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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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Sinen O, Akçalı İ, Akkan SS, Bülbül M. The role of hypothalamic Orexin-A in stress-induced gastric dysmotility: An agonistic interplay with corticotropin releasing factor. Neurogastroenterol Motil 2024; 36:e14719. [PMID: 38105366 DOI: 10.1111/nmo.14719] [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: 06/25/2023] [Revised: 09/20/2023] [Accepted: 10/17/2023] [Indexed: 12/19/2023]
Abstract
BACKGROUND Central Orexin-A (OXA) modulates gastrointestinal (GI) functions and stress response. This study aimed to investigate whether OXA and CRF interact at hypothalamic level. METHODS Solid gastric emptying (GE), fecal output (FO), plasma corticosterone (CORT), and postprandial antro-pyloric motility were assessed in rats that underwent acute restraint stress (ARS) and pretreated with central OX1R and/or CRF receptor antagonists SB-334867 and alpha-helical CRF9,41 . Microdialysis was performed to assess ARS-induced release of OXA and CRF in PVN and LHA, respectively. Immunofluorescence labeling was performed to detect the stress-induced changes in OXA and to assess the hypothalamic distribution of OX1R and CRF1/2 receptors. ARS-induced c-Fos immunoreactivity was evaluated in PVN and LHA of rats received OX1R and CRF receptor antagonists. KEY RESULTS ARS delayed GE by disturbing the coordination of antro-pyloric contractions while stimulating FO and CORT secretion. ARS-induced alterations in GE, FO, plasma CORT, and antro-pyloric motility were attenuated by OX1R and/or CRF receptor antagonists, however, these changes were completely restored in rats received both antagonists. ARS stimulated release of OXA and CRF which were significantly attenuated by α-CRF9,41 and SB-334867, respectively. The OX1R was detected in CRF-immunoreactive cells, whereas dense expression of CRF2 receptor but not CRF1 was observed in LHA. ARS remarkably increased OXA immunoreactivity in LHA. ARS-induced c-Fos expression in LHA and PVN was abolished by α-CRF9,41 and SB-334867, respectively. CONCLUSIONS & INFERENCES Our findings suggest a reciprocal contribution of OXA and CRF which seems to be involved in the mediation of stress-induced alterations in neuroendocrine and GI motor functions.
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Affiliation(s)
- Osman Sinen
- Department of Physiology, Faculty of Medicine, Akdeniz University, Antalya, Turkey
| | - İrem Akçalı
- Department of Physiology, Faculty of Medicine, Akdeniz University, Antalya, Turkey
| | - Simla Su Akkan
- Department of Physiology, Faculty of Medicine, Akdeniz University, Antalya, Turkey
| | - Mehmet Bülbül
- Department of Physiology, Faculty of Medicine, Akdeniz University, Antalya, Turkey
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Vincent SM, Madani M, Dikeman D, Golden K, Crocker N, Jackson C, Wimmer SP, Dover M, Tucker A, Ghiani CA, Colwell CS, LeBaron TW, Tarnava A, Paul KN. Hydrogen-rich water improves sleep consolidation and enhances forebrain neuronal activation in mice. SLEEP ADVANCES : A JOURNAL OF THE SLEEP RESEARCH SOCIETY 2023; 5:zpad057. [PMID: 38264142 PMCID: PMC10803172 DOI: 10.1093/sleepadvances/zpad057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 12/14/2023] [Indexed: 01/25/2024]
Abstract
Study Objectives Sleep loss contributes to various health issues and impairs neurological function. Molecular hydrogen has recently gained popularity as a nontoxic ergogenic and health promoter. The effect of molecular hydrogen on sleep and sleep-related neural systems remains unexplored. This study investigates the impact of hydrogen-rich water (HRW) on sleep behavior and neuronal activation in sleep-deprived mice. Methods Adult C57BL/6J mice were implanted with electroencephalography (EEG) and electromyography (EMG) recording electrodes and given HRW (0.7-1.4 mM) or regular water for 7 days ad libitum. Sleep-wake cycles were recorded under baseline conditions and after acute sleep loss. Neuronal activation in sleep- and wake-related regions was assessed using cFos immunostaining. Results HRW increased sleep consolidation in undisturbed mice and increased non-rapid-eye movement and rapid-eye-movement sleep amount in sleep-deprived mice. HRW also decreased the average amount of time for mice to fall asleep after light onset. Neuronal activation in the lateral septum, medial septum, ventrolateral preoptic area, and median preoptic area was significantly altered in all mice treated with HRW. Conclusions HRW improves sleep consolidation and increases neuronal activation in sleep-related brain regions. It may serve as a simple, effective treatment to improve recovery after sleep loss.
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Affiliation(s)
- Scott M Vincent
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Melika Madani
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Dante Dikeman
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Kyle Golden
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Naomi Crocker
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Cameron Jackson
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Sam P Wimmer
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Mary Dover
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Alexis Tucker
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Cristina A Ghiani
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Christopher S Colwell
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Tyler W LeBaron
- Department of Kinesiology and Outdoor Recreation, Southern Utah University, Cedar City, UT, USA
- Molecular Hydrogen Institute, Enoch, UT, USA
| | - Alex Tarnava
- Natural Wellness Now Health Products Inc, Maple ridge, BC, Canada
| | - Ketema N Paul
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
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Shin H, Kim J, Choi SR, Kang DW, Moon JY, Roh DH, Bae M, Hwang J, Kim HW. Antinociceptive effect of intermittent fasting via the orexin pathway on formalin-induced acute pain in mice. Sci Rep 2023; 13:20245. [PMID: 37985842 PMCID: PMC10661460 DOI: 10.1038/s41598-023-47278-3] [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: 08/14/2023] [Accepted: 11/11/2023] [Indexed: 11/22/2023] Open
Abstract
It has been suggested that stress responses induced by fasting have analgesic effects on nociception by elevating the levels of stress-related hormones, while there is limited understanding of pain control mechanisms. Here, we investigated whether acute or intermittent fasting alleviates formalin-induced pain in mice and whether spinal orexin A (OXA) plays a role in this process. 6, 12, or 24 h acute fasting (AF) and 12 or 24 h intermittent fasting (IF) decreased the second phase of pain after intraplantar formalin administration. There was no difference in walking time in the rota-rod test and distance traveld in the open field test in all groups. Plasma corticosterone level and immobility time in the forced swim test were increased after 12 h AF, but not after 12 h IF. 12 h AF and IF increased not only the activation of OXA neurons in the lateral hypothalamus but also the expression of OXA in the lateral hypothalamus and spinal cord. Blockade of spinal orexin 1 receptor with SB334867 restored formalin-induced pain and spinal c-Fos immunoreactivity that were decreased after 12 h IF. These results suggest that 12 h IF produces antinociceptive effects on formalin-induced pain not by corticosterone elevation but by OXA-mediated pathway.
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Affiliation(s)
- Hyunjin Shin
- Department of Physiology and Medical Science, College of Medicine and Brain Research Institute, Chungnam National University, 266 Munhwa-ro, Jung-gu, Daejeon, 35015, Korea
| | - Jaehyuk Kim
- Department of Physiology and Medical Science, College of Medicine and Brain Research Institute, Chungnam National University, 266 Munhwa-ro, Jung-gu, Daejeon, 35015, Korea
- CNS Team, N-DIC, Hwaseong, 18469, Korea
| | - Sheu-Ran Choi
- Department of Pharmacology, Catholic Kwandong University College of Medicine, Gangneung, 25601, Korea
| | - Dong-Wook Kang
- Department of Physiology and Medical Science, College of Medicine and Brain Research Institute, Chungnam National University, 266 Munhwa-ro, Jung-gu, Daejeon, 35015, Korea
| | - Ji-Young Moon
- Animal Protection and Welfare Division, Animal and Plant Quarantine Agency, Gimcheon, 39660, Korea
| | - Dae-Hyun Roh
- Department of Oral Physiology, School of Dentistry, Kyung Hee University, Seoul, 02447, Korea
| | - Miok Bae
- Preclinical Research Center, Chungnam National University Hospital, Daejeon, 35015, Korea
| | - Jungmo Hwang
- Department of Orthopaedic Surgery, College of Medicine, Chungnam National University, 266 Munhwa-ro, Jung-gu, Daejeon, 35015, Korea.
| | - Hyun-Woo Kim
- Department of Physiology and Medical Science, College of Medicine and Brain Research Institute, Chungnam National University, 266 Munhwa-ro, Jung-gu, Daejeon, 35015, Korea.
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Kolmos MG, Arribas AP, Kornum BR, Justinussen JL. Experimental sickness reduces hypocretin receptor 1 expression in the lateral hypothalamus and ventral tegmental area of female mice. Eur J Neurosci 2023; 58:4002-4010. [PMID: 37818927 DOI: 10.1111/ejn.16151] [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: 04/28/2023] [Revised: 08/23/2023] [Accepted: 09/11/2023] [Indexed: 10/13/2023]
Abstract
Recent studies have focused on how sickness behaviours, including lethargy, are coordinated in the brain in response to peripheral infections. Decreased hypocretin (orexin) signalling is associated with lethargy and previous research suggests that hypocretin signalling is downregulated during sickness. However, there are studies that find increases or no change in hypocretin signalling during sickness. It is further unknown whether hypocretin receptor expression changes during sickness. Using lipopolysaccharide (LPS) to induce sickness in female mice, we investigated how LPS-injection affects gene expression of hypocretin receptors and prepro-hypocretin as well as hypocretin-1 peptide concentrations in brain tissue. We found that hypocretin receptor 1 gene expression was downregulated during sickness in the lateral hypothalamus and ventral tegmental area, but not in the dorsal raphe nucleus or locus coeruleus. We found no changes in hypocretin receptor 2 expression. Using a gene expression calculation that accounts for primer efficiencies and multiple endogenous controls, we were unable to detect changes in prepro-hypocretin expression. Using radioimmunoassay, we found no change in hypocretin-1 peptide in rostral brain tissue. Our results indicate that hypocretin receptor expression can fluctuate during sickness, adding an additional level of complexity to understanding hypocretin signalling during sickness.
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Affiliation(s)
- Mie Gunni Kolmos
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Alba Pérez Arribas
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Birgitte Rahbek Kornum
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jessica Lauren Justinussen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Żakowski W, Zawistowski P. Neurochemistry of the mammillary body. Brain Struct Funct 2023; 228:1379-1398. [PMID: 37378855 PMCID: PMC10335970 DOI: 10.1007/s00429-023-02673-4] [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: 10/25/2022] [Accepted: 06/19/2023] [Indexed: 06/29/2023]
Abstract
The mammillary body (MB) is a component of the extended hippocampal system and many studies have shown that its functions are vital for mnemonic processes. Together with other subcortical structures, such as the anterior thalamic nuclei and tegmental nuclei of Gudden, the MB plays a crucial role in the processing of spatial and working memory, as well as navigation in rats. The aim of this paper is to review the distribution of various substances in the MB of the rat, with a description of their possible physiological roles. The following groups of substances are reviewed: (1) classical neurotransmitters (glutamate and other excitatory transmitters, gamma-aminobutyric acid, acetylcholine, serotonin, and dopamine), (2) neuropeptides (enkephalins, substance P, cocaine- and amphetamine-regulated transcript, neurotensin, neuropeptide Y, somatostatin, orexins, and galanin), and (3) other substances (calcium-binding proteins and calcium sensor proteins). This detailed description of the chemical parcellation may facilitate a better understanding of the MB functions and its complex relations with other structures of the extended hippocampal system.
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Affiliation(s)
- Witold Żakowski
- Department of Animal and Human Physiology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland.
| | - Piotr Zawistowski
- Department of Animal and Human Physiology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland
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Jin R, Sun S, Hu Y, Zhang H, Sun X. Neuropeptides Modulate Feeding via the Dopamine Reward Pathway. Neurochem Res 2023:10.1007/s11064-023-03954-4. [PMID: 37233918 DOI: 10.1007/s11064-023-03954-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/13/2023] [Accepted: 05/16/2023] [Indexed: 05/27/2023]
Abstract
Dopamine (DA) is a catecholamine neurotransmitter widely distributed in the central nervous system. It participates in various physiological functions, such as feeding, anxiety, fear, sleeping and arousal. The regulation of feeding is exceptionally complex, involving energy homeostasis and reward motivation. The reward system comprises the ventral tegmental area (VTA), nucleus accumbens (NAc), hypothalamus, and limbic system. This paper illustrates the detailed mechanisms of eight typical orexigenic and anorexic neuropeptides that regulate food intake through the reward system. According to recent literature, neuropeptides released from the hypothalamus and other brain regions regulate reward feeding predominantly through dopaminergic neurons projecting from the VTA to the NAc. In addition, their effect on the dopaminergic system is mediated by the prefrontal cortex, paraventricular thalamus, laterodorsal tegmental area, amygdala, and complex neural circuits. Research on neuropeptides involved in reward feeding can help identify more targets to treat diseases with metabolic disorders, such as obesity.
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Affiliation(s)
- Ruijie Jin
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
- Department of Clinical Medicine, Medical College, Qingdao University, Qingdao, China
| | - Shanbin Sun
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
- Department of Clinical Medicine, Medical College, Qingdao University, Qingdao, China
| | - Yang Hu
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
- Department of Clinical Medicine, Medical College, Qingdao University, Qingdao, China
| | - Hongfei Zhang
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China
- Department of Clinical Medicine, Medical College, Qingdao University, Qingdao, China
| | - Xiangrong Sun
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China.
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Abdelmissih S. A Bitter Experience That Enlightens the Future: COVID-19 Neurological Affection and Perspectives on the Orexigenic System. Cureus 2022; 14:e30788. [DOI: 10.7759/cureus.30788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2022] [Indexed: 11/06/2022] Open
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Youn DH, Jun J, Kim TW, Park K. Spinal orexin A attenuates opioid-induced mechanical hypersensitivity in the rat. Korean J Pain 2022; 35:433-439. [PMID: 36175342 PMCID: PMC9530684 DOI: 10.3344/kjp.2022.35.4.433] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 08/04/2022] [Accepted: 08/09/2022] [Indexed: 11/05/2022] Open
Abstract
Background Repeated administration of opioid analgesics for pain treatment can produce paradoxical hyperalgesia via peripheral and/or central mechanisms. Thus, this study investigated whether spinally (centrally) administered orexin A attenuates opioid-induced hyperalgesia (OIH). Methods [D-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO), a selective μ-opioid receptor agonist, was used to induce mechanical hypersensitivity and was administered intradermally (4 times, 1-hour intervals) on the rat hind paw dorsum. To determine whether post- or pretreatments with spinal orexin A, dynorphin A, and anti-dynorphin A were effective in OIH, the drugs were injected through an intrathecal catheter whose tip was positioned dorsally at the L3 segment of the spinal cord (5 μg for all). Mechanical hypersensitivity was assessed using von Frey monofilaments. Results Repeated intradermal injections of DAMGO resulted in mechanical hypersensitivity in rats, lasting more than 8 days. Although the first intrathecal treatment of orexin A on the 6th day after DAMGO exposure did not show any significant effect on the mechanical threshold, the second (on the 8th day) significantly attenuated the DAMGO-induced mechanical hypersensitivity, which disappeared when the type 1 orexin receptor (OX1R) was blocked. However, intrathecal administration of dynorphin or an anti-dynorphin antibody (dynorphin antagonists) had no effect on DAMGO-induced hypersensitivity. Lastly, pretreatment with orexin A, dynorphin, or anti-dynorphin did not prevent DAMGO-induced mechanical hypersensitivity. Conclusions Spinal orexin A attenuates mechanical hyperalgesia induced by repetitive intradermal injections of DAMGO through OX1R. These data suggest that OIH can be potentially treated by activating the orexin A-OX1R pathway in the spinal dorsal horn.
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Affiliation(s)
- Dong-Ho Youn
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Korea.,Advanced Dental Device Development Institute, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Jiyeon Jun
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, Korea.,Advanced Dental Device Development Institute, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Tae Wan Kim
- Department of Physiology, College of Veterinary Medicine, Kyungpook National University, Daegu, Korea
| | - Kibeom Park
- Department of Anesthesiology and Pain Medicine, Keimyung University Dongsan Hospital, Keimyung University School of Medicine, Daegu, Korea
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Nasudi G, Elahdadi Salmani M, Hosseinmardi N, Moradpour F, Lashkarbolouki T, Goudarzi I. Hippocampal orexin-1 and endocannabinoid-1 receptors underlie the kainate-induced occlusion in theta-burst long- term potentiation. Neuropeptides 2022; 95:102263. [PMID: 35716469 DOI: 10.1016/j.npep.2022.102263] [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: 06/02/2022] [Accepted: 06/02/2022] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Seizures may result from the hyperexcitable neuronal activity of the brain. Multiple neurotransmitter receptors, including orexin (OX) and endocannabinoids interfere with forming the synaptic responses linked to the seizures. Therefore, this study investigates the involvement of OX-1 (OX1R) and endocannbinoid-1 (CB1R) receptors in the kainate- induced excitability in the synaptic field responses. MATERIAL AND METHODS Theta pattern used to stimulate Schaffer collaterals and then metal microelectrodes to record the CA1 field excitatory postsynaptic potentials (fEPSPs). Input/ output stimulation and responses and paired- pulse (PP) stimuli employed to measure the state of synaptic activity in normal and kainate- induced seizure-like hyperexcitable activities and the slope of fEPSPs used as a measure of the change in the synaptic activity. Furthermore, agonists and antagonists of OX and endocannabinoids infused to investigate the involvement of their receptors. RESULT The results showed that kainate application increased the fEPSP slope either in input stimuli with different intensities/output synaptic responses (I/O), or test pulse stimulated baseline synaptic responses (BSR) and, hence, increased the excitability of field responses in the CA1 region. However, neither kainate nor theta burst stimulation (TBS) could alter the PP stimuli -induced synaptic responses. TBS increased the fEPSP slope of the kainate-applied I/O and BSR, however, the increase was not high enough in BSR to be classified as long-term potentiation (LTP). The single-antagonist OX1R and CB1R administration prevented TBS- induced potentiation and partially recovered the effect by adding eCB or OX agonists in kainate-injected animals. In contrast, OX or combined eCB-OX antagonist application group demonstrated nearly full recovery of LTP induction. CONCLUSION Our study concludes that blockade of OX1 or CB1 prevents the induction of LTP, and OX infusion or both receptor blockade recovers the LTP.
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Affiliation(s)
- Giti Nasudi
- School of Biology, Damghan University, Damghan, Iran
| | | | - Narges Hosseinmardi
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Iran
| | - Farshad Moradpour
- Department of Physiology, Faculty of Medicine, Kermanshah University of Medical Sciences, Iran
| | | | - Iran Goudarzi
- School of Biology, Damghan University, Damghan, Iran
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López JM, Carballeira P, Pozo J, León-Espinosa G, Muñoz A. Hypothalamic orexinergic neuron changes during the hibernation of the Syrian hamster. Front Neuroanat 2022; 16:993421. [PMID: 36157325 PMCID: PMC9501701 DOI: 10.3389/fnana.2022.993421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/09/2022] [Indexed: 11/23/2022] Open
Abstract
Hibernation in small mammals is a highly regulated process with periods of torpor involving drops in body temperature and metabolic rate, as well as a general decrease in neural activity, all of which proceed alongside complex brain adaptive changes that appear to protect the brain from extreme hypoxia and low temperatures. All these changes are rapidly reversed, with no apparent brain damage occurring, during the short periods of arousal, interspersed during torpor—characterized by transitory and partial rewarming and activity, including sleep activation, and feeding in some species. The orexins are neuropeptides synthesized in hypothalamic neurons that project to multiple brain regions and are known to participate in the regulation of a variety of processes including feeding behavior, the sleep-wake cycle, and autonomic functions such as brown adipose tissue thermogenesis. Using multiple immunohistochemical techniques and quantitative analysis, we have characterized the orexinergic system in the brain of the Syrian hamster—a facultative hibernator. Our results revealed that orexinergic neurons in this species consisted of a neuronal population restricted to the lateral hypothalamic area, whereas orexinergic fibers distribute throughout the rostrocaudal extent of the brain, particularly innervating catecholaminergic and serotonergic neuronal populations. We characterized the changes of orexinergic cells in the different phases of hibernation based on the intensity of immunostaining for the neuronal activity marker C-Fos and orexin A (OXA). During torpor, we found an increase in C-Fos immunostaining intensity in orexinergic neurons, accompanied by a decrease in OXA immunostaining. These changes were accompanied by a volume reduction and a fragmentation of the Golgi apparatus (GA) as well as a decrease in the colocalization of OXA and the GA marker GM-130. Importantly, during arousal, C-Fos and OXA expression in orexinergic neurons was highest and the structural appearance and the volume of the GA along with the colocalization of OXA/GM-130 reverted to euthermic levels. We discuss the involvement of orexinergic cells in the regulation of mammalian hibernation and, in particular, the possibility that the high activation of orexinergic cells during the arousal stage guides the rewarming as well as the feeding and sleep behaviors characteristic of this phase.
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Affiliation(s)
- Jesús M. López
- Departamento de Biología Celular, Universidad Complutense, Madrid, Spain
| | - Paula Carballeira
- Departamento de Biología Celular, Universidad Complutense, Madrid, Spain
| | - Javier Pozo
- Departamento de Biología Celular, Universidad Complutense, Madrid, Spain
| | - Gonzalo León-Espinosa
- Departamento de Química y Bioquímica, Facultad de Farmacia, Universidad San Pablo-Centro de Estudios Universitarios (CEU), Madrid, Spain
| | - Alberto Muñoz
- Departamento de Biología Celular, Universidad Complutense, Madrid, Spain
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica (CTB), Universidad Politécnica de Madrid, Madrid, Spain
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- *Correspondence: Alberto Muñoz,
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12
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Ghalebandi S, Zareie F, Askari K, Yuzugulen J, Haghparast A. Intra-CA1 injection of orexin receptors antagonism attenuates the stress-induced analgesia in a rat acute pain model. Behav Brain Res 2022; 423:113785. [PMID: 35122794 DOI: 10.1016/j.bbr.2022.113785] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/31/2022] [Accepted: 01/31/2022] [Indexed: 11/27/2022]
Abstract
Orexins or hypocretins are excitatory neuropeptides predominantly produced by neuronal clusters in the lateral hypothalamus. The orexinergic system's involvement in pain modulation makes it a candidate for pain control alternative to the opioid system. Moreover, orexin-1 and orexin -2 receptors (OX1r and OX2r, respectively) play a role in responsiveness to stressful stimuli. Some evidence indicates that the Cornu Ammonis 1 (CA1) region of the hippocampus potentially participates in the modulation of both pain and stress. In quest of better understanding the interaction between orexin receptors and stress-induced analgesia (SIA), The present study examined the involvement of OX1r and OX2r within the CA1 in response to acute pain after exposure to forced swim stress (FSS) for a 6-min period. Adult male Wistar rats received different doses of OX1r antagonist (SB334867; 1, 3, 10, and 30 nmol), OX2r antagonist (TCS OX2 29; 3, 10, 30 and 100 nmol), or vehicle (0.5 μl DMSO) through an implanted cannula. After that, animals individually experienced acute pain by performing the tail-flick test. Results indicated that FSS produces antinociceptive responses in the tail-flick test. Blockade of both orexin receptors within the CA1 region attenuated the analgesic effect of FSS. The antinociceptive effect of swim stress was prevented by lower doses of SB334867 than TCS OX2 29. These findings show that the orexinergic system might be partially involved in the SIA via the OX1 and OX2 receptors in the hippocampal CA1 region.
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Affiliation(s)
- Seyedehdelaram Ghalebandi
- Faculty of Pharmacy, Eastern Mediterranean University, Famagusta, T.R. North Cyprus via Mersin 10, Turkey
| | - Fatemeh Zareie
- Neurophysiology Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kobra Askari
- Department of Animal Biology, Faculty of Biological Science, Kharazmi University, Tehran, Iran
| | - Jale Yuzugulen
- Faculty of Pharmacy, Eastern Mediterranean University, Famagusta, T.R. North Cyprus via Mersin 10, Turkey
| | - Abbas Haghparast
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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13
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Peleg-Raibstein D, Burdakov D. Do orexin/hypocretin neurons signal stress or reward? Peptides 2021; 145:170629. [PMID: 34416308 DOI: 10.1016/j.peptides.2021.170629] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/04/2021] [Accepted: 08/14/2021] [Indexed: 12/23/2022]
Abstract
Hypothalamic neurons that produce the peptide transmitters orexins/hypocretins (HONs) broadcast their predominantly neuroexcitatory outputs to the entire brain via their extremely wide axonal projections. HONs were originally reported to be activated by food deprivation, and to stimulate arousal, energy expenditure, and eating. This led to extensive studies of HONs in the context of nutrient-sensing and energy balance control. While activation of HONs by body energy depletion continues to be supported by experimental evidence, it has also become clear that HONs are robustly activated not only by nutrient depletion, but also by diverse sensory stimuli (both neutral and those associated with rewarding or aversive events), seemingly unrelated to each other or to energy balance. One theory that could unify these findings is that all these stimuli signal "stress" - defined either as a potentially harmful state, or an awareness of reward deficiency. If HON activity is conceptualized as a cumulative representation of stress, then many of the reported HONs outputs - including EEG arousal, sympathetic activation, place avoidance, and exploratory behaviours - could be viewed as logical stress-counteracting responses. We discuss evidence for and against this unifying theory of HON function, including the alterations in HON activity observed in anxiety and depression disorders. We propose that, in order to orchestrate stress-countering responses, HONs need to coactivate motivation and aversion brain systems, and the impact of HON stimulation on affective states may be perceived as rewarding or aversive depending on the baseline HON activity.
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Affiliation(s)
| | - Denis Burdakov
- Department of Health Sciences and Technology, ETH Zürich, Switzerland.
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14
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Azeez IA, Igado OO, Olopade JO. An overview of the orexinergic system in different animal species. Metab Brain Dis 2021; 36:1419-1444. [PMID: 34224065 DOI: 10.1007/s11011-021-00761-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 06/06/2021] [Indexed: 01/13/2023]
Abstract
Orexin (hypocretin), is a neuropeptide produced by a subset of neurons in the lateral hypothalamus. From the lateral hypothalamus, the orexin-containing neurons project their fibres extensively to other brain structures, and the spinal cord constituting the central orexinergic system. Generally, the term ''orexinergic system'' usually refers to the orexin peptides and their receptors, as well as to the orexin neurons and their projections to different parts of the central nervous system. The extensive networks of orexin axonal fibres and their terminals allow these neuropeptidergic neurons to exert great influence on their target regions. The hypothalamic neurons containing the orexin neuropeptides have been implicated in diverse functions, especially related to the control of a variety of homeostatic functions including feeding behaviour, arousal, wakefulness stability and energy expenditure. The broad range of functions regulated by the orexinergic system has led to its description as ''physiological integrator''. In the last two decades, the orexinergic system has been a topic of great interest to the scientific community with many reports in the public domain. From the documentations, variations exist in the neuroanatomical profile of the orexinergic neuron soma, fibres and their receptors from animal to animal. Hence, this review highlights the distinct variabilities in the morphophysiological aspects of the orexinergic system in the vertebrate animals, mammals and non-mammals, its presence in other brain-related structures, including its involvement in ageing and neurodegenerative diseases. The presence of the neuropeptide in the cerebrospinal fluid and peripheral tissues, as well as its alteration in different animal models and conditions are also reviewed.
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Affiliation(s)
- Idris A Azeez
- Department of Veterinary Anatomy, University of Jos, Jos, Nigeria
| | - Olumayowa O Igado
- Department of Veterinary Anatomy, University of Ibadan, Ibadan, Nigeria
| | - James O Olopade
- Department of Veterinary Anatomy, University of Ibadan, Ibadan, Nigeria.
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15
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Chrobok L, Jeczmien-Lazur JS, Bubka M, Pradel K, Klekocinska A, Klich JD, Ridla Rahim A, Myung J, Kepczynski M, Lewandowski MH. Daily coordination of orexinergic gating in the rat superior colliculus-Implications for intrinsic clock activities in the visual system. FASEB J 2021; 35:e21930. [PMID: 34533886 DOI: 10.1096/fj.202100779rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 08/24/2021] [Accepted: 08/31/2021] [Indexed: 01/07/2023]
Abstract
The orexinergic system delivers excitation for multiple brain centers to facilitate behavioral arousal, with its malfunction resulting in narcolepsy, somnolence, and notably, visual hallucinations. Since the circadian clock underlies the daily arousal, a timed coordination is expected between the orexin system and its target subcortical visual system, including the superior colliculus (SC). Here, we use a combination of electrophysiological, immunohistochemical, and molecular approaches across 24 h, together with the neuronal tract-tracing methods to investigate the daily coordination between the orexin system and the rodent SC. Higher orexinergic input was found to occur nocturnally in the superficial layers of the SC, in time for nocturnal silencing of spontaneous firing in this visual brain area. We identify autonomous daily and circadian expression of clock genes in the SC, which may underlie these day-night changes. Additionally, we establish the lateral hypothalamic origin of the orexin innervation to the SC and that the SC neurons robustly respond to orexin A via OX2 receptor in both excitatory and GABAA receptor-dependent inhibitory manners. Together, our evidence elucidates the combination of intrinsic and extrinsic clock mechanisms that shape the daily function of the visual layers of the SC.
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Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jagoda Stanislawa Jeczmien-Lazur
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Monika Bubka
- Department of Glycoconjugate Biochemistry, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Aleksandra Klekocinska
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jasmin Daniela Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Amalia Ridla Rahim
- Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, Taipei, Taiwan
| | - Jihwan Myung
- Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, Taipei, Taiwan.,Brain and Consciousness Research Centre, Taipei Medical University-Shuang Ho Hospital, Ministry of Health and Welfare, New Taipei City, Taiwan
| | - Mariusz Kepczynski
- Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University in Krakow, Krakow, Poland
| | - Marian Henryk Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
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16
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Chrobok L, Klich JD, Sanetra AM, Jeczmien-Lazur JS, Pradel K, Palus-Chramiec K, Kepczynski M, Piggins HD, Lewandowski MH. Rhythmic neuronal activities of the rat nucleus of the solitary tract are impaired by high-fat diet - implications for daily control of satiety. J Physiol 2021; 600:751-767. [PMID: 34490628 DOI: 10.1113/jp281838] [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: 04/27/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Temporal partitioning of daily food intake is crucial for survival and involves the integration of internal circadian states and external influences such as the light-dark cycle and dietary composition. These intrinsic and extrinsic factors are interdependent with misalignment of circadian rhythms promoting body weight gain, while consumption of a calorie-dense diet elevates the risk of obesity and blunts circadian rhythms. Recently, we defined the circadian properties of the dorsal vagal complex of the brainstem, a structure implicated in the control of food intake and autonomic tone, but whether and how 24 h rhythms in this area are influenced by diet remains unresolved. Here we focused on a key structure of this complex, the nucleus of the solitary tract (NTS). We used a combination of immunohistochemical and electrophysiological approaches together with daily monitoring of body weight and food intake to interrogate how the neuronal rhythms of the NTS are affected by a high-fat diet. We report that short-term consumption of a high-fat diet increases food intake during the day and blunts NTS daily rhythms in neuronal discharge. Additionally, we found that a high-fat diet dampens NTS responsiveness to metabolic neuropeptides, and decreases orexin immunoreactive fibres in this structure. These alterations occur without prominent body weight gain, suggesting that a high-fat diet acts initially to reduce activity in the NTS to disinhibit mechanisms that suppress daytime feeding. KEY POINTS: The dorsal vagal complex of the rodent hindbrain possesses intrinsic circadian timekeeping mechanisms In particular, the nucleus of the solitary tract (NTS) is a robust circadian oscillator, independent of the master suprachiasmatic clock Here, we reveal that rat NTS neurons display timed daily rhythms in their neuronal activity and responsiveness to ingestive cues These daily rhythms are blunted or eliminated by a short-term high-fat diet, together with increased consumption of calories during the behaviourally quiescent day Our results help us better understand the circadian control of satiety by the brainstem and its malfunctioning under a high-fat diet.
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Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jasmin D Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Anna M Sanetra
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jagoda S Jeczmien-Lazur
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Katarzyna Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Mariusz Kepczynski
- Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University in Krakow, Krakow, Poland
| | - Hugh D Piggins
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Marian H Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
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17
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Li B, Chang L, Peng X. Orexin 2 receptor in the nucleus accumbens is critical for the modulation of acute stress-induced anxiety. Psychoneuroendocrinology 2021; 131:105317. [PMID: 34111776 DOI: 10.1016/j.psyneuen.2021.105317] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 06/02/2021] [Accepted: 06/02/2021] [Indexed: 11/30/2022]
Abstract
Orexin is a neuropeptide mainly synthesized in the lateral hypothalamus/perifornical area and has been traditionally implicated in feeding, sleep-wake cycles, and reward. Intriguingly, patients with anxiety have increased levels of orexin in the cerebrospinal fluid. Pharmacological or genetic manipulation of orexin receptors affects anxiety-like behaviors in rodents, suggesting an involvement of the orexin signaling in the regulation of anxiety. Yet, the neural substrates involved remain largely unknown. The nucleus accumbens (NAc) shell holds a key position in the modulation of anxiety-related behaviors. Therefore, in the present study, by using neuropharmacology, molecular approaches and behavioral tests in rats, the role of orexin/orexin receptors in the NAc shell on the anxiety-like behaviors was investigated. We found that microinjection of orexin-A into the NAc shell induced an anxiogenic-like effect. Quantitative real-time PCR and immunofluorescence showed that the orexin 2 receptor (OX2R) is expressed and distributed in the NAc shell neurons. Activation of OX2R mimicked the anxiogenic effect of orexin-A. Moreover, infusion of an OX2R antagonist had no effect on anxiety-like behaviors in normal rats, but reversed anxiogenic effect induced by acute restraint stress. Finally, we found that downregulation of OX2R in the NAc shell caused an anxiolytic-like effect in acute restraint stressed rats, which was consistent with the pharmacological results. Together, this study suggests that OX2R in the NAc shell is involved in the regulation of acute stress-induced anxiety, and raises the possibility that OX2R antagonist may serve as an effective mean to treat anxiety disorders.
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Affiliation(s)
- Bin Li
- Women & Children Central Laboratory, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
| | - Leilei Chang
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Xiaochun Peng
- School of Life Sciences, Nanjing University, Nanjing, China
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18
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Gao HR, Wu ZJ, Wu SB, Gao HY, Wang J, Zhang JL, Zhou MQ. Roles of central orexinergic system on cardiovascular function and acupuncture on intervention of cardiovascular risk: Orexinergic system mediate the role of acupuncture? Neuropeptides 2021; 87:102132. [PMID: 33636511 DOI: 10.1016/j.npep.2021.102132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 01/09/2021] [Accepted: 02/11/2021] [Indexed: 12/26/2022]
Abstract
Central orexinergic system contributes to the regulation of cardiovascular function. Orexinergic neurons receiving projections of nerve fibers from multiple structures of brain which involved in control and regulation of cardiovascular function locate in hypothalamus, and their axon terminals widely project to various central structures where orexins receptors are expressed. Here, we summarize the present knowledge that describes the influence of central orexinergic system on cardiovascular activity, the relevance of dysfunction in central orexinergic system with hypertension and psychological stress induced cardiovascular reactivity which are serious risk factors for cardiovascular disease and cardiovascular death. We propose that central orexinergic system may be potentially important targets for the prevention of cardiovascular disease and cardiovascular death, and different orexinergic system involved neuronal circuits may be involved in distinct cardiovascular functions. Acupuncture having bidirectional regulatory ability and a much lower incidence of side effects can prevent disease. We review the improvement of acupuncture on hypertension and psychological stress induced cardiovascular reactivity. We think that acupuncture intervenes hypertension and psychological stress induced cardiovascular reactivity to prevent cardiovascular disease and cardiovascular death. We also summarize relation between acupuncture and central orexinergic system. We propose a hypothesis that acupuncture improve hypertension and psychological stress induced cardiovascular reactivity through regulating central orexinergic system. The knowledge is beneficial for the development of potential therapeutic targets and methods to prevent cardiovascular disease and cardiovascular death.
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Affiliation(s)
- He-Ren Gao
- Key Laboratory of Acupuncture and Moxibustion Foundation and Technology of Anhui Province, Research Institute of Acupuncture and Meridian, College of Acupuncture and Tuina, Anhui Academy of Chinese Medicine, Anhui University of Chinese Medicine, Hefei, China.
| | - Zi-Jian Wu
- Key Laboratory of Acupuncture and Moxibustion Foundation and Technology of Anhui Province, Research Institute of Acupuncture and Meridian, College of Acupuncture and Tuina, Anhui Academy of Chinese Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - Sheng-Bing Wu
- Key Laboratory of Acupuncture and Moxibustion Foundation and Technology of Anhui Province, Research Institute of Acupuncture and Meridian, College of Acupuncture and Tuina, Anhui Academy of Chinese Medicine, Anhui University of Chinese Medicine, Hefei, China; Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei, China
| | - He-Yuan Gao
- Department of Pediatrics, The First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Jie Wang
- Key Laboratory of Acupuncture and Moxibustion Foundation and Technology of Anhui Province, Research Institute of Acupuncture and Meridian, College of Acupuncture and Tuina, Anhui Academy of Chinese Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - Jin-Li Zhang
- Anhui Vocational College of Grain Engineering, Hefei, China
| | - Mei-Qi Zhou
- Key Laboratory of Acupuncture and Moxibustion Foundation and Technology of Anhui Province, Research Institute of Acupuncture and Meridian, College of Acupuncture and Tuina, Anhui Academy of Chinese Medicine, Anhui University of Chinese Medicine, Hefei, China; Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei, China; Bozhou Institute of Traditional Chinese Medicine, Anhui Academy of Chinese Medicine, Bozhou, China.
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19
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Amodeo LR, Liu W, Wills DN, Vetreno RP, Crews FT, Ehlers CL. Adolescent alcohol exposure increases orexin-A/hypocretin-1 in the anterior hypothalamus. Alcohol 2020; 88:65-72. [PMID: 32619610 DOI: 10.1016/j.alcohol.2020.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 06/23/2020] [Accepted: 06/25/2020] [Indexed: 12/30/2022]
Abstract
Adolescence is a time of marked changes in sleep, neuromaturation, and alcohol use. While there is substantial evidence that alcohol disrupts sleep and that disrupted sleep may play a role in the development of alcohol use disorders (AUD), there is very little known about the brain mechanisms underlying this phenomenon. The orexin (also known as hypocretin) system is fundamental for a number of homeostatic mechanisms, including the initiation and maintenance of wakefulness that may be impacted by adolescent alcohol exposure. The current study investigated the impact of adolescent ethanol exposure on adult orexin-A/hypocretin-1 immunoreactive (orexin-A + IR) cells in hypothalamic nuclei in two models of adolescent intermittent ethanol (AIE) exposure. Both models assess adult hypothalamic orexin following either an AIE vapor exposure paradigm, or an AIE intragastric gavage paradigm during adolescence. Both AIE exposure models found that binge levels of ethanol intoxication during adolescence significantly increased adult orexin-A + IR expression in the anterior hypothalamic nucleus (AHN). Further, both AIE models found no change in orexin-A + IR in the posterior hypothalamic area (PH), perifornical nucleus (PeF), dorsomedial hypothalamic nucleus dorsal part (DMD) or lateral hypothalamic area (LH). However, AIE vapor exposure reduced orexin-A + IR in the paraventricular nucleus (PVN), but AIE gavage exposure did not. These findings suggest that the AHN orexinergic system is increased in adults following binge-like patterns of intoxication during adolescence. Altered adult AHN orexin could contribute to long-lasting changes in sleep.
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Affiliation(s)
- Leslie R Amodeo
- Department of Psychology, California State University, San Bernardino, San Bernardino, CA, 92407, United States
| | - Wen Liu
- Bowles Center for Alcohol Studies, School of Medicine, University of North Carolina, Chapel Hill, NC, 27599, United States
| | - Derek N Wills
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, 92037, United States
| | - Ryan P Vetreno
- Bowles Center for Alcohol Studies, School of Medicine, University of North Carolina, Chapel Hill, NC, 27599, United States
| | - Fulton T Crews
- Bowles Center for Alcohol Studies, School of Medicine, University of North Carolina, Chapel Hill, NC, 27599, United States
| | - Cindy L Ehlers
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, 92037, United States.
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20
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Williams DL, Coiduras II, Parise EM, Maske CB. Hindbrain orexin 1 receptors blunt intake suppression by gastrointestinal nutrients and cholecystokinin in male rats. Peptides 2020; 133:170351. [PMID: 32579900 PMCID: PMC7556705 DOI: 10.1016/j.peptides.2020.170351] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/19/2020] [Accepted: 06/19/2020] [Indexed: 01/06/2023]
Abstract
Hypothalamic orexin neurons project to many brain areas, including hindbrain structures such as the nucleus of the solitary tract (NTS) and area postrema (AP), where orexin 1 receptors (OX1Rs) are expressed. Hindbrain administration of orexin-A increases feeding and meal size, and blockade of hindbrain OX1Rs with the selective antagonist SB334867 has the opposite effect. Here we asked whether hindbrain OX1R stimulation or blockade alter rats' sensitivity to gastrointestinal satiety signals. Rats received 4th intracerebroventricular (icv) injections of vehicle or orexin-A, at a dose with no effect on its own, prior to an intragastric (IG) infusion of saline or a satiating volume of Ensure. IG Ensure suppressed subsequent chow intake, but orexin-A pretreatment significantly attenuated this IG nutrient-induced satiety at 2 h into the dark phase. In a second experiment, rats received NTS injections of vehicle or orexin-A before intraperitoneal (IP) injection of vehicle or the satiation hormone cholecystokinin (CCK). NTS orexin-A pretreatment completely blocked the intake-suppressive effect of CCK on dark-phase chow intake. Finally, we investigated the role of endogenous hindbrain OX1R activation by pretreating rats with 4th-icv injection of vehicle or SB334867 followed by IG infusion of saline or Ensure just before a chocolate Ensure licking test session. IG nutrient infusion suppressed Ensure intake, and blockade of hindbrain OX1Rs significantly prolonged that intake-suppressive effect. We conclude that hindbrain OX1Rs are a mechanism though which hypothalamic orexin neurons can reduce animals' sensitivity to gastrointestinal nutrient load, allowing them to consume more food.
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Affiliation(s)
- Diana L Williams
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL, 32306-4301 USA.
| | - Isabel I Coiduras
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL, 32306-4301 USA
| | - Eric M Parise
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL, 32306-4301 USA
| | - Calyn B Maske
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL, 32306-4301 USA
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21
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Dunietz GL, Vanini G, Shannon C, O'Brien LM, Chervin RD. Associations of plasma hypocretin-1 with metabolic and reproductive health: Two systematic reviews of clinical studies. Sleep Med Rev 2020; 52:101307. [PMID: 32259696 PMCID: PMC7351596 DOI: 10.1016/j.smrv.2020.101307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 01/30/2020] [Accepted: 01/31/2020] [Indexed: 12/11/2022]
Abstract
The hypocretin system consists of two peptides hypocretin-1 and hypocretin-2 (HCRT1 and HCRT2). Hypocretin-containing neurons are located in the posterior and lateral hypothalamus, and have widespread projections throughout the brain and spinal cord. In addition to its presence in the cerebrospinal fluid (CSF), peripheral HCRT1 has been detected in plasma. Robust experimental evidence demonstrates functions of hypothalamic-originated HCRT1 in regulation of multiple biological systems related to sleep-wake states, energy homeostasis and endocrine function. In contrast, HCRT1 studies with human participants are limited by the necessarily invasive assessment of CSF HCRT1 to patients with underlying morbidity. Regulation by HCRT1 of energy homeostasis and reproduction in animals suggests similar regulation in humans and prompts these two systematic reviews. These reviews translate prior experimental findings from animal studies to humans and examine associations between HCRT1 and: 1) metabolic risk factors; 2) reproductive function in men, women and children. A total of 21 studies and six studies met the inclusion criteria for the two searches, respectively. Research question, study design, study population, assessments of HCRT1, reproductive, cardiometabolic data and main findings were extracted. Associations between HCRT1, metabolic and reproductive function are inconsistent. Limitations of studies and future research directions are outlined.
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Affiliation(s)
- Galit L Dunietz
- Division of Sleep Medicine, Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Giancarlo Vanini
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Carol Shannon
- Taubman Health Sciences Library, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Louise M O'Brien
- Division of Sleep Medicine, Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA; Department of Obstetrics & Gynecology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ronald D Chervin
- Division of Sleep Medicine, Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA
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Fakhoury M, Salman I, Najjar W, Merhej G, Lawand N. The Lateral Hypothalamus: An Uncharted Territory for Processing Peripheral Neurogenic Inflammation. Front Neurosci 2020; 14:101. [PMID: 32116534 PMCID: PMC7029733 DOI: 10.3389/fnins.2020.00101] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/24/2020] [Indexed: 12/20/2022] Open
Abstract
The roles of the hypothalamus and particularly the lateral hypothalamus (LH) in the regulation of inflammation and pain have been widely studied. The LH consists of a parasympathetic area that has connections with all the major parts of the brain. It controls the autonomic nervous system (ANS), regulates feeding behavior and wakeful cycles, and is a part of the reward system. In addition, it contains different types of neurons, most importantly the orexin neurons. These neurons, though few in number, perform critical functions such as inhibiting pain transmission and interfering with the reward system, feeding behavior and the hypothalamic pituitary axis (HPA). Recent evidence has identified a new role for orexin neurons in the modulation of pain transmission associated with several inflammatory diseases, including rheumatoid arthritis and ulcerative colitis. Here, we review recent findings on the various physiological functions of the LH with special emphasis on the orexin/receptor system and its role in mediating inflammatory pain.
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Affiliation(s)
- Marc Fakhoury
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Israa Salman
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Wassim Najjar
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - George Merhej
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Nada Lawand
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.,Department of Neurology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
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23
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Chen XY, Xue Y, Chen H, Chen L. The globus pallidus as a target for neuropeptides and endocannabinoids participating in central activities. Peptides 2020; 124:170210. [PMID: 31778724 DOI: 10.1016/j.peptides.2019.170210] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 11/14/2019] [Accepted: 11/21/2019] [Indexed: 12/12/2022]
Abstract
The globus pallidus in the basal ganglia plays an important role in movement regulation. Neuropeptides and endocannabinoids are neuronal signalling molecules that influence the functions of the whole brain. Endocannabinoids, enkephalin, substance P, neurotensin, orexin, somatostatin and pituitary adenylate cyclase-activating polypeptides are richly concentrated in the globus pallidus. Neuropeptides and endocannabinoids exert excitatory or inhibitory effects in the globus pallidus mainly by modulating GABAergic, glutamatergic and dopaminergic neurotransmission, as well as many ionic mechanisms. Pallidal neuropeptides and endocannabinoids are associated with the pathophysiology of a number of neurological disorders, such as Parkinson's disease, Huntington's disease, schizophrenia, and depression. The levels of neuropeptides and endocannabinoids and their receptors in the globus pallidus change in neurological diseases. It has been demonstrated that spontaneous firing activity of globus pallidus neurons is closely related to the manifestations of Parkinson's disease. Therefore, the neuropeptides and endocannabinoids in the globus pallidus may function as potential targets for treatment in some neurological diseases. In this review, we highlight the morphology and function of neuropeptides and endocannabinoids in the globus pallidus and their involvement in neurological diseases.
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Affiliation(s)
- Xin-Yi Chen
- Department of Pathology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China; Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Yan Xue
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Hua Chen
- Department of Pathology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China.
| | - Lei Chen
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, China.
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24
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Li GY, Zhuang QX, Zhang XY, Wang JJ, Zhu JN. Ionic Mechanisms Underlying the Excitatory Effect of Orexin on Rat Subthalamic Nucleus Neurons. Front Cell Neurosci 2019; 13:153. [PMID: 31105528 PMCID: PMC6499184 DOI: 10.3389/fncel.2019.00153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 04/08/2019] [Indexed: 11/24/2022] Open
Abstract
Central orexinergic system deficiency results in cataplexy, a motor deficit characterized with a sudden loss of muscle tone, highlighting a direct modulatory role of orexin in motor control. However, the neural mechanisms underlying the regulation of orexin on motor function are still largely unknown. The subthalamic nucleus (STN), the only excitatory structure of the basal ganglia, holds a key position in the basal ganglia circuitry and motor control. Previous study has revealed a wide distribution of orexinergic fibers as well as orexin receptors in the basal ganglia including the STN. Therefore, in the present study, by using whole-cell patch clamp recording and immunostaining techniques, the direct effect of orexin on the STN neurons in brain slices, especially the underlying receptor and ionic mechanisms, were investigated. Our results show that orexin-A elicits an excitatory effect on STN neurons in rats. Tetrodotoxin (TTX) does not block the orexin-induced excitation on STN neurons, suggesting a direct postsynaptic action of the neuropeptide. The orexin-A-induced inward current on STN neurons is mediated by the activation of both OX1 and OX2 receptors. Immunofluorescence result shows that OX1 and OX2 receptors are co-expressed and co-localized in STN neurons. Furthermore, Na+-Ca2+ exchangers (NCXs) and inward rectifier K+ channels co-mediate the excitatory effect of orexin-A on STN neurons. These results demonstrate a dual receptor in conjunction with the downstream ionic mechanisms underlying the excitatory action of orexin on STN neurons, suggesting a potential modulation of the central orexinergic system on basal ganglia circuitry as well as its related motor control and motor diseases.
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Affiliation(s)
- Guang-Ying Li
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Qian-Xing Zhuang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Xiao-Yang Zhang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Jian-Jun Wang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Jing-Ning Zhu
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing, China
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25
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Targeting the orexinergic system: Mainly but not only for sleep-wakefulness therapies. ALEXANDRIA JOURNAL OF MEDICINE 2019. [DOI: 10.1016/j.ajme.2014.07.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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26
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Wang P, Wang M, Zhang L, Zhong S, Jiang W, Wang Z, Sun C, Zhang S, Liu Z. Functional characterization of an orexin neuropeptide in amphioxus reveals an ancient origin of orexin/orexin receptor system in chordate. SCIENCE CHINA-LIFE SCIENCES 2019; 62:1655-1669. [PMID: 30945108 DOI: 10.1007/s11427-018-9421-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 10/10/2018] [Indexed: 01/09/2023]
Abstract
Amphioxus belongs to the subphylum cephalochordata, an extant representative of the most basal chordates, whose regulation of endocrine system remains ambiguous. Here we clearly demonstrated the existence of a functional orexin neuropeptide in amphioxus, which is able to interact with orexin receptor, activate both PKC and PKA pathways, decrease leptin expression, and stimulate lipogenesis. We also showed the transcription level of amphioxus orexin was affected by fasting or temperature, indicating a role of this gene in the regulation of energy balance. In addition, the expression of the amphioxus orexin was detected at cerebral vesicle, which has been proposed to be a homolog of the vertebrate brain. These data collectively suggest that a functional orexin neuropeptide has already emerged in amphioxus, which provide insights into the evolutionary origin of orexin in chordate and the functional homology between the cerebral vesicle and vertebrate brain.
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Affiliation(s)
- Peng Wang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Meng Wang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Liping Zhang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Shenjie Zhong
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Wanyue Jiang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Ziyue Wang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Chen Sun
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Shicui Zhang
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China.
| | - Zhenhui Liu
- Institute of Evolution & Marine Biodiversity, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China.
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27
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Spinal Orexin-2 Receptors are Involved in Modulation of the Lateral Hypothalamic Stimulation-Induced Analgesia. Neurochem Res 2019; 44:1152-1158. [DOI: 10.1007/s11064-019-02749-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 02/01/2019] [Accepted: 02/01/2019] [Indexed: 12/16/2022]
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28
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Liu MF, Xue Y, Liu C, Liu YH, Diao HL, Wang Y, Pan YP, Chen L. Orexin-A Exerts Neuroprotective Effects via OX1R in Parkinson's Disease. Front Neurosci 2018. [PMID: 30524223 DOI: 10.3389/fnins.2018.00835.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Parkinson's disease (PD) is a common neurodegenerative disorder characterized by progressive and selective death of dopaminergic neurons. Orexin-A is involved in many biological effects of the body. It has been reported that orexin-A has protective effects in cellular models of PD. However, little is known about the protective effects of orexin-A in animal parkinsonian models and the cellular mechanism has not yet been fully clarified. The aim of this study was to evaluate the effects of orexin-A in MPTP mice model of PD as well as the possible neuroprotective mechanisms of orexin-A on dopaminergic neurons. The results from animal experiments demonstrated that orexin-A attenuated the loss of dopaminergic neurons and the decrease of tyrosine hydroxylase (TH) expression in the substantia nigra, normalized the striatal dopaminergic fibers, and prevented the depletion of dopamine and its metabolites in the striatum. MPTP-treated mice showed cognitive impairments accompanied with significant motor deficiency. Orexin-A improved MPTP-induced impairments in both motor activity and spatial memory. Importantly, orexin-A increased the protein level of brain-derived neurotrophic factor (BDNF) in dopaminergic neurons of the substantia nigra. Furthermore, the protective effects of orexin-A on MPTP parkinsonian mice could be blocked by orexinergic receptor 1 (OX1R) antagonist, SB334867. In another set of experiments with SH-SY5Y dopaminergic cells, orexin-A significantly induced the expression of BDNF in a dose and time-dependent manner. The upregulation of BDNF is mainly concerned with PI3K and PKC signaling pathways via OX1R. The present study demonstrated that orexin-A exerted neuroprotective effects on MPTP parkinsonian mice, which may imply orexin-A as a potential therapeutic target for PD.
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Affiliation(s)
- Mei-Fang Liu
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China.,College of Pharmacy, Jining Medical University, Rizhao, China
| | - Yan Xue
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Cui Liu
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Yun-Hai Liu
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Hui-Ling Diao
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Ying Wang
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Yi-Peng Pan
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Lei Chen
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
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29
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Liu MF, Xue Y, Liu C, Liu YH, Diao HL, Wang Y, Pan YP, Chen L. Orexin-A Exerts Neuroprotective Effects via OX1R in Parkinson's Disease. Front Neurosci 2018; 12:835. [PMID: 30524223 PMCID: PMC6262320 DOI: 10.3389/fnins.2018.00835] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/26/2018] [Indexed: 12/22/2022] Open
Abstract
Parkinson’s disease (PD) is a common neurodegenerative disorder characterized by progressive and selective death of dopaminergic neurons. Orexin-A is involved in many biological effects of the body. It has been reported that orexin-A has protective effects in cellular models of PD. However, little is known about the protective effects of orexin-A in animal parkinsonian models and the cellular mechanism has not yet been fully clarified. The aim of this study was to evaluate the effects of orexin-A in MPTP mice model of PD as well as the possible neuroprotective mechanisms of orexin-A on dopaminergic neurons. The results from animal experiments demonstrated that orexin-A attenuated the loss of dopaminergic neurons and the decrease of tyrosine hydroxylase (TH) expression in the substantia nigra, normalized the striatal dopaminergic fibers, and prevented the depletion of dopamine and its metabolites in the striatum. MPTP-treated mice showed cognitive impairments accompanied with significant motor deficiency. Orexin-A improved MPTP-induced impairments in both motor activity and spatial memory. Importantly, orexin-A increased the protein level of brain-derived neurotrophic factor (BDNF) in dopaminergic neurons of the substantia nigra. Furthermore, the protective effects of orexin-A on MPTP parkinsonian mice could be blocked by orexinergic receptor 1 (OX1R) antagonist, SB334867. In another set of experiments with SH-SY5Y dopaminergic cells, orexin-A significantly induced the expression of BDNF in a dose and time-dependent manner. The upregulation of BDNF is mainly concerned with PI3K and PKC signaling pathways via OX1R. The present study demonstrated that orexin-A exerted neuroprotective effects on MPTP parkinsonian mice, which may imply orexin-A as a potential therapeutic target for PD.
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Affiliation(s)
- Mei-Fang Liu
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China.,College of Pharmacy, Jining Medical University, Rizhao, China
| | - Yan Xue
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Cui Liu
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Yun-Hai Liu
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Hui-Ling Diao
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Ying Wang
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Yi-Peng Pan
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
| | - Lei Chen
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, China
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30
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Rezaee L, Karimi-Haghighi S, Fazli-Tabaei S, Haghparast A. Effects of intrathecal administration of orexin-1 receptor antagonist on antinociceptive responses induced by chemical stimulation of lateral hypothalamus in an animal model of tonic nociception. Neuropeptides 2018; 69:19-25. [PMID: 29735274 DOI: 10.1016/j.npep.2018.03.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 02/20/2018] [Accepted: 03/31/2018] [Indexed: 11/25/2022]
Abstract
Orexins are produced in the restricted regions of the lateral hypothalamus (LH). However, orexinergic receptors and projections are localized in wide regions like nucleus accumbens, ventral tegmental area, periaqueductal gray area and spinal cord which are involved in the pain modulation. This study was carried out to investigate the effects of intrathecal administration of orexin-1 receptor antagonist (SB-334867) in the spinal antinociception induced by intra-LH administration of carbachol (cholinergic receptor agonist) in both early and late phases of pain related behaviors in formalin test. In this study, pain-related behaviors (pain scores) were evaluated using the formalin test during 5-min block intervals for a 60-min period in seventy male Wistar rats were given SB-334867 (3, 10, 30 and 100 μM/10 μl) or vehicle (DMSO 12%; 10 μl) intrathecally following intra-LH administration of carbachol (250 nM/rat). Our data showed that intra-LH injection of carbachol attenuated the formalin-induced biphasic pain responses, and intrathecal administration of SB-334867 dose-dependently decreased LH stimulation-induced antinociceptive responses during both phases. Moreover, administration of different doses of SB-334867 during the early phase were more effective than those during the late phase. The antinociceptive role of orexinergic system in the formalin test through a neural pathway from the LH to the spinal cord provides evidence that orexins can be useful in therapeutic targets for pain relief.
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Affiliation(s)
- Laleh Rezaee
- Department of Physiology, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran; Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Saeideh Karimi-Haghighi
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Soheila Fazli-Tabaei
- Department of Physiology, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran.
| | - Abbas Haghparast
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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31
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Mäkelä KA, Karhu T, Jurado Acosta A, Vakkuri O, Leppäluoto J, Herzig KH. Plasma Orexin-A Levels Do Not Undergo Circadian Rhythm in Young Healthy Male Subjects. Front Endocrinol (Lausanne) 2018; 9:710. [PMID: 30568633 PMCID: PMC6289979 DOI: 10.3389/fendo.2018.00710] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 11/12/2018] [Indexed: 11/22/2022] Open
Abstract
Orexin-A (OXA) has been originally isolated from a precursor peptide prepro-orexin from the lateral hypothalamus. The orexin system has been attributed to important functions in sleep, arousal and regulation of energy homeostasis. In addition to its high levels in cerebrospinal fluid, OXA is present in blood. However, reported peptide concentrations in plasma vary significantly depending on the method used. Therefore, a specific and sensitive OXA radioimmunoassay (RIA) with solid phase extraction method was developed to determine whether plasma OXA concentrations is affected by acute feeding and/or wake and sleep in young healthy males. Blood samples were collected for 24 h from nine healthy males (aged 20-24 years; BMI 20.7-26.5) every 2 h starting at 11 a.m. Food was served at 12 p.m, 5:30 p.m, 8 p.m and 8 a.m and the sleep time was between 10 p.m and 7 a.m. Plasma samples were analyzed in addition for cortisol and melatonin levels. Blood pressure was monitored through the experimental period. OXA antibody was raised in rabbits. OXA antiserum had only minor cross-reactivity with prepro-orexin precursor (<0.001%), amino-terminal peptide (<0.001%), carboxy-terminal peptide (0.001%), and orexin-B (0.3%) with high sensitivity (0.15 pg/tube). Plasma OXA levels varied between 0.5 and 16 pg/ml in seven subjects and were undetectable (below 0.5 pg/ml) in two subjects. The OXA concentrations did not correlate to feeding nor wake/sleep, whereas cortisol, melatonin and mean arterial blood pressure presented a clear circadian rhythm in each subject. In conclusion, OXA is present in blood in low amounts and its levels do not follow autonomic nor neuroendocrine circadian rhythms. Thereby, studies examining regulatory mechanisms and influences of OXA from blood samples should interpret results very cautiously.
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Affiliation(s)
- Kari A. Mäkelä
- Research Unit of Biomedicine, Physiology, University of Oulu, Oulu, Finland
- *Correspondence: Karl-Heinz Herzig
| | - Toni Karhu
- Research Unit of Biomedicine, Physiology, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | | | - Olavi Vakkuri
- Research Unit of Biomedicine, Physiology, University of Oulu, Oulu, Finland
| | - Juhani Leppäluoto
- Research Unit of Biomedicine, Physiology, University of Oulu, Oulu, Finland
| | - Karl-Heinz Herzig
- Research Unit of Biomedicine, Physiology, University of Oulu, Oulu, Finland
- Oulu University Hospital and Medical Research Center Oulu, Oulu, Finland
- Department of Gastroenterology and Metabolism, Poznan University of Medical Sciences, Poznan, Poland
- Kari A. Mäkelä
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32
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Davimes JG, Alagaili AN, Bennett NC, Mohammed OB, Bhagwandin A, Manger PR, Gravett N. Neurochemical organization and morphology of the sleep related nuclei in the brain of the Arabian oryx, Oryx leucoryx. J Chem Neuroanat 2017; 81:53-70. [PMID: 28163217 DOI: 10.1016/j.jchemneu.2017.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/30/2017] [Accepted: 02/01/2017] [Indexed: 12/01/2022]
Abstract
The Arabian oryx, Oryx leucoryx, is a member of the superorder Cetartiodactyla and is native to the Arabian Desert. The desert environment can be considered extreme in which to sleep, as the ranges of temperatures experienced are beyond what most mammals encounter. The current study describes the nuclear organization and neuronal morphology of the systems that have been implicated in sleep control in other mammals for the Arabian oryx. The nuclei delineated include those revealed immunohistochemically as belonging to the cholinergic, catecholaminergic, serotonergic and orexinergic systems within the basal forebrain, hypothalamus, midbrain and pons. In addition, we examined the GABAergic neurons and their terminal networks surrounding or within these nuclei. The majority of the neuronal systems examined followed the typical mammalian organizational plan, but some differences were observed: (1) the neuronal morphology of the cholinergic laterodorsal tegmental (LDT) and pedunculopontine tegmental (PPT) nuclei, as well as the parvocellular subdivision of the orexinergic main cluster, exhibited Cetartiodactyl-specific features; (2) the dorsal division of the catecholaminergic anterior hypothalamic group (A15d), which has not been reported in any member of the Artiodactyla studied to date, was present in the brain of the Arabian oryx; and (3) the catecholaminergic tuberal cell group (A12) was notably more expansive than previously seen in any other mammal. The A12 nucleus has been associated functionally to osmoregulation in other mammals, and thus its expansion could potentially be a species specific feature of the Arabian oryx given their native desert environment and the need for extreme water conservation.
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Affiliation(s)
- Joshua G Davimes
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, South Africa
| | - Abdulaziz N Alagaili
- KSU Mammals Research Chair, Department of Zoology, King Saud University, Riyadh 11451, Saudi Arabia
| | - Nigel C Bennett
- SARChI Chair for Mammalian Behavioural Ecology and Physiology, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa
| | - Osama B Mohammed
- KSU Mammals Research Chair, Department of Zoology, King Saud University, Riyadh 11451, Saudi Arabia
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, South Africa
| | - Nadine Gravett
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, South Africa.
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33
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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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34
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López JM, Morales L, González A. Spatiotemporal Development of the Orexinergic (Hypocretinergic) System in the Central Nervous System of Xenopus laevis. BRAIN, BEHAVIOR AND EVOLUTION 2016; 88:127-146. [DOI: 10.1159/000449278] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 08/18/2016] [Indexed: 11/19/2022]
Abstract
The present immunohistochemical study represents a detailed spatiotemporal analysis of the localization of orexin-immunoreactive (OX-ir) cells and fibers throughout development in the brain of the anuran amphibian Xenopus laevis, a model frequently used in developmental studies. Anurans undergo remarkable physiological changes during the early life stages, and very little is known about the ontogeny and the localization of the centers that control functions such as appetite and feed ingestion in the developing brain. We examined the onset of the orexinergic system, demonstrated to be involved in appetite regulation, using antibodies against mammalian orexin-A and orexin-B peptides. Simultaneous detection of orexins with other territorial markers was used to assess the precise location of the orexinergic cells in the hypothalamus, analyzed within a segmental paradigm. Double staining of orexins and tyrosine hydroxylase served to evaluate possible interactions with the catecholaminergic systems. At early embryonic stages, the first OX-ir cells were detected in the hypothalamus and, soon after, long descending projections were observed through the brainstem to the spinal cord. As brain development proceeded, the double-staining techniques demonstrated that this OX-ir cell group was located in the suprachiasmatic nucleus within the alar hypothalamus. Throughout larval development, the number of OX-ir cells increased notably and a widespread fiber network that innervated the main areas of the forebrain and brainstem was progressively formed, including innervation in the posterior tubercle and mesencephalon, the locus coeruleus, and the nucleus of the solitary tract where catecholaminergic cells are present. In addition, orexinergic cells were detected in the preoptic area and the tuberal hypothalamus only at late prometamorphic stages. The final distribution pattern, largely similar to that of the adult, was achieved through metamorphic climax. The early expression of orexins in Xenopus suggests important roles in brain development in the embryonic period before feeding, and the progression of the temporal and spatial complexity of the orexinergic system might be correlated to the maturation of appetite control regulation, among other functions.
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Salimi M, Alishah Z, Khazali H, Mahmoudi F. Orexin Decreases Aromatase Gene Expression in The Hypothalamus of Androgenized Female Rats. INTERNATIONAL JOURNAL OF FERTILITY & STERILITY 2016; 10:190-5. [PMID: 27441052 PMCID: PMC4948071 DOI: 10.22074/ijfs.2016.4909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 07/11/2015] [Indexed: 11/04/2022]
Abstract
BACKGROUND Orexin is a hypothalamic orexigenic neuropeptide, which third cerebral injection of it mainly exerts inhibitory effects on reproductive functions. It increases significantly the Aromatase (Cyp19) gene expression in the hypothalamus of male rats. Aromatase is an enzyme which converts androgens to estradiol in the hypothalamus of rats. Prenatal or neonatal exposure of females to testosterone masculinizes the pattern of Cyp19 mRNA levels in adulthood. In the present study the effects of central injections of orexin-A on hypothalamic Cyp19 gene expression of adult female rats were investigated, while they had been androgenized on third day of postnatal life. MATERIALS AND METHODS In this experimental study, twenty female Wistar rats received subcutaneous injections of testosterone propionate (50 µg/100 µl) on their third day of postnatal life. Adult androgenized rats weighing 180-220 g, received either 3 µl saline or one of 2, 4 or 8 µg/3 µl concentration of orexin via third cerebral ventricle. Five non-androgenized rats, as control group, received intra cerebral ventricle (ICV) injection of 3 µl saline. The hypothalamuses were dissected out and mean Cyp19 mRNA levels were determined by semi-quantitative real time-polymerase chain reaction (PCR) method. Data were analyzed by unpaired t test and one-way ANOVA using SPSS software, version 16. RESULTS Mean relative Cyp19 mRNA level was significantly increased in the hypothalamus of androgenized compared to non-androgenized female rats. Central injec- tions of 2, 4 or 8 µg/3 µl orexin decreased significantly the hypothalamic Cyp19 mRNA level of androgenized rats compared to androgenized-control groups. CONCLUSION The results suggested that the orexin may exert inhibitory effects on the gene expression of Cyp19 in the hypothalamus of neonatal androgenized female rats in adulthood.
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Affiliation(s)
- Maliheh Salimi
- Department of Physiology, Faculty of Biological Sciences, Shahid Beheshti University, Tehran, Iran
| | - Zahra Alishah
- Department of Physiology, Faculty of Biological Sciences, Shahid Beheshti University, Tehran, Iran
| | - Homayoun Khazali
- Department of Physiology, Faculty of Biological Sciences, Shahid Beheshti University, Tehran, Iran
| | - Fariba Mahmoudi
- Department of Biology, Facualty of Basic Sciences, University of Mohaghegh Ardabili, Ardabil, Iran
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Xue Y, Yang YT, Liu HY, Chen WF, Chen AQ, Sheng Q, Chen XY, Wang Y, Chen H, Liu HX, Pang YY, Chen L. Orexin-A increases the activity of globus pallidus neurons in both normal and parkinsonian rats. Eur J Neurosci 2016; 44:2247-57. [PMID: 27336845 DOI: 10.1111/ejn.13323] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 05/04/2016] [Accepted: 06/21/2016] [Indexed: 02/06/2023]
Abstract
Orexin is a member of neuropeptides which was first identified in the hypothalamus. The globus pallidus is a key structure in the basal ganglia, which is involved in both normal motor function and movement disorders. Morphological studies have shown the expression of both OX1 and OX2 receptors in the globus pallidus. Employing single unit extracellular recordings and behavioural tests, the direct in vivo electrophysiological and behavioural effects of orexin-A in the globus pallidus were studied. Micro-pressure administration of orexin-A significantly increased the spontaneous firing rate of pallidal neurons. Correlation analysis revealed a negative correlation between orexin-A induced excitation and the basal firing rate. Furthermore, application of the specific OX1 receptor antagonist, SB-334867, decreased the firing rate of pallidal neurons, suggesting that endogenous orexinergic systems modulate the firing activity of pallidal neurons. Orexin-A increased the excitability of pallidal neurons through both OX1 and OX2 receptors. In 6-hydroxydopamine parkinsonian rats, orexin-A-induced increase in firing rate of pallidal neurons was stronger than that in normal rats. Immunostaining revealed positive OX1 receptor expression in the globus pallidus of both normal and parkinsonian rats. Finally, postural test showed that unilateral microinjection of orexin-A led to contralateral deflection in the presence of systemic haloperidol administration. Further elevated body swing test revealed that pallidal orexin-A and SB-334867 induced contralateral-biased swing and ipsilateral-biased swing respectively. Based on the electrophysiological and behavioural findings of orexin-A in the globus pallidus, the present findings may provide a rationale for the pathogenesis and treatment of Parkinson's disease.
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Affiliation(s)
- Yan Xue
- Department of Physiology, Faculty of Medicine, Qingdao University, Qingdao 266071, Shandong, China
| | - Yu-Ting Yang
- Department of Physiology, Faculty of Medicine, Qingdao University, Qingdao 266071, Shandong, China
| | - Hong-Yun Liu
- Department of Physiology, Faculty of Medicine, Qingdao University, Qingdao 266071, Shandong, China.,Department of Pathology, Qingdao Municipal Hospital, Qingdao, China
| | - Wen-Fang Chen
- Department of Physiology, Faculty of Medicine, Qingdao University, Qingdao 266071, Shandong, China
| | - An-Qi Chen
- Department of Physiology, Faculty of Medicine, Qingdao University, Qingdao 266071, Shandong, China
| | - Qing Sheng
- Department of Physiology, Faculty of Medicine, Qingdao University, Qingdao 266071, Shandong, China
| | - Xin-Yi Chen
- Department of Neurology, Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China
| | - Ying Wang
- Department of Physiology, Faculty of Medicine, Qingdao University, Qingdao 266071, Shandong, China
| | - Hua Chen
- Department of Pathology, Qingdao Municipal Hospital, Qingdao, China
| | - Hong-Xia Liu
- Department of Physiology, Faculty of Medicine, Qingdao University, Qingdao 266071, Shandong, China
| | - Ya-Yan Pang
- Department of Physiology, Faculty of Medicine, Qingdao University, Qingdao 266071, Shandong, China
| | - Lei Chen
- Department of Physiology, Faculty of Medicine, Qingdao University, Qingdao 266071, Shandong, China
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Effects of dorsal hippocampal orexin-2 receptor antagonism on the acquisition, expression, and extinction of morphine-induced place preference in rats. Psychopharmacology (Berl) 2016; 233:2329-41. [PMID: 27048158 DOI: 10.1007/s00213-016-4280-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/22/2016] [Indexed: 10/22/2022]
Abstract
RATIONALE Orexinergic system is involved in reward processing and drug addiction. OBJECTIVES Here, we investigated the effect of intrahippocampal CA1 administration of orexin-2 receptor (OX2r) antagonist on the acquisition, expression, and extinction of morphine-induced place preference in rats. METHODS Conditioned place preference (CPP) was induced by subcutaneous injection of morphine (5 mg/kg) during a 3-day conditioning phase. Three experimental plots were designed; TCS OX2 29 as a selective antagonist of orexin-2 receptors (OX2rs) was dissolved in DMSO, prepared in solutions with different concentrations (1, 3, 10, and 30 nM), and was bilaterally microinjected into the CA1 and some neighboring regions (0.5 μl/side). Conditioning scores and locomotor activities were recorded during the test. RESULTS Results demonstrate that intra-CA1 administration of the OX2r antagonist attenuates the induction of morphine CPP during the acquisition and expression phases. Effect of TCS OX2 29 on reduction of morphine CPP was dose-dependent and was more pronounced during the acquisition than the expression. Furthermore, higher concentrations of TCS OX2 29 facilitated the extinction of morphine-induced CPP and reduced extinction latency period. Nevertheless, administration of TCS OX2 29 solutions did not have any influence on locomotor activity of all phases. CONCLUSIONS Our findings suggest that OX2rs in the CA1 region of hippocampus are involved in the development of the acquisition and expression of morphine CPP. Moreover, blockade of OX2rs could facilitate extinction and may abrogate or extinguish the ability of drug-related cues, implying that the antagonist might be considered as a propitious therapeutic agent in suppressing drug-seeking behavior.
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Zitnik GA. Control of arousal through neuropeptide afferents of the locus coeruleus. Brain Res 2016; 1641:338-50. [DOI: 10.1016/j.brainres.2015.12.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 11/30/2015] [Accepted: 12/02/2015] [Indexed: 10/22/2022]
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Kooshki R, Abbasnejad M, Esmaeili-Mahani S, Raoof M. The role of trigeminal nucleus caudalis orexin 1 receptors in orofacial pain transmission and in orofacial pain-induced learning and memory impairment in rats. Physiol Behav 2016; 157:20-7. [DOI: 10.1016/j.physbeh.2016.01.031] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 01/16/2016] [Accepted: 01/23/2016] [Indexed: 10/22/2022]
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Hannibal J, Georg B, Fahrenkrug J. Altered Circadian Food Anticipatory Activity Rhythms in PACAP Receptor 1 (PAC1) Deficient Mice. PLoS One 2016; 11:e0146981. [PMID: 26757053 PMCID: PMC4710526 DOI: 10.1371/journal.pone.0146981] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 12/23/2015] [Indexed: 11/19/2022] Open
Abstract
Light signals from intrinsically photosensitive retinal ganglion cells (ipRGCs) entrain the circadian clock and regulate negative masking. Two neurotransmitters, glutamate and Pituitary Adenylate Cyclase Activating Polypeptide (PACAP), found in the ipRGCs transmit light signals to the brain via glutamate receptors and the specific PACAP type 1 (PAC1) receptor. Light entrainment occurs during the twilight zones and has little effect on clock phase during daytime. When nocturnal animals have access to food only for a few hours during the resting phase at daytime, they adapt behavior to the restricted feeding (RF) paradigm and show food anticipatory activity (FAA). A recent study in mice and rats demonstrating that light regulates FAA prompted us to investigate the role of PACAP/PAC1 signaling in the light mediated regulation of FAA. PAC1 receptor knock out (PAC1-/-) and wild type (PAC1+/+) mice placed in running wheels were examined in a full photoperiod (FPP) of 12:12 h light/dark (LD) and a skeleton photoperiod (SPP) 1:11:1:11 h L:DD:L:DD at 300 and 10 lux light intensity. Both PAC1-/- mice and PAC1+/+ littermates entrained to FPP and SPP at both light intensities. However, when placed in RF with access to food for 4–5 h during the subjective day, a significant change in behavior was observed in PAC1-/- mice compared to PAC1+/+ mice. While PAC1-/- mice showed similar FAA as PAC1+/+ animals in FPP at 300 lux, PAC1-/- mice demonstrated an advanced onset of FAA with a nearly 3-fold increase in amplitude compared to PAC1+/+ mice when placed in SPP at 300 lux. The same pattern of FAA was observed at 10 lux during both FPP and SPP. The present study indicates a role of PACAP/PAC1 signaling during light regulated FAA. Most likely, PACAP found in ipRGCs mediating non-image forming light information to the brain is involved.
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Affiliation(s)
- Jens Hannibal
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
| | - Birgitte Georg
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jan Fahrenkrug
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
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Justinussen J, Holm A, Kornum B. An optimized method for measuring hypocretin-1 peptide in the mouse brain reveals differential circadian regulation of hypocretin-1 levels rostral and caudal to the hypothalamus. Neuroscience 2015; 310:354-61. [DOI: 10.1016/j.neuroscience.2015.09.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/07/2015] [Accepted: 09/19/2015] [Indexed: 12/25/2022]
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Du MK, Hunt NJ, Waters KA, Machaalani R. Cumulative effects of repetitive intermittent hypercapnic hypoxia on orexin in the developing piglet hypothalamus. Int J Dev Neurosci 2015; 48:1-8. [PMID: 26548856 DOI: 10.1016/j.ijdevneu.2015.10.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 10/30/2015] [Accepted: 10/30/2015] [Indexed: 01/17/2023] Open
Abstract
Orexin neuropeptides (OxA and OxB) and their receptors (OX1R and OX2R) are involved in maintenance of sleep and wakefulness, and are regulated by various environmental stimuli. We studied piglets, in the early neonatal period, exposed to 48-min of intermittent hypercapnic hypoxia (IHH; 7% O2/8% CO2) alternating with air. Three groups of 13-14 day-old piglets with IHH exposure of 1-day (1D-IHH) (n=7), 2-days (2D-IHH) (n=7) and 4-days (4D-IHH) (n=8) were compared to controls (exposed only to air, n=8). Immunoreactivity of OxA and OxB was studied in the piglet hypothalamic regions of the dorsomedial hypothalamus (DMH), perifornical area (PeF) and lateral hypothalamic area (LH). Results showed that after 1D- and 2D-IHH, total OxA and OxB expression decreased by 20% (p ≤ 0.005) and 40% (p<0.001), respectively. After 4D-IHH, the decrease in OxA and OxB was 50% (p<0.001). These findings indicate that a chronic IHH exposure induces greater changes in orexin neuropeptide expression than an acute 1-day exposure in the hypothalamus. This may be causally related to the dysregulation of sleep.
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Affiliation(s)
- Man K Du
- Department of Pathology, University of Sydney, NSW 2006, Australia; The BOSCH Institute, University of Sydney, NSW 2006, Australia
| | - Nicholas J Hunt
- The BOSCH Institute, University of Sydney, NSW 2006, Australia; Department of Medicine, Blackburn Building, D06, University of Sydney, NSW 2006, Australia
| | - Karen A Waters
- Department of Medicine, Blackburn Building, D06, University of Sydney, NSW 2006, Australia; The Children's Hospital, Westmead Sydney, NSW 2145, Australia
| | - Rita Machaalani
- The BOSCH Institute, University of Sydney, NSW 2006, Australia; Department of Medicine, Blackburn Building, D06, University of Sydney, NSW 2006, Australia; The Children's Hospital, Westmead Sydney, NSW 2145, Australia.
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Jeon Y, Park KB, Pervin R, Kim TW, Youn DH. Orexin-A modulates excitatory synaptic transmission and neuronal excitability in the spinal cord substantia gelatinosa. Neurosci Lett 2015; 604:128-33. [PMID: 26254164 DOI: 10.1016/j.neulet.2015.08.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 07/22/2015] [Accepted: 08/03/2015] [Indexed: 10/23/2022]
Abstract
Although intrathecal orexin-A has been known to be antinociceptive in various pain models, the role of orexin-A in antinociception is not well characterized. In the present study, we examined whether orexin-A modulates primary afferent fiber-mediated or spontaneous excitatory synaptic transmission using transverse spinal cord slices with attached dorsal root. Bath-application of orexin-A (100nM) reduced the amplitude of excitatory postsynaptic currents (EPSCs) evoked by electrical stimulation of Aδ- or C-primary afferent fibers. The magnitude of reduction was much larger for EPSCs evoked by polysynaptic C-fibers than polysynaptic Aδ-fibers, whereas it was similar in EPSCs evoked by monosynaptic Aδ- or C-fibers. SB674042, an orexin-1 receptor antagonist, but not EMPA, an orexin-2 receptor antagonist, significantly inhibited the orexin-A-induced reduction in EPSC amplitude from mono- or polysynaptic Aδ-fibers, as well as from mono- or polysynaptic C-fibers. Furthermore, orexin-A significantly increased the frequency of spontaneous EPSCs but not the amplitude. This increase was almost completely blocked by both SB674042 and EMPA. On the other hand, orexin-A produced membrane oscillations and inward currents in the SG neurons that were partially or completely inhibited by SB674042 or EMPA, respectively. Thus, this study suggests that the spinal actions of orexin-A underlie orexin-A-induced antinociceptive effects via different subtypes of orexin receptors.
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Affiliation(s)
- Younghoon Jeon
- Department of Anesthesiology and Pain Medicine, School of Dentistry, Kyungpook National University, Daegu 700-706, Republic of Korea
| | - Ki Bum Park
- Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu 700-721, Republic of Korea.
| | - Rokeya Pervin
- Department of Physiology, College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Tae Wan Kim
- Department of Physiology, College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Dong-ho Youn
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu 700-706, Republic of Korea.
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Distribution of the orexin-1 receptor (OX1R) in the mouse forebrain and rostral brainstem: A characterisation of OX1R-eGFP mice. J Chem Neuroanat 2015; 66-67:1-9. [DOI: 10.1016/j.jchemneu.2015.03.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 03/24/2015] [Accepted: 03/25/2015] [Indexed: 02/02/2023]
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Fang L, Zhou J, Cheng S, Ying J, Yang Z, Yin L, Li S, Hou W, Wang Z. High orexin-A neuron activity and RACK1 expression might be involved in the restricted feeding-entrained behaviors in mice. BIOL RHYTHM RES 2015. [DOI: 10.1080/09291016.2015.1004841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Role of intra-hippocampal orexin 1 and orexin 2 receptors in conditioned place preference induced by chemical stimulation of the lateral hypothalamus. Behav Brain Res 2015; 279:106-11. [DOI: 10.1016/j.bbr.2014.10.051] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 10/24/2014] [Accepted: 10/31/2014] [Indexed: 11/19/2022]
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Hu B, Yang N, Qiao QC, Hu ZA, Zhang J. Roles of the orexin system in central motor control. Neurosci Biobehav Rev 2014; 49:43-54. [PMID: 25511388 DOI: 10.1016/j.neubiorev.2014.12.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/10/2014] [Accepted: 12/03/2014] [Indexed: 12/15/2022]
Abstract
The neuropeptides orexin-A and orexin-B are produced by one group of neurons located in the lateral hypothalamic/perifornical area. However, the orexins are widely released in entire brain including various central motor control structures. Especially, the loss of orexins has been demonstrated to associate with several motor deficits. Here, we first summarize the present knowledge that describes the anatomical and morphological connections between the orexin system and various central motor control structures. In the next section, the direct influence of orexins on related central motor control structures is reviewed at molecular, cellular, circuitry, and motor activity levels. After the summarization, the characteristic and functional relevance of the orexin system's direct influence on central motor control function are demonstrated and discussed. We also propose a hypothesis as to how the orexin system orchestrates central motor control in a homeostatic regulation manner. Besides, the importance of the orexin system's phasic modulation on related central motor control structures is highlighted in this regulation manner. Finally, a scheme combining the homeostatic regulation of orexin system on central motor control and its effects on other brain functions is presented to discuss the role of orexin system beyond the pure motor activity level, but at the complex behavioral level.
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Affiliation(s)
- Bo Hu
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China
| | - Nian Yang
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China
| | - Qi-Cheng Qiao
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China
| | - Zhi-An Hu
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
| | - Jun Zhang
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
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Yu L, Zhang XY, Chen ZP, Zhuang QX, Zhu JN, Wang JJ. Orexin excites rat inferior vestibular nuclear neurons via co-activation of OX1 and OX 2 receptors. J Neural Transm (Vienna) 2014; 122:747-55. [PMID: 25371350 DOI: 10.1007/s00702-014-1330-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 10/28/2014] [Indexed: 12/13/2022]
Abstract
Orexin deficiency results in cataplexy, a motor deficit characterized by sudden loss of muscle tone, strongly indicating an active role of central orexinergic system in motor control. However, effects of orexin on neurons in central motor structures are still largely unknown. Our previous studies have revealed that orexin excites neurons in the cerebellar nuclei and lateral vestibular nucleus, two important subcortical motor centers for control of muscle tone. Here, we report that both orexin-A and orexin-B depolarizes and increases the firing rate of neurons in the inferior vestibular nucleus (IVN), the largest nucleus in the vestibular nuclear complex and holding an important position in integration of information signals in the control of body posture. TTX does not block orexin-induced excitation on IVN neurons, suggesting a direct postsynaptic action of the neuropeptide. Furthermore, bath application of orexin induces an inward current on IVN neurons in a concentration-dependent manner. SB334867 and TCS-OX2-29, specific OX1 and OX2 receptor antagonists, blocked the excitatory effect of orexin, and [Ala(11), D-Leu(15)]-orexin B, a selective OX2 receptor agonist, mimics the orexin-induced inward current on IVN neurons. qPCR and immunofluorescence results show that both OX1 and OX2 receptor mRNAs and proteins are expressed and localized in the rat IVN. These results demonstrate that orexin excites the IVN neurons by co-activation of both OX1 and OX2 receptors, suggesting that via the direct modulation on the IVN, the central orexinergic system may actively participate in the central vestibular-mediated postural and motor control.
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Affiliation(s)
- Lei Yu
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Biological Science and Technology, School of Life Sciences, Nanjing University, Mailbox 426, 22 Hankou Road, Nanjing, 210093, China
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López JM, Sanz-Morello B, González A. Organization of the orexin/hypocretin system in the brain of two basal actinopterygian fishes, the cladistians Polypterus senegalus and Erpetoichthys calabaricus. Peptides 2014; 61:23-37. [PMID: 25169954 DOI: 10.1016/j.peptides.2014.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/19/2014] [Accepted: 08/19/2014] [Indexed: 01/12/2023]
Abstract
Cladistians are primitive actinopterygian fishes mostly neglected in neuroanatomical studies. In the present study, the detailed neuroanatomical distribution of orexin (hypocretin)-like immunoreactive (OX-ir) cell bodies and fibers was analyzed in the brain of two species representative of the two extant genera of cladistians. Antibodies against mammalian orexin-A and orexin-B peptides were used. Simultaneous detection of orexins with neuropeptide Y (NPY), tyrosine hydroxylase (TH), and serotonin (5-HT) was used to establish accurately the topography of the orexin system and to evaluate the possible interactions with NPY and monoaminergic systems. A largely common pattern of OX-ir distribution in the two cladistian species was observed. Most OX-ir cells were located in the suprachiasmatic nucleus and tuberal hypothalamus, whereas scarce cells were observed in the posterior tubercle. In addition, a population of OX-ir cells was found in the preoptic area only in Polypterus and some cells also contained TH. The observed widespread distribution of OX-ir fibers was especially abundant in the retrobulbar area, subpallial areas, preoptic area, suprachiasmatic nucleus, tuberal hypothalamic area, prethalamus, thalamus, pretectum, optic tectum, and tegmentum. Low innervation was found in relation to monoaminergic cell groups, whereas a high NPY innervation was observed in all OX-ir cell groups. These relationships would represent the anatomical substrate for the functional interdependence between these systems. The organization of the orexin system in cladistians revealed a pattern largely consistent with those reported for all studied groups of vertebrates, suggesting that the primitive organization of this peptidergic system occurred in the common ancestor of gnathostome vertebrates.
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Affiliation(s)
- Jesús M López
- Department of Cell Biology, Faculty of Biology, University Complutense, 28040 Madrid, Spain
| | - Berta Sanz-Morello
- Department of Cell Biology, Faculty of Biology, University Complutense, 28040 Madrid, Spain
| | - Agustín González
- Department of Cell Biology, Faculty of Biology, University Complutense, 28040 Madrid, Spain.
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Tokita K, Armstrong WE, St John SJ, Boughter JD. Activation of lateral hypothalamus-projecting parabrachial neurons by intraorally delivered gustatory stimuli. Front Neural Circuits 2014; 8:86. [PMID: 25120438 PMCID: PMC4114292 DOI: 10.3389/fncir.2014.00086] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 07/04/2014] [Indexed: 11/13/2022] Open
Abstract
The present study investigated a subpopulation of neurons in the mouse parabrachial nucleus (PbN), a gustatory and visceral relay area in the brainstem, that project to the lateral hypothalamus (LH). We made injections of the retrograde tracer Fluorogold (FG) into LH, resulting in fluorescent labeling of neurons located in different regions of the PbN. Mice were stimulated through an intraoral cannula with one of seven different taste stimuli, and PbN sections were processed for immunohistochemical detection of the immediate early gene c-Fos, which labels activated neurons. LH projection neurons were found in all PbN subnuclei, but in greater concentration in lateral subnuclei, including the dorsal lateral subnucleus (dl). Fos-like immunoreactivity (FLI) was observed in the PbN in a stimulus-dependent pattern, with the greatest differentiation between intraoral stimulation with sweet (0.5 M sucrose) and bitter (0.003 M quinine) compounds. In particular, sweet and umami-tasting stimuli evoked robust FLI in cells in the dl, whereas quinine evoked almost no FLI in cells in this subnucleus. Double-labeled cells were also found in the greatest quantity in the dl. Overall, these results support the hypothesis that the dl contains direct a projection to the LH that is activated preferentially by appetitive compounds; this projection may be mediated by taste and/or postingestive mechanisms.
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Affiliation(s)
- Kenichi Tokita
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center Memphis, TN, USA
| | - William E Armstrong
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center Memphis, TN, USA
| | | | - John D Boughter
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center Memphis, TN, USA
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