity of addiction disorders is the main impediment to understanding the pathophysiology of the illness. Hence, unveiling the complexity of the brain through basic research, identification of novel signaling pathways, the discovery of new drug targets, and advancement in cutting-edge technologies will help control this disorder. Additionally, there is a great hope of controlling the SUDs through immunotherapeutic measures like therapeutic antibodies and vaccines. Vaccines have played a cardinal role in eliminating many diseases like polio, measles, and smallpox. Further, vaccines have controlled many diseases like cholera, dengue, diphtheria, Haemophilus influenza type b (Hib), human papillomavirus, influenza, Japanese encephalitis, etc. Recently, COVID-19 was controlled in many countries by vaccination. Currently, continuous effort is done to develop vaccines against nicotine, cocaine, morphine, methamphetamine, and heroin. Antibody therapy against SUDs is another important area where serious attention is required. Antibodies have contributed substantially against many serious diseases like diphtheria, rabies, Crohn's disease, asthma, rheumatoid arthritis, and bladder cancer. Antibody therapy is gaining immense momentum due to its success rate in cancer treatment. Furthermore, enormous advancement has been made in antibody therapy due to the generation of high-efficiency humanized antibodies with a long half-life. The advantage of antibody therapy is its instant outcome. This article's main highlight is discussing the drug targets of SUDs and their associated mechanisms. Importantly, we have also discussed the scope of prophylactic measures to eliminate drug dependence.
Collapse
Affiliation(s)
- Jonaid Ahmad Malik
- Immunology laboratory, Indian Institute of Technology Ropar, Rupnagar, Punjab, India
| | - Javed N Agrewala
- Immunology laboratory, Indian Institute of Technology Ropar, Rupnagar, Punjab, India.
| |
Collapse
|
8
|
Plaza-Briceño W, Velásquez VB, Silva-Olivares F, Ceballo K, Céspedes R, Jorquera G, Cruz G, Martínez-Pinto J, Bonansco C, Sotomayor-Zárate R. Chronic Exposure to High Fat Diet Affects the Synaptic Transmission That Regulates the Dopamine Release in the Nucleus Accumbens of Adolescent Male Rats. Int J Mol Sci 2023; 24:ijms24054703. [PMID: 36902133 PMCID: PMC10003643 DOI: 10.3390/ijms24054703] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 03/05/2023] Open
Abstract
Obesity is a pandemic caused by many factors, including a chronic excess in hypercaloric and high-palatable food intake. In addition, the global prevalence of obesity has increased in all age categories, such as children, adolescents, and adults. However, at the neurobiological level, how neural circuits regulate the hedonic consumption of food intake and how the reward circuit is modified under hypercaloric diet consumption are still being unraveled. We aimed to determine the molecular and functional changes of dopaminergic and glutamatergic modulation of nucleus accumbens (NAcc) in male rats exposed to chronic consumption of a high-fat diet (HFD). Male Sprague-Dawley rats were fed a chow diet or HFD from postnatal day (PND) 21 to 62, increasing obesity markers. In addition, in HFD rats, the frequency but not amplitude of the spontaneous excitatory postsynaptic current is increased in NAcc medium spiny neurons (MSNs). Moreover, only MSNs expressing dopamine (DA) receptor type 2 (D2) increase the amplitude and glutamate release in response to amphetamine, downregulating the indirect pathway. Furthermore, NAcc gene expression of inflammasome components is increased by chronic exposure to HFD. At the neurochemical level, DOPAC content and tonic dopamine (DA) release are reduced in NAcc, while phasic DA release is increased in HFD-fed rats. In conclusion, our model of childhood and adolescent obesity functionally affects the NAcc, a brain nucleus involved in the hedonic control of feeding, which might trigger addictive-like behaviors for obesogenic foods and, through positive feedback, maintain the obese phenotype.
Collapse
Affiliation(s)
- Wladimir Plaza-Briceño
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Programa de Doctorado en Ciencias Mención Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Victoria B. Velásquez
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Programa de Doctorado en Ciencias Mención Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Francisco Silva-Olivares
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Programa de Doctorado en Ciencias Mención Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Instituto de Ciencias Naturales, Facultad de Medicina Veterinaria y Agronomía, Universidad de las Américas, Viña del Mar 2520000, Chile
| | - Karina Ceballo
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Programa de Doctorado en Ciencias Mención Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Ricardo Céspedes
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Programa de Doctorado en Ciencias Mención Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Gonzalo Jorquera
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Gonzalo Cruz
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Jonathan Martínez-Pinto
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Christian Bonansco
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Correspondence: (C.B.); (R.S.-Z.)
| | - Ramón Sotomayor-Zárate
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Correspondence: (C.B.); (R.S.-Z.)
| |
Collapse
|
9
|
Kourosh-Arami M, Gholami M, Alavi-Kakhki SS, Komaki A. Neural correlates and potential targets for the contribution of orexin to addiction in cortical and subcortical areas. Neuropeptides 2022; 95:102259. [PMID: 35714437 DOI: 10.1016/j.npep.2022.102259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 05/14/2022] [Accepted: 05/15/2022] [Indexed: 02/01/2023]
Abstract
The orexin (hypocretin) is one of the hypothalamic neuropeptides that plays a critical role in some behaviors including feeding, sleep, arousal, reward processing, and drug addiction. This variety of functions can be described by a united function for orexins in translating states of heightened motivation, for example during physiological requirement states or following exposure to reward opportunities, into planned goal-directed behaviors. An addicted state is characterized by robust activation of orexin neurons from the environment, which triggers downstream circuits to facilitate behavior directed towards obtaining the drug. Two orexin receptors 1 (OX1R) and 2 (OX2R) are widely distributed in the brain. Here, we will introduce and describe the cortical and subcortical brain areas involved in addictive-like behaviors and the impact of orexin on addiction.
Collapse
Affiliation(s)
- Masoumeh Kourosh-Arami
- Department of Neuroscience, School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Masoumeh Gholami
- Department of Physiology, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran.
| | - Seyed Sajjad Alavi-Kakhki
- Student Research Committee, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| |
Collapse
|
10
|
Majidinezhad M, Amirteymouri H, Karimi-haghighi S, Kourosh-Arami M, Haghparast A. Orexin system in the ventral tegmental area is implicated in the rewarding properties of methamphetamine. Eur J Pharmacol 2022; 930:175170. [DOI: 10.1016/j.ejphar.2022.175170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 07/10/2022] [Accepted: 07/21/2022] [Indexed: 11/03/2022]
|
11
|
Demidova A, Kahl E, Fendt M. Orexin deficiency affects sensorimotor gating and its amphetamine-induced impairment. Prog Neuropsychopharmacol Biol Psychiatry 2022; 116:110517. [PMID: 35101602 DOI: 10.1016/j.pnpbp.2022.110517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 11/17/2022]
Abstract
The orexin neuropeptides have an important role in the regulation of the sleep/wake cycle and foraging, as well as in reward processing and emotions. Furthermore, recent research implicates the orexin system in different behavioral endophenotypes of neuropsychiatric diseases such as social avoidance and cognitive flexibility. Utilizing orexin-deficient mice, the present study tested the hypothesis that orexin is involved in two further mouse behavioral endophenotypes of neuropsychiatric disorders, i.e., sensorimotor gating and amphetamine sensitivity. The data revealed that orexin-deficient mice expressed a deficit in sensorimotor gating, measured by prepulse inhibition of the startle response. Amphetamine treatment impaired prepulse inhibition in wildtype and heterozygous orexin-deficient mice, but had no effects in homozygous orexin-deficient mice. Furthermore, locomotor activity and center time in the open field was not affected by orexin deficiency but was similarly increased or decreased, respectively, by amphetamine treatment in all genotypes. These data indicate that the orexin system modulates prepulse inhibition and is involved in mediating amphetamine's effect on prepulse inhibition. Future studies should investigate whether pharmacological manipulations of the orexin system can be used to treat neuropsychiatric diseases associated with deficits in sensorimotor gating, such as schizophrenia or attention deficit hyperactivity disorder.
Collapse
Affiliation(s)
- Alexandrina Demidova
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University Magdeburg, Germany; Psychology Master Program, Otto-von-Guericke University Magdeburg, Germany
| | - Evelyn Kahl
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University Magdeburg, Germany
| | - Markus Fendt
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University Magdeburg, Germany; Psychology Master Program, Otto-von-Guericke University Magdeburg, Germany; Center for Behavioral Brain Sciences, Otto-von-Guericke University Magdeburg, Germany.
| |
Collapse
|
12
|
Chunduri A, Crusio WE, Delprato A. Narcolepsy in Parkinson's disease with insulin resistance. F1000Res 2022; 9:1361. [PMID: 34745571 PMCID: PMC8543173 DOI: 10.12688/f1000research.27413.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/12/2022] [Indexed: 11/20/2022] Open
Abstract
Background: Parkinson’s disease (PD) is characterized by its progression of motor-related symptoms such as tremors, rigidity, slowness of movement, and difficulty with walking and balance. Comorbid conditions in PD individuals include insulin resistance (IR) and narcolepsy-like sleep patterns. The intersecting sleep symptoms of both conditions include excessive daytime sleepiness, hallucinations, insomnia, and falling into REM sleep more quickly than an average person. Understanding of the biological basis and relationship of these comorbid disorders with PD may help with early detection and intervention strategies to improve quality of life. Methods: In this study, an integrative genomics and systems biology approach was used to analyze gene expression patterns associated with PD, IR, and narcolepsy in order to identify genes and pathways that may shed light on how these disorders are interrelated. A correlation analysis with known genes associated with these disorders (LRRK2, HLA-DQB1, and HCRT) was used to query microarray data corresponding to brain regions known to be involved in PD and narcolepsy. This includes the hypothalamus, dorsal thalamus, pons, and subcoeruleus nucleus. Risk factor genes for PD, IR, and narcolepsy were also incorporated into the analysis. Results: The PD and narcolepsy signaling networks are connected through insulin and immune system pathways. Important genes and pathways that link PD, narcolepsy, and IR are CACNA1C, CAMK1D, BHLHE41, HMGB1, and AGE-RAGE. Conclusions: We have identified the genetic signatures that link PD with its comorbid disorders, narcolepsy and insulin resistance, from the convergence and intersection of dopaminergic, insulin, and immune system related signaling pathways. These findings may aid in the design of early intervention strategies and treatment regimes for non-motor symptoms in PD patients as well as individuals with diabetes and narcolepsy.
Collapse
Affiliation(s)
- Alisha Chunduri
- Department of Biotechnology, Chaitanya Bharathi Institute of Technology, Hyderabad, 500075, India
- Department of Research and Education, BioScience Project, Wakefield, MA, 01880, USA
| | - Wim E. Crusio
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS UMR 5287, Pessac, 33615, France
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, UMR 5287 University of Bordeaux, Pessac, 33615, France
| | - Anna Delprato
- Department of Research and Education, BioScience Project, Wakefield, MA, 01880, USA
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS UMR 5287, Pessac, 33615, France
| |
Collapse
|
13
|
Aspesi D, Farinetti A, Marraudino M, Morgan GSK, Marzola E, Abbate-Daga G, Gotti S. Maternal separation alters the reward system of activity-based anorexia rats. Psychoneuroendocrinology 2021; 133:105393. [PMID: 34481327 DOI: 10.1016/j.psyneuen.2021.105393] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 08/02/2021] [Accepted: 08/20/2021] [Indexed: 02/07/2023]
Abstract
Maternal separation (MS) is a known chronic stressor in the postnatal period and when associated with another paradigm like the activity-based anorexia (ABA) rat model, causes different effects in the two sexes. In ABA females, the separation leads to increased hyperactivity and anxiety reduction, whereas, in males, the separation induces decreased locomotor activity without similar reduction of anxiety-like behaviors as observed in females. To understand the mechanisms altered by MS in synergy with the induction of the anorexic-like phenotype, we considered the reward system, which involves neurons synthesizing dopamine (DA) in the ventral tegmental area (VTA), substantia nigra pars compacta, and serotoninergic neurons in the dorsal raphe nucleus. Moreover, we analyzed the orexin circuit in the lateral hypothalamic area (LHA), which affects DA synthesis in the VTA and is also known to regulate food consumption and locomotor activity. Rats of both sexes were exposed to the two paradigms (MS and ABA), leading to four experimental groups for each sex: non-separated control (CON), non-separated ABA groups (ABA), MS control (MSCON), and MS plus ABA groups (MSABA). Immunohistochemistry analysis was performed to determine quantitative differences in the number of cells expressing DA, orexin, and serotonin (5-HT) among the experimental groups. The results showed that, in the DA system, the effect of MS was more evident in females than in males, with a substantial increase in DA cells in the VTA of MSABA. However, the analysis of the orexin system revealed a similar cellular increment in the LHA in the non-separated ABA groups of both sexes. Regarding 5-HT, there was an opposite effect in males and females of the MSABA groups, with only females showing a greater density of 5-HT cells. The changes in the reward system could partially explain the behavioral data: the hyperactivity, weight loss, and decreased anxiety levels of the MSABA females could be linked to an increase in DA and 5-HT cells, whereas in males, MS could mitigate the behavioral effects of the ABA protocol affecting the anxiety levels and locomotor activity through a lack of increased activation of the reward system.
Collapse
Affiliation(s)
- Dario Aspesi
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, Ontario, N1G 2W1 Canada.
| | - Alice Farinetti
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126 Turin, Italy; NICO - Neuroscience Institute Cavalieri Ottolenghi, Orbassano, 10043 Turin, Italy.
| | - Marilena Marraudino
- NICO - Neuroscience Institute Cavalieri Ottolenghi, Orbassano, 10043 Turin, Italy.
| | - Godstime Stephen Kojo Morgan
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126 Turin, Italy; NICO - Neuroscience Institute Cavalieri Ottolenghi, Orbassano, 10043 Turin, Italy.
| | - Enrica Marzola
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126 Turin, Italy; Eating Disorders Center of the "Città della Salute e della Scienza" Hospital, University of Turin, Italy.
| | - Giovanni Abbate-Daga
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126 Turin, Italy; Eating Disorders Center of the "Città della Salute e della Scienza" Hospital, University of Turin, Italy.
| | - Stefano Gotti
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126 Turin, Italy; NICO - Neuroscience Institute Cavalieri Ottolenghi, Orbassano, 10043 Turin, Italy.
| |
Collapse
|
14
|
Saad L, Kalsbeek A, Zwiller J, Anglard P. Rhythmic Regulation of DNA Methylation Factors and Core-Clock Genes in Brain Structures Activated by Cocaine or Sucrose: Potential Role of Chromatin Remodeling. Genes (Basel) 2021; 12:genes12081195. [PMID: 34440369 PMCID: PMC8392220 DOI: 10.3390/genes12081195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 12/25/2022] Open
Abstract
The circadian system interacts with the mesocorticolimbic reward system to modulate reward and memory in a time-of-day dependent manner. The circadian discrimination of reward, however, remains difficult to address between natural reinforcers and drugs of abuse. Circadian rhythms control cocaine sensitization and conversely cocaine causes long-term alteration in circadian periodicity in part through the serotonergic neurotransmission. Since neural circuits activated by cocaine and natural reinforcers do not completely overlap, we compared the effect of cocaine with that of sucrose, a strong reinforcer in rodents, by using passive chronic administration. The expression of fifteen genes playing a major role in DNA methylation (Dnmts, Tets), circadian rhythms (Clock, Bmal1, Per1/2, Cry1/2, Rev-Erbβ, Dbp1), appetite, and satiety (Orexin, Npy) was analyzed in dopamine projection areas like the prefrontal cortex, the caudate putamen, and the hypothalamus interconnected with the reward system. The corresponding proteins of two genes (Orexin, Per2) were examined by IHC. For many factors controlling biological and cognitive functions, striking opposite responses were found between the two reinforcers, notably for genes controlling DNA methylation/demethylation processes and in global DNA methylation involved in chromatin remodeling. The data are consistent with a repression of critical core-clock genes by cocaine, suggesting that, consequently, both agents differentially modulate day/night cycles. Whether observed cocaine and sucrose-induced changes in DNA methylation in a time dependent manner are long lasting or contribute to the establishment of addiction requires further neuroepigenetic investigation. Understanding the mechanisms dissociating drugs of abuse from natural reinforcers remains a prerequisite for the design of selective therapeutic tools for compulsive behaviors.
Collapse
Affiliation(s)
- Lamis Saad
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), UMR 7364 CNRS, Université de Strasbourg, Neuropôle de Strasbourg, 67000 Strasbourg, France; (L.S.); (J.Z.)
- The Netherlands Institute for Neuroscience (NIN), Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA Amsterdam, The Netherlands
- Department of Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, 1066 EA Amsterdam, The Netherlands
| | - Andries Kalsbeek
- The Netherlands Institute for Neuroscience (NIN), Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA Amsterdam, The Netherlands
- Department of Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, 1066 EA Amsterdam, The Netherlands
- Correspondence: (A.K.); or (P.A.)
| | - Jean Zwiller
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), UMR 7364 CNRS, Université de Strasbourg, Neuropôle de Strasbourg, 67000 Strasbourg, France; (L.S.); (J.Z.)
- CNRS, Centre National de la Recherche Scientifique, 75016 Paris, France
| | - Patrick Anglard
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), UMR 7364 CNRS, Université de Strasbourg, Neuropôle de Strasbourg, 67000 Strasbourg, France; (L.S.); (J.Z.)
- INSERM, Institut National de la Santé et de la Recherche Médicale, 75013 Paris, France
- Correspondence: (A.K.); or (P.A.)
| |
Collapse
|
15
|
Targeting the Orexin System for Prescription Opioid Use Disorder. Brain Sci 2020; 10:brainsci10040226. [PMID: 32290110 PMCID: PMC7225970 DOI: 10.3390/brainsci10040226] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 01/09/2023] Open
Abstract
Prescription opioids are potent analgesics that are used for clinical pain management. However, the nonmedical use of these medications has emerged as a major concern because of dramatic increases in abuse and overdose. Therefore, effective strategies to prevent prescription opioid use disorder are urgently needed. The orexin system has been implicated in the regulation of motivation, arousal, and stress, making this system a promising target for the treatment of substance use disorder. This review discusses recent preclinical studies that suggest that orexin receptor blockade could be beneficial for the treatment of prescription opioid use disorder.
Collapse
|
16
|
Matzeu A, Martin-Fardon R. Targeting the orexin system for prescription opioid use disorder: Orexin-1 receptor blockade prevents oxycodone taking and seeking in rats. Neuropharmacology 2019; 164:107906. [PMID: 31841797 DOI: 10.1016/j.neuropharm.2019.107906] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 11/22/2019] [Accepted: 12/03/2019] [Indexed: 12/22/2022]
Abstract
Prescription opioids, such as oxycodone, are potent analgesics that are used to treat and manage pain. However, oxycodone is one of the most commonly abused prescription drugs. Finding an effective strategy to prevent prescription opioid use disorder is urgent. Orexin receptors (OrxR1 and OrxR2) have been implicated in the regulation of motivation, arousal, and stress, making them possible targets for the treatment of substance use disorder. To study the significance of environmental stimuli in maintaining the vulnerability to relapse to oxycodone use, resistance to the extinction of oxycodone-seeking behavior that was elicited by an oxycodone-related stimulus was examined. Rats were trained to self-administer oxycodone in the presence of a contextual/discriminative stimulus (SD). Using this procedure, the rats readily acquired oxycodone self-administration and exhibited increases in physical signs of opioid withdrawal. Following extinction, response-reinstating effects of re-exposure to the SD perseverated. We then tested whether OrxR blockade prevents oxycodone intake and relapse. The effects of the OrxR1 antagonist SB334867 and OrxR2 antagonist TCSOX229 on oxycodone self-administration were tested. SB334867 significantly decreased oxycodone self-administration, whereas TCSOX229 did not produce any effect. To investigate whether OrxR1 and OrxR2 blockade prevents oxycodone seeking, the rats were tested for the ability of SB334867 and TCSOX229 to prevent the SD-induced conditioned reinstatement of oxycodone-seeking behavior. SB334867 decreased oxycodone-seeking behavior, whereas TCSOX229 was ineffective. These results suggest that OrxR1 antagonism prevents excessive prescription opioid use and relapse and might be beneficial for the treatment of prescription opioid use disorder.
Collapse
Affiliation(s)
- Alessandra Matzeu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.
| | - Rémi Martin-Fardon
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| |
Collapse
|
17
|
Stanojlovic M, Pallais JP, Lee MK, Kotz CM. Pharmacological and chemogenetic orexin/hypocretin intervention ameliorates Hipp-dependent memory impairment in the A53T mice model of Parkinson's disease. Mol Brain 2019; 12:87. [PMID: 31666100 PMCID: PMC6822428 DOI: 10.1186/s13041-019-0514-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/18/2019] [Indexed: 01/01/2023] Open
Abstract
Parkinson's disease (PD), classically defined as a progressive motor disorder accompanied with dopaminergic neuron loss and presence of Lewy bodies, is the second most common neurodegenerative disease. PD also has various non-classical symptoms, including cognitive impairments. In addition, inflammation and astrogliosis are recognized as an integral part of PD pathology. The hippocampus (Hipp) is a brain region involved in cognition and memory, and the neuropeptide orexin has been shown to enhance learning and memory. Previous studies show impairments in Hipp-dependent memory in a transgenic mouse model of Parkinson's disease (A53T mice), and we hypothesized that increasing orexin tone will reverse this. To test this, we subjected 3, 5, and 7-month old A53T mice to a Barnes maze and a contextual object recognition test to determine Hipp dependent memory. Inflammation and astrogliosis markers in the Hipp were assessed by immuno-fluorescence densitometry. The data show that early cognitive impairment is coupled with an increase in expression of inflammatory and astrogliosis markers. Next, in two separate experiments, mice were given intra-hippocampal injections of orexin or chemogenetic viral injections of an orexin neuron specific Designer Receptor Exclusively Activated by Designer Drug (DREADD). For the pharmacological approach mice were intracranially treated with orexin A, whereas the chemogenetic approach utilized clozapine N-oxide (CNO). Both pharmacological orexin A intervention as well as chemogenetic activation of orexin neurons ameliorated Hipp-dependent early memory impairment observed in A53T mice. This study implicates orexin in PD-associated cognitive impairment and suggests that exogenous orexin treatment and/or manipulation of endogenous orexin levels may be a potential strategy for addressing early cognitive loss in PD.
Collapse
Affiliation(s)
- Milos Stanojlovic
- Integrative Biology and Physiology, University of Minnesota, 2231 6th St SE, Minneapolis, MN, 55455, USA.
| | - Jean Pierre Pallais
- Integrative Biology and Physiology, University of Minnesota, 2231 6th St SE, Minneapolis, MN, 55455, USA
| | - Michael K Lee
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
- Institute for Translational Neuroscience (ITN), University of Minnesota, Minneapolis, MN, USA
| | - Catherine M Kotz
- Integrative Biology and Physiology, University of Minnesota, 2231 6th St SE, Minneapolis, MN, 55455, USA
- Minneapolis VA Health Care System, GRECC, Minneapolis, MN, USA
| |
Collapse
|
18
|
Orexin activated emergence from isoflurane anaesthesia involves excitation of ventral tegmental area dopaminergic neurones in rats. Br J Anaesth 2019; 123:497-505. [DOI: 10.1016/j.bja.2019.07.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 07/02/2019] [Accepted: 07/10/2019] [Indexed: 11/22/2022] Open
|
19
|
Saad L, Sartori M, Pol Bodetto S, Romieu P, Kalsbeek A, Zwiller J, Anglard P. Regulation of Brain DNA Methylation Factors and of the Orexinergic System by Cocaine and Food Self-Administration. Mol Neurobiol 2019; 56:5315-5331. [PMID: 30603957 DOI: 10.1007/s12035-018-1453-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/07/2018] [Indexed: 12/22/2022]
Abstract
Inhibitors of DNA methylation and orexin type-1 receptor antagonists modulate the neurobiological effects driving drugs of abuse and natural reinforcers by activating common brain structures of the mesolimbic reward system. In this study, we applied a self-administration paradigm to assess the involvement of factors regulating DNA methylation processes and satiety or appetite signals. These factors include Dnmts and Tets, miR-212/132, orexins, and orx-R1 genes. The study focused on dopamine projection areas such as the prefrontal cortex (PFCx) and caudate putamen (CPu) and in the hypothalamus (HP) that is interconnected with the reward system. Striking changes were observed in response to both reinforcers, but differed depending on contingent and non-contingent delivery. Expression also differed in the PFCx and the CPu. Cocaine and food induced opposite effects on Dnmt3a expression in both brain structures, whereas they repressed both miRs to a different extent, without affecting their primary transcript in the CPu. Unexpectedly, orexin mRNAs were found in the CPu, suggesting a transport from their transcription site in the HP. The orexin receptor1 gene was found to be induced by cocaine in the PFCx, consistent with a regulation by DNA methylation. Global levels of 5-methylcytosines in the PFCx were not significantly altered by cocaine, suggesting that it is rather their distribution that contributes to long-lasting behaviors. Together, our data demonstrate that DNA methylation regulating factors are differentially altered by cocaine and food. At the molecular level, they support the idea that neural circuits activated by both reinforcers do not completely overlap.
Collapse
Affiliation(s)
- Lamis Saad
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), UMR 7364 CNRS, Neuropôle de Strasbourg, Université de Strasbourg, Strasbourg, France
- The Netherlands Institute for Neuroscience (NIN), Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, The Netherlands
| | - Maxime Sartori
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), UMR 7364 CNRS, Neuropôle de Strasbourg, Université de Strasbourg, Strasbourg, France
- IGBMC, Inserm U 964, CNRS UMR 7104, University of Strasbourg, Illkirch, France
| | - Sarah Pol Bodetto
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), UMR 7364 CNRS, Neuropôle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Pascal Romieu
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), UMR 7364 CNRS, Neuropôle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Andries Kalsbeek
- The Netherlands Institute for Neuroscience (NIN), Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, The Netherlands
- Department of Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Jean Zwiller
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), UMR 7364 CNRS, Neuropôle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Patrick Anglard
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA), UMR 7364 CNRS, Neuropôle de Strasbourg, Université de Strasbourg, Strasbourg, France.
- INSERM, Institut National de la Santé et de la Recherche Médicale, Paris, France.
| |
Collapse
|
20
|
Stanojlovic M, Pallais JP, Kotz CM. Chemogenetic Modulation of Orexin Neurons Reverses Changes in Anxiety and Locomotor Activity in the A53T Mouse Model of Parkinson's Disease. Front Neurosci 2019; 13:702. [PMID: 31417337 PMCID: PMC6682689 DOI: 10.3389/fnins.2019.00702] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 06/21/2019] [Indexed: 01/02/2023] Open
Abstract
Parkinson’s disease (PD) is the second most common neurodegenerative disease. PD symptomology is recognized as heterogeneous and in addition to motor function decline includes cognitive, mood, sleep, and metabolic disorders. Previous studies showed early reductions in anxiety and locomotion in the A53T mice model of PD. Since inflammation and astrogliosis are an integral part of PD pathology and impair proper neuronal function, we were keen to investigate if behavioral changes in A53T mice are accompanied by increased inflammation and astrogliosis in the hippocampus (Hipp) and motor cortex (mCtx) brain regions involved in the regulation of anxiety and locomotion, respectively. To test this, we used 3-, 5-, and 7-month-old A53T mice to examine anxiety-like behavior, locomotion, and expression of inflammation and astrogliosis markers in the Hipp and mCtx. Further, we examined the presence of alpha-synuclein accumulation in orexin neurons and orexin neuronal loss. The data show early reductions in anxiety-like behavior as well as increased locomotor activity, which was accompanied by inflammation and astrogliosis in the Hipp and mCtx. Due to the persistence of the orexin neuron population in A53T mice and the involvement of orexin in anxiety and locomotor regulation, we hypothesized that chemogenetic modulation of orexin neurons would reverse the observed reductions in anxiety-like behavior and the increases in locomotor activity in these animals. We showed that chemogenetic activation of orexin neurons in A53T mice restores anxiety-like behavior back to control levels without affecting locomotor activity, whereas the inhibition of orexin neurons reverses the elevated locomotor activity without any effects on anxiety-like behavior. This study exemplifies the complex role of orexin neurons in this model of PD and demonstrates the novel finding that changes in locomotor and anxiety-like behavior are accompanied by inflammation and astrogliosis. Together, these data suggest that the orexin system may play a significant role in early and late stages of PD.
Collapse
Affiliation(s)
- Milos Stanojlovic
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, United States
| | - Jean Pierre Pallais
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, United States
| | - Catherine M Kotz
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, United States.,Minneapolis VA Health Care System, Geriatric Research, Education and Clinical Center, Minneapolis, MN, United States
| |
Collapse
|
21
|
Modafinil treatment modulates functional connectivity in stroke survivors with severe fatigue. Sci Rep 2019; 9:9660. [PMID: 31273283 PMCID: PMC6609702 DOI: 10.1038/s41598-019-46149-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 06/20/2019] [Indexed: 01/21/2023] Open
Abstract
Post-stroke fatigue has a significant impact on stroke survivors’ mental and physical well-being. Our recent clinical trial showed significant reduction of post-stroke fatigue with modafinil treatment, however functional connectivity changes in response to modafinil have not yet been explored in stroke survivors with post-stroke fatigue. Twenty-eight participants (multidimensional fatigue inventory-20 ≥ 60) had MRI scans at baseline, and during modafinil and placebo treatment. Resting-state functional MRI data were obtained, and independent component analysis was used to extract functional networks. Resting-state functional connectivity (rsFC) was examined between baseline, modafinil and placebo treatment using permutation testing with threshold-free cluster enhancement. Overall twenty-eight participants (mean age: 62 ± 14.3, mean baseline MFI-20: 72.3 ± 9.24) were included. During modafinil treatment, increased rsFC was observed in the right hippocampus (p = 0.004, 11 voxels) compared to placebo. This coincided with lower rsFC in the left frontoparietal (inferior parietal lobule, p = 0.023, 13 voxels), somatosensory (primary somatosensory cortex; p = 0.009, 32 voxels) and mesolimbic network (temporal pole, p = 0.016, 35 voxels). In conclusion, modafinil treatment induces significant changes in rsFC in post-stroke fatigue. This modulation of rsFC may relate to a reduction of post-stroke fatigue; however, the relationship between sensory processing, neurotransmitter expression and fatigue requires further exploration.
Collapse
|
22
|
Stanojlovic M, Pallais Yllescas JP, Vijayakumar A, Kotz C. Early Sociability and Social Memory Impairment in the A53T Mouse Model of Parkinson's Disease Are Ameliorated by Chemogenetic Modulation of Orexin Neuron Activity. Mol Neurobiol 2019; 56:8435-8450. [PMID: 31250383 DOI: 10.1007/s12035-019-01682-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/14/2019] [Indexed: 02/08/2023]
Abstract
Parkinson's disease (PD) is a multi-layered progressive neurodegenerative disease. Signature motor system impairments are accompanied by a variety of other symptoms such as mood, sleep, metabolic, and cognitive disorders. Interestingly, social cognition impairments can be observed from the earliest stages of the disease, prior to the onset of the motor symptoms. In this study, we investigated age-related reductions in sociability and social memory in the A53T mouse model of PD. Since inflammation and astrogliosis are an integral part of PD pathology and impair proper neuronal function, we examined astrogliosis and inflammation markers and parvalbumin expression in medial pre-frontal cortex (mPFC), part of the brain responsible for social cognition regulation. Finally, we used DREADDs (Designer Receptors Exclusively Activated by Designer Drugs) for the stimulation and inhibition of orexin neuronal activity to modulate sociability and social memory in A53T mice. We observed that social cognition impairment in A53T mice is accompanied by an increase in astrogliosis and inflammation markers, in addition to loss of parvalbumin neurons and inhibitory pre-synaptic terminals in the mPFC. Moreover, DREADD-induced activation of orexin neurons restores social cognition in the A53T mouse model of PD. SIGNIFICANCE STATEMENT: Social cognition is severely affected in the early stages of Parkinson's disease. In this study, we identified the A53T mouse as a model of social cognitive impairment in PD. Observed alterations in sociability and social memory are accompanied by loss of parvalbumin positive neurons and loss of inhibitory input to mPFC. Stimulating orexin neurons using a chemogenetic approach (DREADDs) ameliorated social cognitive impairment. This study identifies a role for orexin neurons in social cognition in PD and suggests potential therapeutic targets for PD-related social cognition impairments.
Collapse
Affiliation(s)
- Milos Stanojlovic
- Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA.
| | | | - Aarthi Vijayakumar
- Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Catherine Kotz
- Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA.,GRECC, Minneapolis VA Health Care System, Minneapolis, MN, USA
| |
Collapse
|
23
|
Vichaya EG, Laumet G, Christian DL, Grossberg AJ, Estrada DJ, Heijnen CJ, Kavelaars A, Dantzer R. Motivational changes that develop in a mouse model of inflammation-induced depression are independent of indoleamine 2,3 dioxygenase. Neuropsychopharmacology 2019; 44:364-371. [PMID: 29760410 PMCID: PMC6300560 DOI: 10.1038/s41386-018-0075-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 03/18/2018] [Accepted: 04/16/2018] [Indexed: 12/27/2022]
Abstract
Despite years of research, our understanding of the mechanisms by which inflammation induces depression is still limited. As clinical data points to a strong association between depression and motivational alterations, we sought to (1) characterize the motivational changes that are associated with inflammation in mice, and (2) determine if they depend on inflammation-induced activation of indoleamine 2,3 dioxygenase-1 (IDO1). Lipopolysaccharide (LPS)-treated or spared nerve injured (SNI) wild type (WT) and Ido1-/- mice underwent behavioral tests of antidepressant activity (e.g., forced swim test) and motivated behavior, including assessment of (1) reward expectancy using a food-related anticipatory activity task, (2) willingness to work for reward using a progressive ratio schedule of food reinforcement, (3) effort allocation using a concurrent choice task, and (4) ability to associate environmental cues with reward using conditioned place preference. LPS- and SNI-induced deficits in behavioral tests of antidepressant activity in WT but not Ido1-/- mice. Further, LPS decreased food related-anticipatory activity, reduced performance in the progressive ratio task, and shifted effort toward the preferred reward in the concurrent choice task. These effects were observed in both WT and Ido1-/- mice. Finally, SNI mice developed a conditioned place preference based on relief from pain in an IDO1-independent manner. These findings demonstrate that the motivational effects of inflammation do not require IDO1. Further, they indicate that the motivational component of inflammation-induced depression is mechanistically distinct from that measured by behavioral tests of antidepressant activity.
Collapse
Affiliation(s)
- Elisabeth G. Vichaya
- 0000 0001 2291 4776grid.240145.6Division of Internal Medicine, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| | - Geoffroy Laumet
- 0000 0001 2291 4776grid.240145.6Division of Internal Medicine, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| | - Diana L. Christian
- 0000 0001 2291 4776grid.240145.6Division of Internal Medicine, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| | - Aaron J. Grossberg
- 0000 0001 2291 4776grid.240145.6Division of Internal Medicine, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| | - Darlene J. Estrada
- 0000 0001 2291 4776grid.240145.6Division of Internal Medicine, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| | - Cobi J. Heijnen
- 0000 0001 2291 4776grid.240145.6Division of Internal Medicine, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| | - Annemieke Kavelaars
- 0000 0001 2291 4776grid.240145.6Division of Internal Medicine, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| | - Robert Dantzer
- 0000 0001 2291 4776grid.240145.6Division of Internal Medicine, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| |
Collapse
|
24
|
Farrell MR, Schoch H, Mahler SV. Modeling cocaine relapse in rodents: Behavioral considerations and circuit mechanisms. Prog Neuropsychopharmacol Biol Psychiatry 2018; 87:33-47. [PMID: 29305936 PMCID: PMC6034989 DOI: 10.1016/j.pnpbp.2018.01.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 12/18/2017] [Accepted: 01/02/2018] [Indexed: 12/29/2022]
Abstract
Addiction is a chronic relapsing disorder, in that most addicted individuals who choose to quit taking drugs fail to maintain abstinence in the long-term. Relapse is especially likely when recovering addicts encounter risk factors like small "priming" doses of drug, stress, or drug-associated cues and locations. In rodents, these same factors reinstate cocaine seeking after a period of abstinence, and extensive preclinical work has used priming, stress, or cue reinstatement models to uncover brain circuits underlying cocaine reinstatement. Here, we review common rat models of cocaine relapse, and discuss how specific features of each model influence the neural circuits recruited during reinstated drug seeking. To illustrate this point, we highlight the surprisingly specific roles played by ventral pallidum subcircuits in cocaine seeking reinstated by either cocaine-associated cues, or cocaine itself. One goal of such studies is to identify, and eventually to reverse the specific circuit activity that underlies the inability of some humans to control their drug use. Based on preclinical findings, we posit that circuit activity in humans also differs based on the triggers that precipitate craving and relapse, and that associated neural responses could help predict the triggers most likely to elicit relapse in a given person. If so, examining circuit activity could facilitate diagnosis of subgroups of addicted people, allowing individualized treatment based on the most problematic risk factors.
Collapse
Affiliation(s)
- Mitchell R Farrell
- Department of Neurobiology & Behavior, University of California, 1203 McGaugh Hall, Irvine, United States
| | - Hannah Schoch
- Department of Neurobiology & Behavior, University of California, 1203 McGaugh Hall, Irvine, United States
| | - Stephen V Mahler
- Department of Neurobiology & Behavior, University of California, 1203 McGaugh Hall, Irvine, United States.
| |
Collapse
|
25
|
Herring WJ, Roth T, Krystal AD, Michelson D. Orexin receptor antagonists for the treatment of insomnia and potential treatment of other neuropsychiatric indications. J Sleep Res 2018; 28:e12782. [DOI: 10.1111/jsr.12782] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/06/2018] [Accepted: 09/22/2018] [Indexed: 01/06/2023]
Affiliation(s)
| | - Thomas Roth
- Sleep Disorders and Research Center Henry Ford Hospital Detroit MI USA
| | - Andrew D. Krystal
- Department of Psychiatry University of California San Francisco California USA
| | - David Michelson
- Clinical ResearchMerck & Co., Inc. Kenilworth New Jersey USA
| |
Collapse
|
26
|
Bernstein DL, Badve PS, Barson JR, Bass CE, España RA. Hypocretin receptor 1 knockdown in the ventral tegmental area attenuates mesolimbic dopamine signaling and reduces motivation for cocaine. Addict Biol 2018; 23:1032-1045. [PMID: 28971565 DOI: 10.1111/adb.12553] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 08/01/2017] [Accepted: 08/03/2017] [Indexed: 01/24/2023]
Abstract
The hypocretin receptor 1 (HCRTr1) is a critical participant in the regulation of motivated behavior. Previous observations demonstrate that acute pharmacological blockade of HCRTr1 disrupts dopamine (DA) signaling and the motivation for cocaine when delivered systemically or directly into the ventral tegmental area (VTA). To further examine the involvement of HCRTr1 in regulating reward and reinforcement processing, we employed an adeno-associated virus to express a short hairpin RNA designed to knock down HCRTr1. We injected virus into the VTA and examined the effects of HCRTr1 knockdown on cocaine self-administration and DA signaling in the nucleus accumbens (NAc) core. We determined that the viral approach was effective at reducing HCRTr1 expression without affecting the expression of hypocretin receptor 2 or DA-related mRNAs. We next examined the effects of HCRTr1 knockdown on cocaine self-administration, observing delayed acquisition under a fixed-ratio schedule and reduced motivation for cocaine under a progressive ratio schedule. These effects did not appear to be associated with alterations in sleep/wake activity. Using fast-scan cyclic voltammetry, we then examined whether HCRTr1 knockdown alters DA signaling dynamics in the NAc core. We observed reduced DA release and slower uptake rate as well as attenuated cocaine-induced DA uptake inhibition in rats with knockdown of HCRTr1. These observations indicate that HCRTr1 within the VTA influence the motivation for cocaine, likely via alterations in DA signaling in the NAc.
Collapse
Affiliation(s)
- David L. Bernstein
- Department of Neurobiology and Anatomy; Drexel University College of Medicine; Philadelphia PA USA
| | - Preeti S. Badve
- Department of Neurobiology and Anatomy; Drexel University College of Medicine; Philadelphia PA USA
| | - Jessica R. Barson
- Department of Neurobiology and Anatomy; Drexel University College of Medicine; Philadelphia PA USA
| | - Caroline E. Bass
- Department of Pharmacology and Toxicology, Jacobs School of Medicine; State University of New York at Buffalo; Buffalo NY USA
| | - Rodrigo A. España
- Department of Neurobiology and Anatomy; Drexel University College of Medicine; Philadelphia PA USA
| |
Collapse
|
27
|
Hypocretin receptor 1 involvement in cocaine-associated behavior: Therapeutic potential and novel mechanistic insights. Brain Res 2018; 1731:145894. [PMID: 30071195 DOI: 10.1016/j.brainres.2018.07.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/05/2018] [Accepted: 07/12/2018] [Indexed: 12/28/2022]
Abstract
Since its discovery in 1998, the hypocretin/orexin system has been identified as a critical modulator of behavior. Through interactions with dopamine neurons of the ventral tegmental area, this system is poised to regulate motivation for drug rewards by impacting dopamine neurotransmission in target structures including the nucleus accumbens. Across numerous experiments, we and others have identified a critical influence of hypocretin receptor 1 in mediating the behavioral and physiological effects of cocaine which positions this receptor as a potential target for the treatment of cocaine addiction. Here we discuss evidence for hypocretin receptor 1 involvement in driving cocaine-associated behavior and how hypocretin receptor 1 in the ventral tegmental area are critical for supporting dopamine neuron activity and dopamine neurotransmission. We then present new data supporting the novel hypothesis that in addition to exerting acute actions on dopamine systems, pharmacological hypocretin manipulations also produce lasting adaptations to dopamine terminals that impact sensitivity to cocaine, and ultimately, future behavior.
Collapse
|
28
|
Moorman DE. The hypocretin/orexin system as a target for excessive motivation in alcohol use disorders. Psychopharmacology (Berl) 2018; 235:1663-1680. [PMID: 29508004 PMCID: PMC5949267 DOI: 10.1007/s00213-018-4871-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/20/2018] [Indexed: 12/17/2022]
Abstract
The hypocretin/orexin (ORX) system has been repeatedly demonstrated to regulate motivation for drugs of abuse, including alcohol. In particular, ORX seems to be critically involved in highly motivated behaviors, as is observed in high-seeking individuals in a population, in the seeking of highly palatable substances, and in models of dependence. It seems logical that this system could be considered as a potential target for treatment for addiction, particularly alcohol addiction, as ORX pharmacological manipulations significantly reduce drinking. However, the ORX system also plays a role in a wide range of other behaviors, emotions, and physiological functions and is disrupted in a number of non-dependence-associated disorders. It is therefore important to consider how the ORX system might be optimally targeted for potential treatment for alcohol use disorders either in combination with or separate from its role in other functions or diseases. This review will focus on the role of ORX in alcohol-associated behaviors and whether and how this system could be targeted to treat alcohol use disorders while avoiding impacts on other ORX-relevant functions. A brief overview of the ORX system will be followed by a discussion of some of the factors that makes it particularly intriguing as a target for alcohol addiction treatment, a consideration of some potential challenges associated with targeting this system and, finally, some future directions to optimize new treatments.
Collapse
Affiliation(s)
- David E Moorman
- Department of Psychological and Brain Sciences, Neuroscience and Behavior Graduate Program, University of Massachusetts Amherst, 528 Tobin Hall, 135 Hicks Way, Amherst, MA, 01003, USA.
| |
Collapse
|
29
|
Brain Activity during Methamphetamine Anticipation in a Non-Invasive Self-Administration Paradigm in Mice. eNeuro 2018; 5:eN-NWR-0433-17. [PMID: 29632871 PMCID: PMC5889482 DOI: 10.1523/eneuro.0433-17.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/14/2018] [Accepted: 02/21/2018] [Indexed: 12/13/2022] Open
Abstract
The ability to sense time and anticipate events is critical for survival. Learned responses that allow anticipation of the availability of food or water have been intensively studied. While anticipatory behaviors also occur prior to availability of regularly available rewards, there has been relatively little work on anticipation of drugs of abuse, specifically methamphetamine (MA). In the present study, we used a protocol that avoided possible CNS effects of stresses of handling or surgery by testing anticipation of MA availability in animals living in their home cages, with daily voluntary access to the drug at a fixed time of day. Anticipation was operationalized as the amount of wheel running prior to MA availability. Mice were divided into four groups given access to either nebulized MA or water, in early or late day. Animals with access to MA, but not water controls, showed anticipatory activity, with more anticipation in early compared to late day and significant interaction effects. Next, we explored the neural basis of the MA anticipation, using c-FOS expression, in animals euthanized at the usual time of nebulization access. In the dorsomedial hypothalamus (DMH) and orbitofrontal cortex (OFC), the pattern of c-FOS expression paralleled that of anticipatory behavior, with significant main and interaction effects of treatment and time of day. The results for the lateral septum (LS) were significant for main effects and marginally significant for interaction effects. These studies suggest that anticipation of MA is associated with activation of brain regions important in circadian timing, emotional regulation, and decision making.
Collapse
|
30
|
Łupina M, Tarnowski M, Baranowska-Bosiacka I, Talarek S, Listos P, Kotlińska J, Gutowska I, Listos J. SB-334867 (an Orexin-1 Receptor Antagonist) Effects on Morphine-Induced Sensitization in Mice-a View on Receptor Mechanisms. Mol Neurobiol 2018; 55:8473-8485. [PMID: 29557083 PMCID: PMC6153720 DOI: 10.1007/s12035-018-0993-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 03/07/2018] [Indexed: 12/20/2022]
Abstract
The present study focused upon the role of SB-334867, an orexin-1 receptor antagonist, in the acquisition of morphine-induced sensitization to locomotor activity in mice. Behavioral sensitization is an enhanced systemic reaction to the same dose of an addictive substance, which assumingly increases both the desire for the drug and the risk of relapse to addiction. Morphine-induced sensitization in mice was achieved by sporadic doses (five injections every 3 days) of morphine (10 mg/kg, i.p.), while a challenge dose of morphine (10 mg/kg) was injected 7 days later. In order to assess the impact of orexin system blockade on the acquisition of sensitization, SB-334867 was administered before each morphine injection, except the morphine challenge dose. The locomotor activity test was performed on each day of morphine administration. Brain structures (striatum, hippocampus, and prefrontal cortex) were collected after behavioral tests for molecular experiments in which mRNA expression of orexin, dopamine, and adenosine receptors was explored by the qRT-PCR technique. Additionally, the mRNA expression of markers, such as GFAP and Iba-1, was also analyzed by the same technique. SB-334867 inhibited the acquisition of morphine-induced sensitization to locomotor activity of mice. Significant alterations were observed in mRNA expression of orexin, dopamine, and adenosine receptors and in the expression of GFAP and Iba-1, showing a broad range of interactions in the mesolimbic system among orexin, dopamine, adenosine, and glial cells during behavioral sensitization. Summing up, the orexin system may be an effective measure to inhibit morphine-induced behavioral sensitization.
Collapse
Affiliation(s)
- Małgorzata Łupina
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodźki 4a St., 20-093, Lublin, Poland.
| | - Maciej Tarnowski
- Department of Physiology, Pomeranian Medical University, Powstańców Wlkp. 72 Av., 70-111, Szczecin, Poland
| | - Irena Baranowska-Bosiacka
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Powstańców Wlkp. 72 Av., 70-111, Szczecin, Poland
| | - Sylwia Talarek
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodźki 4a St., 20-093, Lublin, Poland
| | - Piotr Listos
- Department and Clinic of Animal Internal Diseases, Sub-Department of Pathomorphology and Forensic Medicine, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, 30 Av, 20-612, Lublin, Poland
| | - Jolanta Kotlińska
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodźki 4a St., 20-093, Lublin, Poland
| | - Izabela Gutowska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University, Broniewskiego 24 Str., 71-460, Szczecin, Poland
| | - Joanna Listos
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodźki 4a St., 20-093, Lublin, Poland
| |
Collapse
|
31
|
Anderson RI, Moorman DE, Becker HC. Contribution of Dynorphin and Orexin Neuropeptide Systems to the Motivational Effects of Alcohol. Handb Exp Pharmacol 2018. [PMID: 29526023 DOI: 10.1007/164_2018_100] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Understanding the neural systems that drive alcohol motivation and are disrupted in alcohol use disorders is of critical importance in developing novel treatments. The dynorphin and orexin/hypocretin neuropeptide systems are particularly relevant with respect to alcohol use and misuse. Both systems are strongly associated with alcohol-seeking behaviors, particularly in cases of high levels of alcohol use as seen in dependence. Furthermore, both systems also play a role in stress and anxiety, indicating that disruption of these systems may underlie long-term homeostatic dysregulation seen in alcohol use disorders. These systems are also closely interrelated with one another - dynorphin/kappa opioid receptors and orexin/hypocretin receptors are found in similar regions and hypocretin/orexin neurons also express dynorphin - suggesting that these two systems may work together in the regulation of alcohol seeking and may be mutually disrupted in alcohol use disorders. This chapter reviews studies demonstrating a role for each of these systems in motivated behavior, with a focus on their roles in regulating alcohol-seeking and self-administration behaviors. Consideration is also given to evidence indicating that these neuropeptide systems may be viable targets for the development of potential treatments for alcohol use disorders.
Collapse
Affiliation(s)
- Rachel I Anderson
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA.,Science and Technology Policy Fellowships, American Association for the Advancement of Science, Washington, DC, USA
| | - David E Moorman
- Department of Psychological and Brain Sciences, Neuroscience and Behavior Graduate Program, University of Massachusetts Amherst, Amherst, MA, USA
| | - Howard C Becker
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA. .,Charleston Alcohol Research Center, Medical University of South Carolina, Charleston, SC, USA. .,Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA. .,Department of Veterans Affairs, Ralph H. Johnson VA Medical Center, Charleston, SC, USA.
| |
Collapse
|
32
|
Gentile TA, Simmons SJ, Barker DJ, Shaw JK, España RA, Muschamp JW. Suvorexant, an orexin/hypocretin receptor antagonist, attenuates motivational and hedonic properties of cocaine. Addict Biol 2018; 23:247-255. [PMID: 28419646 DOI: 10.1111/adb.12507] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/23/2017] [Accepted: 02/24/2017] [Indexed: 12/12/2022]
Abstract
Orexins ('hypocretins') are peptides produced by neurons of the hypothalamus that project to structures implicated in reward and emotion processing. Converging evidence demonstrates functional roles of orexin signaling in arousal, sleep/wakefulness and motivated behaviors for natural and drug rewards. Suvorexant, a dual orexin receptor antagonist, recently received approval from the US Food and Drug Administration to treat insomnia. In Experiment 1, rats self-administered cocaine under a progressive-ratio schedule of reinforcement and the effects of suvorexant on motivation to self-administer cocaine were measured. In Experiment 2, the effects of suvorexant on cocaine reward were assessed by using a place conditioning paradigm, and 50-kHz ultrasonic vocalizations were also recorded to track changes in hedonic reactivity to cocaine. To rule out potentially confounding effects of suvorexant-induced somnolence, locomotor activity was also measured. In Experiment 3, the effects of suvorexant on cocaine-evoked elevations in ventral striatal dopamine were examined. Data reveal that suvorexant (i) reduced the number of cocaine infusions earned during progressive-ratio self-administration; (ii) attenuated initial positive hedonic reactivity to cocaine and prevented cocaine place preference; (iii) did not affect cocaine-induced hyperlocomotion and (iv) reduced cocaine-induced elevations in extracellular ventral striatal dopamine. The present study examined the therapeutic potential of suvorexant in rodent models of cocaine use disorder. These results contribute toward a growing literature supporting therapeutic roles of orexin receptor antagonists in treating substance use disorders.
Collapse
Affiliation(s)
- Taylor A. Gentile
- Center for Substance Abuse Research; Lewis Katz School of Medicine, Temple University; Philadelphia PA USA
| | - Steven J. Simmons
- Center for Substance Abuse Research; Lewis Katz School of Medicine, Temple University; Philadelphia PA USA
| | - David J. Barker
- National Institute on Drug Abuse, Neuronal Networks Sections; National Institutes of Health; Baltimore MD, USA
| | - Jessica K. Shaw
- Department of Neurobiology and Anatomy; Drexel University College of Medicine; Philadelphia PA USA
| | - Rodrigo A. España
- Department of Neurobiology and Anatomy; Drexel University College of Medicine; Philadelphia PA USA
| | - John W. Muschamp
- Center for Substance Abuse Research; Lewis Katz School of Medicine, Temple University; Philadelphia PA USA
| |
Collapse
|
33
|
Dunn JP, Abumrad NN, Kessler RM, Patterson BW, Li R, Marks-Shulman P, Tamboli RA. Caloric Restriction-Induced Decreases in Dopamine Receptor Availability are Associated with Leptin Concentration. Obesity (Silver Spring) 2017; 25:1910-1915. [PMID: 28944597 PMCID: PMC5718041 DOI: 10.1002/oby.22023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/16/2017] [Accepted: 08/21/2017] [Indexed: 11/08/2022]
Abstract
OBJECTIVE It has been previously reported that early after Roux-en-Y-gastric bypass, dopamine (DA) type 2 and 3 receptor (D2/3R) binding potential (BPND ) was decreased from preoperative levels. The current study aimed to determine whether calorie restriction without weight loss modifies D2/3R BPND and whether such changes are explained by neuroendocrine regulation. METHODS Fifteen females with obesity (BMI = 39 ± 6 kg/m2 ) were studied before and after ∼10 days of a very-low-calorie-diet (VLCD). Outcome measures included fasting insulin, leptin, acyl ghrelin, and glucose, and insulin sensitivity and disposition index were estimated using the oral-minimal model (OMM) method. Participants underwent positron emission tomography scanning with the displaceable radioligand [18 F]fallypride to estimate available regional D2/3R levels. Regions of interest included the caudate, putamen, ventral striatum, hypothalamus, and substantia nigra (SN). RESULTS With the VLCD, weight decreased slightly (-3 kg). Insulin, glucose, and leptin decreased significantly, but there was no change in acyl ghrelin or measures from OMM. SN D2/3R BPND decreased significantly, with trends toward decreased levels in the remaining regions. The decrease in leptin concentration strongly predicted the change in D2/3R BPND in all regions (all P ≤ 0.004). CONCLUSIONS In obesity, reductions in regional D2/3R availability after VLCD are suggestive of increased endogenous DA competing with the radioligand. Changes in regional D2/3R availability were associated with decreases in leptin concentrations that occurred before clinically significant weight loss.
Collapse
Affiliation(s)
- Julia P. Dunn
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
- Veterans Administration St. Louis Health Care System, St. Louis, Missouri, U.S.A
| | - Naji N. Abumrad
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
| | - Robert M. Kessler
- Department of Radiology, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
| | - Bruce W. Patterson
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Rui Li
- Department of Radiology, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
| | - Pamela Marks-Shulman
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
| | - Robyn A. Tamboli
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, U.S.A
| |
Collapse
|
34
|
Levy KA, Brodnik ZD, Shaw JK, Perrey DA, Zhang Y, España RA. Hypocretin receptor 1 blockade produces bimodal modulation of cocaine-associated mesolimbic dopamine signaling. Psychopharmacology (Berl) 2017; 234:2761-2776. [PMID: 28667509 PMCID: PMC5709206 DOI: 10.1007/s00213-017-4673-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/06/2017] [Indexed: 02/07/2023]
Abstract
RATIONALE Cocaine addiction is a chronic psychiatric disorder characterized by pathological motivation to obtain cocaine and behavioral and neurochemical hypersensitivity to cocaine-associated cues. These features of cocaine addiction are thought to be driven by aberrant phasic dopamine signaling. We previously demonstrated that blockade of the hypocretin receptor 1 (HCRTr1) attenuates cocaine self-administration and reduces cocaine-induced enhancement of dopamine signaling. Despite this evidence, the effects of HCRTr1 blockade on endogenous phasic dopamine release are unknown. OBJECTIVE In the current studies, we assessed whether blockade of HCRTr1 alters spontaneous and cue-evoked dopamine release in the nucleus accumbens core of freely moving rats. METHODS We first validated the behavioral and neurochemical effects of the novel, highly selective, HCRTr1 antagonist RTIOX-276 using cocaine self-administration and fast-scan cyclic voltammetry (FSCV) in anesthetized rats. We then used FSCV in freely moving rats to examine whether RTIOX-276 impacts spontaneous and cue-evoked dopamine release. Finally, we used ex vivo slice FSCV to determine whether the effects of RTIOX-276 on dopamine signaling involve dopamine terminal adaptations. RESULTS Doses of RTIOX-276 that attenuate the motivation for cocaine reduce spontaneous dopamine transient amplitude and cue-evoked dopamine release. Further, these doses attenuated cocaine-induced dopamine uptake inhibition at the level of dopamine terminals. CONCLUSION Our results provide support for the standing hypothesis that HCRTr1 blockade suppresses endogenous phasic dopamine signals, likely via actions at dopamine cell bodies. These results also elucidate a second process through which HCRTr1 blockade attenuates the effects of cocaine by reducing cocaine sensitivity at dopamine terminals.
Collapse
Affiliation(s)
- KA Levy
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, U.S.A
| | - ZD Brodnik
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, U.S.A
| | - JK Shaw
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, U.S.A
| | - DA Perrey
- Research Triangle Institute, Research Triangle Park, North Carolina 27709, U.S.A
| | - Y Zhang
- Research Triangle Institute, Research Triangle Park, North Carolina 27709, U.S.A
| | - RA España
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, U.S.A
| |
Collapse
|
35
|
Beyond Daytime Sleepiness: Medical, Behavioral, Psychiatric, and Sleep Co-morbid Conditions Associated with Pediatric Narcolepsy. CURRENT SLEEP MEDICINE REPORTS 2016. [DOI: 10.1007/s40675-016-0032-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
36
|
Zhou Y, Leri F. Neuroscience of opiates for addiction medicine. PROGRESS IN BRAIN RESEARCH 2016; 223:237-51. [DOI: 10.1016/bs.pbr.2015.09.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
37
|
Mensen A, Poryazova R, Huegli G, Baumann CR, Schwartz S, Khatami R. The Roles of Dopamine and Hypocretin in Reward: A Electroencephalographic Study. PLoS One 2015; 10:e0142432. [PMID: 26599765 PMCID: PMC4658140 DOI: 10.1371/journal.pone.0142432] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 10/21/2015] [Indexed: 11/19/2022] Open
Abstract
The proper functioning of the mesolimbic reward system is largely dependent on the neurotransmitter dopamine. Recent evidence suggests that the hypocretin system has significant projections to this reward system. We examined the distinct effects of reduced dopamine or reduced hypocretin levels on reward activity in patients with Parkinson’s disease, dopamine deficient, as well as patients with narcolepsy-cataplexy, hypocretin depleted, and healthy controls. Participants performed a simple game-like task while high-density electroencephalography was recorded. Topography and timing of event-related potentials for both reward cue, and reward feedback was examined across the entire dataset. While response to reward cue was similar in all groups, two distinct time points were found to distinguish patients and controls for reward feedback. Around 160ms both patient groups had reduced ERP amplitude compared to controls. Later at 250ms, both patient groups also showed a clear event-related potential (ERP), which was absent in controls. The initial differences show that both patient groups show a similar, blunted response to reward delivery. The second potential corresponds to the classic feedback-related negativity (FRN) potential which relies on dopamine activity and reflects reward prediction-error signaling. In particular the mismatch between predicted reward and reward subsequently received was significantly higher in PD compared to NC, independent of reward magnitude and valence. The intermediate FRN response in NC highlights the contribution of hypocretin in reward processing, yet also shows that this is not as detrimental to the reward system as in Parkinson’s. Furthermore, the inability to generate accurate predictions in NC may explain why hypocretin deficiency mediates cataplexy triggered by both positive and negative emotions.
Collapse
Affiliation(s)
- Armand Mensen
- Department of Sleep Medicine, Clinic Barmelweid, 5017 Aargau, Switzerland
| | - Rositsa Poryazova
- Department of Neurology, University Hospital Zurich, 8006 Zurich, Switzerland
| | - Gordana Huegli
- Department of Sleep Medicine, Clinic Barmelweid, 5017 Aargau, Switzerland
| | | | - Sophie Schwartz
- Department of Neuroscience, University of Geneva, 1211 Geneva, Switzerland
| | - Ramin Khatami
- Department of Sleep Medicine, Clinic Barmelweid, 5017 Aargau, Switzerland
- * E-mail:
| |
Collapse
|
38
|
Involvement of the dopaminergic system in the central orexin-induced antinociceptive action against colonic distension in conscious rats. Neurosci Lett 2015; 605:34-8. [DOI: 10.1016/j.neulet.2015.08.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 07/30/2015] [Accepted: 08/07/2015] [Indexed: 12/12/2022]
|
39
|
Brodnik ZD, Bernstein DL, Prince CD, España RA. Hypocretin receptor 1 blockade preferentially reduces high effort responding for cocaine without promoting sleep. Behav Brain Res 2015; 291:377-384. [PMID: 26049058 DOI: 10.1016/j.bbr.2015.05.051] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 05/25/2015] [Accepted: 05/30/2015] [Indexed: 11/25/2022]
Abstract
Recent evidence suggests that blockade of the hypocretin receptor 1 may act as a useful pharmacotherapy for cocaine abuse. Here we investigated the extent to which various doses of a hypocretin receptor 1 antagonist, SB-334867, affect cocaine self-administration at varying doses of cocaine and across a range of effort requirements, and tested if these SB-334867 doses produce sedative effects. First, we trained animals to self-administer one of three doses of cocaine on a progressive ratio schedule, and then tested the effects of three doses of SB-334867. Responding for cocaine was then analyzed to segregate features of relatively high and low effort requirements across the progressive ratio session. In another set of experiments, we tested potential sleep-promoting effects of the same doses of SB-334867. Our data indicate that blockade of hypocretin receptor 1 preferentially reduces high effort responding for cocaine at levels that do not promote sedation.
Collapse
Affiliation(s)
- Zachary D Brodnik
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - David L Bernstein
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Courtney D Prince
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Rodrigo A España
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA.
| |
Collapse
|
40
|
Modestino EJ, Blum K, Oscar-Berman M, Gold MS, Duane DD, Sultan SG, Auerbach SH. Reward Deficiency Syndrome: Attentional/Arousal Subtypes, Limitations of Current Diagnostic Nosology, and Future Research. JOURNAL OF REWARD DEFICIENCY SYNDROME 2015; 1:6-9. [PMID: 26306327 PMCID: PMC4545661 DOI: 10.17756/jrds.2015-002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We theorise that in some cases Attention Deficit Hyperactivity Disorder (ADHD) predisposes to narcolepsy and hypersomnia, and that there may be a shared pathophysiology with various addictions [Reward Deficiency Syndrome (RDS)]. Reticence to acknowledge such connections may be due to a narrow nosological framework. Additionally, we theorise that the development of narcolepsy on a baseline of ADHD/RDS leads to an additional assault on the dopaminergic reward system in such individuals. In this study, we propose to test these hypotheses by using a combination of broad genetic screening, and neuroimaging with and without pharmacological intervention, in those with pure ADHD, pure narcolepsy, and the combined ADHD-narcolepsy phenotype. Results of this proposed study may reveal a common pathophysiology of ADHD, narcolepsy and RDS, and perhaps an additional compromise to the reward system in those with combined ADHD-narcolepsy. If the evidence supports the hypothesis that indeed there is a shared pathophysiology for narcolepsy with RDS and thus its subtype ADHD, early intervention/preventative treatment amongst those with ADHD may be beneficial with the putative dopaminergic compound KB220Z™.
Collapse
Affiliation(s)
- Edward Justin Modestino
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- Department of Neurology, Boston VA Healthcare System, Boston, MA, USA
| | - Kenneth Blum
- Department of Psychiatry & McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL,USA
- Human Integrated Services Unit University of Vermont Center for Clinical & Translational Science, Department of Psychiatry, College of Medicine, Burlington, VT, USA
- Dominion Diagnostics, LLC, North Kingstown, RI, USA
- Department of Addiction Research & Therapy, Malibu Beach Recovery Center, Malibu Beach, CA, USA
| | - Marlene Oscar-Berman
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- Departments of Psychiatry, Anatomy & Neurobiology, Boston University School of Medicine, Boston, MA, USA
- Boston VA Healthcare System, Boston, MA, USA
| | - Mark S. Gold
- Departments of Psychiatry & Behavioral Sciences at the Keck, University of Southern California, School of Medicine, CA, USA
- Director of Research, Drug Enforcement Administration (DEA) Educational Foundation, Washington, D.C, USA
| | - Drake D. Duane
- Institute for Developmental Behavioral Neurology Scottsdale, AZ, USA
- Department of Speech and Hearing Sciences, Arizona State University, Tempe, AZ, USA
- Department of Neurology, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Sarah G.S. Sultan
- Department of Psychiatry, St. Mary's Hospital Centre, Montreal, QC, Canada
- Department of Psychiatry, Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Sanford H. Auerbach
- Departments of Neurology & Psychiatry, Boston University School of Medicine, Boston, MA, USA
- Sleep Disorders Center & Behavioral Neurology, Boston Medical Center, Boston, MA, USA
| |
Collapse
|
41
|
Prince CD, Rau AR, Yorgason JT, España RA. Hypocretin/Orexin regulation of dopamine signaling and cocaine self-administration is mediated predominantly by hypocretin receptor 1. ACS Chem Neurosci 2015; 6:138-46. [PMID: 25496218 PMCID: PMC4304483 DOI: 10.1021/cn500246j] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
![]()
Extensive
evidence suggests that the hypocretins/orexins influence
cocaine reinforcement and dopamine signaling via actions at hypocretin
receptor 1. By comparison, the involvement of hypocretin receptor
2 in reward and reinforcement processes has received relatively little
attention. Thus, although there is some evidence that hypocretin receptor
2 regulates intake of some drugs of abuse, it is currently unclear
to what extent hypocretin receptor 2 participates in the regulation
of dopamine signaling or cocaine self-administration, particularly
under high effort conditions. To address this, we examined the effects
of hypocretin receptor 1, and/or hypocretin receptor 2 blockade on
dopamine signaling and cocaine reinforcement. We used in vivo fast
scan cyclic voltammetry to test the effects of hypocretin antagonists
on dopamine signaling in the nucleus accumbens core and a progressive
ratio schedule to examine the effects of these antagonists on cocaine
self-administration. Results demonstrate that blockade of either hypocretin
receptor 1 or both hypocretin receptor 1 and 2 significantly reduces
the effects of cocaine on dopamine signaling and decreases the motivation
to take cocaine. In contrast, blockade of hypocretin receptor 2 alone
had no significant effects on dopamine signaling or self-administration.
These findings suggest a differential involvement of the two hypocretin
receptors, with hypocretin receptor 1 appearing to be more involved
than hypocretin receptor 2 in the regulation of dopamine signaling
and cocaine self-administration. When considered with the existing
literature, these data support the hypothesis that hypocretins exert
a permissive influence on dopamine signaling and motivated behavior
via preferential actions on hypocretin receptor 1.
Collapse
Affiliation(s)
- Courtney D. Prince
- Department
of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, United States
| | - Andrew R. Rau
- Department
of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Jordan T. Yorgason
- Vollum
Institute, Oregon Health and Science University, Portland, Oregon 97239, United States
| | - Rodrigo A. España
- Department
of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, United States
| |
Collapse
|
42
|
de Souza MF, Gonçales TA, Steinmetz A, Moura DJ, Saffi J, Gomez R, Barros HMT. Cocaine induces DNA damage in distinct brain areas of female rats under different hormonal conditions. Clin Exp Pharmacol Physiol 2014; 41:265-9. [PMID: 24552452 DOI: 10.1111/1440-1681.12218] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 02/06/2014] [Accepted: 02/09/2014] [Indexed: 11/29/2022]
Abstract
We evaluated levels of neuronal DNA damage after acute or repeated cocaine treatment in different brain areas of female rats after ovariectomy or sham surgery. Rats in the control and acute groups were given saline i.p., whereas in the repeated group were given 15 mg/kg, i.p., cocaine for 8 days. After a 10 day washout period, the control group was given saline i.p., whereas rats in the acute and repeated groups were given a challenge dose of 15 mg/kg, i.p., cocaine. After behavioural assessment, rats were killed and the cerebellum, hippocampus, hypothalamus, prefrontal cortex and striatum were dissected for the Comet assay. Acute cocaine exposure induced DNA damage in all brain areas. This effect persisted after repeated administration, except in the hypothalamus, where repeated treatment did not cause increased DNA damage. Sexual hormones exhibited a neuroprotective effect, decreasing cocaine-induced DNA damage in cycling rats in all brain areas.
Collapse
Affiliation(s)
- Marilise F de Souza
- Laboratory of Behavioral Neuroscience, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | | | | | | | | | | | | |
Collapse
|
43
|
Mahler SV, Moorman DE, Smith RJ, James MH, Aston-Jones G. Motivational activation: a unifying hypothesis of orexin/hypocretin function. Nat Neurosci 2014; 17:1298-303. [PMID: 25254979 PMCID: PMC4335648 DOI: 10.1038/nn.3810] [Citation(s) in RCA: 264] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 08/19/2014] [Indexed: 12/15/2022]
Abstract
Orexins (hypocretins) are two peptides (orexin A and B) produced from the pre-pro-orexin precursor and expressed in a limited region of dorsolateral hypothalamus. Orexins were originally thought to specifically mediate feeding and promote wakefulness, but it is now clear that they participate in a wide range of behavioral and physiological processes under select circumstances. Orexins primarily mediate behavior under situations of high motivational relevance, such as during physiological need states, exposure to threats or reward opportunities. We hypothesize that many behavioral functions of orexins (including regulation of sleep/wake cycling) reflect a fundamentally integrated function for orexins in translating motivational activation into organized suites of psychological and physiological processes supporting adaptive behaviors. We also discuss how numerous forms of neural heterogeneity modulate this function, allowing orexin neurons to organize diverse, adaptive responses in a variety of motivationally relevant situations. Thus, the involvement of orexins in diverse behaviors may reflect a common underlying function for this peptide system.
Collapse
Affiliation(s)
- Stephen V Mahler
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina, USA
| | - David E Moorman
- 1] Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina, USA. [2] Department of Psychological and Brain Sciences, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Rachel J Smith
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Morgan H James
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Gary Aston-Jones
- Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina, USA
| |
Collapse
|
44
|
Quarta D, Smolders I. Rewarding, reinforcing and incentive salient events involve orexigenic hypothalamic neuropeptides regulating mesolimbic dopaminergic neurotransmission. Eur J Pharm Sci 2014; 57:2-10. [DOI: 10.1016/j.ejps.2014.01.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 01/19/2014] [Indexed: 12/22/2022]
|
45
|
Abstract
The hypocretin system is constituted by a small group of hypothalamic neurons with widespread connections within the entire central nervous system producing two neuropeptides involved in several key physiological functions such as the regulation of sleep and wakefulness, motor control, autonomic functions, metabolism, feeding behavior, and reward. Narcolepsy with cataplexy is a neurological disorder regarded as a disease model for the selective hypocretin system damage, and also shares several psychopatological traits and comorbidities with psychiatric disorders. We reviewed the available literature on the involvement of the hypocretin system in psychiatric nosography. Different evidences such as cerebrospinal hypocretin-1 levels, genetic polymorphisms of the neuropeptides or their receptors, response to treatments, clinical, experimental and functional data directly or indirectly linked the hypocretin system to schizophrenia, mood, anxiety and eating disorders, as well as to addiction. Future genetic and pharmacological studies will disentangle the hypocretin system role in the field of psychiatry.
Collapse
Affiliation(s)
- Fabio Pizza
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Ugo Foscolo 7, 40123, Bologna, Italy
| | | | | | | |
Collapse
|
46
|
Mensen A, Poryazova R, Schwartz S, Khatami R. Humor as a reward mechanism: event-related potentials in the healthy and diseased brain. PLoS One 2014; 9:e85978. [PMID: 24489683 PMCID: PMC3906016 DOI: 10.1371/journal.pone.0085978] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 12/03/2013] [Indexed: 12/04/2022] Open
Abstract
Humor processing involves distinct processing stages including incongruity detection, emotional response, and engagement of mesolimbic reward regions. Dysfunctional reward processing and clinical symptoms in response to humor have been previously described in both hypocretin deficient narcolepsy-cataplexy (NC) and in idiopathic Parkinson disease (PD). For NC patients, humor is the strongest trigger for cataplexy, a transient loss of muscle tone, whereas dopamine-deficient PD-patients show blunted emotional responses to humor. To better understand the role of reward system and the various contributions of hypocretinergic and dopaminergic mechanisms to different stages of humor processing we examined the electrophysiological response to humorous and neutral pictures when given as reward feedback in PD, NC and healthy controls. Humor compared to neutral feedback demonstrated modulation of early ERP amplitudes likely corresponding to visual processing stages, with no group differences. At 270 ms post-feedback, conditions showed topographical and amplitudinal differences for frontal and left posterior electrodes, in that humor feedback was absent in PD patients but increased in NC patients. We suggest that this effect relates to a relatively early affective response, reminiscent of increased amygdala response reported in NC patients. Later ERP differences, corresponding to the late positive potential, revealed a lack of sustained activation in PD, likely due to altered dopamine regulation in reward structures in these patients. This research provides new insights into the temporal dynamics and underlying mechanisms of humor detection and appreciation in health and disease.
Collapse
Affiliation(s)
- Armand Mensen
- Department of Sleep Medicine, Clinic Barmelweid, Barmelweid, Switzerland
| | - Rositsa Poryazova
- Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Sophie Schwartz
- Department of Neuroscience, University of Geneva, Geneva, Switzerland
| | - Ramin Khatami
- Department of Sleep Medicine, Clinic Barmelweid, Barmelweid, Switzerland
- * E-mail:
| |
Collapse
|
47
|
Teske JA, Billington CJ, Kotz CM. Mechanisms underlying obesity resistance associated with high spontaneous physical activity. Neuroscience 2013; 256:91-100. [PMID: 24161277 DOI: 10.1016/j.neuroscience.2013.10.028] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 10/11/2013] [Accepted: 10/11/2013] [Indexed: 12/12/2022]
Abstract
Obesity resistance due to elevated orexin signaling is accompanied by high levels of spontaneous physical activity (SPA). The behavioral and neural mechanisms underlying this observation have not been fully worked out. We determined the contribution of hypothalamic orexin receptors (OXRs) to SPA stimulated by orexin A (OXA), whether OXA-stimulated SPA was secondary to arousal and whether voluntary wheel running led to compensations in 24-h SPA. We further tested whether orexin action on dopamine one receptors (DA1R) in the substantia nigra (SN) plays an important role in the generation of SPA. To test this, SPA response was determined in lean and obese rats with cannulae targeted toward the rostral lateral hypothalamus (rLH) or SN. Sleep/wake states were also measured in rats with rLH cannula and electroencephalogram/electromyogram radiotelemetry transmitters. SPA in lean rats was more sensitive to antagonism of the OX1R and in the early response to the orexin 2 agonist. OXA increased arousal equally in lean and obese rodents, which is discordant from the greater SPA response in lean rats. Obesity-resistant rats ran more and wheel running was directly related to 24-h SPA levels. The OX1R antagonist, SB-334867-A, and the DA1R antagonist, SCH3390, in SN more effectively reduced SPA stimulated by OXA in obesity-resistant rats. These data suggest OXA-stimulated SPA is not secondary to enhanced arousal, propensity for SPA parallels inclination to run and that orexin action on dopaminergic neurons in SN may participate in the mediation of SPA and running wheel activity.
Collapse
Affiliation(s)
- J A Teske
- Department of Nutritional Sciences, University of Arizona and Southern Arizona, VA Health Care System, Tucson, AZ, USA; Minneapolis VA Health Care System, Minneapolis, MN 55417, USA; Minnesota Obesity Center, 1334 Eckles Avenue, Saint Paul, MN 55108, USA; Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Avenue, Saint Paul, MN 55108, USA.
| | - C J Billington
- Minneapolis VA Health Care System, Minneapolis, MN 55417, USA; Minnesota Obesity Center, 1334 Eckles Avenue, Saint Paul, MN 55108, USA; Department of Medicine, University of Minnesota, 420 Delaware Street SE, Minneapolis, MN 55455, USA; Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Avenue, Saint Paul, MN 55108, USA.
| | - C M Kotz
- Minneapolis VA Health Care System, Minneapolis, MN 55417, USA; Minnesota Obesity Center, 1334 Eckles Avenue, Saint Paul, MN 55108, USA; Geriatric Research, Education and Clinical Center, One Veterans Drive, Minneapolis, MN 55417, USA; Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Avenue, Saint Paul, MN 55108, USA.
| |
Collapse
|
48
|
An orexin hotspot in ventral pallidum amplifies hedonic 'liking' for sweetness. Neuropsychopharmacology 2013; 38:1655-64. [PMID: 23463152 PMCID: PMC3717533 DOI: 10.1038/npp.2013.62] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 01/12/2013] [Accepted: 01/15/2013] [Indexed: 11/08/2022]
Abstract
Orexin (hypocretin) is implicated in stimulating appetite as well as arousal, and in both food reward and drug reward. The ventral pallidum (VP) receives orexin projections from lateral hypothalamus neurons (LH), and orexin terminals are especially dense in the posterior half of VP, which is also the location of an opioid hedonic hotspot. The VP hotspot is a roughly cubic-millimeter site where mu opioid stimulation can amplify the hedonic impact of sweetness, expressed as an increase in 'liking' reactions to sucrose taste. The anatomical overlap in posterior VP between opioid hotspot and orexin inputs raises the possibility that the hedonic hotspot might allow orexin to amplify 'liking' too. We examined whether microinjections of orexin-A into the VP hotspot enhance the hedonic impact of sucrose, as assessed via affective taste reactivity measures of 'liking' reactions, and additionally compared effects at nearby sites in adjacent LH and extended amygdala. Taste reactivity results indicated that orexin stimulation specifically in the VP hotspot nearly doubled the magnitude of positive 'liking' reactions elicited by the taste of sucrose. Mapping results for localization of function, aided by Fos plume measures of the local spread of orexin impact, suggested that hedonic enhancement was generated by essentially the same cubic-millimeter of posterior VP previously identified as the opioid hotspot. By contrast, microinjection sites in the anterior half of VP, or in LH or extended amygdala, generally failed to produce any hedonic enhancement. We conclude that an orexin hedonic hotspot exists in posterior VP, with similar boundaries to the opioid hotspot. An orexin hedonic hotspot may permit regulatory hypothalamic circuitry to make foods more 'liked' during hunger by acting through VP. Dysfunction in a VP orexin hotspot in addiction or mood disorders might also contribute to some types of affective psychopathology.
Collapse
|
49
|
Boutrel B, Steiner N, Halfon O. The hypocretins and the reward function: what have we learned so far? Front Behav Neurosci 2013; 7:59. [PMID: 23781178 PMCID: PMC3680710 DOI: 10.3389/fnbeh.2013.00059] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 05/19/2013] [Indexed: 01/15/2023] Open
Abstract
A general consensus acknowledges that drug consumption (including alcohol, tobacco, and illicit drugs) constitutes the leading cause of preventable death worldwide. But the global burden of drug abuse extends the mortality statistics. Indeed, the comorbid long-term debilitating effects of the disease also significantly deteriorate the quality of life of individuals suffering from addiction disorders. Despite the large body of evidence delineating the cellular and molecular adaptations induced by chronic drug consumption, the brain mechanisms responsible for drug craving and relapse remain insufficiently understood, and even the most recent developments in the field have not brought significant improvement in the management of drug dependence. Though, recent preclinical evidence suggests that disrupting the hypocretin (orexin) system may serve as an anticraving medication therapy. Here, we discuss how the hypocretins, which orchestrate normal wakefulness, metabolic health and the execution of goal-oriented behaviors, may be compromised and contribute to elicit compulsive drug seeking. We propose an overview on the most recent studies demonstrating an important role for the hypocretin neuropeptide system in the regulation of drug reward and the prevention of drug relapse, and we question the relevance of disrupting the hypocretin system to alleviate symptoms of drug addiction.
Collapse
Affiliation(s)
- Benjamin Boutrel
- Department of Psychiatry, Center for Psychiatric Neuroscience, Lausanne University Hospital Lausanne, Switzerland ; Department of Psychiatry, Division of Child and Adolescent Psychiatry, Lausanne University Hospital Lausanne, Switzerland
| | | | | |
Collapse
|
50
|
Alexandre C, Andermann ML, Scammell TE. Control of arousal by the orexin neurons. Curr Opin Neurobiol 2013; 23:752-9. [PMID: 23683477 DOI: 10.1016/j.conb.2013.04.008] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 04/02/2013] [Accepted: 04/09/2013] [Indexed: 01/01/2023]
Abstract
The orexin-producing neurons in the lateral hypothalamus play an essential role in promoting arousal and maintaining wakefulness. These neurons receive a broad variety of signals related to environmental, physiological and emotional stimuli; they project to almost every brain region involved in the regulation of wakefulness; and they fire most strongly during active wakefulness, high motor activation, and sustained attention. This review focuses on the specific neuronal pathways through which the orexin neurons promote wakefulness and maintain high level of arousal, and how recent studies using optogenetic and pharmacogenetic methods have demonstrated that the locus coeruleus, the tuberomammillary nucleus, and the basal forebrain are some of the key sites mediating the arousing actions of orexins.
Collapse
Affiliation(s)
- Chloe Alexandre
- Department of Neurology, Beth Israel Medical Deaconess Center, Boston, MA 02215, United States
| | | | | |
Collapse
|