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Szczepańska-Sadowska E, Żera T. Vasopressin: a possible link between hypoxia and hypertension. EXPLORATION OF MEDICINE 2022. [DOI: 10.37349/emed.2022.00103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Cardiovascular and respiratory diseases are frequently associated with transient and prolonged hypoxia, whereas hypoxia exerts pro-hypertensive effects, through stimulation of the sympathetic system and release of pressor endocrine factors. This review is focused on the role of arginine vasopressin (AVP) in dysregulation of the cardiovascular system during hypoxia associated with cardiovascular disorders. AVP is synthesized mainly in the neuroendocrine neurons of the hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON), which send axons to the posterior pituitary and various regions of the central nervous system (CNS). Vasopressinergic neurons are innervated by multiple neuronal projections releasing several neurotransmitters and other regulatory molecules. AVP interacts with V1a, V1b and V2 receptors that are present in the brain and peripheral organs, including the heart, vessels, lungs, and kidneys. Release of vasopressin is intensified during hypernatremia, hypovolemia, inflammation, stress, pain, and hypoxia which frequently occur in cardiovascular patients, and blood AVP concentration is markedly elevated in cardiovascular diseases associated with hypoxemia. There is evidence that hypoxia stimulates AVP release through stimulation of chemoreceptors. It is suggested that acting in the carotid bodies, AVP may fine-tune respiratory and hemodynamic responses to hypoxia and that this effect is intensified in hypertension. There is also evidence that during hypoxia, augmentation of pro-hypertensive effects of vasopressin may result from inappropriate interaction of this hormone with other compounds regulating the cardiovascular system (catecholamines, angiotensins, natriuretic peptides, steroids, nitric oxide). In conclusion, current literature indicates that abnormal mutual interactions between hypoxia and vasopressin may significantly contribute to pathogenesis of hypertension.
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Affiliation(s)
- Ewa Szczepańska-Sadowska
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, 02-097 Warsaw, Poland
| | - Tymoteusz Żera
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, 02-097 Warsaw, Poland
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2
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Leithead AB, Tasker JG, Harony‐Nicolas H. The interplay between glutamatergic circuits and oxytocin neurons in the hypothalamus and its relevance to neurodevelopmental disorders. J Neuroendocrinol 2021; 33:e13061. [PMID: 34786775 PMCID: PMC8951898 DOI: 10.1111/jne.13061] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 10/14/2021] [Accepted: 10/30/2021] [Indexed: 11/27/2022]
Abstract
Oxytocin (OXT) neurons of the hypothalamus are at the center of several physiological functions, including milk ejection, uterus contraction, and maternal and social behavior. In lactating females, OXT neurons show a pattern of burst firing and inter-neuron synchronization during suckling that leads to pulsatile release of surges of OXT into the bloodstream to stimulate milk ejection. This pattern of firing and population synchronization may be facilitated in part by hypothalamic glutamatergic circuits, as has been observed in vitro using brain slices obtained from male rats and neonates. However, it remains unknown how hypothalamic glutamatergic circuits influence OXT cell activity outside the context of lactation. In this review, we summarize the in vivo and in vitro studies that describe the synchronized burst firing pattern of OXT neurons and the implication of hypothalamic glutamate in this pattern of firing. We also make note of the few studies that have traced glutamatergic afferents to the hypothalamic paraventricular and supraoptic nuclei. Finally, we discuss the genetic findings implicating several glutamatergic genes in neurodevelopmental disorders, including autism spectrum disorder, thus underscoring the need for future studies to investigate the impact of these mutations on hypothalamic glutamatergic circuits and the OXT system.
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Affiliation(s)
- Amanda B. Leithead
- Department of PsychiatryIcahn School of Medicine at Mount SinaiNew YorkNYUSA
- Seaver Autism Center for Research and TreatmentNew YorkNYUSA
- Department of NeuroscienceIcahn School of Medicine at Mount SinaiNew YorkNYUSA
- Friedman Brain Institute at the Icahn School of Medicine at Mount SinaiNew YorkNYUSA
| | - Jeffrey G. Tasker
- Neurobiology DivisionDepartment of Cell and Molecular BiologyTulane UniversityNew OrleansLAUSA
| | - Hala Harony‐Nicolas
- Department of PsychiatryIcahn School of Medicine at Mount SinaiNew YorkNYUSA
- Seaver Autism Center for Research and TreatmentNew YorkNYUSA
- Department of NeuroscienceIcahn School of Medicine at Mount SinaiNew YorkNYUSA
- Friedman Brain Institute at the Icahn School of Medicine at Mount SinaiNew YorkNYUSA
- Mindich Child Health and Development Institute at the Icahn School of Medicine at Mount SinaiNew YorkNYUSA
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3
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Fernandes TP, Almeida NL, Silva GM, Santos NA. Nicotine gum enhances visual processing in healthy nonsmokers. Brain Imaging Behav 2021; 15:2593-2605. [PMID: 33675460 DOI: 10.1007/s11682-021-00461-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2021] [Indexed: 10/22/2022]
Abstract
OBJECTIVE The main purpose of this study was to investigate the isolated effects of nicotine on visual processing, namely contrast processing. METHODS Thirteen participants, aged 18-40 years, were enrolled in this double blind, randomized and pilot controlled trial involving nicotine gum administration (placebo, 2-mg and 4-mg doses). The participants' instruction was to detect the location of vertical gratings (0.2; 1.0; 3.3; 5.7; 8.8; 13.2 and 15.9 cycles per degree) when it was presented either left or right on the monitor screen. A repeated multivariate analysis of variance was conducted to analyse the results for the visual processing tasks. Bayesian analyses were also carried out considering maximum robustness to avoid bias. RESULTS The findings that nicotine gum administration resulted in better contrast discrimination when compared to placebo gum (p < .001). More specifically, the 4-mg resulted in better visual sensitivity when compared to the 2-mg (p < .01) and the placebo (p < .001) gum. Demographic data were not related to the outcomes. CONCLUSIONS These data bring the need for support the findings. If proved, it is possible that nicotine, in small doses, can have a potential therapeutic use for those populations with low vision. TRIAL REGISTRATION NUMBER RBR-46tjy3.
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Affiliation(s)
- Thiago P Fernandes
- Federal University of Paraiba, Joao Pessoa, Brazil. .,Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Joao Pessoa, Brazil.
| | - Natalia L Almeida
- Federal University of Paraiba, Joao Pessoa, Brazil. .,Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Joao Pessoa, Brazil.
| | - Gabriella M Silva
- Federal University of Paraiba, Joao Pessoa, Brazil.,Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Joao Pessoa, Brazil
| | - Natanael A Santos
- Federal University of Paraiba, Joao Pessoa, Brazil.,Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Joao Pessoa, Brazil
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Mukai Y, Nagayama A, Itoi K, Yamanaka A. Identification of substances which regulate activity of corticotropin-releasing factor-producing neurons in the paraventricular nucleus of the hypothalamus. Sci Rep 2020; 10:13639. [PMID: 32788592 PMCID: PMC7424526 DOI: 10.1038/s41598-020-70481-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 07/30/2020] [Indexed: 12/24/2022] Open
Abstract
The stress response is a physiological system for adapting to various internal and external stimuli. Corticotropin-releasing factor-producing neurons in the paraventricular nucleus of the hypothalamus (PVN-CRF neurons) are known to play an important role in the stress response as initiators of the hypothalamic-pituitary-adrenal axis. However, the mechanism by which activity of PVN-CRF neurons is regulated by other neurons and bioactive substances remains unclear. Here, we developed a screening method using calcium imaging to identify how physiological substances directly affect the activity of PVN-CRF neurons. We used acute brain slices expressing a genetically encoded calcium indicator in PVN-CRF neurons using CRF-Cre recombinase mice and an adeno-associated viral vector under Cre control. PVN-CRF neurons were divided into ventral and dorsal portions. Bath application of candidate substances revealed 12 substances that increased and 3 that decreased intracellular calcium concentrations. Among these substances, angiotensin II and histamine mainly increased calcium in the ventral portion of the PVN-CRF neurons via AT1 and H1 receptors, respectively. Conversely, carbachol mainly increased calcium in the dorsal portion of the PVN-CRF neurons via both nicotinic and muscarinic acetylcholine receptors. Our method provides a precise and reliable means of evaluating the effect of a substance on PVN-CRF neuronal activity.
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Affiliation(s)
- Yasutaka Mukai
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, 464-8601, Japan.,Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.,CREST, JST, Honcho, Kawaguchi, Saitama, 332-0012, Japan.,JSPS Research Fellowship for Young Scientists, Tokyo, 102-0083, Japan
| | - Ayako Nagayama
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, 464-8601, Japan.,Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Keiichi Itoi
- Department of Neuroendocrinology, Graduate School of Medicine, Tohoku University, Sendai, 980-8575, Japan
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, 464-8601, Japan. .,Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan. .,CREST, JST, Honcho, Kawaguchi, Saitama, 332-0012, Japan.
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5
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Sunstrum JK, Inoue W. Heterosynaptic modulation in the paraventricular nucleus of the hypothalamus. Neuropharmacology 2018; 154:87-95. [PMID: 30408488 DOI: 10.1016/j.neuropharm.2018.11.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/18/2018] [Accepted: 11/03/2018] [Indexed: 12/21/2022]
Abstract
The stress response-originally described by Hans Selye as "the nonspecific response of the body to any demand made upon it"-is chiefly mediated by the hypothalamic-pituitary-adrenal (HPA) axis and is activated by diverse sensory stimuli that inform threats to homeostasis. The diversity of signals regulating the HPA axis is partly achieved by the complexity of afferent inputs that converge at the apex of the HPA axis: this apex is formed by a group of neurosecretory neurons that synthesize corticotropin-releasing hormone (CRH) in the paraventricular nucleus of the hypothalamus (PVN). The afferent synaptic inputs onto these PVN-CRH neurons originate from a number of brain areas, and PVN-CRH neurons respond to a long list of neurotransmitters/neuropeptides. Considering this complexity, an important question is how these diverse afferent signals independently and/or in concert influence the excitability of PVN-CRH neurons. While many of these inputs directly act on the postsynaptic PVN-CRH neurons for the summation of signals, accumulating data indicates that they also modulate each other's transmission in the PVN. This mode of transmission, termed heterosynaptic modulation, points to mechanisms through which the activity of a specific modulatory input (conveying a specific sensory signal) can up- or down-regulate the efficacy of other afferent synapses (mediating other stress modalities) depending on receptor expression for and spatial proximity to the heterosynaptic signals. Here, we review examples of heterosynaptic modulation in the PVN and discuss its potential role in the regulation of PVN-CRH neurons' excitability and resulting HPA axis activity. This article is part of the Special Issue entitled 'Hypothalamic Control of Homeostasis'.
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Affiliation(s)
- Julia K Sunstrum
- Neuroscience Program, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Wataru Inoue
- Neuroscience Program, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada; Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.
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Zanos P, Keyworth H, Georgiou P, Hambsch B, Otte DM, Kitchen I, Zimmer A, Bailey A. Chronic nicotine administration restores brain region specific upregulation of oxytocin receptor binding levels in a G72 mouse model of schizophrenia. Eur J Neurosci 2018; 50:2255-2263. [DOI: 10.1111/ejn.14155] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 08/07/2018] [Accepted: 08/26/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Panos Zanos
- Department of Biochemistry and Physiology Faculty of Health and Medical Sciences University of Surrey Guildford Surrey UK
- Department of Psychiatry School of Medicine University of Maryland Baltimore Maryland USA
| | - Helen Keyworth
- Department of Biochemistry and Physiology Faculty of Health and Medical Sciences University of Surrey Guildford Surrey UK
| | - Polymnia Georgiou
- Department of Biochemistry and Physiology Faculty of Health and Medical Sciences University of Surrey Guildford Surrey UK
- Department of Psychiatry School of Medicine University of Maryland Baltimore Maryland USA
| | - Boris Hambsch
- GKM Gesellschaft für Therapieforschung mbH Lessingstraße München Germany
| | - David M. Otte
- Institute for Molecular Psychiatry Medical Faculty University of Bonn Bonn Germany
| | - Ian Kitchen
- Department of Biochemistry and Physiology Faculty of Health and Medical Sciences University of Surrey Guildford Surrey UK
| | - Andreas Zimmer
- Institute for Molecular Psychiatry Medical Faculty University of Bonn Bonn Germany
| | - Alexis Bailey
- Department of Biochemistry and Physiology Faculty of Health and Medical Sciences University of Surrey Guildford Surrey UK
- Institute of Medical and Biomedical Education St George's University of London London SW17 0RE UK
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Nagano H, Sobue Y, Matsuyama H, Saito S, Sakai H, Alom F, Tanahashi Y, Ishii T, Unno T. Muscarinic M 2 receptor promotes vasopressin synthesis in mice supraoptic nuclei. J Endocrinol 2018; 237:207-216. [PMID: 29563233 DOI: 10.1530/joe-17-0630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Accepted: 03/21/2018] [Indexed: 11/08/2022]
Abstract
Muscarinic acetylcholine receptors have been suggested to be implicated in arginine-vasopressin secretion because intracerebroventricular muscarinic agonist administration induces arginine-vasopressin release into the circulation. Although which subtype is involved in the regulation of arginine-vasopressin secretion is unclear, M2 receptors have been reported to be highly expressed in the hypothalamus. In the present study, M2 receptor-knockout mice were used to elucidate whether M2 receptor regulates arginine-vasopressin synthesis in the paraventricular nuclei and supraoptic nuclei of the hypothalamus. The number of arginine-vasopressin-immunoreactive neurons in M2 receptor-knockout mice was significantly decreased in the supraoptic nuclei, but not in the paraventricular nuclei compared with wild-type mice. Plasma arginine-vasopressin level in M2 receptor-knockout mice was also significantly lower than in the wild-type mice. Urinary volume and frequency as well as water intake in M2 receptor-knockout mice were significantly higher than those in wild-type mice. The V2 vasopressin receptor expression in kidneys of M2 receptor-knockout mice was comparable with that of wild-type mice, and increased urination in M2 receptor-knockout mice was significantly decreased by administration of desmopressin, a specific V2 receptor agonist, suggesting that V2 receptors in the kidneys of M2 receptor-knockout mice are intact. These results suggest that M2 receptors promote arginine-vasopressin synthesis in the supraoptic nuclei and play a role in the regulation and maintenance of body fluid.
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Affiliation(s)
- Hiroshi Nagano
- Department of Pathogenetic Veterinary ScienceUnited Graduate School of Veterinary Science, Gifu University, Gifu, Japan
| | - Yuki Sobue
- Laboratory of Veterinary PharmacologyFaculty of Applied Biological Science, Gifu University, Gifu, Japan
| | - Hayato Matsuyama
- Laboratory of Veterinary PharmacologyFaculty of Applied Biological Science, Gifu University, Gifu, Japan
| | - Shoichiro Saito
- Laboratory of Veterinary AnatomyFaculty of Applied Biological Science, Gifu University, Gifu, Japan
| | - Hiroki Sakai
- Laboratory of Veterinary PathologyFaculty of Applied Biological Science, Gifu University, Gifu, Japan
| | - Firoj Alom
- Department of Pathogenetic Veterinary ScienceUnited Graduate School of Veterinary Science, Gifu University, Gifu, Japan
| | - Yasuyuki Tanahashi
- Department of Animal Medical SciencesFaculty of Life Science, Kyoto Sangyo University, Kyoto, Japan
| | - Toshiaki Ishii
- Department of Basic Veterinary MedicineObihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
| | - Toshihiro Unno
- Laboratory of Veterinary PharmacologyFaculty of Applied Biological Science, Gifu University, Gifu, Japan
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8
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Nicotine excites corticotropin-releasing hormone mRNA-expressing neuron in the hypothalamic paraventricular nucleus in vitro in rats. Neuroreport 2018; 27:580-6. [PMID: 27022819 DOI: 10.1097/wnr.0000000000000573] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nicotine is known to modulate the activity of the hypothalamic-pituitary-adrenal axis by stimulating corticotropin-releasing hormone (CRH) release from the hypothalamic paraventricular nucleus (PVN). However, the mechanism by which nicotine affects the hypothalamic-pituitary-adrenal axis by modulating PVN CRH neuronal activity is currently unclear. Here, we examined the effects of nicotine on PVN CRH-mRNA-expressing neurons in vitro in rats by whole-cell patch-clamp recordings, biocytin staining, and single-cell reverse transcription-multiplex PCR techniques. Of the 146 PVN putative parvocellular neurons, 17.1% (25/146) coexpressed GAPDH mRNA and CRH mRNA. Under current-clamp recording conditions, application of nicotine (1 μM) induced excitation in 92% (23/25) PVN CRH-mRNA-expressing neurons, which showed a significant increase in the spike firing rate accompanied by a depolarization of the membrane potential. Nicotine induced an increase in the spike firing rate of PVN CRH-mRNA-expressing neurons in a concentration-dependent manner. The half-effective concentration (EC50) of nicotine for increasing the spike firing rate of PVN CRH-mRNA-expressing neurons was 1.6 μM. Extracellular application of ionotropic glutamate receptor antagonist kynurenic acid (1 mM) abolished the nicotine-induced excitation of PVN CRH-mRNA-expressing neurons. Moreover, application of nicotine induced a significant increase in the spontaneous excitatory postsynaptic currents frequency, but without significantly altering the spontaneous excitatory postsynaptic currents amplitude of the CRH-mRNA-expressing neurons. Biocytin staining confirmed that the nicotine-sensitive CRH-mRNA-expressing neurons were located in the PVN parvocellular division. These results indicated that extracellular administration of nicotine indirectly excited PVN CRH-mRNA-expressing neurons, suggesting that nicotine modulated PVN CRH secretion by enhancement of both the presynaptic action potential drive and quantal glutamate release.
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Zhang KM, Zhao GY, Zhang BB, Xu Q, Chu CP, Jin H, Qiu DL. Nicotine enhances GABAergic inhibition of oxytocin mRNA-expressing neuron in the hypothalamic paraventricular nucleus in vitro in rats. Neurosci Lett 2016; 638:5-11. [PMID: 27923665 DOI: 10.1016/j.neulet.2016.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 11/22/2016] [Accepted: 12/02/2016] [Indexed: 01/31/2023]
Abstract
We recently found that extracellular administration of nicotine indirectly excited hypothalamic paraventricular nucleus (PVN) corticotropin-releasing hormone (CRH) mRNA-expressing neurons. In this study, we studied the effect of nicotine on PVN oxytocin (OT) mRNA-expressing neuron in vitro in rats, by whole-cell patch-clamp recording technique, immunohistochemistry methods and single-cell reverse-transcription multiplex polymerase chain reaction (SC-RT-mPCR) methods Our results showed that 79.3% (73/92) of the 92 PVN putative magnocellular neurons co-expressed GAPDH mRNA and OT mRNA. Under current-clamp recording conditions, local micro application of nicotine (1-300μM) induced a decrease in spontaneous firing rate accompanied with a hyperpolarization of membrane potential in 76.7% (56/73) of PVN OT mRNA-expressing magnocellular neurons. The nicotine induced inhibition in spontaneous activity of PVN OT mRNA-expressing magnocellular neurons was dose-dependent. The half-inhibitory concentration (IC50) is 2.9μM. The nicotine induced hyperpolarization of PVN OT mRNA-expressing magnocellular neurons was sensitive to GABAA receptor antagonist, SR95531 (10μM) and tetrodotoxin (TTX, 1μM). In addition, local micro application of nicotine induced a significant increase in frequency of spontaneous inhibitory postsynaptic potentials (sIPSPs), but without changes in the sEPSPs amplitude of the OT-mRNA expressing neurons. Biocytin staining confirmed that the nicotine-sensitive OT-mRNA expressing neurons were the PVN magnocellular neurons. These results demonstrated that nicotine enhances the GABAergic inhibition, resulting in a decrease in spontaneous firing rate of the PVN OT-mRNA expressing neurons. These findings suggested that nicotine modulated PVN OT secretion via enhancement of both presynaptic action potential drive and quantal GABA release.
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Affiliation(s)
- Ke-Min Zhang
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, Yanbian University, Yanji City, Jilin Province, 133002, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji City, Jilin Province, China
| | - Guo-Yan Zhao
- Department of physiology, Jilin Medical College, Jilin City, Jinlin Province, China
| | - Bin-Bin Zhang
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, Yanbian University, Yanji City, Jilin Province, 133002, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji City, Jilin Province, China
| | - Qi Xu
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, Yanbian University, Yanji City, Jilin Province, 133002, China
| | - Chun-Ping Chu
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, Yanbian University, Yanji City, Jilin Province, 133002, China
| | - Hua Jin
- Department of Nephrology, Affiliated Hospital of Yanbian University, Yanji City, Jilin Province, China.
| | - De-Lai Qiu
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, Yanbian University, Yanji City, Jilin Province, 133002, China; Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji City, Jilin Province, China.
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10
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Wang L, Ennis M, Szabó G, Armstrong WE. Characteristics of GABAergic and cholinergic neurons in perinuclear zone of mouse supraoptic nucleus. J Neurophysiol 2014; 113:754-67. [PMID: 25376783 DOI: 10.1152/jn.00561.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The perinuclear zone (PNZ) of the supraoptic nucleus (SON) contains some GABAergic and cholinergic neurons thought to innervate the SON proper. In mice expressing enhanced green fluorescent protein (eGFP) in association with glutamate decarboxylase (GAD)65 we found an abundance of GAD65-eGFP neurons in the PNZ, whereas in mice expressing GAD67-eGFP, there were few labeled PNZ neurons. In mice expressing choline acetyltransferase (ChAT)-eGFP, large, brightly fluorescent and small, dimly fluorescent ChAT-eGFP neurons were present in the PNZ. The small ChAT-eGFP and GAD65-eGFP neurons exhibited a low-threshold depolarizing potential consistent with a low-threshold spike, with little transient outward rectification. Large ChAT-eGFP neurons exhibited strong transient outward rectification and a large hyperpolarizing spike afterpotential, very similar to that of magnocellular vasopressin and oxytocin neurons. Thus the large soma and transient outward rectification of large ChAT-eGFP neurons suggest that these neurons would be difficult to distinguish from magnocellular SON neurons in dissociated preparations by these criteria. Large, but not small, ChAT-eGFP neurons were immunostained with ChAT antibody (AB144p). Reconstructed neurons revealed a few processes encroaching near and passing through the SON from all types but no clear evidence of a terminal axon arbor. Large ChAT-eGFP neurons were usually oriented vertically and had four or five dendrites with multiple branches and an axon with many collaterals and local arborizations. Small ChAT-eGFP neurons had a more restricted dendritic tree compared with parvocellular GAD65 neurons, the latter of which had long thin processes oriented mediolaterally. Thus many of the characteristics found previously in unidentified, small PNZ neurons are also found in identified GABAergic neurons and in a population of smaller ChAT-eGFP neurons.
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Affiliation(s)
- Lie Wang
- Department of Anatomy and Neurobiology and Neuroscience Institute, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Matthew Ennis
- Department of Anatomy and Neurobiology and Neuroscience Institute, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Gábor Szabó
- Department of Gene Technology and Developmental Biology, Institute of Experimental Medicine, Budapest, Hungary
| | - William E Armstrong
- Department of Anatomy and Neurobiology and Neuroscience Institute, University of Tennessee Health Science Center, Memphis, Tennessee; and
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Sahdeo S, Wallace T, Hirakawa R, Knoflach F, Bertrand D, Maag H, Misner D, Tombaugh GC, Santarelli L, Brameld K, Milla ME, Button DC. Characterization of RO5126946, a Novel α7 nicotinic acetylcholine receptor-positive allosteric modulator. J Pharmacol Exp Ther 2014; 350:455-68. [PMID: 24917542 DOI: 10.1124/jpet.113.210963] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Both preclinical evidence and clinical evidence suggest that α7 nicotinic acetylcholine receptor activation (α7nAChR) improves cognitive function, the decline of which is associated with conditions such as Alzheimer's disease and schizophrenia. Moreover, allosteric modulation of α7nAChR is an emerging therapeutic strategy in an attempt to avoid the rapid desensitization properties associated with the α7nAChR after orthosteric activation. We used a calcium assay to screen for positive allosteric modulators (PAMs) of α7nAChR and report on the pharmacologic characterization of the novel compound RO5126946 (5-chloro-N-[(1S,3R)-2,2-dimethyl-3-(4-sulfamoyl-phenyl)-cyclopropyl]-2-methoxy-benzamide), which allosterically modulates α7nAChR activity. RO5126946 increased acetylcholine-evoked peak current and delayed current decay but did not affect the recovery of α7nAChRs from desensitization. In addition, RO5126946's effects were absent when nicotine-evoked currents were completely blocked by coapplication of the α7nAChR-selective antagonist methyl-lycaconitine. RO5126946 enhanced α7nAChR synaptic transmission and positively modulated GABAergic responses. The absence of RO5126946 effects at human α4β2nAChR and 5-hydroxytryptamine 3 receptors, among others, indicated selectivity for α7nAChRs. In vivo, RO5126946 is orally bioavailable and brain-penetrant and improves associative learning in a scopolamine-induced deficit model of fear conditioning in rats. In addition, procognitive effects of RO5126946 were investigated in the presence of nicotine to address potential pharmacologic interactions on behavior. RO5126946 potentiated nicotine's effects on fear memory when both compounds were administered at subthreshold doses and did not interfere with procognitive effects observed when both compounds were administered at effective doses. Overall, RO5126946 is a novel α7nAChR PAM with cognitive-enhancing properties.
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Affiliation(s)
- Sunil Sahdeo
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
| | - Tanya Wallace
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
| | - Ryoko Hirakawa
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
| | - Frederic Knoflach
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
| | - Daniel Bertrand
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
| | - Hans Maag
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
| | - Dinah Misner
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
| | - Geoffrey C Tombaugh
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
| | - Luca Santarelli
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
| | - Ken Brameld
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
| | - Marcos E Milla
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
| | - Donald C Button
- Roche Palo Alto, Palo Alto, California (S.S., T.W., R.H., H.M., K.B., M.E.M., D.C.B.); F. Hoffmann-La Roche AG, pRED, Pharma Research and Early Development, Discovery Neuroscience, Grenzacherstrasse, Basel, Switzerland (F.K., L.S.); gRED South San Francisco, California (D.M.); HiQScreen Sarl, Geneva, Switzerland (D.B.); and Psychogenics Inc., Tarrytown, New York (G.C.T.)
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12
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Brown CH, Bains JS, Ludwig M, Stern JE. Physiological regulation of magnocellular neurosecretory cell activity: integration of intrinsic, local and afferent mechanisms. J Neuroendocrinol 2013; 25:678-710. [PMID: 23701531 PMCID: PMC3852704 DOI: 10.1111/jne.12051] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Revised: 05/08/2013] [Accepted: 05/20/2013] [Indexed: 01/12/2023]
Abstract
The hypothalamic supraoptic and paraventricular nuclei contain magnocellular neurosecretory cells (MNCs) that project to the posterior pituitary gland where they secrete either oxytocin or vasopressin (the antidiuretic hormone) into the circulation. Oxytocin is important for delivery at birth and is essential for milk ejection during suckling. Vasopressin primarily promotes water reabsorption in the kidney to maintain body fluid balance, but also increases vasoconstriction. The profile of oxytocin and vasopressin secretion is principally determined by the pattern of action potentials initiated at the cell bodies. Although it has long been known that the activity of MNCs depends upon afferent inputs that relay information on reproductive, osmotic and cardiovascular status, it has recently become clear that activity depends critically on local regulation by glial cells, as well as intrinsic regulation by the MNCs themselves. Here, we provide an overview of recent advances in our understanding of how intrinsic and local extrinsic mechanisms integrate with afferent inputs to generate appropriate physiological regulation of oxytocin and vasopressin MNC activity.
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Affiliation(s)
- C H Brown
- Department of Physiology and Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand.
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13
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Morganstern I, Ye Z, Liang S, Fagan S, Leibowitz SF. Involvement of cholinergic mechanisms in the behavioral effects of dietary fat consumption. Brain Res 2012; 1470:24-34. [PMID: 22765913 DOI: 10.1016/j.brainres.2012.06.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 05/25/2012] [Accepted: 06/02/2012] [Indexed: 02/06/2023]
Abstract
Clinical reports suggest a positive association between fat consumption and the incidence of hyperactivity, impulsivity and cognitive abnormalities. To investigate possible mechanisms underlying these disturbances under short-term conditions, we examined in Sprague-Dawley rats the influence of 7-day consumption of a high-fat diet (HFD) compared to chow on anxiety, novelty-seeking and exploratory behaviors and also on acetylcholine (ACh) neurotransmission that may mediate these behaviors. The HFD consumption, which elevated circulating fatty acids but produced no change in caloric intake or body weight, stimulated novelty-seeking and exploration in an open field, while reducing anxiety in an elevated plus maze. Using the Ellman assay to measure ACh esterase (AChE) activity that breaks down ACh, the second experiment showed HFD consumption to significantly reduce AChE activity in the frontal cortex, hypothalamus and midbrain. With measurements of [¹²⁵I]-epibatidine or [¹²⁵I]-bungarotoxin binding to nicotinic ACh receptors (nAChRs) containing β2 or α7 subunits, respectively, the results also showed HFD consumption to increase both β2-nAChR binding in the medial prefrontal cortex and substantia nigra and α7-nAChR binding in the lateral and ventromedial hypothalamus. When treated with an acute dose of the nicotinic antagonist, mecamylamine (0.5 mg/kg, sc), the HFD animals responded with significantly reduced exploratory and novelty-seeking behaviors, whereas the chow-consuming rats exhibited no response. These findings suggest that the exploratory and novelty-seeking behaviors induced by dietary fat may be mediated by enhanced nicotinic cholinergic activity, which is accompanied by increased density of β2-nAChRs in cortical and midbrain regions associated with impulsivity and locomotor activity and of α7-nAChRs in hypothalamic regions associated with arousal and energy balance.
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Affiliation(s)
- Irene Morganstern
- The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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14
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Intravenous CDP-choline activates neurons in supraoptic and paraventricular nuclei and induces hormone secretion. Brain Res Bull 2011; 87:286-94. [PMID: 22138197 DOI: 10.1016/j.brainresbull.2011.11.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 11/15/2011] [Accepted: 11/17/2011] [Indexed: 01/31/2023]
Abstract
The aim of the present study was to assess the effects of intravenous (i.v.) cytidine-5'-diphosphate (CDP)-choline administration on the activation of oxytocin and vasopressin neurons in the supraoptic (SON) and paraventricular nuclei (PVN), using the immunohistochemical identification of c-Fos expression as a marker of neuronal activation and to correlate this with the plasma hormone levels. Rats were catheterized under sevofluorane anesthesia and experiments were conducted 24h later. Blood samples were withdrawn from arterial catheter at 2, 5, 10, 20, 40 and 60 min after CDP-choline (0.5, 1.0 and 2.0 g/kg; i.v.) or saline (1.0 ml/kg; i.v.) for the measurement of plasma oxytocin and vasopressin levels by radioimmunoassay. Animals were sacrificed 90 min after CDP-choline administration for dual immunohistochemistry which was performed on paraformaldehyde-fixed vibratome sections. Dual immunohistochemistry for c-Fos and oxytocin or vasopressin revealed that CDP-choline activates these neurons in a dose-dependent manner. Light microscopic analyses showed that, about 41%, 75% or 87% of the oxytocin neurons and about 18%, 46% or 82% of the vasopressin neurons in SON express c-Fos, thus activated, by the dosages of 0.5, 1.0 or 2.0 g/kg CDP-choline, respectively. Increases in c-Fos expression were about 29%, 62% or 81% for the oxytocin neurons and about 38%, 70% or 78% for the vasopressin neurons in PVN with the dosages of 0.5, 1.0 or 2.0 g/kg CDP-choline, respectively. When compared to the control groups (8% and 7% oxytocin or 2% and 5% vasopressin neuronal activation in SON or PVN, respectively), these increases were found to be statistically significant (p<0.05). In the PVN most of the magnocellular neurons were activated while less number of parvocellular neurons expressed c-Fos in response to CDP-choline challenge. In correlation with c-Fos data, CDP-choline increased plasma oxytocin and vasopressin levels both dose- and time-dependently. Results of the present study suggested that peripheral administration of CDP-choline is able to increase plasma oxytocin and vasopressin levels while activating the respective neurons.
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15
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Ogier R, Tribollet E, Bertrand D, Raggenbass M. Pudendal motoneurons of the rat located in separated spinal nuclei possess nicotinic acetylcholine receptors having distinct pharmacological profiles. Eur J Neurosci 2008; 28:924-30. [DOI: 10.1111/j.1460-9568.2008.06403.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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16
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Dunlop J, Roncarati R, Jow B, Bothmann H, Lock T, Kowal D, Bowlby M, Terstappen GC. In vitro screening strategies for nicotinic receptor ligands. Biochem Pharmacol 2007; 74:1172-81. [PMID: 17706607 DOI: 10.1016/j.bcp.2007.07.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 06/29/2007] [Accepted: 07/03/2007] [Indexed: 11/17/2022]
Abstract
A common historical strategy to the discovery of nicotinic receptor ligands has involved the use of radioligand-binding assays for ligand identification in combination with two-electrode voltage clamp in Xenopus oocytes for electrophysiological characterization. More recently, higher-throughput methodologies have replaced these approaches to accommodate screening of large compound libraries and to provide increased capacity for electrophysiological profiling in mammalian cell lines. We, and others, have implemented cell-based screening assays using the fluorometric imaging plate reader (FLIPR) for primary and lead optimization screening of nicotinic receptor agonists and positive allosteric modulators (PAMs). Using GH4C1 cells expressing the rat alpha7 nicotinic receptor, both acetylcholine and nicotine produced concentration-dependent elevations of intracellular calcium with EC(50) values of 5.5 and 1.6 microM, respectively. PAM activity was robustly detected using the FLIPR assay; for example, the known alpha7 receptor PAM 5-hydroxyindole failed to directly activate the receptor but produced a leftward shift of the nicotine concentration-response curve in combination with a potentiation of the maximum evoked response to nicotine. Electrophysiological confirmation of agonist activity was achieved using the Dynaflow rapid perfusion system and patch clamp in the same GH4C1 cell expression system. Estimated EC(50) values for acetylcholine-evoked currents in GH4C1/alpha7 cells were 55 and 576 microM for area-under-the-curve (AUC) and maximum peak height calculations, respectively. Similarly, PAM activity was confirmed using electrophysiological recordings while also allowing for the mechanistic discrimination of compounds, not possible using the FLIPR assay. Specifically, PAMs capable of slowing the rapid desensitization of alpha7 receptors to different extents were discernable in these studies. Further improvements in the capacity to screen compounds using electrophysiology has been achieved by implementation of high-throughput gigaohm quality recording systems such as the QPatch and PatchXpress where agonist EC(50) values are highly comparable to those obtained using conventional manual patch clamp.
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Affiliation(s)
- John Dunlop
- Neuroscience Discovery Research, Wyeth Research, CN-8000, Princeton, NJ 08543, USA.
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17
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Charpantier E, Wiesner A, Huh KH, Ogier R, Hoda JC, Allaman G, Raggenbass M, Feuerbach D, Bertrand D, Fuhrer C. Alpha7 neuronal nicotinic acetylcholine receptors are negatively regulated by tyrosine phosphorylation and Src-family kinases. J Neurosci 2006; 25:9836-49. [PMID: 16251431 PMCID: PMC6725579 DOI: 10.1523/jneurosci.3497-05.2005] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Nicotine, a component of tobacco, is highly addictive but possesses beneficial properties such as cognitive improvements and memory maintenance. Involved in these processes is the neuronal nicotinic acetylcholine receptor (nAChR) alpha7, whose activation triggers depolarization, intracellular signaling cascades, and synaptic plasticity underlying addiction and cognition. It is therefore important to investigate intracellular mechanisms by which a cell regulates alpha7 nAChR activity. We have examined the role of phosphorylation by combining molecular biology, biochemistry, and electrophysiology in SH-SY5Y neuroblastoma cells, Xenopus oocytes, rat hippocampal interneurons, and neurons from the supraoptic nucleus, and we found tyrosine phosphorylation of alpha7 nAChRs. Tyrosine kinase inhibition by genistein decreased alpha7 nAChR phosphorylation but strongly increased acetylcholine-evoked currents, whereas tyrosine phosphatase inhibition by pervanadate produced opposite effects. Src-family kinases (SFKs) directly interacted with the cytoplasmic loop of alpha7 nAChRs and phosphorylated the receptors at the plasma membrane. SFK inhibition by PP2 [4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine] or SU6656 (2,3-dihydro-N,N-dimethyl-2-oxo-3-[(4,5,6,7-tetrahydro-1H-indol-2-yl)methylene]-1H-indole-5-sulfonamide) increased alpha7 nAChR-mediated responses, whereas expression of active Src reduced alpha7 nAChR activity. Mutant alpha7 nAChRs lacking cytoplasmic loop tyrosine residues because of alanine replacement of Tyr-386 and Tyr-442 were more active than wild-type receptors and insensitive to kinase or phosphatase inhibition. Because the amount of surface alpha7 receptors was not affected by kinase or phosphatase inhibitors, these data show that functional properties of alpha7 nAChRs depend on the tyrosine phosphorylation status of the receptor and are the result of a balance between SFKs and tyrosine phosphatases. These findings reveal novel regulatory mechanisms that may help to understand nicotinic receptor-dependent plasticity, addiction, and pathology.
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Affiliation(s)
- Eric Charpantier
- Department of Neurosciences, University Medical Center, CH-1211 Geneva 4, Switzerland
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18
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Bertrand D. The possible contribution of neuronal nicotinic acetylcholine receptors in depression. DIALOGUES IN CLINICAL NEUROSCIENCE 2005. [PMID: 16156379 PMCID: PMC3181734 DOI: 10.31887/dcns.2005.7.3/dbertrand] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although tobacco use and smoking were introduced long ago, it was only recently that the nicotine contained in the tobacco leaves was recognized as an addictive substance acting on the central nervous system (CNS). However, even prior to this recognition, several studies have reported an association between smoking and psychiatric disorders. One of the many observations was that smoking cessation is accompanied by a marked increase in the probability of major depression. In parallel with the discovery of the neuronal nicotinic acetylcholine receptors and their extensive expression in the CNS, this association sheds new light on the influence of cholinergic transmission in depression. In this article, we examine the various modes of action of nicotine in the CNS and discuss the mechanisms by which this alkaloid can prevent or precipitate mood disorders, and the possibility of discovering new therapeutic avenues for the treatment of depression.
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Affiliation(s)
- Daniel Bertrand
- Department of Neuroscience, Medical Faculty, Geneva University Hospitals, Geneva, Switzerland
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19
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di Corcia G, Blasetti A, De Simone M, Verrotti A, Chiarelli F. Recent advances on autosomal dominant nocturnal frontal lobe epilepsy: "understanding the nicotinic acetylcholine receptor (nAChR)". Eur J Paediatr Neurol 2005; 9:59-66. [PMID: 15843070 DOI: 10.1016/j.ejpn.2004.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2004] [Revised: 12/09/2004] [Accepted: 12/13/2004] [Indexed: 10/25/2022]
Abstract
Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is characterized by clusters of nocturnal motor seizures, which are often stereotyped and brief. They vary from simple arousals during sleep to dramatic, bizarre, hyperkinetic events with tonic or dystonic features. A minority of patients may experience aura. This disease is caused by various mutations of genes coding for subunits of neuronal acetylcholine receptor comprising the sodium/potassium ion channel. Recent advances in molecular genetics have provided the means for a better understanding of human epileptogenesis at a molecular level, which can facilitate clinical diagnosis and provides a more rational basis of therapy of this form of epilepsy. In this review, we report the recent data in the genetics of ADNFLE.
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Affiliation(s)
- G di Corcia
- Department of Pediatrics, Policlinico SS Annunziata, University of Chieti, Via dei Vestini 5, 66013 Chieti, Italy
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20
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21
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Jin L, Liu R, Wang GP, Zhang P, Ju G. Nicotinic receptor alpha subunits in magnocellular neurons of rat hypothalamus. Neuroreport 2004; 15:2333-6. [PMID: 15640750 DOI: 10.1097/00001756-200410250-00006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mab35 is a monoclonal antibody against one specific immunogenic region in alpha1, alpha3, alpha5 subunits of nicotinic acetylcholine receptors (N-AChR) of a variety of species. It has previously been claimed that N-AChR-like immunoreactivity (-LI) identified by mab35 is present in vasopressin-containing magnocellular neurons. However, we show here by double immunofluorescence labelling that mab35 immunoreactivity is predominantly localized to oxytocinergic rather than vasopressinergic magnocellular neurons. We further infer that mab35 predominantly stained the alpha3 and/or alpha5 subunits in rat oxytocinergic neurons, and suggest that the unbalanced distribution of these subunits may contribute to some specific physiological properties of oxytocinergic neurons.
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Affiliation(s)
- Liang Jin
- Department of Neurology, Tang Du Hospital, Fourth Military Medical University, Chang Le West Street 17, Xi'an 710032, China.
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22
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Brown CH, Bull PM, Bourque CW. Phasic bursts in rat magnocellular neurosecretory cells are not intrinsically regenerative in vivo. Eur J Neurosci 2004; 19:2977-83. [PMID: 15182304 DOI: 10.1111/j.0953-816x.2004.03408.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Vasopressinergic hypothalamic magnocellular neurosecretory cells fire in phasic bursts. Burst initiation involves summation of postsynaptic potentials to generate action potentials. Action potentials are each followed by a nonsynaptic depolarizing after-potential that summates temporally to generate a plateau potential and so sustain activity throughout the burst. It is unknown whether this plateau potential exceeds spike threshold in vivo to cause intrinsic regenerative firing or simply approaches threshold to increase the probability that excitatory postsynaptic potentials will trigger further action potentials. Here we show that pharmacological blockade of ionotropic glutamatergic transmission by microdialysis application of kynurenic acid into the supraoptic nucleus of anaesthetized rats prevents spontaneous bursts and bursts (after-discharge) evoked by short trains of antidromically stimulated action potentials in magnocellular neurosecretory cells. Even during prolonged depolarization induced by 1 m NaCl infusion, kynurenic acid microdialysis application still blocked after-discharge. The ability of kynurenic acid to block after-discharge during osmotic stimulation was not caused by an unmasking of inhibitory postsynaptic potentials as kynurenic acid was equally effective in the presence of the ionotropic gamma-aminobutyric acid receptor antagonist, bicuculline, nor did it result from inhibition of plateau potential amplitude as this was unaffected by kynurenic acid and bicuculline in vitro, as was after-discharge evoked in vitro. We conclude that phasic bursts are nonregenerative in vivo but rather require continued excitatory synaptic input activity superimposed upon a subthreshold plateau potential to sustain burst activity.
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Affiliation(s)
- Colin H Brown
- School of Biomedical and Clinical Laboratory Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland, UK.
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23
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Hogg RC, Raggenbass M, Bertrand D. Nicotinic acetylcholine receptors: from structure to brain function. Rev Physiol Biochem Pharmacol 2003; 147:1-46. [PMID: 12783266 DOI: 10.1007/s10254-003-0005-1] [Citation(s) in RCA: 365] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels and can be divided into two groups: muscle receptors, which are found at the skeletal neuromuscular junction where they mediate neuromuscular transmission, and neuronal receptors, which are found throughout the peripheral and central nervous system where they are involved in fast synaptic transmission. nAChRs are pentameric structures that are made up of combinations of individual subunits. Twelve neuronal nAChR subunits have been described, alpha2-alpha10 and beta2-beta4; these are differentially expressed throughout the nervous system and combine to form nAChRs with a wide range of physiological and pharmacological profiles. The nAChR has been proposed as a model of an allosteric protein in which effects arising from the binding of a ligand to a site on the protein can lead to changes in another part of the molecule. A great deal is known about the structure of the pentameric receptor. The extracellular domain contains binding sites for numerous ligands, which alter receptor behavior through allosteric mechanisms. Functional studies have revealed that nAChRs contribute to the control of resting membrane potential, modulation of synaptic transmission and mediation of fast excitatory transmission. To date, ten genes have been identified in the human genome coding for the nAChRs. nAChRs have been demonstrated to be involved in cognitive processes such as learning and memory and control of movement in normal subjects. Recent data from knockout animals has extended the understanding of nAChR function. Dysfunction of nAChR has been linked to a number of human diseases such as schizophrenia, Alzheimer's and Parkinson's diseases. nAChRs also play a significant role in nicotine addiction, which is a major public health concern. A genetically transmissible epilepsy, ADNFLE, has been associated with specific mutations in the gene coding for the alpha4 or beta2 subunits, which leads to altered receptor properties.
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Affiliation(s)
- R C Hogg
- Department of Physiology, CMU, 1 rue Michel Servet, 1211 Geneva 4, Switzerland.
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Brierley MJ, Ashworth AJ, Craven TP, Woodburn M, Banks JR, Lu W, Riccardi D, Balment RJ, McCrohan CR. Electrical activity of caudal neurosecretory neurons in seawater- and freshwater-adapted flounder: responses to cholinergic agonists. J Exp Biol 2003; 206:4011-20. [PMID: 14555741 DOI: 10.1242/jeb.00631] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
The caudal neurosecretory system (CNSS) of the euryhaline flounder is involved in osmoregulatory responses underlying adaptation to seawater and freshwater. This study compared electrophysiological activity and responses to cholinergic agonists in the neuroendocrine Dahlgren cells in an in vitro preparation taken from fully seawater- (SWA) or freshwater-adapted(FWA) fish. Resting membrane and action potential parameters showed few differences between SWA and FWA cells. The hyperpolarisation-activated sag potential and depolarising afterpotential were present under both conditions;however, amplitude of the latter was significantly greater in SWA cells. The proportions of cells within the population exhibiting different firing patterns were similar in both adaptation states. However, bursting parameters were more variable in FWA cells, suggesting that bursting activity was less robust. The muscarinic agonist, oxotremorine, was largely inhibitory in Dahlgren cells, but increased activity in a non-Dahlgren cell population,α neurons. Nicotine promoted bursting activity in SWA Dahlgren cells,whereas it inhibited over half of FWA cells.
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Affiliation(s)
- M J Brierley
- School of Biological Sciences, University of Manchester, Manchester M13 9PT, UK
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