1
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Zhang Y, Hu Z, Wang Y, Kais S. Quantum Simulation of the Radical Pair Dynamics of the Avian Compass. J Phys Chem Lett 2023; 14:832-837. [PMID: 36655839 DOI: 10.1021/acs.jpclett.2c03617] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The simulation of open quantum dynamics on quantum circuits has attracted wide interests recently with a variety of quantum algorithms developed and demonstrated. Among these, one particular design of a unitary-dilation-based quantum algorithm is capable of simulating general and complex physical systems. In this paper, we apply this quantum algorithm to simulating the dynamics of the radical pair mechanism in the avian compass. This application is demonstrated on the IBM QASM quantum simulator. This work is the first application of any quantum algorithm to simulating the radical pair mechanism in the avian compass, which not only demonstrates the generality of the quantum algorithm but also opens new opportunities for studying the avian compass with quantum computing devices.
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Affiliation(s)
| | - Zixuan Hu
- Department of Chemistry, Department of Physics, and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana47907, United States
| | - Yuchen Wang
- Department of Chemistry, Department of Physics, and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana47907, United States
| | - Sabre Kais
- Department of Chemistry, Department of Physics, and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana47907, United States
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2
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Beshkar M. The QBIT Theory: Consciousness from Entangled Qubits. Integr Psychol Behav Sci 2022:10.1007/s12124-022-09745-w. [PMID: 36567412 DOI: 10.1007/s12124-022-09745-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2022] [Indexed: 12/26/2022]
Abstract
How does the brain generate consciousness? The present paper is an attempt to answer this question from the perspective of the QBIT theory. In sum, the theory argues that the brain has a prior belief (P) about the stimulus that has caused a sensory representation (R) to be created in the brain. When the conditional entropy of P given R becomes less than zero, the brain becomes more than certain about (i.e. becomes conscious of) the stimulus. Conditional entropy can become negative (and thus the brain can become more than certain) only if the brain uses entangled quantum information in its computations. The QBIT theory suggests that, at the most fundamental level, consciousness is nothing but a special kind of entangled information.
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Affiliation(s)
- Majid Beshkar
- Tehran University of Medical Sciences, Tehran, Iran.
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3
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Zadeh-Haghighi H, Simon C. Magnetic field effects in biology from the perspective of the radical pair mechanism. J R Soc Interface 2022; 19:20220325. [PMID: 35919980 PMCID: PMC9346374 DOI: 10.1098/rsif.2022.0325] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 07/14/2022] [Indexed: 04/07/2023] Open
Abstract
Hundreds of studies have found that weak magnetic fields can significantly influence various biological systems. However, the underlying mechanisms behind these phenomena remain elusive. Remarkably, the magnetic energies implicated in these effects are much smaller than thermal energies. Here, we review these observations, and we suggest an explanation based on the radical pair mechanism, which involves the quantum dynamics of the electron and nuclear spins of transient radical molecules. While the radical pair mechanism has been studied in detail in the context of avian magnetoreception, the studies reviewed here show that magnetosensitivity is widespread throughout biology. We review magnetic field effects on various physiological functions, discussing static, hypomagnetic and oscillating magnetic fields, as well as isotope effects. We then review the radical pair mechanism as a potential unifying model for the described magnetic field effects, and we discuss plausible candidate molecules for the radical pairs. We review recent studies proposing that the radical pair mechanism provides explanations for isotope effects in xenon anaesthesia and lithium treatment of hyperactivity, magnetic field effects on the circadian clock, and hypomagnetic field effects on neurogenesis and microtubule assembly. We conclude by discussing future lines of investigation in this exciting new area of quantum biology.
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Affiliation(s)
- Hadi Zadeh-Haghighi
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - Christoph Simon
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 1N4
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4
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Zadeh-Haghighi H, Simon C. Radical pairs may play a role in microtubule reorganization. Sci Rep 2022; 12:6109. [PMID: 35414166 PMCID: PMC9005667 DOI: 10.1038/s41598-022-10068-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 04/01/2022] [Indexed: 12/14/2022] Open
Abstract
The exact mechanism behind general anesthesia remains an open question in neuroscience. It has been proposed that anesthetics selectively prevent consciousness and memory via acting on microtubules (MTs). It is known that the magnetic field modulates MT organization. A recent study shows that a radical pair model can explain the isotope effect in xenon-induced anesthesia and predicts magnetic field effects on anesthetic potency. Further, reactive oxygen species are also implicated in MT stability and anesthesia. Based on a simple radical pair mechanism model and a simple mathematical model of MT organization, we show that magnetic fields can modulate spin dynamics of naturally occurring radical pairs in MT. We propose that the spin dynamics influence a rate in the reaction cycle, which translates into a change in the MT density. We can reproduce magnetic field effects on the MT concentration that have been observed. Our model also predicts additional effects at slightly higher fields. Our model further predicts that the effect of zinc on the MT density exhibits isotopic dependence. The findings of this work make a connection between microtubule-based and radical pair-based quantum theories of consciousness.
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Affiliation(s)
- Hadi Zadeh-Haghighi
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Institute for Quantum Science and Technology, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 1N4, Canada.
| | - Christoph Simon
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Institute for Quantum Science and Technology, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 1N4, Canada.
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5
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Zadeh-Haghighi H, Simon C. Radical pairs can explain magnetic field and lithium effects on the circadian clock. Sci Rep 2022; 12:269. [PMID: 34997158 PMCID: PMC8742017 DOI: 10.1038/s41598-021-04334-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 12/14/2021] [Indexed: 12/21/2022] Open
Abstract
Drosophila's circadian clock can be perturbed by magnetic fields, as well as by lithium administration. Cryptochromes are critical for the circadian clock. Further, the radical pairs in cryptochrome also can explain magnetoreception in animals. Based on a simple radical pair mechanism model of the animal magnetic compass, we show that both magnetic fields and lithium can influence the spin dynamics of the naturally occurring radical pairs and hence modulate the circadian clock's rhythms. Using a simple chemical oscillator model for the circadian clock, we show that the spin dynamics influence a rate in the chemical oscillator model, which translates into a change in the circadian period. Our model can reproduce the results of two independent experiments, magnetic field and lithium effects on the circadian clock. Our model predicts that stronger magnetic fields would shorten the clock's period. We also predict that lithium influences the clock in an isotope-dependent manner. Furthermore, our model also predicts that magnetic fields and hyperfine interactions modulate oxidative stress. The findings of this work suggest that the quantum nature of radical pairs might play roles in the brain, as another piece of evidence in addition to recent results on xenon anesthesia and lithium effects on hyperactivity.
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Affiliation(s)
- Hadi Zadeh-Haghighi
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Institute for Quantum Science and Technology, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 1N4, Canada.
| | - Christoph Simon
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Institute for Quantum Science and Technology, University of Calgary, Calgary, AB, T2N 1N4, Canada.
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 1N4, Canada.
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6
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Sajjan M, Sureshbabu SH, Kais S. Quantum Machine-Learning for Eigenstate Filtration in Two-Dimensional Materials. J Am Chem Soc 2021; 143:18426-18445. [PMID: 34705449 DOI: 10.1021/jacs.1c06246] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Quantum machine-learning algorithms have emerged to be a promising alternative to their classical counterparts as they leverage the power of quantum computers. Such algorithms have been developed to solve problems like electronic structure calculations of molecular systems and spin models in magnetic systems. However, the discussion in all these recipes focuses specifically on targeting the ground state. Herein we demonstrate a quantum algorithm that can filter any energy eigenstate of the system based on either symmetry properties or a predefined choice of the user. The workhorse of our technique is a shallow neural network encoding the desired state of the system with the amplitude computed by sampling the Gibbs-Boltzmann distribution using a quantum circuit and the phase information obtained classically from the nonlinear activation of a separate set of neurons. We show that the resource requirements of our algorithm are strictly quadratic. To demonstrate its efficacy, we use state filtration in monolayer transition metal dichalcogenides which are hitherto unexplored in any flavor of quantum simulations. We implement our algorithm not only on quantum simulators but also on actual IBM-Q quantum devices and show good agreement with the results procured from conventional electronic structure calculations. We thus expect our protocol to provide a new alternative in exploring the band structures of exquisite materials to usual electronic structure methods or machine-learning techniques that are implementable solely on a classical computer.
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Affiliation(s)
- Manas Sajjan
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Shree Hari Sureshbabu
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Sabre Kais
- Department of Chemistry, Department of Physics and Astronomy, and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, United States
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7
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Jain R, Poonia VS, Saha K, Saha D, Ganguly S. The avian compass can be sensitive even without sustained electron spin coherence. Proc Math Phys Eng Sci 2021. [DOI: 10.1098/rspa.2020.0778] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Theoretical studies indicating the presence of long-lived coherence in the radical pair system have engendered questions about its utilitarian role in the avian compass. In this paper, we investigate the role of electron spin coherence in a multinuclear radical pair system including its impact on compass sensitivity. We find that sustenance of long-lived electron spin coherence is unlikely in a multinuclear hyperfine environment. After probing the role of the hyperfine interactions in the compass, we affirm the hyperfine anisotropy to be an essential parameter for the necessary sensitivity required for the compass action. Thereby, we identify a parameter regime where the compass would exhibit good sensitivity even without sustained electron spin coherence.
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Affiliation(s)
- Rakshit Jain
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14850, USA
| | - Vishvendra S. Poonia
- Department of Electronics and Communication Engineering, Indian Institute of Technology Roorkee, India
| | - Kasturi Saha
- Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Dipankar Saha
- Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Swaroop Ganguly
- Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
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8
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Kale SS, Ding Y, Chen YP, Friedrich B, Kais S. Spin-momentum entanglement in a Bose–Einstein condensate. Phys Chem Chem Phys 2020; 22:25669-25674. [DOI: 10.1039/d0cp03945d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mechanisms including two types of Raman laser coupling (Ω1 & Ω2) and rf field coupling (Ωrf) are applied to drive transitions between different hyperfine spin states. We investigated the entanglement between the spin and momentum degrees of freedom.
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Affiliation(s)
| | - Yijue Ding
- Department of Chemistry
- Purdue University
- USA
| | - Yong P. Chen
- Purdue Quantum Science and Engineering Institute
- Purdue University
- West Lafayette
- USA
- Department of Physics and Astronomy
| | | | - Sabre Kais
- Department of Chemistry
- Purdue University
- USA
- Purdue Quantum Science and Engineering Institute
- Purdue University
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9
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Fay TP, Lindoy LP, Manolopoulos DE, Hore PJ. How quantum is radical pair magnetoreception? Faraday Discuss 2020; 221:77-91. [DOI: 10.1039/c9fd00049f] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Semiclassical methods cannot accurately simulate magnetic field effects relevant to avian magnetoreception, which may therefore deserve the label “quantum biology”.
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Affiliation(s)
- Thomas P. Fay
- Department of Chemistry
- Physical & Theoretical Chemistry Laboratory
- University of Oxford
- Oxford OX1 3QZ
- UK
| | - Lachlan P. Lindoy
- Department of Chemistry
- Physical & Theoretical Chemistry Laboratory
- University of Oxford
- Oxford OX1 3QZ
- UK
| | - David E. Manolopoulos
- Department of Chemistry
- Physical & Theoretical Chemistry Laboratory
- University of Oxford
- Oxford OX1 3QZ
- UK
| | - P. J. Hore
- Department of Chemistry
- Physical & Theoretical Chemistry Laboratory
- University of Oxford
- Oxford OX1 3QZ
- UK
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10
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Binhi VN. Nonspecific magnetic biological effects: A model assuming the spin-orbit coupling. J Chem Phys 2019; 151:204101. [DOI: 10.1063/1.5127972] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- V. N. Binhi
- Prokhorov General Physics Institute, Moscow 119991, Russian Federation
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11
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Atkins C, Bajpai K, Rumball J, Kattnig DR. On the optimal relative orientation of radicals in the cryptochrome magnetic compass. J Chem Phys 2019. [DOI: 10.1063/1.5115445] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Chadsley Atkins
- Institute and Department of Physics, University of Exeter, North Park Road, Exeter EX4 4QL, United Kingdom
| | - Kieran Bajpai
- Institute and Department of Physics, University of Exeter, North Park Road, Exeter EX4 4QL, United Kingdom
| | - Jeremy Rumball
- Institute and Department of Physics, University of Exeter, North Park Road, Exeter EX4 4QL, United Kingdom
| | - Daniel R. Kattnig
- Institute and Department of Physics, University of Exeter, North Park Road, Exeter EX4 4QL, United Kingdom
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
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12
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Hore PJ. Upper bound on the biological effects of 50/60 Hz magnetic fields mediated by radical pairs. eLife 2019; 8:44179. [PMID: 30801245 PMCID: PMC6417859 DOI: 10.7554/elife.44179] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 02/02/2019] [Indexed: 01/02/2023] Open
Abstract
Prolonged exposure to weak (~1 μT) extremely-low-frequency (ELF, 50/60 Hz) magnetic fields has been associated with an increased risk of childhood leukaemia. One of the few biophysical mechanisms that might account for this link involves short-lived chemical reaction intermediates known as radical pairs. In this report, we use spin dynamics simulations to derive an upper bound of 10 parts per million on the effect of a 1 μT ELF magnetic field on the yield of a radical pair reaction. By comparing this figure with the corresponding effects of changes in the strength of the Earth’s magnetic field, we conclude that if exposure to such weak 50/60 Hz magnetic fields has any effect on human biology, and results from a radical pair mechanism, then the risk should be no greater than travelling a few kilometres towards or away from the geomagnetic north or south pole.
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Affiliation(s)
- P J Hore
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford, United Kingdom
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13
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Quantifying Magnetic Sensitivity of Radical Pair Based Compass by Quantum Fisher Information. Sci Rep 2017; 7:5826. [PMID: 28725054 PMCID: PMC5517522 DOI: 10.1038/s41598-017-06187-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 06/07/2017] [Indexed: 11/08/2022] Open
Abstract
The radical pair (RP) based compass is considered as one of the principal models of avian magnetoreception. Different from the conventional approach where the sensitivity of RP based compass is described by the singlet yield, we introduce the quantum Fisher information (QFI), which represents the maximum information about the magnetic field's direction extracted from the RP state, to quantify the sensitivity of RP based compass. The consistency between our results and experimental observations suggests that the QFI may serve as a measure to describe the sensitivity of RP based compass. Besides, within the framework of quantum metrology, we give two specific possible measurement schemes and find that the conventional singlet yield is corresponding to the measurement of total angular momentum. Moreover, we show that the measurement of fluctuation of the total magnetic moment is much more accurate than the singlet yield measurement, and is close to the optimal measurement scheme. Finally, the effects of entanglement and decoherence are also discussed in the spirit of our approach.
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14
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Zhang HT, Zhang ZJ, Mo WC, Hu PD, Ding HM, Liu Y, Hua Q, He RQ. Shielding of the geomagnetic field reduces hydrogen peroxide production in human neuroblastoma cell and inhibits the activity of CuZn superoxide dismutase. Protein Cell 2017; 8:527-537. [PMID: 28447293 PMCID: PMC5498340 DOI: 10.1007/s13238-017-0403-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 03/18/2017] [Indexed: 11/01/2022] Open
Abstract
Accumulative evidence has shown the adverse effects of a geomagnetic field shielded condition, so called a hypomagnetic field (HMF), on the metabolic processes and oxidative stress in animals and cells. However, the underlying mechanism remains unclear. In this study, we evaluate the role of HMF on the regulation of cellular reactive oxygen species (ROS) in human neuroblastoma SH-SY5Y cells. We found that HMF exposure led to ROS decrease, and that restoring the decrease by additional H2O2 rescued the HMF-enhanced cell proliferation. The measurements on ROS related indexes, including total anti-oxidant capacity, H2O2 and superoxide anion levels, and superoxide dismutase (SOD) activity and expression, indicated that the HMF reduced H2O2 production and inhibited the activity of CuZn-SOD. Moreover, the HMF accelerated the denaturation of CuZn-SOD as well as enhanced aggregation of CuZn-SOD protein, in vitro. Our findings indicate that CuZn-SOD is able to response to the HMF stress and suggest it a mediator of the HMF effect.
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Affiliation(s)
- Hai-Tao Zhang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zi-Jian Zhang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- Institute of Beijing Chinese Traditional Medicine, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Wei-Chuan Mo
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Ping-Dong Hu
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hai-Min Ding
- Institute of Beijing Chinese Traditional Medicine, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Ying Liu
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Qian Hua
- Institute of Beijing Chinese Traditional Medicine, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Rong-Qiao He
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, 100101, China
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15
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Affiliation(s)
- P. J. Hore
- Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom;
| | - Henrik Mouritsen
- Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität Oldenburg, DE-26111 Oldenburg, Germany;
- Research Centre for Neurosensory Sciences, University of Oldenburg, DE-26111 Oldenburg, Germany
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16
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Hiscock HG, Worster S, Kattnig DR, Steers C, Jin Y, Manolopoulos DE, Mouritsen H, Hore PJ. The quantum needle of the avian magnetic compass. Proc Natl Acad Sci U S A 2016; 113:4634-9. [PMID: 27044102 PMCID: PMC4855607 DOI: 10.1073/pnas.1600341113] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Migratory birds have a light-dependent magnetic compass, the mechanism of which is thought to involve radical pairs formed photochemically in cryptochrome proteins in the retina. Theoretical descriptions of this compass have thus far been unable to account for the high precision with which birds are able to detect the direction of the Earth's magnetic field. Here we use coherent spin dynamics simulations to explore the behavior of realistic models of cryptochrome-based radical pairs. We show that when the spin coherence persists for longer than a few microseconds, the output of the sensor contains a sharp feature, referred to as a spike. The spike arises from avoided crossings of the quantum mechanical spin energy-levels of radicals formed in cryptochromes. Such a feature could deliver a heading precision sufficient to explain the navigational behavior of migratory birds in the wild. Our results (i) afford new insights into radical pair magnetoreception, (ii) suggest ways in which the performance of the compass could have been optimized by evolution, (iii) may provide the beginnings of an explanation for the magnetic disorientation of migratory birds exposed to anthropogenic electromagnetic noise, and (iv) suggest that radical pair magnetoreception may be more of a quantum biology phenomenon than previously realized.
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Affiliation(s)
- Hamish G Hiscock
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Susannah Worster
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Daniel R Kattnig
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Charlotte Steers
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Ye Jin
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - David E Manolopoulos
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Henrik Mouritsen
- Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany; Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany
| | - P J Hore
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom;
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17
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Fu JP, Mo WC, Liu Y, He RQ. Decline of cell viability and mitochondrial activity in mouse skeletal muscle cell in a hypomagnetic field. Bioelectromagnetics 2016; 37:212-22. [PMID: 27003876 DOI: 10.1002/bem.21968] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 02/26/2016] [Indexed: 01/17/2023]
Abstract
Hypomagnetic field (HMF), one of the key environmental risk factors for astronauts traveling in outer space, has previously been shown to repress locomotion of mammalians. However, underlying mechanisms of how HMF affects the motor system remains poorly understood. In this study, we created an HMF (<3 μT) by eliminating geomagnetic field (GMF, ∼50 μT) and exposed primary mouse skeletal muscle cells to this low magnetic field condition for a period of three days. HMF-exposed cells showed a decline in cell viability relative to GMF control, even though cells appeared normal in terms of morphology and survival rate. After a 3-day HMF-exposure, glucose consumption of skeletal muscle cells was significantly lower than GMF control, accompanied by less adenosine triphosphate (ATP) and adenosine diphosphate (ADP) content and higher ADP/ATP ratio. In agreement with these findings, mitochondrial membrane potential of HMF-exposed cells was also lower, whereas levels of cellular Reactive Oxygen Species were higher. Moreover, viability and membrane potential of isolated mitochondria were reduced after 1 h HMF-exposure in vitro. Our results indicate that mitochondria can directly respond to HMF at functional level, and suggest that HMF-induced decline in cell functionality results from a reduction in energy production and mitochondrial activity.
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Affiliation(s)
- Jing-Peng Fu
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of the Chinese Academy of Sciences, Beijing, China
| | - Wei-Chuan Mo
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Ying Liu
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of the Chinese Academy of Sciences, Beijing, China
| | - Rong-Qiao He
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of the Chinese Academy of Sciences, Beijing, China
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18
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Xu BM, Zou J. Dark state population determines magnetic sensitivity in radical pair magnetoreception model. Sci Rep 2016; 6:22417. [PMID: 26926264 PMCID: PMC4772487 DOI: 10.1038/srep22417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 02/15/2016] [Indexed: 11/30/2022] Open
Abstract
What is the real role of the quantum coherence and entanglement in the radical pair (RP) compass, and what determines the singlet yield have not been fully understood. In this paper, we find that the dark states of the two-electron Zeeman energy operator (TEZE) play an important role in the RP compass. We respectively calculate the singlet yields for two initial states in this dark state basis: the coherent state and the same state just removing the dark state coherence. For the later there is neither dark state coherence nor entanglement in the whole dynamical process. Surprisingly we find that in both cases the singlet yields are the same, and based on this result, we believe that the dark state population determines the singlet yield completely, and the dark state coherence and entanglement have little contribution to it. Finally, we also find that the dark state population as well as the singlet yield anisotropy is fragile to the vertical magnetic noise. However, the orientation is robust and is even enhanced by the parallel magnetic noise because the dark states expand a decoherence-free subspace. The dark state population as well as the orientation is more robust to the hyperfine coupling noise.
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Affiliation(s)
- Bao-Ming Xu
- School of Physics, Qufu Normal University, Qufu 273165, China
| | - Jian Zou
- School of Physics, Beijing Institute of Technology, Beijing 100081, China
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