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Ranglani S, Hasan S, Komorowska J, Medina NM, Mahfooz K, Ashton A, Garcia-Ratés S, Greenfield S. A Novel Peptide Driving Neurodegeneration Appears Exclusively Linked to the α7 Nicotinic Acetylcholine Receptor. Mol Neurobiol 2024; 61:8206-8218. [PMID: 38483654 DOI: 10.1007/s12035-024-04079-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 02/28/2024] [Indexed: 09/21/2024]
Abstract
T14, a 14mer peptide, is significantly increased in the pre-symptomatic Alzheimer's disease brain, and growing evidence implies its pivotal role in neurodegeneration. Here, we explore the subsequent intracellular events following binding of T14 to its target α7 nicotinic acetylcholine receptor (nAChR). Specifically, we test how various experimental manipulations of PC12 cells impact T14-induced functional outcomes. Three preparations were compared: (i) undifferentiated vs. NGF-differentiated cells; (ii) cells transfected with an overexpression of the target α7 nAChR vs. wild type cells; (iii) cells transfected with a mutant α7 nAChR containing a mutation in the G protein-binding cluster, vs. cells transfected with an overexpression of the target α7 nAChR, in three functional assays - calcium influx, cell viability, and acetylcholinesterase release. NGF-differentiated PC12 cells were less sensitive than undifferentiated cells to the concentration-dependent T14 treatment, in all the functional assays performed. The overexpression of α7 nAChR in PC12 cells promoted enhanced calcium influx when compared with the wild type PC12 cells. The α7345-348 A mutation effectively abolished the T14-triggered responses across all the readouts observed. The close relationship between T14 and the α7 nAChR was further evidenced in the more physiological preparation of ex vivo rat brain, where T30 increased α7 nAChR mRNA, and finally in human brain post-mortem, where levels of T14 and α7 nAChR exhibited a strong correlation, reflecting the progression of neurodegeneration. Taken together these data would make it hard to account for T14 binding to any other receptor, and thus interception at this binding site would make a very attractive and remarkably specific therapeutic strategy.
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Affiliation(s)
- Sanskar Ranglani
- Culham Science Centre, Neuro-Bio Ltd, Building F5, Abingdon, OX14 3DB, UK
| | - Sibah Hasan
- Culham Science Centre, Neuro-Bio Ltd, Building F5, Abingdon, OX14 3DB, UK.
| | - Joanna Komorowska
- Culham Science Centre, Neuro-Bio Ltd, Building F5, Abingdon, OX14 3DB, UK
| | | | - Kashif Mahfooz
- Culham Science Centre, Neuro-Bio Ltd, Building F5, Abingdon, OX14 3DB, UK
| | - Anna Ashton
- Culham Science Centre, Neuro-Bio Ltd, Building F5, Abingdon, OX14 3DB, UK
| | - Sara Garcia-Ratés
- Culham Science Centre, Neuro-Bio Ltd, Building F5, Abingdon, OX14 3DB, UK
| | - Susan Greenfield
- Culham Science Centre, Neuro-Bio Ltd, Building F5, Abingdon, OX14 3DB, UK
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2
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Thomson K, Karouta C, Ashby R. Administration of Nicotine Can Inhibit Myopic Growth in Animal Models. Invest Ophthalmol Vis Sci 2024; 65:29. [PMID: 39292451 PMCID: PMC11412605 DOI: 10.1167/iovs.65.11.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2024] Open
Abstract
Purpose While previously investigating the mechanism by which atropine inhibits ocular growth, we observed that stimulation of nicotinic receptors can inhibit experimental myopia. This study expands on that preliminary finding and investigates the safety and efficacy of nicotinic stimulation in the inhibition of ocular growth. Methods Nicotine's ability to inhibit form-deprivation myopia (FDM), following intravitreal injection (9 chicks per group) or topical application (6 chicks per group), was investigated over three doses. The ability of nicotine to inhibit lens-induced myopia (LIM) was also tested (in 12 chicks). For ocular safety, following 4 weeks of topical treatment with nicotine (n = 10), pupillary reflex, intraocular pressure, corneal curvature/thickness, lens thickness, retinal health (retinal thickness/cell apoptosis), as well as retinal function (electroretinogram recordings) were assessed. We also examined the effects of nicotine on non-ocular autonomic functions in both chicks (n = 5) and mice (n = 5). Results Nicotine was observed to significantly inhibit the development of FDM in chicks when administered as an intravitreal injection (P < 0.05) or topical eye drops (P < 0.05), albeit not in a dose-dependent manner. Nicotine also inhibited LIM (P < 0.05) to a similar degree to that seen for FDM. Although ocular health was (for the most part) unaffected by nicotine, the highest topical dose induced a temporary reduction in cardiorespiratory output (P < 0.05). Conclusions Nicotine, administered as an intravitreal injection or topical eye drop, significantly inhibits the development of experimental myopia. Although the anti-myopic effects observed presently are interesting, the well-reported side effects (expanded on presently) and addictive properties of nicotine would preclude its clinical use.
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Affiliation(s)
- Kate Thomson
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Bruce, Canberra, Australia
| | - Cindy Karouta
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Bruce, Canberra, Australia
| | - Regan Ashby
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Bruce, Canberra, Australia
- Research School of Biology, Australian National University, Acton, Australia
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3
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Collier CA, Salikhova A, Sabir S, Foncerrada S, Raghavan SA. Crisis in the gut: navigating gastrointestinal challenges in Gulf War Illness with bioengineering. Mil Med Res 2024; 11:45. [PMID: 38978144 PMCID: PMC11229309 DOI: 10.1186/s40779-024-00547-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 06/26/2024] [Indexed: 07/10/2024] Open
Abstract
Gulf War Illness (GWI) is characterized by a wide range of symptoms that manifests largely as gastrointestinal symptoms. Among these gastrointestinal symptoms, motility disorders are highly prevalent, presenting as chronic constipation, stomach pain, indigestion, diarrhea, and other conditions that severely impact the quality of life of GWI veterans. However, despite a high prevalence of gastrointestinal impairments among these veterans, most research attention has focused on neurological disturbances. This perspective provides a comprehensive overview of current in vivo research advancements elucidating the underlying mechanisms contributing to gastrointestinal disorders in GWI. Generally, these in vivo and in vitro models propose that neuroinflammation alters gut motility and drives the gastrointestinal symptoms reported in GWI. Additionally, this perspective highlights the potential and challenges of in vitro bioengineering models, which could be a crucial contributor to understanding and treating the pathology of gastrointestinal related-GWI.
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Affiliation(s)
- Claudia A Collier
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Aelita Salikhova
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Sufiyan Sabir
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Steven Foncerrada
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Shreya A Raghavan
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA.
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4
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Namba K, Tominaga T, Ishihara Y. Decreases in the number of microglia and neural circuit dysfunction elicited by developmental exposure to neonicotinoid pesticides in mice. ENVIRONMENTAL TOXICOLOGY 2024; 39:3944-3955. [PMID: 38581179 DOI: 10.1002/tox.24263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 03/09/2024] [Accepted: 03/23/2024] [Indexed: 04/08/2024]
Abstract
Neonicotinoids are insecticides widely used in the world. Although neonicotinoids are believed to be toxic only to insects, their developmental neurotoxicity in mammals is a concern. Therefore, we examined the effects of developmental exposure to neonicotinoids on immune system in the brain and post-developmental behaviors in this study. Imidacloprid or clothianidin was orally administered to dams at a dosage of 0.1 mg/kg/day from embryonic day 11 to postnatal day 21. Imidacloprid decreased sociability, and both imidacloprid and clothianidin decreased locomotor activity and induced anxiety, depression and abnormal repetitive behaviors after the developmental period. There was no change in the number of neurons in the hippocampus of mice exposed to imidacloprid. However, the number and activity of microglia during development were significantly decreased by imidacloprid exposure. Imidacloprid also induced neural circuit dysfunction in the CA1 and CA3 regions of the hippocampus during the early postnatal period. Exposure to imidacloprid suppressed the expression of csf1r during development. Collectively, these results suggest that developmental exposure to imidacloprid decreases the number and activity of microglia, which can cause neural circuit dysfunction and abnormal behaviors after the developmental period. Care must be taken to avoid exposure to neonicotinoids, especially during development.
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Affiliation(s)
- Kaede Namba
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Takashi Tominaga
- Institute of Neuroscience, Tokushima Bunri University, Sanuki, Japan
| | - Yasuhiro Ishihara
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
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5
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Ye Q, Nunez J, Zhang X. Multiple cholinergic receptor subtypes coordinate dual modulation of acetylcholine on anterior and posterior paraventricular thalamic neurons. J Neurochem 2024; 168:995-1018. [PMID: 38664195 PMCID: PMC11136594 DOI: 10.1111/jnc.16115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 03/31/2024] [Accepted: 04/05/2024] [Indexed: 05/31/2024]
Abstract
Paraventricular thalamus (PVT) plays important roles in the regulation of emotion and motivation through connecting many brain structures including the midbrain and the limbic system. Although acetylcholine (ACh) neurons of the midbrain were reported to send projections to PVT, little is known about how cholinergic signaling regulates PVT neurons. Here, we used both RNAscope and slice patch-clamp recordings to characterize cholinergic receptor expression and ACh modulation of PVT neurons in mice. We found ACh excited a majority of anterior PVT (aPVT) neurons but predominantly inhibited posterior PVT (pPVT) neurons. Compared to pPVT with more inhibitory M2 receptors, aPVT expressed higher levels of all excitatory receptor subtypes including nicotinic α4, α7, and muscarinic M1 and M3. The ACh-induced excitation was mimicked by nicotine and antagonized by selective blockers for α4β2 and α7 nicotinic ACh receptor (nAChR) subtypes as well as selective antagonists for M1 and M3 muscarinic ACh receptors (mAChR). The ACh-induced inhibition was attenuated by selective M2 and M4 mAChR receptor antagonists. Furthermore, we found ACh increased the frequency of excitatory postsynaptic currents (EPSCs) on a majority of aPVT neurons but decreased EPSC frequency on a larger number of pPVT neurons. In addition, ACh caused an acute increase followed by a lasting reduction in inhibitory postsynaptic currents (IPSCs) on PVT neurons of both subregions. Together, these data suggest that multiple AChR subtypes coordinate a differential modulation of ACh on aPVT and pPVT neurons.
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Affiliation(s)
- Qiying Ye
- Department of Psychology, Florida State University, Tallahassee, Florida, USA
| | - Jeremiah Nunez
- Department of Psychology, Florida State University, Tallahassee, Florida, USA
| | - Xiaobing Zhang
- Department of Psychology, Florida State University, Tallahassee, Florida, USA
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6
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Burke SM, Avstrikova M, Noviello CM, Mukhtasimova N, Changeux JP, Thakur GA, Sine SM, Cecchini M, Hibbs RE. Structural mechanisms of α7 nicotinic receptor allosteric modulation and activation. Cell 2024; 187:1160-1176.e21. [PMID: 38382524 PMCID: PMC10950261 DOI: 10.1016/j.cell.2024.01.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/05/2023] [Accepted: 01/22/2024] [Indexed: 02/23/2024]
Abstract
The α7 nicotinic acetylcholine receptor is a pentameric ligand-gated ion channel that plays an important role in cholinergic signaling throughout the nervous system. Its unique physiological characteristics and implications in neurological disorders and inflammation make it a promising but challenging therapeutic target. Positive allosteric modulators overcome limitations of traditional α7 agonists, but their potentiation mechanisms remain unclear. Here, we present high-resolution structures of α7-modulator complexes, revealing partially overlapping binding sites but varying conformational states. Structure-guided functional and computational tests suggest that differences in modulator activity arise from the stable rotation of a channel gating residue out of the pore. We extend the study using a time-resolved cryoelectron microscopy (cryo-EM) approach to reveal asymmetric state transitions for this homomeric channel and also find that a modulator with allosteric agonist activity exploits a distinct channel-gating mechanism. These results define mechanisms of α7 allosteric modulation and activation with implications across the pentameric receptor superfamily.
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Affiliation(s)
- Sean M Burke
- Molecular Biophysics Graduate Program, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mariia Avstrikova
- Institut de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, 67081 Strasbourg Cedex, France
| | - Colleen M Noviello
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nuriya Mukhtasimova
- Receptor Biology Laboratory, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55902, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55902, USA
| | - Jean-Pierre Changeux
- Neuroscience Department, Institut Pasteur, Collège de France, 75015 Paris, France
| | - Ganesh A Thakur
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Steven M Sine
- Receptor Biology Laboratory, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55902, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55902, USA; Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN 55902, USA.
| | - Marco Cecchini
- Institut de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, 67081 Strasbourg Cedex, France.
| | - Ryan E Hibbs
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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7
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Borkar NA, Thompson MA, Bartman CM, Khalfaoui L, Sine S, Sathish V, Prakash YS, Pabelick CM. Nicotinic receptors in airway disease. Am J Physiol Lung Cell Mol Physiol 2024; 326:L149-L163. [PMID: 38084408 PMCID: PMC11280694 DOI: 10.1152/ajplung.00268.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/27/2023] [Accepted: 11/30/2023] [Indexed: 01/26/2024] Open
Abstract
With continued smoking of tobacco products and expanded use of nicotine delivery devices worldwide, understanding the impact of smoking and vaping on respiratory health remains a major global unmet need. Although multiple studies have shown a strong association between smoking and asthma, there is a relative paucity of mechanistic understanding of how elements in cigarette smoke impact the airway. Recognizing that nicotine is a major component in both smoking and vaping products, it is critical to understand the mechanisms by which nicotine impacts airways and promotes lung diseases such as asthma. There is now increasing evidence that α7 nicotinic acetylcholine receptors (α7nAChRs) are critical players in nicotine effects on airways, but the mechanisms by which α7nAChR influences different airway cell types have not been widely explored. In this review, we highlight and integrate the current state of knowledge regarding nicotine and α7nAChR in the context of asthma and identify potential approaches to alleviate the impact of smoking and vaping on the lungs.
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Affiliation(s)
- Niyati A Borkar
- Department of Anesthesiology and Perioperative Medicine, North Dakota State University, Fargo, North Dakota, United States
| | - Michael A Thompson
- Department of Anesthesiology and Perioperative Medicine, North Dakota State University, Fargo, North Dakota, United States
| | - Colleen M Bartman
- Department of Anesthesiology and Perioperative Medicine, North Dakota State University, Fargo, North Dakota, United States
| | - Latifa Khalfaoui
- Department of Anesthesiology and Perioperative Medicine, North Dakota State University, Fargo, North Dakota, United States
| | - Steven Sine
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States
| | - Venkatachalem Sathish
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota, United States
| | - Y S Prakash
- Department of Anesthesiology and Perioperative Medicine, North Dakota State University, Fargo, North Dakota, United States
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States
| | - Christina M Pabelick
- Department of Anesthesiology and Perioperative Medicine, North Dakota State University, Fargo, North Dakota, United States
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States
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8
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Aroniadou-Anderjaska V, Figueiredo TH, de Araujo Furtado M, Pidoplichko VI, Braga MFM. Mechanisms of Organophosphate Toxicity and the Role of Acetylcholinesterase Inhibition. TOXICS 2023; 11:866. [PMID: 37888716 PMCID: PMC10611379 DOI: 10.3390/toxics11100866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 10/11/2023] [Accepted: 10/17/2023] [Indexed: 10/28/2023]
Abstract
Organophosphorus compounds (OPs) have applications in agriculture (e.g., pesticides), industry (e.g., flame retardants), and chemical warfare (nerve agents). In high doses or chronic exposure, they can be toxic or lethal. The primary mechanism, common among all OPs, that initiates their toxic effects is the inhibition of acetylcholinesterase. In acute OP exposure, the subsequent surge of acetylcholine in cholinergic synapses causes a peripheral cholinergic crisis and status epilepticus (SE), either of which can lead to death. If death is averted without effective seizure control, long-term brain damage ensues. This review describes the mechanisms by which elevated acetylcholine can cause respiratory failure and trigger SE; the role of the amygdala in seizure initiation; the role of M1 muscarinic receptors in the early stages of SE; the neurotoxic pathways activated by SE (excitotoxicity/Ca++ overload/oxidative stress, neuroinflammation); and neurotoxic mechanisms linked to low-dose, chronic exposure (Ca++ dyshomeostasis/oxidative stress, inflammation), which do not depend on SE and do not necessarily involve acetylcholinesterase inhibition. The evidence so far indicates that brain damage from acute OP exposure is a direct result of SE, while the neurotoxic mechanisms activated by low-dose chronic exposure are independent of SE and may not be associated with acetylcholinesterase inhibition.
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Affiliation(s)
- Vassiliki Aroniadou-Anderjaska
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (V.A.-A.); (V.I.P.)
- Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Taiza H. Figueiredo
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (V.A.-A.); (V.I.P.)
| | - Marcio de Araujo Furtado
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (V.A.-A.); (V.I.P.)
| | - Volodymyr I. Pidoplichko
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (V.A.-A.); (V.I.P.)
| | - Maria F. M. Braga
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (V.A.-A.); (V.I.P.)
- Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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9
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Krok AC, Maltese M, Mistry P, Miao X, Li Y, Tritsch NX. Intrinsic dopamine and acetylcholine dynamics in the striatum of mice. Nature 2023; 621:543-549. [PMID: 37558873 DOI: 10.1038/s41586-023-05995-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 03/22/2023] [Indexed: 08/11/2023]
Abstract
External rewards such as food and money are potent modifiers of behaviour1,2. Pioneering studies established that these salient sensory stimuli briefly interrupt the tonic discharge of neurons that produce the neuromodulators dopamine (DA) and acetylcholine (ACh): midbrain DA neurons (DANs) fire a burst of action potentials that broadly elevates DA in the striatum3,4 at the same time that striatal cholinergic interneurons (CINs) produce a characteristic pause in firing5,6. These phasic responses are thought to create unique, temporally limited conditions that motivate action and promote learning7-11. However, the dynamics of DA and ACh outside explicitly rewarded situations remain poorly understood. Here we show that extracellular DA and ACh levels fluctuate spontaneously and periodically at a frequency of approximately 2 Hz in the dorsal striatum of mice and maintain the same temporal relationship relative to one another as that evoked by reward. We show that this neuromodulatory coordination does not arise from direct interactions between DA and ACh within the striatum. Instead, we provide evidence that periodic fluctuations in striatal DA are inherited from midbrain DANs, while striatal ACh transients are driven by glutamatergic inputs, which act to locally synchronize the spiking of CINs. Together, our findings show that striatal neuromodulatory dynamics are autonomously organized by distributed extra-striatal afferents. The dominance of intrinsic rhythms in DA and ACh offers new insights for explaining how reward-associated neural dynamics emerge and how the brain motivates action and promotes learning from within.
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Affiliation(s)
- Anne C Krok
- Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
- Fresco Institute for Parkinson's and Movement Disorders, New York University Langone Health, New York, NY, USA
| | - Marta Maltese
- Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
- Fresco Institute for Parkinson's and Movement Disorders, New York University Langone Health, New York, NY, USA
| | - Pratik Mistry
- Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
- Fresco Institute for Parkinson's and Movement Disorders, New York University Langone Health, New York, NY, USA
| | - Xiaolei Miao
- Department of Anesthesiology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - Nicolas X Tritsch
- Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA.
- Fresco Institute for Parkinson's and Movement Disorders, New York University Langone Health, New York, NY, USA.
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10
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Soplata AE, Adam E, Brown EN, Purdon PL, McCarthy MM, Kopell N. Rapid thalamocortical network switching mediated by cortical synchronization underlies propofol-induced EEG signatures: a biophysical model. J Neurophysiol 2023; 130:86-103. [PMID: 37314079 PMCID: PMC10312318 DOI: 10.1152/jn.00068.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/08/2023] [Accepted: 06/08/2023] [Indexed: 06/15/2023] Open
Abstract
Propofol-mediated unconsciousness elicits strong alpha/low-beta and slow oscillations in the electroencephalogram (EEG) of patients. As anesthetic dose increases, the EEG signal changes in ways that give clues to the level of unconsciousness; the network mechanisms of these changes are only partially understood. Here, we construct a biophysical thalamocortical network involving brain stem influences that reproduces transitions in dynamics seen in the EEG involving the evolution of the power and frequency of alpha/low-beta and slow rhythm, as well as their interactions. Our model suggests that propofol engages thalamic spindle and cortical sleep mechanisms to elicit persistent alpha/low-beta and slow rhythms, respectively. The thalamocortical network fluctuates between two mutually exclusive states on the timescale of seconds. One state is characterized by continuous alpha/low-beta-frequency spiking in thalamus (C-state), whereas in the other, thalamic alpha spiking is interrupted by periods of co-occurring thalamic and cortical silence (I-state). In the I-state, alpha colocalizes to the peak of the slow oscillation; in the C-state, there is a variable relationship between an alpha/beta rhythm and the slow oscillation. The C-state predominates near loss of consciousness; with increasing dose, the proportion of time spent in the I-state increases, recapitulating EEG phenomenology. Cortical synchrony drives the switch to the I-state by changing the nature of the thalamocortical feedback. Brain stem influence on the strength of thalamocortical feedback mediates the amount of cortical synchrony. Our model implicates loss of low-beta, cortical synchrony, and coordinated thalamocortical silent periods as contributing to the unconscious state.NEW & NOTEWORTHY GABAergic anesthetics induce alpha/low-beta and slow oscillations in the EEG, which interact in dose-dependent ways. We constructed a thalamocortical model to investigate how these interdependent oscillations change with propofol dose. We find two dynamic states of thalamocortical coordination, which change on the timescale of seconds and dose-dependently mirror known changes in EEG. Thalamocortical feedback determines the oscillatory coupling and power seen in each state, and this is primarily driven by cortical synchrony and brain stem neuromodulation.
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Affiliation(s)
- Austin E Soplata
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts, United States
| | - Elie Adam
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | - Emery N Brown
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | - Patrick L Purdon
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Michelle M McCarthy
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts, United States
| | - Nancy Kopell
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts, United States
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11
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Mohebi A, Collins VL, Berke JD. Accumbens cholinergic interneurons dynamically promote dopamine release and enable motivation. eLife 2023; 12:e85011. [PMID: 37272423 PMCID: PMC10259987 DOI: 10.7554/elife.85011] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 05/30/2023] [Indexed: 06/06/2023] Open
Abstract
Motivation to work for potential rewards is critically dependent on dopamine (DA) in the nucleus accumbens (NAc). DA release from NAc axons can be controlled by at least two distinct mechanisms: (1) action potentials propagating from DA cell bodies in the ventral tegmental area (VTA), and (2) activation of β2* nicotinic receptors by local cholinergic interneurons (CINs). How CIN activity contributes to NAc DA dynamics in behaving animals is not well understood. We monitored DA release in the NAc Core of awake, unrestrained rats using the DA sensor RdLight1, while simultaneously monitoring or manipulating CIN activity at the same location. CIN stimulation rapidly evoked DA release, and in contrast to slice preparations, this DA release showed no indication of short-term depression or receptor desensitization. The sound of unexpected food delivery evoked a brief joint increase in CIN population activity and DA release, with a second joint increase as rats approached the food. In an operant task, we observed fast ramps in CIN activity during approach behaviors, either to start the trial or to collect rewards. These CIN ramps co-occurred with DA release ramps, without corresponding changes in the firing of lateral VTA DA neurons. Finally, we examined the effects of blocking CIN influence over DA release through local NAc infusion of DHβE, a selective antagonist of β2* nicotinic receptors. DHβE dose-dependently interfered with motivated approach decisions, mimicking the effects of a DA antagonist. Our results support a key influence of CINs over motivated behavior via the local regulation of DA release.
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Affiliation(s)
- Ali Mohebi
- Department of Neurology, University of California, San FranciscoSan FranciscoUnited States
| | - Val L Collins
- Department of Neurology, University of California, San FranciscoSan FranciscoUnited States
| | - Joshua D Berke
- Department of Neurology, University of California, San FranciscoSan FranciscoUnited States
- Department of Psychiatry and Behavioral Sciences, University of California, San FranciscoSan FranciscoUnited States
- Neuroscience Graduate Program, University of California, San FranciscoSan FranciscoUnited States
- Weill Institute for Neurosciences, University of California, San FranciscoSan FranciscoUnited States
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12
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Chrestia JF, Turani O, Araujo NR, Hernando G, Esandi MDC, Bouzat C. Regulation of nicotinic acetylcholine receptors by post-translational modifications. Pharmacol Res 2023; 190:106712. [PMID: 36863428 DOI: 10.1016/j.phrs.2023.106712] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/21/2023] [Accepted: 02/24/2023] [Indexed: 03/04/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) comprise a family of pentameric ligand-gated ion channels widely distributed in the central and peripheric nervous system and in non-neuronal cells. nAChRs are involved in chemical synapses and are key actors in vital physiological processes throughout the animal kingdom. They mediate skeletal muscle contraction, autonomic responses, contribute to cognitive processes, and regulate behaviors. Dysregulation of nAChRs is associated with neurological, neurodegenerative, inflammatory and motor disorders. In spite of the great advances in the elucidation of nAChR structure and function, our knowledge about the impact of post-translational modifications (PTMs) on nAChR functional activity and cholinergic signaling has lagged behind. PTMs occur at different steps of protein life cycle, modulating in time and space protein folding, localization, function, and protein-protein interactions, and allow fine-tuned responses to changes in the environment. A large body of evidence demonstrates that PTMs regulate all levels of nAChR life cycle, with key roles in receptor expression, membrane stability and function. However, our knowledge is still limited, restricted to a few PTMs, and many important aspects remain largely unknown. There is thus a long way to go to decipher the association of aberrant PTMs with disorders of cholinergic signaling and to target PTM regulation for novel therapeutic interventions. In this review we provide a comprehensive overview of what is known about how different PTMs regulate nAChR.
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Affiliation(s)
- Juan Facundo Chrestia
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Ornella Turani
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Noelia Rodriguez Araujo
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Guillermina Hernando
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - María Del Carmen Esandi
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Cecilia Bouzat
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina.
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13
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Papke RL, Stokes C. Insights Into the Differential Desensitization of α4 β2 Nicotinic Acetylcholine Receptor Isoforms Obtained With Positive Allosteric Modulation of Mutant Receptors. Mol Pharmacol 2023; 103:63-76. [PMID: 36414373 PMCID: PMC9881010 DOI: 10.1124/molpharm.122.000591] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/25/2022] [Accepted: 11/03/2022] [Indexed: 11/23/2022] Open
Abstract
The development of highly efficacious positive allosteric modulators (PAMs) of α7 nicotinic acetylcholine receptors (nAChR) has proven useful in defining the ligand dependence of the conformational dynamics of α7 receptors. No such effective modulators are known to exist for the α4β2 nAChR of the brain, limiting our ability to understand the importance of desensitization for the activity profile of specific ligands. In this study, we used mutant β2 subunits that allowed the use of the α7 PAM 3a,4,5,9b-tetrahydro-4-(1-naphthalenyl)-3H-cyclopentan[c]quinoline-8-sulfonamide (TQS) to probe the desensitizing effects of nicotinic ligands on the two forms of α4β2 receptors; high sensitivity (HS) (two α4 and three β2 subunits) and low sensitivity (LS) (three α4 and two β2 subunits). A total of 28 different ligands of 8 different categories, based on activity and selectivity, were tested for their ability to induce TQS-sensitive desensitization of HS and LS α4β2 receptors. Results confirm that HS α4β2 receptor responses are strongly limited by desensitization, by at least an order of magnitude more so than the responses of LS receptors. The activation of α4β2 receptors by the smoking-cessation drugs cytisine and varenicline is strongly limited by desensitization, as is the activation of LS receptors by the HS-selective agonists 6-[5-[(2S)-2-Azetidinylmethoxy]-3-pyridinyl]-5-hexyn-1-ol dihydrochloride and 4-(5-ethoxy-3-pyridinyl)-N-methyl-(3E)-3-buten-1-amine difumarate. The evaluation of drugs previously identified as α7-selective agonists revealed varying patterns of α4β2 cross-desensitization that were predictive of the effects of these drugs on the activation of wild-type α4β2 receptors by acetylcholine, supporting the utility of TQS-sensitive receptors for the development of focused therapeutics. SIGNIFICANCE STATEMENT: To varying degrees, ligands regulate the balance of active and desensitized states of the two forms of the primary nAChR subtypes in brain. Using mutant beta subunits, an allosteric modulator can reverse ligand-induced desensitization, revealing the differential desensitization of the receptors by specific ligands. This study shows that drugs believed to be selective for therapeutic targets may cross-desensitize other targets and that, within a class of drugs, improved specificity can be achieved by using agents that reduce such cross-desensitization.
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Affiliation(s)
- Roger L Papke
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida
| | - Clare Stokes
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida
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14
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Hasan S, Ahmed M, Garcia-Ratés S, Greenfield S. Antagonising a novel toxin "T14" in Alzheimer's disease: Comparison of receptor blocker versus antibody effects in vitro. Biomed Pharmacother 2023; 158:114120. [PMID: 36521245 DOI: 10.1016/j.biopha.2022.114120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
A 14mer peptide, T14, is a possible signaling molecule driving neurodegeneration. Its levels are doubled in the Alzheimer brain, but its effects can be blocked at the target alpha-7 receptor by a cyclised variant, 'NBP14', which has beneficial effects, in a transgenic mouse model, on the behavioral and histochemical profile. Since the antagonism of T14 has evident therapeutic potential, we explore here an alternative method of preventing its action by comparing the efficacy of NBP14 with a proprietorial polyclonal antibody against T14, 'Ab-19', at inhibiting three distinct effects of the peptide in PC12 cells: calcium influx, cell viability and compensatory acetylcholinesterase (AChE) release. None of these three parameters was affected by either blocking agent when applied alone. However, both NBP14 and the Ab-19 exhibited a dose-dependent profile against the actions of T14 in all three scenarios: the least sensitive effect observed was in the lower dose range, for both the antibody and the receptor blocker, in antagonizing T14-triggered release of AChE: this parameter is interpreted as indirect compensation for the T14-induced compromise of cell viability, triggered by the enhanced influx of calcium through the initial binding of the peptide to an allosteric site on the alpha-7 receptor. As such, it is the most delayed and indirect index of T14 action and thus the least relatively impacted by lowest doses of either NBP14 or Ab-19. In all three scenarios however the effects of T14 are successfully offset by either agent and thus offer two potentially very different therapies against Alzheimer's disease.
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Affiliation(s)
- Sibah Hasan
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Abingdon OX14 3DB, UK.
| | - Mehreen Ahmed
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Sara Garcia-Ratés
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Susan Greenfield
- Neuro-Bio Ltd, Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
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15
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Tryon SC, Bratsch-Prince JX, Warren JW, Jones GC, McDonald AJ, Mott DD. Differential Regulation of Prelimbic and Thalamic Transmission to the Basolateral Amygdala by Acetylcholine Receptors. J Neurosci 2023; 43:722-735. [PMID: 36535767 PMCID: PMC9899087 DOI: 10.1523/jneurosci.2545-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
The amygdalar anterior basolateral nucleus (BLa) plays a vital role in emotional behaviors. This region receives dense cholinergic projections from basal forebrain which are critical in regulating neuronal activity in BLa. Cholinergic signaling in BLa has also been shown to modulate afferent glutamatergic inputs to this region. However, these studies, which have used cholinergic agonists or prolonged optogenetic stimulation of cholinergic fibers, may not reflect the effect of physiological acetylcholine release in the BLa. To better understand these effects of acetylcholine, we have used electrophysiology and optogenetics in male and female mouse brain slices to examine cholinergic regulation of afferent BLa input from cortex and midline thalamic nuclei. Phasic ACh release evoked by single pulse stimulation of cholinergic terminals had a biphasic effect on transmission at cortical input, producing rapid nicotinic receptor-mediated facilitation followed by slower mAChR-mediated depression. In contrast, at this same input, sustained ACh elevation through application of the cholinesterase inhibitor physostigmine suppressed glutamatergic transmission through mAChRs only. This suppression was not observed at midline thalamic nuclei inputs to BLa. In agreement with this pathway specificity, the mAChR agonist, muscarine more potently suppressed transmission at inputs from prelimbic cortex than thalamus. Muscarinic inhibition at prelimbic cortex input required presynaptic M4 mAChRs, while at thalamic input it depended on M3 mAChR-mediated stimulation of retrograde endocannabinoid signaling. Muscarinic inhibition at both pathways was frequency-dependent, allowing only high-frequency activity to pass. These findings demonstrate complex cholinergic regulation of afferent input to BLa that is pathway-specific and frequency-dependent.SIGNIFICANCE STATEMENT Cholinergic modulation of the basolateral amygdala regulates formation of emotional memories, but the underlying mechanisms are not well understood. Here, we show, using mouse brain slices, that ACh differentially regulates afferent transmission to the BLa from cortex and midline thalamic nuclei. Fast, phasic ACh release from a single optical stimulation biphasically regulates glutamatergic transmission at cortical inputs through nicotinic and muscarinic receptors, suggesting that cholinergic neuromodulation can serve precise, computational roles in the BLa. In contrast, sustained ACh elevation regulates cortical input through muscarinic receptors only. This muscarinic regulation is pathway-specific with cortical input inhibited more strongly than midline thalamic nuclei input. Specific targeting of these cholinergic receptors may thus provide a therapeutic strategy to bias amygdalar processing and regulate emotional memory.
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Affiliation(s)
- Sarah C Tryon
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Columbia, South Carolina 29208
| | - Joshua X Bratsch-Prince
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Columbia, South Carolina 29208
| | - James W Warren
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Columbia, South Carolina 29208
| | - Grace C Jones
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Columbia, South Carolina 29208
| | - Alexander J McDonald
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Columbia, South Carolina 29208
| | - David D Mott
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Columbia, South Carolina 29208
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16
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Recent Advances in the Discovery of Nicotinic Acetylcholine Receptor Allosteric Modulators. Molecules 2023; 28:molecules28031270. [PMID: 36770942 PMCID: PMC9920195 DOI: 10.3390/molecules28031270] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/18/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023] Open
Abstract
Positive allosteric modulators (PAMs), negative allosteric modulators (NAMs), silent agonists, allosteric activating PAMs and neutral or silent allosteric modulators are compounds capable of modulating the nicotinic receptor by interacting at allosteric modulatory sites distinct from the orthosteric sites. This survey is focused on the compounds that have been shown or have been designed to interact with nicotinic receptors as allosteric modulators of different subtypes, mainly α7 and α4β2. Minimal chemical changes can cause a different pharmacological profile, which can then lead to the design of selective modulators. Experimental evidence supports the use of allosteric modulators as therapeutic tools for neurological and non-neurological conditions.
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17
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Neurobiology and Mechanisms of Nicotine Addiction. Respir Med 2023. [DOI: 10.1007/978-3-031-24914-3_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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18
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Keeley RJ, Prillaman ME, Scarlata M, Vrana A, Tsai PJ, Gomez JL, Bonaventura J, Lu H, Michaelides M, Stein EA. Adolescent nicotine administration increases nicotinic acetylcholine receptor binding and functional connectivity in specific cortico-striatal-thalamic circuits. Brain Commun 2022; 4:fcac291. [PMID: 36440101 PMCID: PMC9683397 DOI: 10.1093/braincomms/fcac291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 07/05/2022] [Accepted: 11/17/2022] [Indexed: 11/28/2023] Open
Abstract
Nicotine exposure is associated with regional changes in brain nicotinic acetylcholine receptors subtype expression patterns as a function of dose and age at the time of exposure. Moreover, nicotine dependence is associated with changes in brain circuit functional connectivity, but the relationship between such connectivity and concomitant regional distribution changes in nicotinic acetylcholine receptor subtypes following nicotine exposure is not understood. Although smoking typically begins in adolescence, developmental changes in brain circuits and nicotinic acetylcholine receptors following chronic nicotine exposure remain minimally investigated. Here, we combined in vitro nicotinic acetylcholine receptor autoradiography with resting state functional magnetic resonance imaging to measure changes in [3H]nicotine binding and α4ß2 subtype nicotinic acetylcholine receptor binding and circuit connectivity across the brain in adolescent (postnatal Day 33) and adult (postnatal Day 68) rats exposed to 6 weeks of nicotine administration (0, 1.2 and 4.8 mg/kg/day). Chronic nicotine exposure increased nicotinic acetylcholine receptor levels and induced discrete, developmental stage changes in regional nicotinic acetylcholine receptor subtype distribution. These effects were most pronounced in striatal, thalamic and cortical regions when nicotine was administered during adolescence but not in adults. Using these regional receptor changes as seeds, resting state functional magnetic resonance imaging identified dysregulations in cortico-striatal-thalamic-cortical circuits that were also dysregulated following adolescent nicotine exposure. Thus, nicotine-induced increases in cortical, striatal and thalamic nicotinic acetylcholine receptors during adolescence modifies processing and brain circuits within cortico-striatal-thalamic-cortical loops, which are known to be crucial for multisensory integration, action selection and motor output, and may alter the developmental trajectory of the adolescent brain. This unique multimodal study significantly advances our understanding of nicotine dependence and its effects on the adolescent brain.
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Affiliation(s)
- Robin J Keeley
- National Institute on Drug Abuse, Intramural Research Program (NIDA-IRP), National Institutes of Health, Baltimore, MD 21224, USA
| | - McKenzie E Prillaman
- National Institute on Drug Abuse, Intramural Research Program (NIDA-IRP), National Institutes of Health, Baltimore, MD 21224, USA
| | - Miranda Scarlata
- National Institute on Drug Abuse, Intramural Research Program (NIDA-IRP), National Institutes of Health, Baltimore, MD 21224, USA
| | - Antonia Vrana
- National Institute on Drug Abuse, Intramural Research Program (NIDA-IRP), National Institutes of Health, Baltimore, MD 21224, USA
| | - Pei-Jung Tsai
- National Institute on Drug Abuse, Intramural Research Program (NIDA-IRP), National Institutes of Health, Baltimore, MD 21224, USA
| | - Juan L Gomez
- National Institute on Drug Abuse, Intramural Research Program (NIDA-IRP), National Institutes of Health, Baltimore, MD 21224, USA
| | - Jordi Bonaventura
- National Institute on Drug Abuse, Intramural Research Program (NIDA-IRP), National Institutes of Health, Baltimore, MD 21224, USA
- Departament de Patologia Terapèutica Experimental, Institut de Neurociènes, Universitat de Barcelona, Gran Via de les Corts Catalanes, 585, 08007 Barcelona, Spain
| | - Hanbing Lu
- National Institute on Drug Abuse, Intramural Research Program (NIDA-IRP), National Institutes of Health, Baltimore, MD 21224, USA
| | - Michael Michaelides
- National Institute on Drug Abuse, Intramural Research Program (NIDA-IRP), National Institutes of Health, Baltimore, MD 21224, USA
| | - Elliot A Stein
- National Institute on Drug Abuse, Intramural Research Program (NIDA-IRP), National Institutes of Health, Baltimore, MD 21224, USA
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Scharf P, Rizzetto F, Xavier LF, Farsky SHP. Xenobiotics Delivered by Electronic Nicotine Delivery Systems: Potential Cellular and Molecular Mechanisms on the Pathogenesis of Chronic Kidney Disease. Int J Mol Sci 2022; 23:10293. [PMID: 36142207 PMCID: PMC9498982 DOI: 10.3390/ijms231810293] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/01/2022] [Accepted: 09/05/2022] [Indexed: 11/20/2022] Open
Abstract
Chronic kidney disease (CKD) is characterized as sustained damage to the renal parenchyma, leading to impaired renal functions and gradually progressing to end-stage renal disease (ESRD). Diabetes mellitus (DM) and arterial hypertension (AH) are underlying diseases of CKD. Genetic background, lifestyle, and xenobiotic exposures can favor CKD onset and trigger its underlying diseases. Cigarette smoking (CS) is a known modified risk factor for CKD. Compounds from tobacco combustion act through multi-mediated mechanisms that impair renal function. Electronic nicotine delivery systems (ENDS) consumption, such as e-cigarettes and heated tobacco devices, is growing worldwide. ENDS release mainly nicotine, humectants, and flavorings, which generate several byproducts when heated, including volatile organic compounds and ultrafine particles. The toxicity assessment of these products is emerging in human and experimental studies, but data are yet incipient to achieve truthful conclusions about their safety. To build up the knowledge about the effect of currently employed ENDS on the pathogenesis of CKD, cellular and molecular mechanisms of ENDS xenobiotic on DM, AH, and kidney functions were reviewed. Unraveling the toxic mechanisms of action and endpoints of ENDS exposures will contribute to the risk assessment and implementation of proper health and regulatory interventions.
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Affiliation(s)
| | | | | | - Sandra Helena Poliselli Farsky
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of Sao Paulo, São Paulo 05508-220, Brazil
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20
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Vallés AS, Barrantes FJ. Interactions between the Nicotinic and Endocannabinoid Receptors at the Plasma Membrane. MEMBRANES 2022; 12:812. [PMID: 36005727 PMCID: PMC9414690 DOI: 10.3390/membranes12080812] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/08/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Compartmentalization, together with transbilayer and lateral asymmetries, provide the structural foundation for functional specializations at the cell surface, including the active role of the lipid microenvironment in the modulation of membrane-bound proteins. The chemical synapse, the site where neurotransmitter-coded signals are decoded by neurotransmitter receptors, adds another layer of complexity to the plasma membrane architectural intricacy, mainly due to the need to accommodate a sizeable number of molecules in a minute subcellular compartment with dimensions barely reaching the micrometer. In this review, we discuss how nature has developed suitable adjustments to accommodate different types of membrane-bound receptors and scaffolding proteins via membrane microdomains, and how this "effort-sharing" mechanism has evolved to optimize crosstalk, separation, or coupling, where/when appropriate. We focus on a fast ligand-gated neurotransmitter receptor, the nicotinic acetylcholine receptor, and a second-messenger G-protein coupled receptor, the cannabinoid receptor, as a paradigmatic example.
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Affiliation(s)
- Ana Sofía Vallés
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (UNS-CONICET), Bahía Blanca 8000, Argentina
| | - Francisco J. Barrantes
- Laboratory of Molecular Neurobiology, Institute of Biomedical Research (BIOMED), UCA-CONICET, Av. Alicia Moreau de Justo 1600, Buenos Aires C1107AFF, Argentina
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21
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Spasova V, Mehmood S, Minhas A, Azhar R, Anand S, Abdelaal S, Sham S, Chauhan TM, Dragas D. Impact of Nicotine on Cognition in Patients With Schizophrenia: A Narrative Review. Cureus 2022; 14:e24306. [PMID: 35475247 PMCID: PMC9020415 DOI: 10.7759/cureus.24306] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 04/20/2022] [Indexed: 12/24/2022] Open
Abstract
Nicotine is the psychoactive component given tobacco has several main components and acts as an agonist for nicotinic acetylcholine receptors (nAChRs) in the nervous system. Although the ligand-gated cation channels known as nAChRs are found throughout the nervous system and body, this review focuses on neuronal nAChRs. Individuals with psychiatric diseases such as schizophrenia, comorbid substance use disorders, attention-deficit hyperactivity disorder, major depression, and bipolar disorder have increased rates of smoking. These psychiatric disorders are associated with various cognitive deficits, including working memory, deficits in attention, and response inhibition functions. The cognitive-enhancing effects of nicotine may be particularly relevant predictors of smoking initiation and continuation in this comorbid population. Individuals with schizophrenia make up a significant proportion of smokers. Literature suggests that patients smoke to alleviate cognitive deficiencies due to the stimulating effects of nicotine. This narrative review examines the role of nicotine on cognition in schizophrenia.
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22
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Mechanisms of the end-plate potential noise and its implication for the neuromuscular junction anatomy. J Theor Biol 2022; 540:111089. [DOI: 10.1016/j.jtbi.2022.111089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 01/25/2022] [Accepted: 03/03/2022] [Indexed: 11/19/2022]
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23
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Risdiana N, Susilowati R, Nurwening Sholikhah E, Partadiredja G. The Effects of Erythrina subumbrans (Hassk.) Merr. Leaves Extract on Nicotine Withdrawal Syndrome and β2 nAChRs Expression in The Ventral Tegmental Area of Rats. BIO WEB OF CONFERENCES 2022. [DOI: 10.1051/bioconf/20224901002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Erythrina subumbrans (Hassk.) Merr. is an alkaloid plant with dihydro-β-erythroidine (DhβE) content which is considered to block α4β2 nAChRs subtype and, therefore, may suppress the desire to use nicotine. This study aimed to investigate these possible effects of E.subumbrans (Hassk.) Merr. extract on nicotine withdrawal syndrome and β2 nAChRs expression in rats' ventral tegmental area (VTA). The rats were divided into six groups, i.e., control (OO), nicotine treated (NO), nicotine, and E. subumbrans (Hassk.) Merr.-treated (NE 100, NE 200, NE 400), and E. subumbrans (Hassk.) Merr.-treated (OE 200) groups. Nicotine was given ad libitum via drinking water with a step-wise increase of dosage every four days for 30 days. Somatic and affective signs were observed during the dark cycle of 24 hours abstinent period (days 31and 46). The expression of β2 nAChRs in the VTA was examined semi-quantitatively. It has been found that the rearing behavior of the NE 100 group was fewer on day 46 than on day 31. The body scratching behavior of the NE 100 group was fewer than that of the OO group on day 46. The front paws and penile licking behaviors of the NE 100 group were fewer than those of the NO group on day 46. The open arm entries of the NO group were fewer than that of the NE 200 group on day 46. The β2nAChRs expression of the NO group was lower than that of the OO group. E. Subumbrans (Hassk.) Merr. at a dosage of 100mg/kg BW may decrease some somatic signs of nicotine withdrawal syndrome.
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Kawasaki H, Hino H, Takayama F, Kitamura Y, Sendou T, Takatori S. Regulatory effects of nicotine on neurite outgrowth in rat superior cervical ganglia cells. J Pharmacol Sci 2021; 148:103-107. [PMID: 34924113 DOI: 10.1016/j.jphs.2021.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/21/2021] [Accepted: 10/24/2021] [Indexed: 11/28/2022] Open
Abstract
We have reported that nicotine has a neurotrophic action on peripheral adrenergic nerves in vivo, which is mediated by α7 nicotinic acetylcholine receptors (nAChRs). To clarify the possible mechanisms, the present study further investigated the effect of nicotine on neurite outgrowth in tyrosine hydroxylase (TH)-positive superior cervical ganglia (SCG) cells isolated from neonatal rats in vitro. Nicotine at low concentrations (0.01-0.3 mM) increased the number of neurite outgrowths in TH-immunopositive SCG cells, while high concentrations of nicotine (1-10 mM) gradually reduced it, and only 10 mM nicotine was markedly inhibited compared to the control. A 100 μM of nicotine-induced increase in neurite numbers depended on the exposure time and was inhibited by treatment with the nAChR antagonist hexamethonium (Hex) and α7 nAChR antagonist α-bungarotoxin (α-Bgtx). The nicotine (10 mM)-induced a significant decrease in neurite outgrowth in SCG, which was perfectly canceled by Hex to the control level but not by α-Bgtx. These results suggest that nicotine has a regulatory neurotrophic action mediated by both α7 nAChR and other subtypes in TH-positive SCG cells of rats.
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Affiliation(s)
- Hiromu Kawasaki
- Department of Clinical Pharmacy, College of Pharmaceutical Sciences, Matsuyama University, 4-2 Bunkyo-cho, Matsuyama, Ehime 790-8578, Japan
| | - Hayato Hino
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Division of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan; Department of Pharmacy, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | - Fusako Takayama
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Division of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Yoshihisa Kitamura
- Department of Pharmacotherapy, School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-ku, Okayama 703-8516, Japan
| | - Toshiaki Sendou
- Department of Pharmacy, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | - Shingo Takatori
- Department of Clinical Pharmacy, College of Pharmaceutical Sciences, Matsuyama University, 4-2 Bunkyo-cho, Matsuyama, Ehime 790-8578, Japan.
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25
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Loser D, Grillberger K, Hinojosa MG, Blum J, Haufe Y, Danker T, Johansson Y, Möller C, Nicke A, Bennekou SH, Gardner I, Bauch C, Walker P, Forsby A, Ecker GF, Kraushaar U, Leist M. Acute effects of the imidacloprid metabolite desnitro-imidacloprid on human nACh receptors relevant for neuronal signaling. Arch Toxicol 2021; 95:3695-3716. [PMID: 34628512 PMCID: PMC8536575 DOI: 10.1007/s00204-021-03168-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 09/20/2021] [Indexed: 12/15/2022]
Abstract
Several neonicotinoids have recently been shown to activate the nicotinic acetylcholine receptor (nAChR) on human neurons. Moreover, imidacloprid (IMI) and other members of this pesticide family form a set of diverse metabolites within crops. Among these, desnitro-imidacloprid (DN-IMI) is of special toxicological interest, as there is evidence (i) for human dietary exposure to this metabolite, (ii) and that DN-IMI is a strong trigger of mammalian nicotinic responses. We set out here to quantify responses of human nAChRs to DN-IMI and an alternative metabolite, IMI-olefin. To evaluate toxicological hazards, these data were then compared to those of IMI and nicotine. Ca2+-imaging experiments on human neurons showed that DN-IMI exhibits an agonistic effect on nAChRs at sub-micromolar concentrations (equipotent with nicotine) while IMI-olefin activated the receptors less potently (in a similar range as IMI). Direct experimental data on the interaction with defined receptor subtypes were obtained by heterologous expression of various human nAChR subtypes in Xenopus laevis oocytes and measurement of the transmembrane currents evoked by exposure to putative ligands. DN-IMI acted on the physiologically important human nAChR subtypes α7, α3β4, and α4β2 (high-sensitivity variant) with similar potency as nicotine. IMI and IMI-olefin were confirmed as nAChR agonists, although with 2-3 orders of magnitude lower potency. Molecular docking studies, using receptor models for the α7 and α4β2 nAChR subtypes supported an activity of DN-IMI similar to that of nicotine. In summary, these data suggest that DN-IMI functionally affects human neurons similar to the well-established neurotoxicant nicotine by triggering α7 and several non-α7 nAChRs.
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Affiliation(s)
- Dominik Loser
- NMI Natural and Medical Sciences Institute at the University of Tübingen, 72770, Reutlingen, Germany
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457, Konstanz, Germany
| | - Karin Grillberger
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Maria G Hinojosa
- Department of Biochemistry and Biophysics, Stockholm University, 106 91, Stockholm, Sweden
| | - Jonathan Blum
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457, Konstanz, Germany
| | - Yves Haufe
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, 80336, Munich, Germany
| | - Timm Danker
- NMI Natural and Medical Sciences Institute at the University of Tübingen, 72770, Reutlingen, Germany
| | - Ylva Johansson
- Department of Biochemistry and Biophysics, Stockholm University, 106 91, Stockholm, Sweden
| | - Clemens Möller
- Life Sciences Faculty, Albstadt-Sigmaringen University, 72488, Sigmaringen, Germany
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, 80336, Munich, Germany
| | | | - Iain Gardner
- CERTARA UK Limited, Simcyp Division, Level 2-Acero, 1 Concourse Way, Sheffield, S1 2BJ, UK
| | - Caroline Bauch
- Cyprotex Discovery Ltd, No. 24 Mereside, Alderley Park, Cheshire, SK10 4TG, UK
| | - Paul Walker
- Cyprotex Discovery Ltd, No. 24 Mereside, Alderley Park, Cheshire, SK10 4TG, UK
| | - Anna Forsby
- Department of Biochemistry and Biophysics, Stockholm University, 106 91, Stockholm, Sweden
| | - Gerhard F Ecker
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Udo Kraushaar
- NMI Natural and Medical Sciences Institute at the University of Tübingen, 72770, Reutlingen, Germany
| | - Marcel Leist
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457, Konstanz, Germany.
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26
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Locomotion dependent neuron-glia interactions control neurogenesis and regeneration in the adult zebrafish spinal cord. Nat Commun 2021; 12:4857. [PMID: 34381039 PMCID: PMC8357999 DOI: 10.1038/s41467-021-25052-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 07/21/2021] [Indexed: 01/09/2023] Open
Abstract
Physical exercise stimulates adult neurogenesis, yet the underlying mechanisms remain poorly understood. A fundamental component of the innate neuroregenerative capacity of zebrafish is the proliferative and neurogenic ability of the neural stem/progenitor cells. Here, we show that in the intact spinal cord, this plasticity response can be activated by physical exercise by demonstrating that the cholinergic neurotransmission from spinal locomotor neurons activates spinal neural stem/progenitor cells, leading to neurogenesis in the adult zebrafish. We also show that GABA acts in a non-synaptic fashion to maintain neural stem/progenitor cell quiescence in the spinal cord and that training-induced activation of neurogenesis requires a reduction of GABAA receptors. Furthermore, both pharmacological stimulation of cholinergic receptors, as well as interference with GABAergic signaling, promote functional recovery after spinal cord injury. Our findings provide a model for locomotor networks’ activity-dependent neurogenesis during homeostasis and regeneration in the adult zebrafish spinal cord. The mechanisms stimulating adult neurogenesis are unclear. Here, the authors show the contribution of cholinergic and GABAergic signalling within the locomotor network to spinal cord neurogenesis during homeostasis and regeneration, showing neurogenesis depends on circuit activity in the adult zebrafish.
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27
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Neurotoxic Effects of Neonicotinoids on Mammals: What Is There beyond the Activation of Nicotinic Acetylcholine Receptors?-A Systematic Review. Int J Mol Sci 2021; 22:ijms22168413. [PMID: 34445117 PMCID: PMC8395098 DOI: 10.3390/ijms22168413] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/29/2021] [Accepted: 08/02/2021] [Indexed: 02/07/2023] Open
Abstract
Neonicotinoids are a class of insecticides that exert their effect through a specific action on neuronal nicotinic acetylcholine receptors (nAChRs). The success of these insecticides is due to this mechanism of action, since they act as potent agonists of insect nAChRs, presenting low affinity for vertebrate nAChRs, which reduces potential toxic risk and increases safety for non-target species. However, although neonicotinoids are considered safe, their presence in the environment could increase the risk of exposure and toxicity. On the other hand, although neonicotinoids have low affinity for mammalian nAChRs, the large quantity, variety, and ubiquity of these receptors, combined with its diversity of functions, raises the question of what effects these insecticides can produce in non-target species. In the present systematic review, we investigate the available evidence on the biochemical and behavioral effects of neonicotinoids on the mammalian nervous system. In general, exposure to neonicotinoids at an early age alters the correct neuronal development, with decreases in neurogenesis and alterations in migration, and induces neuroinflammation. In adulthood, neonicotinoids induce neurobehavioral toxicity, these effects being associated with their modulating action on nAChRs, with consequent neurochemical alterations. These alterations include decreased expression of nAChRs, modifications in acetylcholinesterase activity, and significant changes in the function of the nigrostriatal dopaminergic system. All these effects can lead to the activation of a series of intracellular signaling pathways that generate oxidative stress, neuroinflammation and, finally, neuronal death. Neonicotinoid-induced changes in nAChR function could be responsible for most of the effects observed in the different studies.
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28
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Kashyap SS, Verma S, McHugh M, Wolday M, Williams PD, Robertson AP, Martin RJ. Anthelmintic resistance and homeostatic plasticity (Brugia malayi). Sci Rep 2021; 11:14499. [PMID: 34262123 PMCID: PMC8280109 DOI: 10.1038/s41598-021-93911-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 07/01/2021] [Indexed: 11/18/2022] Open
Abstract
Homeostatic plasticity refers to the capacity of excitable cells to regulate their activity to make compensatory adjustments to long-lasting stimulation. It is found across the spectrum of vertebrate and invertebrate species and is driven by changes in cytosolic calcium; it has not been explored in parasitic nematodes when treated with therapeutic drugs. Here we have studied the adaptation of Brugia malayi to exposure to the anthelmintic, levamisole that activates muscle AChR ion-channels. We found three phases of the Brugia malayi motility responses as they adapted to levamisole: an initial spastic paralysis; a flaccid paralysis that follows; and finally, a recovery of motility with loss of sensitivity to levamisole at 4 h. Motility, calcium-imaging, patch-clamp and molecular experiments showed the muscle AChRs are dynamic with mechanisms that adjust their subtype composition and sensitivity to levamisole. This homeostatic plasticity allows the parasite to adapt resisting the anthelmintic.
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Affiliation(s)
- Sudhanva S Kashyap
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Saurabh Verma
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Mark McHugh
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Mengisteab Wolday
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Paul D Williams
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Alan P Robertson
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Richard J Martin
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA.
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29
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Buls Wollman L, Fregosi RF. Chronic, Episodic Nicotine Alters Hypoglossal Motor Neuron Function at a Critical Developmental Time Point in Neonatal Rats. eNeuro 2021; 8:ENEURO.0203-21.2021. [PMID: 34193508 PMCID: PMC8366915 DOI: 10.1523/eneuro.0203-21.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/03/2021] [Accepted: 06/09/2021] [Indexed: 02/07/2023] Open
Abstract
Developmental nicotine exposure (DNE), alters brainstem neurons that control breathing, including hypoglossal motor neurons (XIIMNs), which innervate the tongue. Here, we tested the hypothesis that chronic, episodic DNE (eDNE), which mimics nicotine replacement therapies such as e-cigarettes or nicotine gum, alters the function of nicotinic acetylcholine receptors (nAChRs), XIIMN intrinsic properties, and tongue muscle function in vivo similar to what we have observed with a chronic, sustained exposure model. We delivered nicotine to pregnant Sprague Dawley rats through drinking water and studied pups of either sex in two age groups: postnatal day (P)1-P5 and P10-P12, which encompasses a critical period in brain development. At P1-P5, eDNE was associated with delayed recovery of nAChRs from desensitization; however, there were no changes in the magnitude of desensitization, XIIMN intrinsic properties, or tongue muscle function in vivo. By P10-P12, eDNE XIIMNs had lower peak firing frequencies in response to depolarizing current injection, larger delayed rectifier potassium currents, and continued to exhibit delayed nAChR recovery. Moreover, this age group exhibited a blunted and delayed tongue muscle response to nasal occlusion in vivo, indicating that changes to XIIMN intrinsic properties is an important mechanism behind this effect, as it is not produced by altered nAChR function alone. Together, these results show that eDNE alters XIIMNs and tongue muscle function during a critical period in brain development and that the specific effects of chronic nicotine exposure may be pattern dependent.
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Affiliation(s)
- Lila Buls Wollman
- Department of Physiology, The University of Arizona, Tucson, AZ 85724
| | - Ralph F Fregosi
- Department of Physiology, The University of Arizona, Tucson, AZ 85724
- Department of Neuroscience, The University of Arizona, Tucson, AZ 85724
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30
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Prönneke A, Witte M, Möck M, Staiger JF. Neuromodulation Leads to a Burst-Tonic Switch in a Subset of VIP Neurons in Mouse Primary Somatosensory (Barrel) Cortex. Cereb Cortex 2021; 30:488-504. [PMID: 31210267 DOI: 10.1093/cercor/bhz102] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 04/26/2019] [Accepted: 04/26/2019] [Indexed: 12/14/2022] Open
Abstract
Neocortical GABAergic interneurons expressing vasoactive intestinal polypeptide (VIP) contribute to sensory processing, sensorimotor integration, and behavioral control. In contrast to other major subpopulations of GABAergic interneurons, VIP neurons show a remarkable diversity. Studying morphological and electrophysiological properties of VIP cells, we found a peculiar group of neurons in layer II/III of mouse primary somatosensory (barrel) cortex, which showed a highly dynamic burst firing behavior at resting membrane potential that switched to tonic mode at depolarized membrane potentials. Furthermore, we demonstrate that burst firing depends on T-type calcium channels. The burst-tonic switch could be induced by acetylcholine (ACh) and serotonin. ACh mediated a depolarization via nicotinic receptors whereas serotonin evoked a biphasic depolarization via ionotropic and metabotropic receptors in 48% of the population and a purely monophasic depolarization via metabotropic receptors in the remaining cells. These data disclose an electrophysiologically defined subpopulation of VIP neurons that via neuromodulator-induced changes in firing behavior is likely to regulate the state of cortical circuits in a profound manner.
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Affiliation(s)
- Alvar Prönneke
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität, D-37075 Göttingen, Germany
| | - Mirko Witte
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität, D-37075 Göttingen, Germany
| | - Martin Möck
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität, D-37075 Göttingen, Germany
| | - Jochen F Staiger
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität, D-37075 Göttingen, Germany
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31
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Perrier S, Moreau E, Deshayes C, El-Adouzi M, Goven D, Chandre F, Lapied B. Compensatory mechanisms in resistant Anopheles gambiae AcerKis and KdrKis neurons modulate insecticide-based mosquito control. Commun Biol 2021; 4:665. [PMID: 34079061 PMCID: PMC8172894 DOI: 10.1038/s42003-021-02192-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 05/06/2021] [Indexed: 02/04/2023] Open
Abstract
In the malaria vector Anopheles gambiae, two point mutations in the acetylcholinesterase (ace-1R) and the sodium channel (kdrR) genes confer resistance to organophosphate/carbamate and pyrethroid insecticides, respectively. The mechanisms of compensation that recover the functional alterations associated with these mutations and their role in the modulation of insecticide efficacy are unknown. Using multidisciplinary approaches adapted to neurons isolated from resistant Anopheles gambiae AcerKis and KdrKis strains together with larval bioassays, we demonstrate that nAChRs, and the intracellular calcium concentration represent the key components of an adaptation strategy ensuring neuronal functions maintenance. In AcerKis neurons, the increased effect of acetylcholine related to the reduced acetylcholinesterase activity is compensated by expressing higher density of nAChRs permeable to calcium. In KdrKis neurons, changes in the biophysical properties of the L1014F mutant sodium channel, leading to enhance overlap between activation and inactivation relationships, diminish the resting membrane potential and reduce the fraction of calcium channels available involved in acetylcholine release. Together with the lower intracellular basal calcium concentration observed, these factors increase nAChRs sensitivity to maintain the effect of low concentration of acetylcholine. These results explain the opposite effects of the insecticide clothianidin observed in AcerKis and KdrKis neurons in vitro and in vivo.
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Affiliation(s)
| | | | | | | | | | - Fabrice Chandre
- MIVEGEC, UMR IRD 224-CNRS 5290-Université de Montpellier, 911 avenue Agropolis, Montpellier, Cedex 05, France
| | - Bruno Lapied
- Univ Angers, INRAE, SIFCIR, SFR QUASAV, Angers, France.
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32
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Suyama H, Egger V, Lukas M. Top-down acetylcholine signaling via olfactory bulb vasopressin cells contributes to social discrimination in rats. Commun Biol 2021; 4:603. [PMID: 34021245 PMCID: PMC8140101 DOI: 10.1038/s42003-021-02129-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/19/2021] [Indexed: 02/04/2023] Open
Abstract
Social discrimination in rats requires activation of the intrinsic bulbar vasopressin system, but it is unclear how this system comes into operation, as olfactory nerve stimulation primarily inhibits bulbar vasopressin cells (VPCs). Here we show that stimulation with a conspecific can activate bulbar VPCs, indicating that VPC activation depends on more than olfactory cues during social interaction. A series of in vitro electrophysiology, pharmacology and immunohistochemistry experiments implies that acetylcholine, probably originating from centrifugal projections, can enable olfactory nerve-evoked action potentials in VPCs. Finally, cholinergic activation of the vasopressin system contributes to vasopressin-dependent social discrimination, since recognition of a known rat was blocked by bulbar infusion of the muscarinic acetylcholine receptor antagonist atropine and rescued by additional bulbar application of vasopressin. Thus, our results implicate that top-down cholinergic modulation of bulbar VPC activity is involved in social discrimination in rats.
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Affiliation(s)
- Hajime Suyama
- Institute of Zoology, Neurophysiology, University of Regensburg, Regensburg, Germany
| | - Veronica Egger
- Institute of Zoology, Neurophysiology, University of Regensburg, Regensburg, Germany
| | - Michael Lukas
- Institute of Zoology, Neurophysiology, University of Regensburg, Regensburg, Germany.
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33
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Smart K, Naganawa M, Baldassarri SR, Nabulsi N, Ropchan J, Najafzadeh S, Gao H, Navarro A, Barth V, Esterlis I, Cosgrove KP, Huang Y, Carson RE, Hillmer AT. PET Imaging Estimates of Regional Acetylcholine Concentration Variation in Living Human Brain. Cereb Cortex 2021; 31:2787-2798. [PMID: 33442731 PMCID: PMC8355478 DOI: 10.1093/cercor/bhaa387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/06/2020] [Accepted: 12/01/2020] [Indexed: 11/13/2022] Open
Abstract
Acetylcholine (ACh) has distinct functional roles in striatum compared with cortex, and imbalance between these systems may contribute to neuropsychiatric disease. Preclinical studies indicate markedly higher ACh concentrations in the striatum. The goal of this work was to leverage positron emission tomography (PET) imaging estimates of drug occupancy at cholinergic receptors to explore ACh variation across the human brain, because these measures can be influenced by competition with endogenous neurotransmitter. PET scans were analyzed from healthy human volunteers (n = 4) and nonhuman primates (n = 2) scanned with the M1-selective radiotracer [11C]LSN3172176 in the presence of muscarinic antagonist scopolamine, and human volunteers (n = 10) scanned with the α4β2* nicotinic ligand (-)-[18F]flubatine during nicotine challenge. In all cases, occupancy estimates within striatal regions were consistently lower (M1/scopolamine human scans, 31 ± 3.4% occupancy in striatum, 43 ± 2.9% in extrastriatal regions, p = 0.0094; nonhuman primate scans, 42 ± 26% vs. 69 ± 28%, p < 0.0001; α4β2*/nicotine scans, 67 ± 15% vs. 74 ± 16%, p = 0.0065), indicating higher striatal ACh concentration. Subject-level measures of these concentration differences were estimated, and whole-brain images of regional ACh concentration gradients were generated. These results constitute the first in vivo estimates of regional variation in ACh concentration in the living brain and offer a novel experimental method to assess potential ACh imbalances in clinical populations.
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Affiliation(s)
- Kelly Smart
- Yale PET Center, Yale School of Medicine, New Haven, CT 06510, USA
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT 06520, USA
| | - Mika Naganawa
- Yale PET Center, Yale School of Medicine, New Haven, CT 06510, USA
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT 06520, USA
| | - Stephen R Baldassarri
- Department of Internal Medicine, Section of Pulmonary, Critical Care, and Sleep Medicine, Yale School of Medicine, New Haven, CT 06510, USA
| | - Nabeel Nabulsi
- Yale PET Center, Yale School of Medicine, New Haven, CT 06510, USA
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT 06520, USA
| | - Jim Ropchan
- Yale PET Center, Yale School of Medicine, New Haven, CT 06510, USA
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT 06520, USA
| | | | - Hong Gao
- Yale PET Center, Yale School of Medicine, New Haven, CT 06510, USA
| | | | | | - Irina Esterlis
- Department of Psychiatry, Yale School of Medicine, New Haven, CT 06511, USA
| | - Kelly P Cosgrove
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT 06520, USA
- Department of Psychiatry, Yale School of Medicine, New Haven, CT 06511, USA
| | - Yiyun Huang
- Yale PET Center, Yale School of Medicine, New Haven, CT 06510, USA
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT 06520, USA
| | - Richard E Carson
- Yale PET Center, Yale School of Medicine, New Haven, CT 06510, USA
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT 06520, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT 06511, USA
| | - Ansel T Hillmer
- Yale PET Center, Yale School of Medicine, New Haven, CT 06510, USA
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT 06520, USA
- Department of Psychiatry, Yale School of Medicine, New Haven, CT 06511, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT 06511, USA
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34
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Melgoza IP, Jilani R, Shehzad Z, Anam AK. Comment on Rhee et al. Association Between Glycemic Status and the Risk of Parkinson Disease: A Nationwide Population-Based Study. Diabetes Care 2020;43:2169-2175. Diabetes Care 2021; 44:e95-e96. [PMID: 33972316 DOI: 10.2337/dc20-2406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Itzel Paola Melgoza
- The Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY
| | - Rayman Jilani
- The Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY
| | - Zarrar Shehzad
- The Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY
| | - Anika K Anam
- Section of Endocrinology, Department of Internal Medicine, Yale School of Medicine, New Haven, CT
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35
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Aryal SP, Fu X, Sandin JN, Neupane KR, Lakes JE, Grady ME, Richards CI. Nicotine induces morphological and functional changes in astrocytes via nicotinic receptor activity. Glia 2021; 69:2037-2053. [PMID: 33851731 DOI: 10.1002/glia.24011] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 03/26/2021] [Accepted: 04/08/2021] [Indexed: 01/16/2023]
Abstract
Nicotine is a highly addictive compound present in tobacco, which causes the release of dopamine in different regions of the brain. Recent studies have shown that astrocytes express nicotinic acetylcholine receptors (nAChRs) and mediate calcium signaling. In this study, we examine the morphological and functional adaptations of astrocytes due to nicotine exposure. Utilizing a combination of fluorescence and atomic force microscopy, we show that nicotine-treated astrocytes exhibit time-dependent remodeling in the number and length of both proximal and fine processes. Blocking nAChR activity with an antagonist completely abolishes nicotine's influence on astrocyte morphology indicating that nicotine's action is mediated by these receptors. Functional studies show that 24-hr nicotine treatment induces higher levels of calcium activity in both the cell soma and the processes with a more substantial change observed in the processes. Nicotine does not induce reactive astrocytosis even at high concentrations (10 μM) as determined by cytokine release and glial fibrillary acidic protein expression. We designed tissue clearing experiments to test whether morphological changes occur in vivo using astrocyte specific Aldh1l1-tdTomato knock in mice. We find that nicotine induces a change in the volume of astrocytes in the prefrontal cortex, CA1 of the hippocampus, and the substantia nigra. These results indicate that nicotine directly alters the functional and morphological properties of astrocytes potentially contributing to the underlying mechanism of nicotine abuse.
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Affiliation(s)
- Surya P Aryal
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA
| | - Xu Fu
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA
| | - Joree N Sandin
- Department of Mechanical Engineering, University of Kentucky, Lexington, Kentucky, USA
| | - Khaga R Neupane
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA
| | - Jourdan E Lakes
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA
| | - Martha E Grady
- Department of Mechanical Engineering, University of Kentucky, Lexington, Kentucky, USA
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36
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Loser D, Hinojosa MG, Blum J, Schaefer J, Brüll M, Johansson Y, Suciu I, Grillberger K, Danker T, Möller C, Gardner I, Ecker GF, Bennekou SH, Forsby A, Kraushaar U, Leist M. Functional alterations by a subgroup of neonicotinoid pesticides in human dopaminergic neurons. Arch Toxicol 2021; 95:2081-2107. [PMID: 33778899 PMCID: PMC8166715 DOI: 10.1007/s00204-021-03031-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 03/17/2021] [Indexed: 12/16/2022]
Abstract
Neonicotinoid pesticides, originally developed to target the insect nervous system, have been reported to interact with human receptors and to activate rodent neurons. Therefore, we evaluated in how far these compounds may trigger signaling in human neurons, and thus, affect the human adult or developing nervous system. We used SH-SY5Y neuroblastoma cells as established model of nicotinic acetylcholine receptor (nAChR) signaling. In parallel, we profiled dopaminergic neurons, generated from LUHMES neuronal precursor cells, as novel system to study nAChR activation in human post-mitotic neurons. Changes of the free intracellular Ca2+ concentration ([Ca2+]i) were used as readout, and key findings were confirmed by patch clamp recordings. Nicotine triggered typical neuronal signaling responses that were blocked by antagonists, such as tubocurarine and mecamylamine. Pharmacological approaches suggested a functional expression of α7 and non-α7 nAChRs on LUHMES cells. In this novel test system, the neonicotinoids acetamiprid, imidacloprid, clothianidin and thiacloprid, but not thiamethoxam and dinotefuran, triggered [Ca2+]i signaling at 10-100 µM. Strong synergy of the active neonicotinoids (at low micromolar concentrations) with the α7 nAChR-positive allosteric modulator PNU-120596 was observed in LUHMES and SH-SY5Y cells, and specific antagonists fully inhibited such signaling. To provide a third line of evidence for neonicotinoid signaling via nAChR, we studied cross-desensitization: pretreatment of LUHMES and SH-SY5Y cells with active neonicotinoids (at 1-10 µM) blunted the signaling response of nicotine. The pesticides (at 3-30 µM) also blunted the response to the non-α7 agonist ABT 594 in LUHMES cells. These data show that human neuronal cells are functionally affected by low micromolar concentrations of several neonicotinoids. An effect of such signals on nervous system development is a toxicological concern.
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Affiliation(s)
- Dominik Loser
- NMI Natural and Medical Sciences Institute at the University of Tübingen, 72770, Reutlingen, Germany
- NMI TT GmbH, 72770, Reutlingen, Germany
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Universitaetsstr. 10, 78457, Konstanz, Germany
| | - Maria G Hinojosa
- Department of Biochemistry and Biophysics, Stockholm University, 106 91, Stockholm, Sweden
| | - Jonathan Blum
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Universitaetsstr. 10, 78457, Konstanz, Germany
| | - Jasmin Schaefer
- NMI Natural and Medical Sciences Institute at the University of Tübingen, 72770, Reutlingen, Germany
- NMI TT GmbH, 72770, Reutlingen, Germany
| | - Markus Brüll
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Universitaetsstr. 10, 78457, Konstanz, Germany
| | - Ylva Johansson
- Department of Biochemistry and Biophysics, Stockholm University, 106 91, Stockholm, Sweden
| | - Ilinca Suciu
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Universitaetsstr. 10, 78457, Konstanz, Germany
| | - Karin Grillberger
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Timm Danker
- NMI Natural and Medical Sciences Institute at the University of Tübingen, 72770, Reutlingen, Germany
- NMI TT GmbH, 72770, Reutlingen, Germany
| | - Clemens Möller
- Life Sciences Faculty, Albstadt-Sigmaringen University, 72488, Sigmaringen, Germany
| | - Iain Gardner
- CERTARA UK Limited, Simcyp Division, Level 2-Acero, 1 Concourse Way, Sheffield, S1 2BJ, UK
| | - Gerhard F Ecker
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | | | - Anna Forsby
- Department of Biochemistry and Biophysics, Stockholm University, 106 91, Stockholm, Sweden
| | - Udo Kraushaar
- NMI Natural and Medical Sciences Institute at the University of Tübingen, 72770, Reutlingen, Germany
| | - Marcel Leist
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Universitaetsstr. 10, 78457, Konstanz, Germany.
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Marcovich I, Moglie MJ, Carpaneto Freixas AE, Trigila AP, Franchini LF, Plazas PV, Lipovsek M, Elgoyhen AB. Distinct Evolutionary Trajectories of Neuronal and Hair Cell Nicotinic Acetylcholine Receptors. Mol Biol Evol 2021; 37:1070-1089. [PMID: 31821508 PMCID: PMC7086180 DOI: 10.1093/molbev/msz290] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The expansion and pruning of ion channel families has played a crucial role in the evolution of nervous systems. Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels with distinct roles in synaptic transmission at the neuromuscular junction, the central and peripheral nervous system, and the inner ear. Remarkably, the complement of nAChR subunits has been highly conserved along vertebrate phylogeny. To ask whether the different subtypes of receptors underwent different evolutionary trajectories, we performed a comprehensive analysis of vertebrate nAChRs coding sequences, mouse single-cell expression patterns, and comparative functional properties of receptors from three representative tetrapod species. We found significant differences between hair cell and neuronal receptors that were most likely shaped by the differences in coexpression patterns and coassembly rules of component subunits. Thus, neuronal nAChRs showed high degree of coding sequence conservation, coupled to greater coexpression variance and conservation of functional properties across tetrapod clades. In contrast, hair cell α9α10 nAChRs exhibited greater sequence divergence, narrow coexpression pattern, and great variability of functional properties across species. These results point to differential substrates for random change within the family of gene paralogs that relate to the segregated roles of nAChRs in synaptic transmission.
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Affiliation(s)
- Irina Marcovich
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Marcelo J Moglie
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Agustín E Carpaneto Freixas
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Anabella P Trigila
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Lucia F Franchini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Paola V Plazas
- Instituto de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Marcela Lipovsek
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Centre for Developmental Neurobiology, King's College London, Institute of Psychiatry, Psychology and Neuroscience, Guy's Campus, London, United Kingdom
| | - Ana Belén Elgoyhen
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.,Instituto de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
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38
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Chun-Kai H, Hsi-Hsien C, Shang-Jen C, Shei-Dei Stephen Y, Kuo-Feng H. Methyl palmitate modulates the nicotine-induced increase in basilar arterial blood flow. Microcirculation 2021; 28:e12686. [PMID: 33595915 DOI: 10.1111/micc.12686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 02/10/2021] [Indexed: 11/28/2022]
Abstract
Methyl palmitate (MP) is a fatty acid methyl ester. Our recent study indicated that adrenergic nerve-dependent functional sympathetic-sensory nerve interactions were abolished by MP in mesenteric arteries. However, the effect of MP on perivascular nerves and cerebral blood flow remains unclear. In this study, the increase in basilar arterial blood flow (BABF) after the topical application of nicotinic acetylcholine receptor agonists was measured using laser Doppler flowmetry in anesthetized rats. The choline (a selective α7-nicotinic acetylcholine receptor agonist)-induced increase in BABF was abolished by tetrodotoxin (a neurotoxin), NG -nitro-L-arginine (a nonselective NO synthase inhibitor), α-bungarotoxin (a selective α7-nicotinic acetylcholine receptor inhibitor), and chronic sympathetic denervation. In addition, the nicotine (a nicotinic acetylcholine receptor agonist)-induced increase in BABF was inhibited by MP in a concentration-dependent manner. The acetylcholine-induced increase in BABF was not affected by MP. The myography results revealed that nicotine-induced vasorelaxation was significantly inhibited by MP, but was reversed by chelerythrine (a protein kinase C inhibitor). MP-induced vasodilation was significantly greater in BA rings without endothelium compared to those with endothelium. Meanwhile, MP did not affect baseline BABF. Our results indicate that MP acts as a neuromodulator in the cerebral circulation where it activates the PKC pathway and causes a diminished nicotine-induced increase in blood flow in the brainstem, and that the vasorelaxation effect of MP may play a minor role.
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Affiliation(s)
- Hsu Chun-Kai
- Division of Urology, Department of Surgery, Taipei Tzu Chi Hospital, The Buddhist Medical Foundation, New Taipei, Taiwan
| | - Chang Hsi-Hsien
- Division of Urology, Department of Surgery, Taipei Tzu Chi Hospital, The Buddhist Medical Foundation, New Taipei, Taiwan
| | - Chang Shang-Jen
- Division of Urology, Department of Surgery, Taipei Tzu Chi Hospital, The Buddhist Medical Foundation, New Taipei, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Yang Shei-Dei Stephen
- Division of Urology, Department of Surgery, Taipei Tzu Chi Hospital, The Buddhist Medical Foundation, New Taipei, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan.,Division of Neurosurgery, Department of Surgery, Taipei Tzu Chi Hospital, New Taipei, Taiwan
| | - Huang Kuo-Feng
- School of Medicine, Tzu Chi University, Hualien, Taiwan.,Division of Neurosurgery, Department of Surgery, Taipei Tzu Chi Hospital, New Taipei, Taiwan
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39
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Scholze P, Huck S. The α5 Nicotinic Acetylcholine Receptor Subunit Differentially Modulates α4β2 * and α3β4 * Receptors. Front Synaptic Neurosci 2020; 12:607959. [PMID: 33343327 PMCID: PMC7744819 DOI: 10.3389/fnsyn.2020.607959] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/11/2020] [Indexed: 11/30/2022] Open
Abstract
Nicotine, the principal reinforcing compound in tobacco, acts in the brain by activating neuronal nicotinic acetylcholine receptors (nAChRs). This review summarizes our current knowledge regarding how the α5 accessory nAChR subunit, encoded by the CHRNA5 gene, differentially modulates α4β2* and α3β4* receptors at the cellular level. Genome-wide association studies have linked a gene cluster in chromosomal region 15q25 to increased susceptibility to nicotine addiction, lung cancer, chronic obstructive pulmonary disease, and peripheral arterial disease. Interestingly, this gene cluster contains a non-synonymous single-nucleotide polymorphism (SNP) in the human CHRNA5 gene, causing an aspartic acid (D) to asparagine (N) substitution at amino acid position 398 in the α5 nAChR subunit. Although other SNPs have been associated with tobacco smoking behavior, efforts have focused predominantly on the D398 and N398 variants in the α5 subunit. In recent years, significant progress has been made toward understanding the role that the α5 nAChR subunit—and the role of the D398 and N398 variants—plays on nAChR function at the cellular level. These insights stem primarily from a wide range of experimental models, including receptors expressed heterologously in Xenopus oocytes, various cell lines, and neurons derived from human induced pluripotent stem cells (iPSCs), as well as endogenous receptors in genetically engineered mice and—more recently—rats. Despite providing a wealth of available data, however, these studies have yielded conflicting results, and our understanding of the modulatory role that the α5 subunit plays remains incomplete. Here, we review these reports and the various techniques used for expression and analysis in order to examine how the α5 subunit modulates key functions in α4β2* and α3β4* receptors, including receptor trafficking, sensitivity, efficacy, and desensitization. In addition, we highlight the strikingly different role that the α5 subunit plays in Ca2+ signaling between α4β2* and α3β4* receptors, and we discuss whether the N398 α5 subunit variant can partially replace the D398 variant.
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Affiliation(s)
- Petra Scholze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Sigismund Huck
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
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40
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Unraveling the Molecular Players at the Cholinergic Efferent Synapse of the Zebrafish Lateral Line. J Neurosci 2020; 41:47-60. [PMID: 33203744 DOI: 10.1523/jneurosci.1772-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/25/2020] [Accepted: 10/30/2020] [Indexed: 12/26/2022] Open
Abstract
The lateral line (LL) is a sensory system that allows fish and amphibians to detect water currents. LL responsiveness is modulated by efferent neurons that aid in distinguishing between external and self-generated stimuli, maintaining sensitivity to relevant cues. One component of the efferent system is cholinergic, the activation of which inhibits afferent activity. LL hair cells (HCs) share structural, functional, and molecular similarities with those of the cochlea, making them a popular model for studying human hearing and balance disorders. Because of these commonalities, one could propose that the receptor at the LL efferent synapse is a α9α10 nicotinic acetylcholine receptor (nAChR). However, the identities of the molecular players underlying ACh-mediated inhibition in the LL remain unknown. Surprisingly, through the analysis of single-cell expression studies and in situ hybridization, we describe that α9, but not the α10, subunits are enriched in zebrafish HCs. Moreover, the heterologous expression of zebrafish α9 subunits indicates that homomeric receptors are functional and exhibit robust ACh-gated currents blocked by α-bungarotoxin and strychnine. In addition, in vivo Ca2+ imaging on mechanically stimulated zebrafish LL HCs show that ACh elicits a decrease in evoked Ca2+ signals, regardless of HC polarity. This effect is blocked by both α-bungarotoxin and apamin, indicating coupling of ACh-mediated effects to small-conductance Ca2+-activated potassium (SKs) channels. Our results indicate that an α9-containing (α9*) nAChR operates at the zebrafish LL efferent synapse. Moreover, the activation of α9* nAChRs most likely leads to LL HC hyperpolarization served by SK channels.SIGNIFICANCE STATEMENT The fish lateral line (LL) mechanosensory system shares structural, functional, and molecular similarities with those of the mammalian cochlea. Thus, it has become an accessible model for studying human hearing and balance disorders. However, the molecular players serving efferent control of LL hair cell (HC) activity have not been identified. Here we demonstrate that, different from the hearing organ of vertebrate species, a nicotinic acetylcholine receptor composed only of α9 subunits operates at the LL efferent synapse. Activation of α9-containing receptors leads to LL HC hyperpolarization because of the opening of small-conductance Ca2+-activated potassium channels. These results will further aid in the interpretation of data obtained from LL HCs as a model for cochlear HCs.
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Wittenberg RE, Wolfman SL, De Biasi M, Dani JA. Nicotinic acetylcholine receptors and nicotine addiction: A brief introduction. Neuropharmacology 2020; 177:108256. [PMID: 32738308 PMCID: PMC7554201 DOI: 10.1016/j.neuropharm.2020.108256] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/22/2020] [Accepted: 07/26/2020] [Indexed: 12/13/2022]
Abstract
Nicotine is a highly addictive drug found in tobacco that drives its continued use despite the harmful consequences. The initiation of nicotine abuse involves the mesolimbic dopamine system, which contributes to the rewarding sensory stimuli and associative learning processes in the beginning stages of addiction. Nicotine binds to neuronal nicotinic acetylcholine receptors (nAChRs), which come in a diverse collection of subtypes. The nAChRs that contain the α4 and β2 subunits, often in combination with the α6 subunit, are particularly important for nicotine's ability to increase midbrain dopamine neuron firing rates and phasic burst firing. Chronic nicotine exposure results in numerous neuroadaptations, including the upregulation of particular nAChR subtypes associated with long-term desensitization of the receptors. When nicotine is no longer present, for example during attempts to quit smoking, a withdrawal syndrome develops. The expression of physical withdrawal symptoms depends mainly on the α2, α3, α5, and β4 nicotinic subunits in the epithalamic habenular complex and its target regions. Thus, nicotine affects diverse neural systems and an array of nAChR subtypes to mediate the overall addiction process. This article is part of the special issue on 'Contemporary Advances in Nicotine Neuropharmacology'.
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Affiliation(s)
- Ruthie E Wittenberg
- Departments of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Shannon L Wolfman
- Departments of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Mariella De Biasi
- Departments of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Psychiatry, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - John A Dani
- Departments of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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Kumar M, Adeluyi A, Anderson EL, Turner JR. Glial cells as therapeutic targets for smoking cessation. Neuropharmacology 2020; 175:108157. [PMID: 32461156 PMCID: PMC7791555 DOI: 10.1016/j.neuropharm.2020.108157] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 12/17/2022]
Abstract
Smoking remains the leading cause of morbidity and mortality in the United States, with less than 5% of smokers attempting to quit succeeding. This low smoking cessation success rate is thought to be due to the long-term adaptations and alterations in synaptic plasticity that occur following chronic nicotine exposure and withdrawal. Glial cells have recently emerged as active players in the development of dependence phenotypes due to their roles in modulating neuronal functions and synaptic plasticity. Fundamental studies have demonstrated that microglia and astrocytes are crucial for synapse formation and elimination in the developing brain, likely contributing to why glial dysfunction is implicated in numerous neurological and psychiatric disorders. Recently, there is increasing evidence for the involvement of glial cells in drug dependence and its associated behavioral manifestations. This review summarizes the newly evaluated role of microglia and astrocytes as molecular drivers of nicotine dependence and withdrawal phenotypes. This article is part of the special issue on 'Contemporary Advances in Nicotine Neuropharmacology.
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Affiliation(s)
- Mohit Kumar
- Department of Pharmaceutical Sciences, University of Kentucky College of Pharmacy, Lexington, KY, USA.
| | - Adewale Adeluyi
- Department of Pharmaceutical Sciences, University of Kentucky College of Pharmacy, Lexington, KY, USA; Ann Romney Center for Neurologic Disease, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Erin L Anderson
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, USA.
| | - Jill R Turner
- Department of Pharmaceutical Sciences, University of Kentucky College of Pharmacy, Lexington, KY, USA.
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43
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Calarco CA, Picciotto MR. Nicotinic Acetylcholine Receptor Signaling in the Hypothalamus: Mechanisms Related to Nicotine's Effects on Food Intake. Nicotine Tob Res 2020; 22:152-163. [PMID: 30690485 DOI: 10.1093/ntr/ntz010] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 01/17/2019] [Indexed: 12/12/2022]
Abstract
Despite health risks associated with smoking, up to 20% of the US population persist in this behavior; many smoke to control body weight or appetite, and fear of post-cessation weight gain can motivate continued smoking. Nicotine and tobacco use is associated with lower body weight, and cessation yields an average weight gain of about 4 kg, which is thought to reflect a return to the body weight of a typical nonsmoker. Nicotine replacement therapies can delay this weight gain but do not prevent it altogether, and the underlying mechanism for how nicotine is able to reduce weight is not fully understood. In rodent models, nicotine reduces weight gain, reduces food consumption, and alters energy expenditure, but these effects vary with duration and route of nicotine administration. Nicotine, acting through nicotinic acetylcholine receptors (nAChRs), increases the firing rate of both orexigenic agouti-related peptide and anorexigenic proopiomelanocortin neurons in the arcuate nucleus of the hypothalamus (ARC). Manipulation of nAChR subunit expression within the ARC can block the ability of nicotine and the nicotinic agonist cytisine from decreasing food intake; however, it is unknown exactly how this reduces food intake. This review summarizes the clinical and preclinical work on nicotine, food intake, and weight gain, then explores the feeding circuitry of the ARC and how it is regulated by nicotine. Finally, we propose a novel hypothesis for how nicotine acts on this hypothalamic circuit to reduce food intake. Implications: This review provides a comprehensive and updated summary of the clinical and preclinical work examining nicotine and food intake, as well as a summary of recent work examining feeding circuits of the hypothalamus. Synthesis of these two topics has led to new understanding of how nAChR signaling regulates food intake circuits in the hypothalamus.
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Affiliation(s)
- Cali A Calarco
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT.,Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT
| | - Marina R Picciotto
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT.,Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT
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Chrna5 is Essential for a Rapid and Protected Response to Optogenetic Release of Endogenous Acetylcholine in Prefrontal Cortex. J Neurosci 2020; 40:7255-7268. [PMID: 32817066 DOI: 10.1523/jneurosci.1128-20.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/01/2020] [Accepted: 08/09/2020] [Indexed: 12/16/2022] Open
Abstract
Optimal attention performance requires cholinergic modulation of corticothalamic neurons in the prefrontal cortex. These pyramidal cells express specialized nicotinic acetylcholine receptors containing the α5 subunit encoded by Chrna5 Disruption of this gene impairs attention, but the advantage α5 confers on endogenous cholinergic signaling is unknown. To ascertain this underlying mechanism, we used optogenetics to stimulate cholinergic afferents in prefrontal cortex brain slices from compound-transgenic wild-type and Chrna5 knock-out mice of both sexes. These electrophysiological experiments identify that Chrna5 is critical for the rapid onset of the postsynaptic cholinergic response. Loss of α5 slows cholinergic excitation and delays its peak, and these effects are observed in two different optogenetic mouse lines. Disruption of Chrna5 does not otherwise perturb the magnitude of the response, which remains strongly mediated by nicotinic receptors and tightly controlled by autoinhibition via muscarinic M2 receptors. However, when conditions are altered to promote sustained cholinergic receptor stimulation, it becomes evident that α5 also works to protect nicotinic responses against desensitization. Rescuing Chrna5 disruption thus presents the double challenge of improving the onset of nicotinic signaling without triggering desensitization. Here, we identify that an agonist for the unorthodox α-α nicotinic binding site can allosterically enhance the cholinergic pathway considered vital for attention. Treatment with NS9283 restores the rapid onset of the postsynaptic cholinergic response without triggering desensitization. Together, this work demonstrates the advantages of speed and resilience that Chrna5 confers on endogenous cholinergic signaling, defining a critical window of interest for cue detection and attentional processing.SIGNIFICANCE STATEMENT The α5 nicotinic receptor subunit (Chrna5) is important for attention, but its advantage in detecting endogenous cholinergic signals is unknown. Here, we show that α5 subunits permit rapid cholinergic responses in prefrontal cortex and protect these responses from desensitization. Our findings clarify why Chrna5 is required for optimal attentional performance under demanding conditions. To treat the deficit arising from Chrna5 disruption without triggering desensitization, we enhanced nicotinic receptor affinity using NS9283 stimulation at the unorthodox α-α nicotinic binding site. This approach successfully restored the rapid-onset kinetics of endogenous cholinergic neurotransmission. In summary, we reveal a previously unknown role of Chrna5 as well as an effective approach to compensate for genetic disruption and permit fast cholinergic excitation of prefrontal attention circuits.
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45
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Arastoo S, Haptonstall KP, Choroomi Y, Moheimani R, Nguyen K, Tran E, Gornbein J, Middlekauff HR. Acute and chronic sympathomimetic effects of e-cigarette and tobacco cigarette smoking: role of nicotine and non-nicotine constituents. Am J Physiol Heart Circ Physiol 2020; 319:H262-H270. [PMID: 32559135 DOI: 10.1152/ajpheart.00192.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Electronic cigarettes (ECs) and tobacco cigarettes (TCs) both release nicotine, a sympathomimetic drug. We hypothesized that baseline heart rate variability (HRV) and hemodynamics would be similar in chronic EC and TC smokers and that after acute EC use, changes in HRV and hemodynamics would be attributable to nicotine, not non-nicotine, constituents in EC aerosol. In 100 smokers, including 58 chronic EC users and 42 TC smokers, baseline HRV and hemodynamics [blood pressure (BP) and heart rate (HR)] were compared. To isolate the acute effects of nicotine vs. non-nicotine constituents in EC aerosol, we compared changes in HRV, BP, and HR in EC users after using an EC with nicotine (ECN), EC without nicotine (EC0), nicotine inhaler (NI), or sham vaping (control). Outcomes were also compared with TC smokers after smoking one TC. Baseline HRV and hemodynamics were not different in chronic EC users and TC smokers. In EC users, BP and HR, but not HRV outcomes, increased only after using the ECN, consistent with a nicotine effect on BP and HR. Similarly, in TC smokers, BP and HR but not HRV outcomes increased after smoking one TC. Despite a similar increase in nicotine, the hemodynamic increases were significantly greater after TC smokers smoked one TC compared with the increases after EC users used the ECN. In conclusion, chronic EC and TC smokers exhibit a similar pattern of baseline HRV. Acute increases in BP and HR in EC users are attributable to nicotine, not non-nicotine, constituents in EC aerosol. The greater acute pressor effects after TC compared with ECN may be attributable to non-nicotine, combusted constituents in TC smoke.NEW & NOTEWORTHY Chronic electronic cigarette (EC) users and tobacco cigarette (TC) smokers exhibit a similar level of sympathetic nerve activity as estimated by heart rate variability. Acute increases in blood pressure (BP) and heart rate in EC users are attribute to nicotine, not non-nicotine, constituents in EC aerosol. Acute TC smoking increased BP significantly more than acute EC use, despite similar increases in plasma nicotine, suggestive of additional adverse vascular effects attributable to combusted, non-nicotine constituents in TC smoke.
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Affiliation(s)
- Sara Arastoo
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine at University of California, Los Angeles, California
| | - Kacey P Haptonstall
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine at University of California, Los Angeles, California
| | - Yasmine Choroomi
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine at University of California, Los Angeles, California
| | - Roya Moheimani
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine at University of California, Los Angeles, California
| | - Kevin Nguyen
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine at University of California, Los Angeles, California
| | - Elizabeth Tran
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine at University of California, Los Angeles, California
| | - Jeffrey Gornbein
- Departments of Medicine and Computational Medicine, David Geffen School of Medicine at University of California, Los Angeles, California
| | - Holly R Middlekauff
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine at University of California, Los Angeles, California
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Zhang X, Lao K, Qiu Z, Rahman MS, Zhang Y, Gou X. Potential Astrocytic Receptors and Transporters in the Pathogenesis of Alzheimer's Disease. J Alzheimers Dis 2020; 67:1109-1122. [PMID: 30741675 DOI: 10.3233/jad-181084] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia and is characterized by the progressive loss of memory and cognition in the aging population. However, the etiology of and therapies for AD remain far from understood. Astrocytes, the most abundant neuroglia in the brain, have recently aroused substantial concern due to their involvement in synaptotoxicity, amyloidosis, neuroinflammation, and oxidative stress. In this review, we summarize the candidate molecules of astrocytes, especially receptors and transporters, that may be involved in AD pathogenesis. These molecules include excitatory amino acid transporters (EAATs), metabotropic glutamate receptor 5 (mGluR5), the adenosine 2A receptor (A2AR), the α7-nicotinic acetylcholine receptor (α7-nAChR), the calcium-sensing receptor (CaSR), S100β, and cannabinoid receptors. We describe the characteristics of these molecules and the neurological and pharmacological underpinnings of these molecules in AD. Among these molecules, EAATs, A2AR, and mGluR5 are strongly related to glutamate-mediated synaptotoxicity and are involved in glutamate transmission or the clearance of extrasynaptic glutamate in the AD brain. The α7-nAChR, CaSR, and mGluR5 are receptors of Aβ and can induce a plethora of toxic effects, such as the production of excess Aβ, synaptotoxicity, and NO production triggered by changes in intracellular calcium signaling. Antagonists or positive allosteric modulators of these receptors can repair cognitive ability and modify neurobiological changes. Moreover, blocking S100β or activating cannabinoid receptors reduces neuroinflammation, oxidative stress, and reactive astrogliosis. Thus, targeting these molecules might provide alternative approaches for treating AD.
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Affiliation(s)
- Xiaohua Zhang
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, P.R. China
| | - Kejing Lao
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, P.R. China
| | - Zhongying Qiu
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, P.R. China
| | - Md Saidur Rahman
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, P.R. China.,Institute of Neurobiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, P.R. China
| | - Yuelin Zhang
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, P.R. China
| | - Xingchun Gou
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, P.R. China
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Perniss A, Latz A, Boseva I, Papadakis T, Dames C, Meisel C, Meisel A, Scholze P, Kummer W, Krasteva-Christ G. Acute nicotine administration stimulates ciliary activity via α3β4 nAChR in the mouse trachea. Int Immunopharmacol 2020; 84:106496. [PMID: 32304995 DOI: 10.1016/j.intimp.2020.106496] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/20/2020] [Accepted: 04/07/2020] [Indexed: 12/30/2022]
Abstract
Mucociliary clearance, the continuous removal of mucus-trapped particles by cilia-driven directed transport of the airway lining fluid, is the primary innate defense mechanism of the airways. It is potently activated by acetylcholine (ACh) addressing muscarinic receptors with a currently less defined role of nicotinic ACh receptors (nAChR). We here set out to determine their contribution in driving ciliary activity in an explanted mouse trachea preparation utilizing selected agonists and antagonists and nAChR-subunit deficient mice. Nicotine (100 µM) induced an increase in ciliary beat frequency, accompanied by a sharp, but not long lasting increase in particle transport speed (PTS) on the mucosal surface showing marked desensitization within the next 30 min. Nicotine-induced PTS acceleration was sensitive to the general nAChR inhibitors mecamylamine and d-tubocurarine as well as to the α3β4-nAChR antagonist α-conotoxin AulB, but not to other antagonists primarily addressing α3β2-nAChR or α4-, α7- and α9-containing nAChR. Agonists at α3β*-nAChR (epibatidine, cytisine), but not cotinine mimicked the effect. Tracheas from mice with genetic deletion of nAChR subunits α5, α7, α9, α10, α9/10, and β2 retained full PTS response to nicotine, whereas this was entirely lost in tracheas from mice lacking the β4-subunit. Collectively, our data show that nicotinic stimulation of α3β4-nAChR acutely increases PTS to the same extent as the established strong activator ATP. In view of the marked desensitization observed in the present setting, the physiological relevance of these receptors in adapting mucociliary clearance to rapidly changing endogenous or environmental stimuli remains open.
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Affiliation(s)
- Alexander Perniss
- Institute of Anatomy and Cell Biology, German Center for Lung Research, Justus-Liebig-University Giessen, Giessen, Germany.
| | - Ariane Latz
- Institute of Anatomy and Cell Biology, German Center for Lung Research, Justus-Liebig-University Giessen, Giessen, Germany
| | - Ivelina Boseva
- Institute of Anatomy and Cell Biology, German Center for Lung Research, Justus-Liebig-University Giessen, Giessen, Germany
| | - Tamara Papadakis
- Institute of Anatomy and Cell Biology, German Center for Lung Research, Justus-Liebig-University Giessen, Giessen, Germany
| | - Claudia Dames
- Charité Berlin, Institute of Medical Immunology, Berlin, Germany
| | - Christian Meisel
- Charité Berlin, Institute of Medical Immunology, Berlin, Germany
| | - Andreas Meisel
- Charité Berlin, Departments of Neurology and Experimental Neurology, NeuroCure Clinical Research Center, Berlin, Germany
| | - Petra Scholze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University Vienna, Vienna, Austria
| | - Wolfgang Kummer
- Institute of Anatomy and Cell Biology, German Center for Lung Research, Justus-Liebig-University Giessen, Giessen, Germany
| | - Gabriela Krasteva-Christ
- Institute of Anatomy and Cell Biology, German Center for Lung Research, Justus-Liebig-University Giessen, Giessen, Germany; Present address: Department of Anatomy and Cell Biology, Saarland University, Homburg/Saar, Germany
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de Moura FB, Wilkerson JL, McMahon LR. Unexpected loss of sensitivity to the nicotinic acetylcholine receptor antagonist activity of mecamylamine and dihydro-β-erythroidine in nicotine-tolerant mice. Brain Behav 2020; 10:e01581. [PMID: 32092237 PMCID: PMC7177571 DOI: 10.1002/brb3.1581] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 01/28/2020] [Accepted: 02/04/2020] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES There is a long-standing interest in developing nicotinic acetylcholine receptor (nAChR) antagonists for concomitant use with nAChR agonists (e.g., nicotine replacement) as complementary smoking cessation aids. Previous studies demonstrate that daily nicotine treatment confers tolerance to some effects of nicotine, as well as cross-tolerance to other nAChR agonists. The current study assessed the extent to which antagonism of nicotine varies as a function of daily nicotine treatment. METHODS Schedule-controlled responding and hypothermia were selected for study because they have been previously used to examine the pharmacology of nicotine, and both are sensitive to the development nicotine tolerance. The rate-decreasing and hypothermic effects of nicotine, as well as antagonism of those effects, were examined in C57BL/6J mice before, during treatment with, and after discontinuation of three daily injections of 1.78 mg/kg nicotine. The nonselective nAChR antagonist mecamylamine and the β2 nAChR antagonist dihydro-β-erythroidine (DHβE) were studied in combination with nicotine. RESULTS The ED50 values of nicotine to produce rate-decreasing and hypothermic effects were, respectively, 0.44 and 0.82 mg/kg prior, 1.6 and 3.2 mg/kg during, and 0.74 and 1.1 mg/kg after discontinuation of daily nicotine treatment. Prior to daily nicotine treatment, mecamylamine decreased response rate and rectal temperature. However, during daily nicotine, mecamylamine (up to 5.6 mg/kg) only decreased rectal temperature. DHβE (up to 5.6 mg/kg) when studied prior to daily nicotine decreased rectal temperature, but that decrease was abolished during chronic nicotine treatment. Mecamylamine and DHβE antagonized the rate-decreasing and hypothermic effects of nicotine before and after daily nicotine; however, during daily nicotine, mecamylamine and DHβE antagonized only the hypothermic effects of nicotine. CONCLUSIONS The differential antagonism of rate-decreasing and hypothermic effects implicates differential involvement of nAChR subtypes. The decreased capacity of mecamylamine and DHβE to antagonize nicotine during chronic nicotine treatment may indicate that their effectiveness as smoking cessations might vary as a function of nicotine tolerance and dependence.
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Affiliation(s)
- Fernando B de Moura
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Behavioral Biology Program, McLean Hospital, Belmont, MA, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Jenny L Wilkerson
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, USA
| | - Lance R McMahon
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, USA
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Terry AV, Callahan PM. α7 nicotinic acetylcholine receptors as therapeutic targets in schizophrenia: Update on animal and clinical studies and strategies for the future. Neuropharmacology 2020; 170:108053. [PMID: 32188568 DOI: 10.1016/j.neuropharm.2020.108053] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 10/24/2022]
Abstract
Schizophrenia is a devastating mental illness and its effective treatment is among the most challenging issues in psychiatry. The symptoms of schizophrenia are heterogeneous ranging from positive symptoms (e.g., delusions, hallucinations) to negative symptoms (e.g., anhedonia, social withdrawal) to cognitive dysfunction. Antipsychotics are effective at ameliorating positive symptoms in some patients; however, they are not reliably effective at improving the negative symptoms or cognitive impairments. The inability to address the cognitive impairments is a particular concern since they have the greatest long-term impact on functional outcomes. While decades of research have been devoted to the development of pro-cognitive agents for schizophrenia, to date, no drug has been approved for clinical use. Converging behavioral, neurobiological, and genetic evidence led to the identification of the α7-nicotinic acetylcholine receptor (α7-nAChR) as a therapeutic target several years ago and there is now extensive preclinical evidence that α7-nAChR ligands have pro-cognitive effects and other properties that should be beneficial to schizophrenia patients. However, like the other pro-cognitive strategies, no α7-nAChR ligand has been approved for clinical use in schizophrenia thus far. In this review, several topics are discussed that may impact the success of α7-nAChR ligands as pro-cognitive agents for schizophrenia including the translational value of the animal models used, clinical trial design limitations, confounding effects of polypharmacy, dose-effect relationships, and chronic versus intermittent dosing considerations. Determining the most optimal pharmacologic strategy at α7-nAChRs: agonist, positive allosteric modulator, or potentially even receptor antagonist is also discussed. article is part of the special issue on 'Contemporary Advances in Nicotine Neuropharmacology'.
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Affiliation(s)
- Alvin V Terry
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, 30912, Georgia; Small Animal Behavior Core, Medical College of Georgia, Augusta University, Augusta, 30912, Georgia.
| | - Patrick M Callahan
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, 30912, Georgia; Small Animal Behavior Core, Medical College of Georgia, Augusta University, Augusta, 30912, Georgia
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50
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Positive and inverse correlation of blood lead level with erythrocyte acetylcholinesterase and intelligence quotient in children: implications for neurotoxicity. Interdiscip Toxicol 2020; 12:136-142. [PMID: 32210702 PMCID: PMC7085300 DOI: 10.2478/intox-2019-0016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 09/12/2019] [Indexed: 11/29/2022] Open
Abstract
Blood lead level (BLL) is insufficiently sensitive for early detection of Lead-induced neurotoxicity (LIN). This study determined the possible role of the combination of BLL, intelligent quotient (IQ) and erythrocyte acetylcholinesterase (AChE) activity in the early detection of LIN in Children. Apparently healthy children (n=309) from eight public primary schools in Ibadan, Nigeria were recruited and classified into: children with Elevated BLL (EBLL) and children with Acceptable BLL (control) based on CDC cut-off for childhood lead exposure. Neurological indices (speech, memory, cranial nerves and cerebellar functions), IQ, BLL and erythrocyte AChE activity were assessed using standard methods, Standard Progressive Matrices, AAS and HPLC respectively. Statistical analysis involved Student’s t-test, Pearson’s correlation and multivariate regression. p<0.05 was considered significant. There were 169 (54.7%) children with EBLL while there were 140 (45.3%) control children. Both groups exhibited normal speech, memory, cranial nerves and cerebellar functions. However, IQ was lower in EBLL children (85.9±11.6) compared with control (91.5±14.0) while BLL and AChE activity were higher in EBLL children (0.4±0.1 μmol/l; 117.5±25.5 μkat/l) compared with control (0.2±0.0 μmol/l; 59.4±10.2 μkat/l). BLL showed inverse correlation with IQ (r=–0.134, p=0.019) but positive correlation with AChE (r=0.978, p≤0.001). 16.2% of the observed variation in BLL could be accounted for by AChE using the equation; [BLL=–0.007+0.003 AChE] p<0.05. Elevated blood lead level is prevalent among the school children and appears to have adverse effect on their IQ. Erythrocyte AChE could be a promising marker for early recognition of significant environmental lead exposure and lead-induced neurotoxicity in children.
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