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Zhou X, Zhou J, Zhang F, Shu Q, Wang QY, Wu Y, Chang HM, Zhang B, Yu Q, Cai RL. A New Target of Electroacupuncture Pretreatment Mediated Sympathetic Nervous to Improve MIRI: Glutamatergic Neurons in Fastigial Nucleus of the Cerebellum. Neuroscience 2023; 535:124-141. [PMID: 37923164 DOI: 10.1016/j.neuroscience.2023.10.012] [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: 08/19/2023] [Revised: 10/11/2023] [Accepted: 10/17/2023] [Indexed: 11/07/2023]
Abstract
Ischemic heart disease is a fatal cardiovascular disease that irreversibly impairs the function of the heart, followed by reperfusion leading to a further increase in infarct size. Clinically, we call it myocardial ischemia-reperfusion injury (MIRI). A growing number of clinical observations and experimental studies have found electroacupuncture (EA) to be effective in alleviating MIRI. This study attempts to investigate whether glutamatergic neurons in fastigial nucleus (FN) of the cerebellum are involved in EA pretreatment to alleviate MIRI via sympathetic nerves, and the potential mechanisms of EA pretreatment process. A MIRI model was established by ligating the coronary artery of the left anterior descending branch of the heart for 30 minutes, followed by 2 hours of reperfusion. Multichannel physiological recordings, electrocardiogram, cardiac ultrasound, chemical genetics, enzyme-linked immunosorbent assay and immunofluorescence staining methods were combined to demonstrate that EA pretreatment inhibited neuronal firing and c-Fos expression in FN of the cerebellum and reduced cardiac sympathetic firing. Meanwhile, EA pretreatment significantly reduced cardiac ejection fraction (EF), shortening fraction (SF), percentage infarct area, decreased myocardial norepinephrine (NE), creatine kinase isoenzyme MB (CK-MB) concentrations, and improved MIRI-induced myocardial tissue morphology. The results were similar to the inhibition of glutamatergic neurons in FN. However, the activation of glutamatergic neurons in FN diminished the aforementioned effects of EA pretreatment. This study revealed that glutamatergic neurons in FN of the cerebellum is involved in EA pretreatment mediated sympathetic nervous and may be a potential mediator for improving MIRI.
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Affiliation(s)
- Xiang Zhou
- College of Acupuncture and Moxibustion, Anhui University of Chinese Medicine, Hefei 230038, Anhui Province, China; Anhui Wannan Rehabilitation Hospital (The Fifth People's Hospital of Wuhu), Wuhu 241000, Anhui Province, China
| | - Jie Zhou
- College of Acupuncture and Moxibustion, Anhui University of Chinese Medicine, Hefei 230038, Anhui Province, China
| | - Fan Zhang
- College of Acupuncture and Moxibustion, Anhui University of Chinese Medicine, Hefei 230038, Anhui Province, China
| | - Qi Shu
- College of Acupuncture and Moxibustion, Anhui University of Chinese Medicine, Hefei 230038, Anhui Province, China
| | - Qian-Yi Wang
- College of Acupuncture and Moxibustion, Anhui University of Chinese Medicine, Hefei 230038, Anhui Province, China
| | - Yan Wu
- College of Acupuncture and Moxibustion, Anhui University of Chinese Medicine, Hefei 230038, Anhui Province, China
| | - Hui-Min Chang
- College of Acupuncture and Moxibustion, Anhui University of Chinese Medicine, Hefei 230038, Anhui Province, China
| | - Bin Zhang
- College of Acupuncture and Moxibustion, Anhui University of Chinese Medicine, Hefei 230038, Anhui Province, China
| | - Qing Yu
- Institute of Acupuncture and Meridian Research, Anhui Academy of Chinese Medicine, Hefei 230038, Anhui Province, China; Anhui Province Key Laboratory of Meridian Viscera Correlationship, Hefei 230038, China.
| | - Rong-Lin Cai
- Institute of Acupuncture and Meridian Research, Anhui Academy of Chinese Medicine, Hefei 230038, Anhui Province, China; Anhui Province Key Laboratory of Meridian Viscera Correlationship, Hefei 230038, China; Key Laboratory of Xin'an Medicine, Ministry of Education, Hefei 230038, China.
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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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DeCarlo AA, Hammes N, Johnson PL, Shekhar A, Samuels BC. Dual Orexin Receptor Antagonist Attenuates Increases in IOP, ICP, and Translaminar Pressure Difference After Stimulation of the Hypothalamus in Rats. Invest Ophthalmol Vis Sci 2022; 63:1. [PMID: 35234838 PMCID: PMC8899853 DOI: 10.1167/iovs.63.3.1] [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] [Indexed: 12/30/2022] Open
Abstract
PURPOSE Intraocular pressure (IOP) remains the only modifiable risk factor for glaucoma progression. Our previous discovery that stimulation of nuclei within the hypothalamus can modulate IOP, intracranial pressure (ICP), and translaminar pressure difference (TLPD) fluctuations led us to investigate this pathway further. Our purpose was to determine the role of orexin neurons, primarily located in the dorsomedial hypothalamus (DMH) and perifornical (PeF) regions of the hypothalamus, in modulating these pressures. METHODS Sprague Dawley rats were pretreated systemically with a dual orexin receptor antagonist (DORA-12) at 30 mg/Kg (n = 8), 10 mg/Kg (n = 8), or vehicle control (n = 8). The IOP, ICP, heart rate (HR), and mean arterial pressure (MAP) were recorded prior to and following excitation of the DMH/PeF using microinjection of the gamma-aminobutyric acid (GABA)A receptor antagonist bicuculline methiodide (BMI). RESULTS Administration of the DORA at 30 mg/Kg significantly attenuated peak IOP by 5.2 ± 3.6 mm Hg (P = 0.007). During the peak response period (8-40 minutes), the area under the curve (AUC) for the 30 mg/Kg DORA cohort was significantly lower than the control cohort during the same period (P = 0.04). IOP responses for peak AUC versus DORA dose, from 0 to 30 mg/Kg, were linear (R2 = 0.18, P = 0.04). The ICP responses during the peak response period (4-16 minutes) versus DORA dose were also linear (R2 = 0.24, P = 0.014). Pretreatment with DORA significantly decreased AUC for the TLPD following stimulation of the DMH/PeF (10 mg/kg, P = 0.045 and 30 mg/kg, P = 0.015). CONCLUSIONS DORAs have the potential to attenuate asynchronous changes in IOP and in ICP and to lessen the extent of TLPDs that may result from central nervous system (CNS) activation.
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Affiliation(s)
- Arthur A. DeCarlo
- University of Alabama at Birmingham, Department of Ophthalmology and Visual Sciences, Birmingham, Alabama, United States
| | - Nathan Hammes
- Indiana University School of Medicine, Department of Ophthalmology, Indianapolis, Indiana, United States,Microsoft Corporation, Redmond, Washington, United States
| | - Philip L. Johnson
- Indiana University School of Medicine, Department of Anatomy, Cell Biology, and Physiology, Indianapolis, Indiana, United States
| | - Anantha Shekhar
- University of Pittsburgh, Department of Psychiatry, Pittsburgh, Pennsylvania, United States
| | - Brian C. Samuels
- University of Alabama at Birmingham, Department of Ophthalmology and Visual Sciences, Birmingham, Alabama, United States
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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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Matsuura W, Nakamoto K, Tokuyama S. Involvement of descending pain control system regulated by orexin receptor signaling in the induction of central post-stroke pain in mice. Eur J Pharmacol 2020; 874:173029. [PMID: 32084419 DOI: 10.1016/j.ejphar.2020.173029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 02/04/2020] [Accepted: 02/17/2020] [Indexed: 02/06/2023]
Abstract
Central post-stroke pain (CPSP) is a type of neuropathic pain for which the mechanism and relevant drug pathways remain unknown. Recently, it was reported that intracerebroventricular (ICV) administration of orexin-A suppresses pain and ischemia. In this study, we tested the role of orexin-A in CPSP induction in mice. Male ddY mice were subjected to 30 min of bilateral carotid artery occlusion (BCAO). CPSP was assessed by von Frey test. Colocalization of orexin 1 receptor (OX1R) with various neuron markers were determined by double-immunofluorescence. The hindpaw withdrawal responses to mechanical stimuli were significantly increased 3 days post-BCAO compared with those of sham groups. ICV injection of orexin-A dose-dependently suppressed BCAO-induced mechanical allodynia. These effects were inhibited by pre-treatment with SB334867 (an OX1R antagonist; ICV injection), yohimbine (a noradrenaline α2 receptor antagonist; intrathecal (IT) injection), and WAY100635 (a serotonin 5-HT1A receptor antagonist; IT injection), but not TCS OX2 29 (an OX2R antagonist; ICV injection). OX1R colocalized with TH (a noradrenergic neuron marker) and TPH (a serotonergic neuron marker) in the locus ceruleus (LC) and the rostral ventromedial medulla (RVM), respectively. The number of c-Fos positive cells in the LC and the RVM of BCAO mice was increased at 90 min after ICV injection of orexin-A compared to saline group. These results indicate that orexin-A/OX1R signaling plays an important role through activation of the descending pain control system in the induction of CPSP in mice.
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Affiliation(s)
- Wataru Matsuura
- Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe, 650-8586, Japan
| | - Kazuo Nakamoto
- Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe, 650-8586, Japan
| | - Shogo Tokuyama
- Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Minatojima, Chuo-ku, Kobe, 650-8586, Japan.
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GABA B receptors in the hypothalamic paraventricular nucleus mediate β-adrenoceptor-induced elevations of plasma noradrenaline in rats. Eur J Pharmacol 2019; 848:88-95. [PMID: 30685430 DOI: 10.1016/j.ejphar.2019.01.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 11/21/2022]
Abstract
In the brain, various neurotransmitters such as noradrenaline and GABA regulate peripheral sympathetic functions. Previously, it has been reported that both β-adrenoceptor activation and GABAB receptor activation in the brain are involved in the elevation of plasma noradrenaline levels. However, it is unknown whether these pathways interact with each other. In the present study, we examined the relationship between the central actions of β-adrenoceptor activation and GABAB receptor activation with regard to plasma noradrenaline responses using urethane-anesthetized rats. Intracerebroventricular pretreatment with the GABAA receptor antagonist bicuculline did not affect the β-adrenoceptor agonist isoproterenol-induced elevation of plasma noradrenaline levels. In contrast, pretreatment with the GABAB receptor antagonist CGP 35348 suppressed the isoproterenol-induced elevation of noradrenaline levels. Intracerebroventricular pretreatment with the β-adrenoceptor antagonist propranolol did not alter the GABAB receptor agonist baclofen-induced elevation of plasma noradrenaline levels. We next examined the central effects of β-adrenoceptor activation on GABA release in the paraventricular hypothalamic nucleus (PVN), the major integrative center for sympathetic regulation in the brain. Intracerebroventricular administration of isoproterenol increased GABA content in PVN dialysates. In addition, baclofen microinjected unilaterally into the PVN resulted in elevated plasma levels of noradrenaline, but not adrenaline. Finally, unilateral blockade of GABAB receptors in the PVN suppressed the isoproterenol-induced elevation of plasma noradrenaline level. Our results suggest that activation of β-adrenoceptors in the brain, likely in the PVN, induces GABA release in the PVN, which in turn activates GABAB receptors in the PVN, leading to elevated plasma noradrenaline.
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Bastianini S, Silvani A. Clinical implications of basic research. CLINICAL AND TRANSLATIONAL NEUROSCIENCE 2018. [DOI: 10.1177/2514183x18789327] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Stefano Bastianini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Alessandro Silvani
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
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Li TL, Chen JYS, Huang SC, Dai YWE, Hwang LL. Cardiovascular pressor effects of orexins in the dorsomedial hypothalamus. Eur J Pharmacol 2017; 818:343-350. [PMID: 29104046 DOI: 10.1016/j.ejphar.2017.11.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 10/27/2017] [Accepted: 11/01/2017] [Indexed: 10/18/2022]
Abstract
Orexins are important regulators of cardiovascular functions in various physiological and pathological conditions. The dorsomedial hypothalamus (DMH), an essential mediator of cardiovascular responses to stress, contains dense orexinergic innervations and receptors. We examined whether orexins can regulate cardiovascular functions through their actions in the DMH in anesthetized rats. An intra-DMH injection of orexin A (30pmol) produced elevation of arterial pressure and heart rate. Orexin A-sensitive sites were located within or immediately adjacent to the DMH and larger responses were induced at the compact part of the dorsomedial hypothalamic nucleus. Orexin A-induced responses were attenuated by intra-DMH pretreatment with an orexin receptor 1 (OX1R) antagonist, SB-334867 (15nmol) (17.7 ± 2.8 vs. 5.2 ± 1.0mmHg; 54.6 ± 10.0 vs. 22.8 ± 7.4 beats/min). Intra-DMH applied [Ala11,D-Leu15]-orexin B (300 pmol), an orexin receptor 2 (OX2R) agonist, elicited cardiovascular responses mimicking the responses of orexin A, except for a smaller pressor response (7.4 ± 1.7 vs. 16.4 ± 1.8mmHg). In a series of experiment, effects of orexin B (100pmol) and then orexin A (30pmol), were examined at a same site. Two patterns of responses were observed in 12 intra-DMH sites: (1) both orexin A and B (9 sites), and (2) only orexin A (3 sites) induced cardiovascular responses, respectively suggesting OX1R/OX2R-mediated and OX1R-predominant mechanisms. In conclusion, orexins regulated cardiovascular functions through OX1R/OX2R- or OX1R-mediated mechanisms at different locations in the DMH.
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Affiliation(s)
- Tzu-Ling Li
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan.
| | - Jennifer Y S Chen
- School of Pharmacy, College of Pharmacy, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan.
| | - Shang-Cheng Huang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan.
| | - Yu-Wen E Dai
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan.
| | - Ling-Ling Hwang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan; Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan.
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Dombrowski MD, Mueller PJ. Sedentary conditions and enhanced responses to GABA in the RVLM: role of the contralateral RVLM. Am J Physiol Regul Integr Comp Physiol 2017; 313:R158-R168. [PMID: 28490450 DOI: 10.1152/ajpregu.00366.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 05/08/2017] [Accepted: 05/08/2017] [Indexed: 02/07/2023]
Abstract
A sedentary lifestyle is a major risk factor for cardiovascular disease, and both conditions are associated with overactivity of the sympathetic nervous system. Ongoing discharge of sympathetic nerves is regulated by the rostral ventrolateral medulla (RVLM), which in turn is modulated by the primary excitatory and inhibitory neurotransmitters glutamate and γ-amino-butyric acid (GABA), respectively. We reported previously that sedentary conditions enhance GABAergic modulation of sympathoexcitation in the RVLM, despite overall increased sympathoexcitation. Thus the purpose of this study was to test the hypothesis that sedentary conditions increase responsiveness to GABA in RVLM. Male Sprague-Dawley rats performed either chronic wheeling running or remained sedentary for 12-15 wk. Animals were instrumented to perform RVLM microinjections under Inactin anesthesia while mean arterial pressure (MAP) and splanchnic sympathetic nerve activity (SSNA) were recorded. Unilateral microinjections of GABA (30 nl, 0.3-600 mM) into the RVLM produced dose-dependent decreases in MAP and SSNA; however, no group differences were observed. Inhibition of the contralateral RVLM (muscimol, 2 mM, 90 nl) caused decreases in MAP and SSNA that were not different between groups but enhanced decreases in SSNA to GABA in sedentary rats only. In sinoaortic denervated rats, GABA microinjections before or after inhibition of the contralateral RVLM caused decreases in MAP and SSNA that were not different between groups. Our results suggest that the contralateral RVLM plays an important role in buffering responses to inhibition of the ipsilateral RVLM under sedentary but not physically active conditions. Based on these studies and others, sedentary conditions appear to enhance both sympathoinhibitory and sympathoexcitatory mechanisms in the RVLM. Enhanced sympathoinhibition may act to reduce already elevated sympathetic nervous system activity following sedentary conditions.
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Affiliation(s)
- Maryetta D Dombrowski
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Patrick J Mueller
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
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Bao L, Si L, Wang Y, Wuyun G, Bo A. Effect of two GABA-ergic drugs on the cognitive functions of rapid eye movement in sleep-deprived and recovered rats. Exp Ther Med 2016; 12:1075-1084. [PMID: 27446323 DOI: 10.3892/etm.2016.3445] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/16/2016] [Indexed: 01/05/2023] Open
Abstract
Rapid eye movement (REM) sleep is closely associated with nervous functions. The present study aimed to evaluate the effects of gabazine and tiagabine on the cognitive functions (CF) of REM sleep-deprived and sleep recovered rats. Rats were divided into REM sleep deprivation, blank control (CC) and environmental groups. The REM sleep deprivation group was further divided into non-operation (nonOP), sham-operated (Sham), gabazine (SR) and tiagabine groups. Each group was evaluated over five time points: Sleep deprived for 1 day (SD 1 day), SD 3 day, SD 5 day, sleep recovery 6 h (RS 6 h) and RS 12 h. A rat model of REM sleep deprivation was established by a modified multi-platform water method, with CF assessed by Morris water maze. Hypothalamic γ-aminobutyric acid (GABA) and glutamic acid contents were measured via high performance liquid chromatography. The number and morphology of hypocretin (Hcrt) neurons and Fos in the hypothalamus, and GABAARα1-induced integral optical density were detected by immunofluorescence. Compared to the CC group, the nonOP and Sham group rats CF were significantly diminished, Fos-positive and Fos-Hcrt double positive cells were significantly increased, and GABA content and GABAARα1 expression levels were significantly elevated (P<0.05). The tiagabine and CC groups exhibited similar results at three time points. The CF of rats in the SR group were diminished and the number of Fos-positive and Fos-Hcrt double positive cells were significantly increased (P<0.05) at RS 6 h and RS l2 h. GABA content and GABAARα1 expression levels were significantly increased in the SR group at all time points (P<0.05), whereas only GABAARα1 expression levels were significantly increased in the tiagabine group at SD 5 day (P<0.05). The results of the present study indicated that REM sleep deprivation diminished CF, increased the number of Hcrt neurons, GABA content and GABAARα1 expression. Furthermore, all alterations were positively correlated with deprivation time and corrected by sleep recovery, as demonstrated by single-factor multi-level variance analysis at the various time points in each group. Therefore, the Hcrt nervous system may be an eligible therapeutic target for the treatment of insomnia.
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Affiliation(s)
- Lidao Bao
- College of Traditional Mongolian Medicine, Inner Mongolia Medical University, Hohhot, Inner Mongolia 010110, P.R. China; Department of Pharmacy, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, Inner Mongolia 010059, P.R. China
| | - Lengge Si
- College of Traditional Mongolian Medicine, Inner Mongolia Medical University, Hohhot, Inner Mongolia 010110, P.R. China
| | - Yuehong Wang
- College of Traditional Mongolian Medicine, Inner Mongolia Medical University, Hohhot, Inner Mongolia 010110, P.R. China
| | - Gerile Wuyun
- College of Traditional Mongolian Medicine, Inner Mongolia Medical University, Hohhot, Inner Mongolia 010110, P.R. China
| | - Agula Bo
- College of Traditional Mongolian Medicine, Inner Mongolia Medical University, Hohhot, Inner Mongolia 010110, P.R. China
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Reporter mouse strain provides a novel look at angiotensin type-2 receptor distribution in the central nervous system. Brain Struct Funct 2014; 221:891-912. [PMID: 25427952 DOI: 10.1007/s00429-014-0943-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 11/07/2014] [Indexed: 02/07/2023]
Abstract
Angiotensin-II acts at its type-1 receptor (AT1R) in the brain to regulate body fluid homeostasis, sympathetic outflow and blood pressure. However, the role of the angiotensin type-2 receptor (AT2R) in the neural control of these processes has received far less attention, largely because of limited ability to effectively localize these receptors at a cellular level in the brain. The present studies combine the use of a bacterial artificial chromosome transgenic AT2R-enhanced green fluorescent protein (eGFP) reporter mouse with recent advances in in situ hybridization (ISH) to circumvent this obstacle. Dual immunohistochemistry (IHC)/ISH studies conducted in AT2R-eGFP reporter mice found that eGFP and AT2R mRNA were highly co-localized within the brain. Qualitative analysis of eGFP immunoreactivity in the brain then revealed localization to neurons within nuclei that regulate blood pressure, metabolism, and fluid balance (e.g., NTS and median preoptic nucleus [MnPO]), as well as limbic and cortical areas known to impact stress responding and mood. Subsequently, dual IHC/ISH studies uncovered the phenotype of specific populations of AT2R-eGFP cells. For example, within the NTS, AT2R-eGFP neurons primarily express glutamic acid decarboxylase-1 (80.3 ± 2.8 %), while a smaller subset express vesicular glutamate transporter-2 (18.2 ± 2.9 %) or AT1R (8.7 ± 1.0 %). No co-localization was observed with tyrosine hydroxylase in the NTS. Although AT2R-eGFP neurons were not observed within the paraventricular nucleus (PVN) of the hypothalamus, eGFP immunoreactivity is localized to efferents terminating in the PVN and within GABAergic neurons surrounding this nucleus. These studies demonstrate that central AT2R are positioned to regulate blood pressure, metabolism, and stress responses.
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