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Jászberényi M, Thurzó B, Bagosi Z, Vécsei L, Tanaka M. The Orexin/Hypocretin System, the Peptidergic Regulator of Vigilance, Orchestrates Adaptation to Stress. Biomedicines 2024; 12:448. [PMID: 38398050 PMCID: PMC10886661 DOI: 10.3390/biomedicines12020448] [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: 01/18/2024] [Revised: 02/10/2024] [Accepted: 02/15/2024] [Indexed: 02/25/2024] Open
Abstract
The orexin/hypocretin neuropeptide family has emerged as a focal point of neuroscientific research following the discovery that this family plays a crucial role in a variety of physiological and behavioral processes. These neuropeptides serve as powerful neuromodulators, intricately shaping autonomic, endocrine, and behavioral responses across species. Notably, they serve as master regulators of vigilance and stress responses; however, their roles in food intake, metabolism, and thermoregulation appear complementary and warrant further investigation. This narrative review provides a journey through the evolution of our understanding of the orexin system, from its initial discovery to the promising progress made in developing orexin derivatives. It goes beyond conventional boundaries, striving to synthesize the multifaceted activities of orexins. Special emphasis is placed on domains such as stress response, fear, anxiety, and learning, in which the authors have contributed to the literature with original publications. This paper also overviews the advancement of orexin pharmacology, which has already yielded some promising successes, particularly in the treatment of sleep disorders.
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Affiliation(s)
- Miklós Jászberényi
- Department of Pathophysiology, University of Szeged, H-6701 Szeged, Hungary; (M.J.); (B.T.); (Z.B.)
| | - Balázs Thurzó
- Department of Pathophysiology, University of Szeged, H-6701 Szeged, Hungary; (M.J.); (B.T.); (Z.B.)
- Emergency Patient Care Unit, Albert Szent-Györgyi Health Centre, University of Szeged, H-6725 Szeged, Hungary
| | - Zsolt Bagosi
- Department of Pathophysiology, University of Szeged, H-6701 Szeged, Hungary; (M.J.); (B.T.); (Z.B.)
| | - László Vécsei
- Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, H-6725 Szeged, Hungary;
- HUN-REN-SZTE Neuroscience Research Group, Hungarian Research Network, University of Szeged (HUN-REN-SZTE), Danube Neuroscience Research Laboratory, Tisza Lajos krt. 113, H-6725 Szeged, Hungary
| | - Masaru Tanaka
- HUN-REN-SZTE Neuroscience Research Group, Hungarian Research Network, University of Szeged (HUN-REN-SZTE), Danube Neuroscience Research Laboratory, Tisza Lajos krt. 113, H-6725 Szeged, Hungary
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Głombik K, Kukla-Bartoszek M, Curzytek K, Basta-Kaim A, Budziszewska B. Contribution of changes in the orexin system and energy sensors in the brain in depressive disorder - a study in an animal model. Pharmacol Rep 2024; 76:51-71. [PMID: 38194217 PMCID: PMC10830606 DOI: 10.1007/s43440-023-00559-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/14/2023] [Accepted: 11/14/2023] [Indexed: 01/10/2024]
Abstract
BACKGROUND Maternal elevated glucocorticoid levels during pregnancy can affect the developing fetus, permanently altering the structure and function of its brain throughout life. Excessive action of these hormones is known to contribute to psychiatric disorders, including depression. MATERIALS The study was performed in a rat model of depression based on prenatal administration of dexamethasone (DEX) in late pregnancy (0.1 mg/kg, days 14-21). We evaluated the effects of prenatal DEX treatment on the cognition and bioenergetic signaling pathways in the brain of adult male rats, in the frontal cortex and hippocampus, and in response to stress in adulthood, using behavioral and biochemical test batteries. RESULTS We revealed cognitive deficits in rats prenatally treated with DEX. At the molecular level, a decrease in the orexin A and orexin B levels and downregulation of the AMPK-SIRT1-PGC1α transduction pathway in the frontal cortex of these animals were observed. In the hippocampus, a decreased expression of orexin B was found and changes in the MR/GR ratio were demonstrated. Furthermore, an increase in HDAC5 level triggered by the prenatal DEX treatment in both brain structures and a decrease in MeCP2 level in the hippocampus were reported. CONCLUSIONS Our study demonstrated that prenatal DEX treatment is associated with cognitive dysfunction and alterations in various proteins leading to metabolic changes in the frontal cortex, while in the hippocampus adaptation mechanisms were activated. The presented results imply that different pathophysiological metabolic processes may be involved in depression development, which may be useful in the search for novel therapies.
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Affiliation(s)
- Katarzyna Głombik
- Laboratory of Immunoendocrinology, Department of Experimental Neuroendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343, Kraków, Poland.
| | - Magdalena Kukla-Bartoszek
- Laboratory of Immunoendocrinology, Department of Experimental Neuroendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343, Kraków, Poland
| | - Katarzyna Curzytek
- Laboratory of Immunoendocrinology, Department of Experimental Neuroendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343, Kraków, Poland
| | - Agnieszka Basta-Kaim
- Laboratory of Immunoendocrinology, Department of Experimental Neuroendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343, Kraków, Poland
| | - Bogusława Budziszewska
- Laboratory of Immunoendocrinology, Department of Experimental Neuroendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343, Kraków, Poland
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Tanaka M, Szabó Á, Vécsei L, Giménez-Llort L. Emerging Translational Research in Neurological and Psychiatric Diseases: From In Vitro to In Vivo Models. Int J Mol Sci 2023; 24:15739. [PMID: 37958722 PMCID: PMC10649796 DOI: 10.3390/ijms242115739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 10/13/2023] [Indexed: 11/15/2023] Open
Abstract
Revealing the underlying pathomechanisms of neurological and psychiatric disorders, searching for new biomarkers, and developing novel therapeutics all require translational research [...].
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Affiliation(s)
- Masaru Tanaka
- Danube Neuroscience Research Laboratory, HUN-REN-SZTE Neuroscience Research Group, Hungarian Research Network, University of Szeged (HUN-REN-SZTE), Tisza Lajos krt. 113, H-6725 Szeged, Hungary;
| | - Ágnes Szabó
- Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary;
- Doctoral School of Clinical Medicine, University of Szeged, Korányi fasor 6, H-6720 Szeged, Hungary
| | - László Vécsei
- Danube Neuroscience Research Laboratory, HUN-REN-SZTE Neuroscience Research Group, Hungarian Research Network, University of Szeged (HUN-REN-SZTE), Tisza Lajos krt. 113, H-6725 Szeged, Hungary;
- Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis u. 6, H-6725 Szeged, Hungary;
| | - Lydia Giménez-Llort
- Institut de Neurociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain
- Department of Psychiatry & Forensic Medicine, Faculty of Medicine, Campus Bellaterra, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain
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Mazur F, Całka J. Hypothalamic orexins as possible therapeutic agents in threat and spatial memory disorders. Front Behav Neurosci 2023; 17:1228056. [PMID: 37576933 PMCID: PMC10412936 DOI: 10.3389/fnbeh.2023.1228056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 07/13/2023] [Indexed: 08/15/2023] Open
Abstract
Orexin-A and orexin-B, neuropeptides produced exclusively in the lateral hypothalamus, have been implicated in various functions, including memory. Their levels are elevated in certain pathological states, such as PTSD, and lowered in other states, e.g., memory deficits. Recent developments have shown the possibilities of using orexins to modulate memory. Their administration can improve the results of test animals in paradigms such as passive avoidance (PA), cued fear conditioning (CFC), and the Morris water maze (MWM), with differences between the orexin used and the route of drug administration. Blocking orexin receptors in different brain structures produces opposing effects of memory impairments in given paradigms. Therefore, influencing the orexinergic balance of the brain becomes a viable way to ameliorate memory deficits, shift PTSD-induced recall of stressful memories to an extinction path, or regulate other memory processes.
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Affiliation(s)
- Filip Mazur
- Department of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Masuria in Olsztyn, Olsztyn, Poland
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Elahdadi Salmani M, Sarfi M, Goudarzi I. Hippocampal orexin receptors: Localization and function. VITAMINS AND HORMONES 2022; 118:393-421. [PMID: 35180935 DOI: 10.1016/bs.vh.2021.12.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Orexin (hypocretin) is secreted from the perifornical/lateral hypothalamus and is well known for sleep regulation. Orexin has two, orexin A and B, transcripts and two receptors, type 1 and 2 (OX1R and OX2R), located in the plasma membrane of neurons in different brain areas, including the hippocampus involved in learning, memory, seizures, and epilepsy, as physiologic and pathologic phenomena. OX1R is expressed in the dentate gyrus and CA1 and the OX2R in the CA3 areas. Orexin enhances learning and memory as well as reward, stress, seizures, and epilepsy, partly through OX1Rs, while either aggravating or alleviating those phenomena via OX2Rs. OX1Rs activation induces long-term changes of synaptic responses in the hippocampus, an age and concentration-dependent manner. Briefly, we will review the localization and functions of hippocampal orexin receptors, their role in learning, memory, stress, reward, seizures, epilepsy, and hippocampal synaptic plasticity.
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Affiliation(s)
| | | | - Iran Goudarzi
- School of Biology, Damghan University, Damghan, Iran
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Abounoori M, Maddah MM, Ardeshiri MR. Orexin neuropeptides modulate the hippocampal-dependent memory through basolateral amygdala interconnections. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2022; 3:100035. [PMID: 36324409 PMCID: PMC9616276 DOI: 10.1016/j.cccb.2021.100035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 12/17/2021] [Accepted: 12/28/2021] [Indexed: 11/25/2022]
Abstract
Orexin neuropeptides roles in hippocampal-dependent memory formation. Orexin neuropeptides activate the neural circuits of the basolateral amygdala. The power of memorization is modulated by the level of orexin neuropeptides.
Orexin neuropeptides have functional roles in hippocampal-dependent memory formation via the consolidation and retrieval of passive avoidance and spatial memories. The effects of these neuropeptides have been confirmed on the induction of long-term potentiation (LTP). The orexinergic system seems to have modulatory effects by sending projection fibers to several brain parts, such as the hippocampus and amygdala. Orexin neuropeptides activate the neural circuits of the basolateral amygdala during different arousal events with various emotional loads. Therefore, this system plays a vital role in creating appropriate behavioral reactions and responses particular to the situation. This review aimed to report new progression and advances in the hippocampus function in memory by focusing on its relationship with the amygdala through the orexinergic system.
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Intranasal insulin and orexins to treat age-related cognitive decline. Physiol Behav 2021; 234:113370. [PMID: 33621561 DOI: 10.1016/j.physbeh.2021.113370] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 02/19/2021] [Indexed: 02/06/2023]
Abstract
The intranasal (IN) administration of neuropeptides, such as insulin and orexins, has been suggested as a treatment strategy for age-related cognitive decline (ARCD). Because dysfunctional neuropeptide signaling is an observed characteristic of ARCD, it has been suggested that IN delivery of insulin and/or orexins may restore endogenous peptide signaling and thereby preserve cognition. IN administration is particularly alluring as it is a relatively non-invasive method that directly targets peptides to the brain. Several laboratories have examined the behavioral effects of IN insulin in young, aged, and cognitively impaired rodents and humans. These studies demonstrated improved performance on various cognitive tasks following IN insulin administration. Fewer laboratories have assessed the effects of IN orexins; however, this peptide also holds promise as an effective treatment for ARCD through the activation of the cholinergic system and/or the reduction of neuroinflammation. Here, we provide a brief overview of the advantages of IN administration and the delivery pathway, then summarize the current literature on IN insulin and orexins. Additional preclinical studies will be useful to ultimately uncover the mechanisms underlying the pro-cognitive effects of IN insulin and orexins, whereas future clinical studies will aid in the determination of the most efficacious dose and dosing paradigm. Eventually, IN insulin and/or orexin administration may be a widely used treatment strategy in the clinic for ARCD.
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Tavakkolifard M, Vousooghi N, Mahboubi S, Golab F, Ejtemaei Mehr S, Zarrindast MR. Evaluation of the relationship between the gene expression level of orexin-1 receptor in the rat blood and prefrontal cortex, novelty-seeking, and proneness to methamphetamine dependence: A candidate biomarker. Peptides 2020; 131:170368. [PMID: 32668268 DOI: 10.1016/j.peptides.2020.170368] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 06/19/2020] [Accepted: 07/06/2020] [Indexed: 01/01/2023]
Abstract
BACKGROUND previous studies have suggested that methamphetamine (METH) abuse may affect orexin regulation. However, the data regarding the relationship between the current level of orexin and the vulnerability to METH abuse are minimal. Here, we have investigated the correlation between the gene expression level of the orexin-1 receptor (OX1R) in the rat prefrontal cortex (PFC) and blood lymphocytes and susceptibility to METH dependence and its impact on novelty-seeking behavior. METHODS male Wistar rats were first examined for novelty-seeking behavior by the novel object recognition test, and the expression level of OX1R in their blood lymphocytes was evaluated by real-time PCR. Then, the susceptibility to METH abuse was investigated by voluntary METH oral consumption test. According to the amounts of METH consumption, the animals were divided into two groups of METH preferring and non-preferring. Half of the rats in each group were sacrificed, and the level of OX1R in their blood lymphocytes and PFC tissue was measured. The other half were sacrificed for the same reason after two weeks of drug abstinence. RESULTS The indexes of novelty-seeking behavior were significantly higher in the METH- preferring group compared to the non-preferring animals. Furthermore, the expression level of OX1R in the blood lymphocytes and PFC in the preferring group was considerably higher than the non-preferring group. CONCLUSION Up-regulation of the mRNA expression level of OX1R in the lymphocytes and PFC may predict vulnerability to the METH consumption and novelty-seeking, which may serve as a potential biomarker for METH abuse.
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Affiliation(s)
- Mahnoosh Tavakkolifard
- Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Nasim Vousooghi
- Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; Research Center for Cognitive and Behavioral Sciences, Tehran University of Medical Sciences, Tehran, Iran; Iranian National Center for Addiction Studies (INCAS), Tehran University of Medical Sciences, Tehran, Iran.
| | - Sara Mahboubi
- Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Fereshteh Golab
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Shahram Ejtemaei Mehr
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Zarrindast
- Iranian National Center for Addiction Studies (INCAS), Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Department of Cognitive Neuroscience, Institute for Cognitive Science Studies, Tehran, Iran.
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Han D, Han F, Shi Y, Zheng S, Wen L. Mechanisms of Memory Impairment Induced by Orexin-A via Orexin 1 and Orexin 2 Receptors in Post-traumatic Stress Disorder Rats. Neuroscience 2020; 432:126-136. [PMID: 32112915 DOI: 10.1016/j.neuroscience.2020.02.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 02/15/2020] [Accepted: 02/18/2020] [Indexed: 12/14/2022]
Abstract
Post-traumatic stress disorder (PTSD) patients exhibit abnormal learning and memory. Axons from orexin neurons in the lateral hypothalamus innervate the hippocampus, modulating learning and memory via the orexin 1 and 2 receptors (OX1R and OX2R). However, the role of the orexin system in the learning and memory dysfunction observed in PTSD is unknown. This was investigated in the present study using PTSD animal model-single prolonged stress (SPS) rats. Spatial learning and memory in the rats were evaluated with the Morris water maze (MWM) test; changes in body weight and food intake were recorded to assess changes in appetite; and the expression of orexin-A and its receptors in the hypothalamus and hippocampus was examined and quantified by immunohistochemistry, western blotting and real-time PCR. The results showed that spatial memory was impaired and food intake was decreased in SPS rats; this was accompanied by downregulation of orexin-A in the hypothalamus and upregulation of OX1R and OX2R in the hippocampus and of OX1R in the hypothalamus. Intracerebroventricular administration of orexin-A improved spatial memory and enhanced appetite in SPS rats and partly reversed the increases in OX1R and OX2R levels in the hippocampus and hypothalamus. These results suggest that the orexin system plays a critical role in the memory and appetite dysfunction observed in PTSD.
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Affiliation(s)
- Dan Han
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical Sciences College, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, Liaoning Province, PR China; Department of Neonatology, The First Hospital of China Medical University, No. 155 Nanjing North Street, Heping Area, Shenyang, PR China
| | - Fang Han
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical Sciences College, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, Liaoning Province, PR China
| | - Yuxiu Shi
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical Sciences College, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, Liaoning Province, PR China.
| | - Shilei Zheng
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical Sciences College, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, Liaoning Province, PR China
| | - Lili Wen
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical Sciences College, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, Liaoning Province, PR China
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Duffy CM, Hofmeister JJ, Nixon JP, Butterick TA. High fat diet increases cognitive decline and neuroinflammation in a model of orexin loss. Neurobiol Learn Mem 2018; 157:41-47. [PMID: 30471346 DOI: 10.1016/j.nlm.2018.11.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/26/2018] [Accepted: 11/16/2018] [Indexed: 12/23/2022]
Abstract
Midlife obesity is a risk factor for cognitive decline and is associated with the earlier onset of Alzheimer's disease (AD). Diets high in saturated fat potentiate the onset of obesity, microglial activation, and neuroinflammation. Signaling deficiencies in the hypothalamic peptide orexin and/or orexin fiber loss are linked to neurodegeneration, cognitive impairment, and neuroinflammation. Prior studies show that orexin is neuroprotective, suppresses neuroinflammation, and that treatment with orexin improves cognitive processes in orexin/ataxin-3 (O/A3) mice, a transgenic mouse model of orexin neurodegeneration. Our overall hypothesis is that loss of orexin contributes to high fat diet (HFD)-induced hippocampal neuroinflammation and cognitive decline. To examine this, we tested male O/A3 mice (7-8 mo. of age) in a two-way active avoidance (TWAA) hippocampus-dependent memory task. We tested whether (1) orexin loss impaired cognitive function; (2) HFD worsened cognitive impairment; and (3) HFD increased microglial activation and neuroinflammation. O/A3 mice showed significant impairments in TWAA task learning vs. wild type (WT) mice (increased escapes p < 0.05, reduced avoidances p < 0.0001). Mice were then placed on HFD (45% total fat, 31.4% saturated fat) or remained on normal chow (NC; 4% total fat and 1% saturated fat), and TWAA was retested at 2 and 4 weeks. Learning impairment was evident at both 2 and 4 weeks in O/A3 mice fed HFD for following diet exposure vs. WT mice on normal chow or HFD (increased escapes, reduced avoidances p < 0.05). Additionally, O/A3 mice had increased gene expression of the microglial activation marker Iba-1 (measured via qRT-PCR, p < 0.001). Further characterization of the microglial immune response genes in hippocampal tissue revealed a significant increase in CX3 chemokine receptor 1 (CX3CR1), tumor necrosis factor-alpha (TNF-α) and the mitochondria-associated enzyme immune responsive gene-1 (Irg1). Collectively, our results indicate that orexin loss impairs memory, and that HFD accelerates hippocampus-dependent learning deficits and the onset of neuroinflammation.
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Affiliation(s)
- C M Duffy
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, United States
| | - J J Hofmeister
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Minneapolis Center for Veterans Research and Education, Minneapolis, MN, United States
| | - J P Nixon
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, United States; Minneapolis Center for Veterans Research and Education, Minneapolis, MN, United States
| | - T A Butterick
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, United States; Minneapolis Center for Veterans Research and Education, Minneapolis, MN, United States.
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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.
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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.
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Zhu R, Liu X, Shi Y, Wang X, Xue L, Zhao H. Propranolol can induce PTSD-like memory impairments in rats. Brain Behav 2018; 8:e00905. [PMID: 29484264 PMCID: PMC5822589 DOI: 10.1002/brb3.905] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 11/17/2017] [Accepted: 11/28/2017] [Indexed: 12/12/2022] Open
Abstract
Introduction One hallmark symptom of post-traumatic stress disorder (PTSD) is an inability to restrict fear responses to the appropriate predictor. An infusion of glucocorticoids (GCs) after a high-intensity shock has been shown to induce PTSD-like memory impairments. In addition to GCs, noradrenergic signalling is also recognized as a key biomarker underlying PTSD symptomatology. Methods To explore the role of the noradrenergic system in PTSD-like memory impairments, in this study, various doses of the β-adrenoceptor antagonist propranolol were systemically or bilaterally injected into the dorsal hippocampus immediately after unpaired cue-shock contextual fear conditioning, and then the rats were tested 24 h later. Results Interestingly, we found that only low-dose propranolol could induce PTSD-like memory impairments, as rats showed reduced freezing to the correct predictor and generalized fear responses to the safe cues, accompanied by increased NE levels in the hippocampus and altered neural activity within the frontal-subcortical circuit. Conclusion These findings demonstrate that the noradrenergic system is involved in regulating the consolidation of contextual fear memory and that propranolol can dose-dependently induce PTSD-like memory impairments.
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Affiliation(s)
- Rong‐Ting Zhu
- Faculty of Forensic MedicineZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
| | - Xiang‐Hui Liu
- Faculty of Forensic MedicineZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
| | - Yan‐Wei Shi
- Faculty of Forensic MedicineZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Brain Function and DiseaseZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
- Guangdong Province Translational Forensic Medicine Engineering Technology Research CenterZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
| | - Xiao‐Guang Wang
- Faculty of Forensic MedicineZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Brain Function and DiseaseZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
- Guangdong Province Translational Forensic Medicine Engineering Technology Research CenterZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
| | - Li Xue
- Faculty of Forensic MedicineZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Brain Function and DiseaseZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
- Guangdong Province Translational Forensic Medicine Engineering Technology Research CenterZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
| | - Hu Zhao
- Faculty of Forensic MedicineZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Brain Function and DiseaseZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
- Guangdong Province Translational Forensic Medicine Engineering Technology Research CenterZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhouChina
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Dang R, Chen Q, Song J, He C, Zhang J, Xia J, Hu Z. Orexin knockout mice exhibit impaired spatial working memory. Neurosci Lett 2018; 668:92-97. [PMID: 29325715 DOI: 10.1016/j.neulet.2018.01.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 01/02/2018] [Accepted: 01/07/2018] [Indexed: 11/15/2022]
Abstract
Orexins play a crucial role in the maintenance of arousal and are involved in the modulation of diverse physiological process, including cognitive function. Recent data have suggested that orexins are involved in learning and memory processes. The purpose of this study was to assess the effects of orexin deficiency on working memory. A delayed non-matching-to-place T-maze task was used to evaluate spatial working memory in mice lacking orexin prepro-peptide (orexin knockout; KO) and wild-type controls. We demonstrated that the number of correct choices in the orexin KO mice became lower than that of the controls over training. In an object exploration task, the controls explored the displaced object more than the mutants did, whereas this difference was not observed for the nondisplaced objects in either group. The orexin KO mice showed locomotor activity comparable to the control mice in terms of total distance traveled across training in both the object exploration task and the open field test. These findings indicate that the orexin system plays an important role in working memory of spatial cues.
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Affiliation(s)
- Ruozhi Dang
- Department of Physiology, Collaborative Innovation Center for Brain Science, Third Military Medical University, Chongqing, 400038, PR China
| | - Qiuhan Chen
- Department of Physiology, Collaborative Innovation Center for Brain Science, Third Military Medical University, Chongqing, 400038, PR China
| | - Jie Song
- Department of Physiology, Collaborative Innovation Center for Brain Science, Third Military Medical University, Chongqing, 400038, PR China
| | - Chao He
- Department of Physiology, Collaborative Innovation Center for Brain Science, Third Military Medical University, Chongqing, 400038, PR China
| | - Jun Zhang
- Department of Physiology, Collaborative Innovation Center for Brain Science, Third Military Medical University, Chongqing, 400038, PR China
| | - Jianxia Xia
- Department of Physiology, Collaborative Innovation Center for Brain Science, Third Military Medical University, Chongqing, 400038, PR China.
| | - Zhian Hu
- Department of Physiology, Collaborative Innovation Center for Brain Science, Third Military Medical University, Chongqing, 400038, PR China.
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14
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Mavanji V, Butterick TA, Duffy CM, Nixon JP, Billington CJ, Kotz CM. Orexin/hypocretin treatment restores hippocampal-dependent memory in orexin-deficient mice. Neurobiol Learn Mem 2017; 146:21-30. [PMID: 29107703 DOI: 10.1016/j.nlm.2017.10.014] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/02/2017] [Accepted: 10/27/2017] [Indexed: 12/31/2022]
Abstract
Orexin A is produced in neurons of the lateral, perifornical and dorsomedial regions of the lateral hypothalamic area, which then project widely throughout the central nervous system to regulate arousal state, sleep-wake architecture, energy homeostasis and cognitive processes. Disruption of orexin signaling leads to sleep disturbances and increased body mass index, but recent studies also indicate that orexin neuron activation improves learning and memory. We hypothesized that hippocampal orexin receptor activation improves memory. To test this idea, we obtained orexin/ataxin-3 (O/A3) mice, which become deficient in orexin neurons by about 12 weeks of age. We first measured hippocampal orexin receptor 1 (OX1R) gene expression and protein levels, then tested acquisition and consolidation of two-way active avoidance (TWAA) memory, a hippocampal-dependent learning and memory task. Finally, we determined if exogenous intra-hippocampal OXA treatment could reverse cognitive impairment (as determined by TWAA) in OA/3 mice. We showed that OX1R mRNA expression and protein levels were significantly elevated in O/A3 mice, indicating the potential for preserved orexin responsiveness. The O/A3 mice were significantly impaired in TWAA memory vs. control mice, but OXA treatment (both acute and chronic) reversed these memory deficits. These results demonstrate that orexin plays an important role in hippocampal-dependent consolidation of two-way active avoidance memory, and orexin replacement can rescue the cognitive impairment.
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Affiliation(s)
- Vijayakumar Mavanji
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA
| | - Tammy A Butterick
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Department of Food Science and Nutrition, University of Minnesota, St Paul, MN 55108 USA; Minnesota Obesity Center, St Paul, MN 55108 USA
| | - Cayla M Duffy
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Department of Food Science and Nutrition, University of Minnesota, St Paul, MN 55108 USA; Minnesota's Discovery, Research and Innovation Economy, Brain Conditions, University of Minnesota, Minneapolis, MN 55455
| | - Joshua P Nixon
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Department of Food Science and Nutrition, University of Minnesota, St Paul, MN 55108 USA
| | - Charles J Billington
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Minnesota Obesity Center, St Paul, MN 55108 USA; Department of Medicine, University of Minnesota, Minneapolis, MN 55455 USA
| | - Catherine M Kotz
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Minnesota Obesity Center, St Paul, MN 55108 USA; Geriatric Research Education Clinical Center, Veterans Affairs Health Care System, Minneapolis, MN 55417 USA; Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN 55455 USA.
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15
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The effect of orexin 1 and orexin 2 receptors antagonisms in the basolateral amygdala on memory processing in a passive avoidance task. Physiol Behav 2017; 174:42-48. [DOI: 10.1016/j.physbeh.2017.03.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/04/2017] [Accepted: 03/03/2017] [Indexed: 01/02/2023]
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Chieffi S, Messina G, Villano I, Messina A, Esposito M, Monda V, Valenzano A, Moscatelli F, Esposito T, Carotenuto M, Viggiano A, Cibelli G, Monda M. Exercise Influence on Hippocampal Function: Possible Involvement of Orexin-A. Front Physiol 2017; 8:85. [PMID: 28261108 PMCID: PMC5306252 DOI: 10.3389/fphys.2017.00085] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 01/30/2017] [Indexed: 01/24/2023] Open
Abstract
In the present article, we provide a brief review of current knowledge regarding the effects induced by physical exercise on hippocampus. Research involving animals and humans supports the view that physical exercise, enhancing hippocampal neurogenesis and function, improves cognition, and regulates mood. These beneficial effects depend on the contribute of more factors including the enhancement of vascularization and upregulation of growth factors. Among these, the BDNF seems to play a significant role. Another putative factor that might contribute to beneficial effects of exercise is the orexin-A. In support of this hypothesis there are the following observations: (1) orexin-A enhances hippocampal neurogenesis and function and (2) the levels of orexin-A increase with physical exercise. The beneficial effects of exercise may represent an important resource to hinder the cognitive decline associated with the aging-related hippocampal deterioration and ameliorate depressive symptoms.
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Affiliation(s)
- Sergio Chieffi
- Section of Human Physiology and Unit of Dietetic and Sport Medicine, Department of Experimental Medicine, Second University of Naples Naples, Italy
| | - Giovanni Messina
- Section of Human Physiology and Unit of Dietetic and Sport Medicine, Department of Experimental Medicine, Second University of NaplesNaples, Italy; Department of Clinical and Experimental Medicine, University of FoggiaFoggia, Italy
| | - Ines Villano
- Section of Human Physiology and Unit of Dietetic and Sport Medicine, Department of Experimental Medicine, Second University of Naples Naples, Italy
| | - Antonietta Messina
- Section of Human Physiology and Unit of Dietetic and Sport Medicine, Department of Experimental Medicine, Second University of Naples Naples, Italy
| | - Maria Esposito
- Department of Mental Health, Physical and Preventive Medicine, Clinic of Child and Adolescent Neuropsychiatry, Center for Childhood Headache, Second University of Naples Naples, Italy
| | - Vincenzo Monda
- Section of Human Physiology and Unit of Dietetic and Sport Medicine, Department of Experimental Medicine, Second University of Naples Naples, Italy
| | - Anna Valenzano
- Department of Clinical and Experimental Medicine, University of Foggia Foggia, Italy
| | - Fiorenzo Moscatelli
- Department of Clinical and Experimental Medicine, University of Foggia Foggia, Italy
| | - Teresa Esposito
- Section of Human Physiology and Unit of Dietetic and Sport Medicine, Department of Experimental Medicine, Second University of Naples Naples, Italy
| | - Marco Carotenuto
- Department of Mental Health, Physical and Preventive Medicine, Clinic of Child and Adolescent Neuropsychiatry, Center for Childhood Headache, Second University of Naples Naples, Italy
| | - Andrea Viggiano
- Department of Medicine and Surgery, University of Salerno Salerno, Italy
| | - Giuseppe Cibelli
- Section of Human Physiology and Unit of Dietetic and Sport Medicine, Department of Experimental Medicine, Second University of Naples Naples, Italy
| | - Marcellino Monda
- Department of Clinical and Experimental Medicine, University of Foggia Foggia, Italy
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Chen XY, Chen L, Du YF. Orexin-A increases the firing activity of hippocampal CA1 neurons through orexin-1 receptors. J Neurosci Res 2016; 95:1415-1426. [PMID: 27796054 DOI: 10.1002/jnr.23975] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 09/29/2016] [Accepted: 10/04/2016] [Indexed: 12/15/2022]
Affiliation(s)
- Xin-Yi Chen
- Department of Neurology; Provincial Hospital Affiliated to Shandong University; Jinan Shandong China
| | - Lei Chen
- Department of Physiology; Qingdao University; Qingdao China
| | - Yi-Feng Du
- Department of Neurology; Provincial Hospital Affiliated to Shandong University; Jinan Shandong China
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Aitta-Aho T, Pappa E, Burdakov D, Apergis-Schoute J. Cellular activation of hypothalamic hypocretin/orexin neurons facilitates short-term spatial memory in mice. Neurobiol Learn Mem 2016; 136:183-188. [PMID: 27746379 PMCID: PMC5139982 DOI: 10.1016/j.nlm.2016.10.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 09/08/2016] [Accepted: 10/06/2016] [Indexed: 12/20/2022]
Abstract
The hypothalamic hypocretin/orexin (HO) system holds a central role in the regulation of several physiological functions critical for food-seeking behavior including mnemonic processes for effective foraging behavior. It is unclear however whether physiological increases in HO neuronal activity can support such processes. Using a designer rM3Ds receptor activation approach increasing HO neuronal activity resulted in improved short-term memory for novel locations. When tested on a non-spatial novelty object recognition task no significant difference was detected between groups indicating that hypothalamic HO neuronal activation can selectively facilitate short-term spatial memory for potentially supporting memory for locations during active exploration.
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Affiliation(s)
- Teemu Aitta-Aho
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| | - Elpiniki Pappa
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| | - Denis Burdakov
- Division of Neurophysiology, MRC National Institute for Medical Research, London NW7 1AA, UK; MRC Centre for Developmental Neurobiology, King's College London, London WC2R 2LS, UK
| | - John Apergis-Schoute
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK; Department of Neuroscience, Psychology & Behaviour, University of Leicester, Leicester LE1 7RH, UK.
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Villain H, Benkahoul A, Drougard A, Lafragette M, Muzotte E, Pech S, Bui E, Brunet A, Birmes P, Roullet P. Effects of Propranolol, a β-noradrenergic Antagonist, on Memory Consolidation and Reconsolidation in Mice. Front Behav Neurosci 2016; 10:49. [PMID: 27014009 PMCID: PMC4789536 DOI: 10.3389/fnbeh.2016.00049] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 02/29/2016] [Indexed: 12/20/2022] Open
Abstract
Memory reconsolidation impairment using the β-noradrenergic receptor blocker propranolol is a promising novel treatment avenue for patients suffering from pathogenic memories, such as post-traumatic stress disorder (PTSD). However, in order to better inform targeted treatment development, the effects of this compound on memory need to be better characterized via translational research. We examined the effects of systemic propranolol administration in mice undergoing a wide range of behavioral tests to determine more specifically which aspects of the memory consolidation and reconsolidation are impaired by propranolol. We found that propranolol (10 mg/kg) affected memory consolidation in non-aversive tasks (object recognition and object location) but not in moderately (Morris water maze (MWM) to highly (passive avoidance, conditioned taste aversion) aversive tasks. Further, propranolol impaired memory reconsolidation in the most and in the least aversive tasks, but not in the moderately aversive task, suggesting its amnesic effect was not related to task aversion. Moreover, in aquatic object recognition and location tasks in which animals were forced to behave (contrary to the classic versions of the tasks); propranolol did not impair memory reconsolidation. Taken together our results suggest that the memory impairment observed after propranolol administration may result from a modification of the emotional valence of the memory rather than a disruption of the contextual component of the memory trace. This is relevant to the use of propranolol to block memory reconsolidation in individuals with PTSD, as such a treatment would not erase the traumatic memory but only reduce the emotional valence associated with this event.
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Affiliation(s)
- Hélène Villain
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier (UPS) Toulouse, France
| | - Aïcha Benkahoul
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier (UPS) Toulouse, France
| | - Anne Drougard
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier (UPS) Toulouse, France
| | - Marie Lafragette
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier (UPS) Toulouse, France
| | - Elodie Muzotte
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier (UPS) Toulouse, France
| | - Stéphane Pech
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier (UPS) Toulouse, France
| | - Eric Bui
- Department of Psychiatry, Massachusetts General Hospital & Harvard Medical School Boston, MA, USA
| | - Alain Brunet
- Department of Psychiatry, Douglas Mental Health University Institute and McGill University Montréal, QC, Canada
| | - Philippe Birmes
- Toulouse NeuroImaging Center, Université de Toulouse, Institut national de la santé et de la recherche médicale (INSERM), Université Paul Sabatier (UPS) Toulouse, France
| | - Pascal Roullet
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier (UPS) Toulouse, France
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20
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Abstract
This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants). This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, United States.
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