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Pan L, Xiao S, Xu Z, Li W, Zhao L, Zhang L, Qi R, Wang J, Cai Y. Orexin-A attenuated motion sickness through modulating neural activity in hypothalamus nuclei. Br J Pharmacol 2024; 181:1474-1493. [PMID: 38129941 DOI: 10.1111/bph.16307] [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: 05/30/2023] [Revised: 12/08/2023] [Accepted: 12/09/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND AND PURPOSE We evaluated the hypothesis that central orexin application could counteract motion sickness responses through regulating neural activity in target brain areas. EXPERIMENTAL APPROACH Thec effects of intracerebroventricular (i.c.v.) injection of orexin-A and SB-334867 (OX1 antagonist) on motion sickness-induced anorexia, nausea-like behaviour (conditioned gaping), hypoactivity and hypothermia were investigated in rats subjected to Ferris wheel-like rotation. Orexin-A responsive brain areas were identified using Fos immunolabelling and were verified via motion sickness responses after intranucleus injection of orexin-A, SB-334867 and TCS-OX2-29 (OX2 antagonist). The efficacy of intranasal application of orexin-A versus scopolamine on motion sickness symptoms in cats was also investigated. KEY RESULTS Orexin-A (i.c.v.) dose-dependently attenuated motion sickness-related behavioural responses and hypothermia. Fos expression was inhibited in the ventral part of the dorsomedial hypothalamus (DMV) and the paraventricular nucleus (PVN), but was enhanced in the ventral part of the premammillary nucleus ventral part (PMV) by orexin-A (20 μg) in rotated animals. Motion sickness responses were differentially inhibited by orexin-A injection into the DMV (anorexia and hypoactivity), the PVN (conditioned gaping) and the PMV (hypothermia). SB-334867 and TCS-OX2-29 (i.c.v. and intranucleus injection) inhibited behavioural and thermal effects of orexin-A. Orexin-A (60 μg·kg-1) and scopolamine inhibited rotation-induced emesis and non-retching/vomiting symptoms, while orexin-A also attenuated anorexia with mild salivation in motion sickness cats. CONCLUSION AND IMPLICATIONS Orexin-A might relieve motion sickness through acting on OX1 and OX2 receptors in various hypothalamus nuclei. Intranasal orexin-A could be a potential strategy against motion sickness.
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Affiliation(s)
- Leilei Pan
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Shuifeng Xiao
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Zichao Xu
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Wenping Li
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Long Zhao
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Ling Zhang
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Ruirui Qi
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Junqin Wang
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Yiling Cai
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Naval Medical University (Second Military Medical University), Shanghai, China
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Hu X, Liu W, Yan Y, Deng H, Cai Y. Tropinone reductase: A comprehensive review on its role as the key enzyme in tropane alkaloids biosynthesis. Int J Biol Macromol 2023; 253:127377. [PMID: 37839598 DOI: 10.1016/j.ijbiomac.2023.127377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 09/28/2023] [Accepted: 10/09/2023] [Indexed: 10/17/2023]
Abstract
TAs, including hyoscyamine and scopolamine, were used to treat neuromuscular disorders ranging from nerve agent poisoning to Parkinson's disease. Tropinone reductase I (TR-I; EC 1.1.1.206) catalyzed the conversion of tropinone into tropine in the biosynthesis of TAs, directing the metabolic flow towards hyoscyamine and scopolamine. Tropinone reductase II (TR-II; EC 1.1.1.236) was responsible for the conversion of tropinone into pseudotropine, diverting the metabolic flux towards calystegine A3. The regulation of metabolite flow through both branches of the TAs pathway seemed to be influenced by the enzymatic activity of both enzymes and their accessibility to the precursor tropinone. The significant interest in the utilization of metabolic engineering for the efficient production of TAs has highlighted the importance of TRs as crucial enzymes that govern both the direction of metabolic flow and the yield of products. This review discussed recent advances for the TRs sources, properties, protein structure and biocatalytic mechanisms, and a detailed overview of its crucial role in the metabolism and synthesis of TAs was summarized. Furthermore, we conducted a detailed investigation into the evolutionary origins of these two TRs. A prospective analysis of potential challenges and applications of TRs was presented.
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Affiliation(s)
- Xiaoxiang Hu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Wenjing Liu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Yi Yan
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Huaxiang Deng
- Center for Synthetic Biochemistry, Institute of Synthetic Biology, Institutes of Advanced Technologies, Shenzhen, China
| | - Yujie Cai
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
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Manno FAM, Cheung P, Basnet V, Khan MS, Mao Y, Pan L, Ma V, Cho WC, Tian S, An Z, Feng Y, Cai YL, Pienkowski M, Lau C. Subtle alterations of vestibulomotor functioning in conductive hearing loss. Front Neurosci 2023; 17:1057551. [PMID: 37706156 PMCID: PMC10495589 DOI: 10.3389/fnins.2023.1057551] [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: 10/21/2022] [Accepted: 06/08/2023] [Indexed: 09/15/2023] Open
Abstract
Introduction Conductive hearing loss (CHL) attenuates the ability to transmit air conducted sounds to the ear. In humans, severe hearing loss is often accompanied by alterations to other neural systems, such as the vestibular system; however, the inter-relations are not well understood. The overall goal of this study was to assess vestibular-related functioning proxies in a rat CHL model. Methods Male Sprague-Dawley rats (N=134, 250g, 2months old) were used in a CHL model which produced a >20dB threshold shift induced by tympanic membrane puncture. Auditory brainstem response (ABRs) recordings were used to determine threshold depth at different times before and after CHL. ABR threshold depths were assessed both manually and by an automated ABR machine learning algorithm. Vestibular-related functioning proxy assessment was performed using the rotarod, balance beam, elevator vertical motion (EVM) and Ferris-wheel rotation (FWR) assays. Results The Pre-CHL (control) threshold depth was 27.92dB±11.58dB compared to the Post-CHL threshold depth of 50.69dB±13.98dB (mean±SD) across the frequencies tested. The automated ABR machine learning algorithm determined the following threshold depths: Pre-CHL=24.3dB, Post-CHL same day=56dB, Post-CHL 7 days=41.16dB, and Post-CHL 1 month=32.5dB across the frequencies assessed (1, 2, 4, 8, 16, and 32kHz). Rotarod assessment of motor function was not significantly different between pre and post-CHL (~1week) rats for time duration (sec) or speed (RPM), albeit the former had a small effect size difference. Balance beam time to transverse was significantly longer for post-CHL rats, likely indicating a change in motor coordination. Further, failure to cross was only noted for CHL rats. The defection count was significantly reduced for CHL rats compared to control rats following FWR, but not EVM. The total distance traveled during open-field examination after EVM was significantly different between control and CHL rats, but not for FWR. The EVM is associated with linear acceleration (acting in the vertical plane: up-down) stimulating the saccule, while the FWR is associated with angular acceleration (centrifugal rotation about a circular axis) stimulating both otolith organs and semicircular canals; therefore, the difference in results could reflect the specific vestibular-organ functional role. Discussion Less movement (EVM) and increase time to transverse (balance beam) may be associated with anxiety and alterations to defecation patterns (FWR) may result from autonomic disturbances due to the impact of hearing loss. In this regard, vestibulomotor deficits resulting in changes in balance and motion could be attributed to comodulation of auditory and vestibular functioning. Future studies should manipulate vestibular functioning directly in rats with CHL.
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Affiliation(s)
- Francis A. M. Manno
- Department of Physics, East Carolina University, Greenville, NC, United States
- Department of Biomedical Engineering, Center for Imaging Science, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, United States
- Center for Advanced Nuclear Safety and Sustainable Development, City University of Hong Kong, Kowloon, Hong Kong SAR, China
- Department of Physics, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Pikting Cheung
- Department of Physics, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Vardhan Basnet
- Department of Physics, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | | | - Yuqi Mao
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Second Military Medical University, Shanghai, China
| | - Leilei Pan
- Department of Nautical Injury Prevention, Faculty of Navy Medicine, Second Military Medical University, Shanghai, China
| | - Victor Ma
- Department of Clinical Oncology, Queen Elizabeth Hospital, Kowloon, Hong Kong SAR, China
| | - William C. Cho
- Department of Clinical Oncology, Queen Elizabeth Hospital, Kowloon, Hong Kong SAR, China
| | - Shile Tian
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Ziqi An
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Yanqiu Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Medical Image Processing and Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Southern Medical University, Guangzhou, China
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yi-Ling Cai
- Department of Physics, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Martin Pienkowski
- Osborne College of Audiology, Salus University, Elkins Park, PA, United States
| | - Condon Lau
- Center for Advanced Nuclear Safety and Sustainable Development, City University of Hong Kong, Kowloon, Hong Kong SAR, China
- Department of Physics, City University of Hong Kong, Kowloon, Hong Kong SAR, China
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Graham AS, Ben-Azu B, Tremblay MÈ, Torre P, Senekal M, Laughton B, van der Kouwe A, Jankiewicz M, Kaba M, Holmes MJ. A review of the auditory-gut-brain axis. Front Neurosci 2023; 17:1183694. [PMID: 37600010 PMCID: PMC10435389 DOI: 10.3389/fnins.2023.1183694] [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: 03/10/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023] Open
Abstract
Hearing loss places a substantial burden on medical resources across the world and impacts quality of life for those affected. Further, it can occur peripherally and/or centrally. With many possible causes of hearing loss, there is scope for investigating the underlying mechanisms involved. Various signaling pathways connecting gut microbes and the brain (the gut-brain axis) have been identified and well established in a variety of diseases and disorders. However, the role of these pathways in providing links to other parts of the body has not been explored in much depth. Therefore, the aim of this review is to explore potential underlying mechanisms that connect the auditory system to the gut-brain axis. Using select keywords in PubMed, and additional hand-searching in google scholar, relevant studies were identified. In this review we summarize the key players in the auditory-gut-brain axis under four subheadings: anatomical, extracellular, immune and dietary. Firstly, we identify important anatomical structures in the auditory-gut-brain axis, particularly highlighting a direct connection provided by the vagus nerve. Leading on from this we discuss several extracellular signaling pathways which might connect the ear, gut and brain. A link is established between inflammatory responses in the ear and gut microbiome-altering interventions, highlighting a contribution of the immune system. Finally, we discuss the contribution of diet to the auditory-gut-brain axis. Based on the reviewed literature, we propose numerous possible key players connecting the auditory system to the gut-brain axis. In the future, a more thorough investigation of these key players in animal models and human research may provide insight and assist in developing effective interventions for treating hearing loss.
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Affiliation(s)
- Amy S. Graham
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
| | - Benneth Ben-Azu
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
- Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada
- Institute for Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada
| | - Peter Torre
- School of Speech, Language, and Hearing Sciences, San Diego State University, San Diego, CA, United States
| | - Marjanne Senekal
- Department of Human Biology, Division of Physiological Sciences, University of Cape Town, Cape Town, South Africa
| | - Barbara Laughton
- Family Clinical Research Unit, Department of Pediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | - Andre van der Kouwe
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States
- Department of Radiology, Harvard Medical School, Boston, MA, United States
| | - Marcin Jankiewicz
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
| | - Mamadou Kaba
- Department of Pathology, Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa
| | - Martha J. Holmes
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- ImageTech, Simon Fraser University, Surrey, BC, Canada
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Zhang T, Guan T, Yao H, Wang LA, Wang Y, Guan Z. Brown Slime Cap Mushroom (Chroogomphus rutilus, Agaricomycetes) Polysaccharide Resists Motion Sickness by Inhibiting the Activity of the Serotonin System in Mice. Int J Med Mushrooms 2023; 25:1-13. [PMID: 37947060 DOI: 10.1615/intjmedmushrooms.2023050471] [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: 11/12/2023]
Abstract
Motion sickness (MS) is a disorder of the autonomic nervous system caused by abnormal exercise with symptoms such as nausea, vomiting and drowsiness. More than 90% of the human population has experienced different degrees of MS. At present, anticholinergics, antihistamines, and sympathomimetic drugs are used for treating MS, but these drugs generally have some adverse reactions and are not suitable for all people. Therefore, it is necessary to develop anti-MS drugs that have high efficiency and no adverse effects. Previous studies have found that Chroogomphus rutilus polysaccharide (CRP) is effective at preventing and treating MS in rats and mice. However, its mechanism of action is not clear. To clarify whether the CRP has anti-MS effects in mice, and to clarify its mechanism, we performed behavioral, biochemical, and morphological tests in a Kunming mouse model. Our results indicate that CRPs can significantly relieve the symptoms of MS, and their effect is equivalent to that of scopolamine, a commonly used anti-MS medicine. Our results indicate that CRPs may directly act on the gastrointestinal chromaffin cells to inhibit the synthesis and release of serotonin (5-hydroxytryptamine, or 5-HT) and thus reduce the signal from the gastrointestinal tract.
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Affiliation(s)
- Tao Zhang
- Hebei Research Center of the Basic Discipline of Cell Biology, Hebei Key Laboratory of Physiology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, P.R. China
| | - Tianyuan Guan
- Department of Neurology, Hebei General Hospital, Shijiazhuang, 050051, P.R. China
| | - Hui Yao
- Hebei Research Center of the Basic Discipline of Cell Biology, Hebei Key Laboratory of Physiology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, P.R. China
| | - Li-An Wang
- Hebei Research Center of the Basic Discipline of Cell Biology, Hebei Key Laboratory of Physiology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, P.R. China
| | - Yanqin Wang
- Hebei Research Center of the Basic Discipline of Cell Biology, Hebei Key Laboratory of Physiology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, P.R. China
| | - Zhenlong Guan
- Hebei Research Center of the Basic Discipline of Cell Biology, Hebei Key Laboratory of Physiology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, P.R. China
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Mao Y, Pan L, Li W, Xiao S, Qi R, Zhao L, Wang J, Cai Y. Stroboscopic lighting with intensity synchronized to rotation velocity alleviates motion sickness gastrointestinal symptoms and motor disorders in rats. Front Integr Neurosci 2022; 16:941947. [PMID: 35965602 PMCID: PMC9366139 DOI: 10.3389/fnint.2022.941947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/06/2022] [Indexed: 11/18/2022] Open
Abstract
Motion sickness (MS) is caused by mismatch between conflicted motion perception produced by motion challenges and expected “internal model” of integrated motion sensory pattern formed under normal condition in the brain. Stroboscopic light could reduce MS nausea symptom via increasing fixation ability for gaze stabilization to reduce visuo-vestibular confliction triggered by distorted vision during locomotion. This study tried to clarify whether MS induced by passive motion could be alleviated by stroboscopic light with emitting rate and intensity synchronized to acceleration–deceleration phase of motion. We observed synchronized and unsynchronized stroboscopic light (SSL: 6 cycle/min; uSSL: 2, 4, and 8 cycle/min) on MS-related gastrointestinal symptoms (conditioned gaping and defecation responses), motor disorders (hypoactivity and balance disturbance), and central Fos protein expression in rats receiving Ferris wheel-like rotation (6 cycle/min). The effects of color temperature and peak light intensity were also examined. We found that SSL (6 cycle/min) significantly reduced rotation-induced conditioned gaping and defecation responses and alleviated rotation-induced decline in spontaneous locomotion activity and disruption in balance beam performance. The efficacy of SSL against MS behavioral responses was affected by peak light intensity but not color temperature. The uSSL (4 and 8 cycle/min) only released defecation but less efficiently than SSL, while uSSL (2 cycle/min) showed no beneficial effect in MS animals. SSL but not uSSL inhibited Fos protein expression in the caudal vestibular nucleus, the nucleus of solitary tract, the parabrachial nucleus, the central nucleus of amygdala, and the paraventricular nucleus of hypothalamus, while uSSL (4 and 8 cycle/min) only decreased Fos expression in the paraventricular nucleus of hypothalamus. These results suggested that stroboscopic light synchronized to motion pattern might alleviate MS gastrointestinal symptoms and motor disorders and inhibit vestibular-autonomic pathways. Our study supports the utilization of motion-synchronous stroboscopic light as a potential countermeasure against MS under abnormal motion condition in future.
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Lee C, Sinha AK, Henry K, Walbaum AW, Crooks PA, Holt JC. Characterizing the Access of Cholinergic Antagonists to Efferent Synapses in the Inner Ear. Front Neurosci 2022; 15:754585. [PMID: 34970112 PMCID: PMC8712681 DOI: 10.3389/fnins.2021.754585] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 11/15/2021] [Indexed: 11/13/2022] Open
Abstract
Stimulation of cholinergic efferent neurons innervating the inner ear has profound, well-characterized effects on vestibular and auditory physiology, after activating distinct ACh receptors (AChRs) on afferents and hair cells in peripheral endorgans. Efferent-mediated fast and slow excitation of vestibular afferents are mediated by α4β2*-containing nicotinic AChRs (nAChRs) and muscarinic AChRs (mAChRs), respectively. On the auditory side, efferent-mediated suppression of distortion product otoacoustic emissions (DPOAEs) is mediated by α9α10nAChRs. Previous characterization of these synaptic mechanisms utilized cholinergic drugs, that when systemically administered, also reach the CNS, which may limit their utility in probing efferent function without also considering central effects. Use of peripherally-acting cholinergic drugs with local application strategies may be useful, but this approach has remained relatively unexplored. Using multiple administration routes, we performed a combination of vestibular afferent and DPOAE recordings during efferent stimulation in mouse and turtle to determine whether charged mAChR or α9α10nAChR antagonists, with little CNS entry, can still engage efferent synaptic targets in the inner ear. The charged mAChR antagonists glycopyrrolate and methscopolamine blocked efferent-mediated slow excitation of mouse vestibular afferents following intraperitoneal, middle ear, or direct perilymphatic administration. Both mAChR antagonists were effective when delivered to the middle ear, contralateral to the side of afferent recordings, suggesting they gain vascular access after first entering the perilymphatic compartment. In contrast, charged α9α10nAChR antagonists blocked efferent-mediated suppression of DPOAEs only upon direct perilymphatic application, but failed to reach efferent synapses when systemically administered. These data show that efferent mechanisms are viable targets for further characterizing drug access in the inner ear.
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Affiliation(s)
- Choongheon Lee
- Department of Otolaryngology, University of Rochester, Rochester, NY, United States
| | - Anjali K Sinha
- Department of Neuroscience, University of Rochester, Rochester, NY, United States
| | - Kenneth Henry
- Department of Otolaryngology, University of Rochester, Rochester, NY, United States.,Department of Neuroscience, University of Rochester, Rochester, NY, United States
| | - Anqi W Walbaum
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Peter A Crooks
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Joseph C Holt
- Department of Otolaryngology, University of Rochester, Rochester, NY, United States.,Department of Neuroscience, University of Rochester, Rochester, NY, United States.,Department of Pharmacology & Physiology, University of Rochester, Rochester, NY, United States
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Deshetty UM, Tamatam A, Patil MM. Menthol, a bioactive constituent of Mentha, attenuates motion sickness in mice model: Involvement of dopaminergic system. J Food Biochem 2021; 45:e13863. [PMID: 34245039 DOI: 10.1111/jfbc.13863] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/25/2021] [Accepted: 06/30/2021] [Indexed: 10/20/2022]
Abstract
Motion sickness (MS) occurs due to contradicting vestibular and visual inputs to the brain causing nausea and vomiting. Antidopaminergic drugs being effective in reducing MS create a path for effective therapy against MS by regulating dopamine levels. We aimed to evaluate the role of the striatum and brainstem dopamine and dopamine D2 receptor (DRD2) in MS and the efficacy of menthol (MNT) to modulate dopamine and DRD2 in vitro and in vivo for possible amelioration of MS. Evaluation of efficacy of MNT to inhibit dopamine release from PC12 cells and anti-MS efficacy in BALB/c mice model was performed. Dopamine, DRD2 expression in PC12 cells, mice striatum, and brainstem were detected using HPLC-ECD, RT-PCR, and Western blot analysis, respectively. DRD2 expression increased in calcium ionophore-treated PC12 cells compared with control cells. Pretreatment with 50 μg/ml menthol decreased dopamine and DRD2 expression. Similarly, dopamine and DRD2 levels in mice striatum and brainstem of MS group (rotation induced) increased significantly compared with control group NC (no rotation). Pretreatment with menthol at 50 mg/kg concentration (rotation induced) showed decreased dopamine and DRD2 expression, thus indicating ameliorative effect on MS. Hence, we suggest that increased striatum and brainstem dopamine and DRD2 levels might lead to MS symptoms, and menthol could be used as a potent herbal alternative medicine for MS. PRACTICAL APPLICATIONS: Antidopaminergic drugs being effective in reducing motion sickness (MS) creates a path for effective therapy against MS by regulating dopamine levels. Increased striatum and brainstem dopamine and Dopamine D2 receptor (DRD2) levels might lead to the MS symptoms induced by rotation stimulation in mice model. Menthol showed a prophylactic effect on rotation-induced MS by reducing striatal and brainstem dopamine levels, DRD2 mRNA, and protein expression. Menthol could be used as an herbal alternative to antidopaminergics to minimize the associated adverse effects.
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Affiliation(s)
- Uma Maheswari Deshetty
- Nutrition, Biochemistry & Toxicology Division, Defence Food Research Laboratory, Mysore, India
| | - Anand Tamatam
- Nutrition, Biochemistry & Toxicology Division, Defence Food Research Laboratory, Mysore, India
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The mammalian efferent vestibular system utilizes cholinergic mechanisms to excite primary vestibular afferents. Sci Rep 2021; 11:1231. [PMID: 33441862 PMCID: PMC7806594 DOI: 10.1038/s41598-020-80367-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 12/18/2020] [Indexed: 02/06/2023] Open
Abstract
Electrical stimulation of the mammalian efferent vestibular system (EVS) predominantly excites primary vestibular afferents along two distinct time scales. Although roles for acetylcholine (ACh) have been demonstrated in other vertebrates, synaptic mechanisms underlying mammalian EVS actions are not well-characterized. To determine if activation of ACh receptors account for efferent-mediated afferent excitation in mammals, we recorded afferent activity from the superior vestibular nerve of anesthetized C57BL/6 mice while stimulating EVS neurons in the brainstem, before and after administration of cholinergic antagonists. Using a normalized coefficient of variation (CV*), we broadly classified vestibular afferents as regularly- (CV* < 0.1) or irregularly-discharging (CV* > 0.1) and characterized their responses to midline or ipsilateral EVS stimulation. Afferent responses to efferent stimulation were predominantly excitatory, grew in amplitude with increasing CV*, and consisted of fast and slow components that could be identified by differences in rise time and post-stimulus duration. Both efferent-mediated excitatory components were larger in irregular afferents with ipsilateral EVS stimulation. Our pharmacological data show, for the first time in mammals, that muscarinic AChR antagonists block efferent-mediated slow excitation whereas the nicotinic AChR antagonist DHβE selectively blocks efferent-mediated fast excitation, while leaving the efferent-mediated slow component intact. These data confirm that mammalian EVS actions are predominantly cholinergic.
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Ilaiyaraja N, Singsit D, Patil MM, Priyadharshini S, Rashmi V, Khanum F. Motion sickness-relieving effects of Tamzin, a herbal formulation: In vitro and in vivo studies. FOOD BIOSCI 2020. [DOI: 10.1016/j.fbio.2020.100595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Leung AK, Hon KL. Motion sickness: an overview. Drugs Context 2019; 8:dic-2019-9-4. [PMID: 32158479 PMCID: PMC7048153 DOI: 10.7573/dic.2019-9-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 12/18/2022] Open
Abstract
Background Motion sickness is a common phenomenon that affects almost everybody at some point in their lifetime. Clinicians should be familiar with the proper management of this condition. Objective To provide an update on the current understanding of the pathophysiology and management of motion sickness. Methods A PubMed search was performed with Clinical Queries using the key term ‘motion sickness.’ The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature. The information retrieved from the earlier search was used in the compilation of the present article. Results Motion sickness is typically triggered by low-frequency vertical, lateral, angular, rotary motion, or virtual stimulator motion, to which an individual has not adapted. Sine qua non for developing motion sickness is when the brain receives conflicting information from different sensors about real body movements or virtual environment. The principal sensors are the eyes, the vestibular apparatus, and proprioceptive receptors. The conflicting information is judged in relation to a pattern of expected associations formed under normal or experienced conditions stored in the brain. Motion sickness typically presents with malaise, anorexia, nausea, yawning, sighing, increased salivation, burping, headache, blurred vision, non-vertiginous dizziness, drowsiness, spatial disorientation, difficulty concentrating, and sometimes vomiting. Simple behavioral and environmental modifications can be effective in the prevention of motion sickness. Medications that are effective in the prophylaxis and/or treatment of motion sickness include anticholinergics, antihistamines, and sympathomimetics. Conclusion In most cases, motion sickness can be prevented by behavioral and environmental modifications (avoidance, habituation, and minimization of motion stimuli). Pharmacotherapy should be considered in the prevention and/or treatment of more severe motion sickness and for patients who do not respond to conservative measures. Medications are most effective when combined with behavioral and environmental modifications. Drugs that are effective in the prophylaxis and/or treatment of motion sickness include anticholinergic agents and antihistamines.
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Affiliation(s)
- Alexander Kc Leung
- Department of Pediatrics, The University of Calgary, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Kam Lun Hon
- Department of Paediatrics, The Chinese University of Hong Kong, Shatin, Hong Kong.,Department of Paediatrics and Adolescent Medicine, The Hong Kong Children's Hospital, Hong Kong
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Mandzhulo A, Vashchenko I, Gerasov A, Vovk M, Rusanov E, Fetyukhin V, Lukin O, Shivanyuk A. Selective synthesis of N-protected exo-spiro[oxirane-3,2′-tropanes]. Org Chem Front 2019. [DOI: 10.1039/c9qo00377k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
N-Cbz- and N-Boc-protected exo-spiro[oxirane-3,2′-tropanes] were selectively synthesized via either epoxidation or hydroxybromination/dehydrobromination of the corresponding alkenes.
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Affiliation(s)
- Aleksandr Mandzhulo
- Life Chemicals Inc
- Kyiv
- Ukraine
- Institute of Organic Chemistry
- National Academy of Sciences of Ukraine
| | | | | | - Mykhaylo Vovk
- Institute of Organic Chemistry
- National Academy of Sciences of Ukraine
- Kyiv
- Ukraine
| | - Eduard Rusanov
- Institute of Organic Chemistry
- National Academy of Sciences of Ukraine
- Kyiv
- Ukraine
| | | | | | - Alexander Shivanyuk
- Life Chemicals Inc
- Kyiv
- Ukraine
- The Institute of High Technologies
- Taras Shevchenko National University of Kyiv
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