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Wang S, Kennedy N, Fujita K, Uchida SI, Eisaki H, Johnson PD, Davis JCS, O'Mahony SM. Discovery of orbital ordering in Bi 2Sr 2CaCu 2O 8+x. Nat Mater 2024; 23:492-498. [PMID: 38438620 PMCID: PMC10990940 DOI: 10.1038/s41563-024-01817-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 01/22/2024] [Indexed: 03/06/2024]
Abstract
The primordial ingredient of cuprate superconductivity is the CuO2 unit cell. Theories usually concentrate on the intra-atom Coulombic interactions dominating the 3d9 and 3d10 configurations of each copper ion. However, if Coulombic interactions also occur between electrons of the 2p6 orbitals of each planar oxygen atom, spontaneous orbital ordering may split their energy levels. This long-predicted intra-unit-cell symmetry breaking should generate an orbitally ordered phase, for which the charge transfer energy ε separating the 2p6 and 3d10 orbitals is distinct for the two oxygen atoms. Here we introduce sublattice-resolved ε(r) imaging to CuO2 studies and discover intra-unit-cell rotational symmetry breaking of ε(r). Spatially, this state is arranged in disordered Ising domains of orthogonally oriented orbital order bounded by dopant ions, and within whose domain walls low-energy electronic quadrupolar two-level systems occur. Overall, these data reveal a Q = 0 orbitally ordered state that splits the oxygen energy levels by ~50 meV, in underdoped CuO2.
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Affiliation(s)
- Shuqiu Wang
- Clarendon Laboratory, University of Oxford, Oxford, UK.
- Department of Physics, Cornell University, Ithaca, NY, USA.
- H. H. Wills Physics Laboratory, University of Bristol, Bristol, UK.
| | - Niall Kennedy
- Clarendon Laboratory, University of Oxford, Oxford, UK
- School of Physics, University College Cork, Cork, Ireland
| | - Kazuhiro Fujita
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | | | - Hiroshi Eisaki
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Peter D Johnson
- Clarendon Laboratory, University of Oxford, Oxford, UK
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - J C Séamus Davis
- Clarendon Laboratory, University of Oxford, Oxford, UK.
- Department of Physics, Cornell University, Ithaca, NY, USA.
- School of Physics, University College Cork, Cork, Ireland.
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.
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O'Mahony SM, Murphy-Armando F, Murray ÉD, Querales-Flores JD, Savić I, Fahy S. Ultrafast Relaxation of Symmetry-Breaking Photo-Induced Atomic Forces. Phys Rev Lett 2019; 123:087401. [PMID: 31491230 DOI: 10.1103/physrevlett.123.087401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/24/2019] [Indexed: 06/10/2023]
Abstract
We present a first-principles method for the calculation of the temperature-dependent relaxation of symmetry-breaking atomic driving forces in photoexcited systems. We calculate the phonon-assisted decay of the photoexcited force on the low-symmetry E_{g} mode following absorption of an ultrafast pulse in Bi, Sb, and As. The force decay lifetimes for Bi and Sb are of the order of 10 fs and in agreement with recent experiments, demonstrating that electron-phonon scattering is the primary mechanism relaxing the symmetry-breaking forces. Calculations for a range of absorbed photon energies suggest that larger amplitude, symmetry-breaking atomic motion may be induced by choosing a pump photon energy which maximizes the product of the initial E_{g} force and its lifetime. The high-symmetry A_{1g} force undergoes a partial decay to a nonzero constant on similar timescales, which has not yet been measured in experiments. The average imaginary part of the electron self-energy over the photoexcited carrier distribution provides a crude indication of the decay rate of symmetry-breaking forces.
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Affiliation(s)
- Shane M O'Mahony
- Department of Physics, University College Cork, Cork T12K8AF, Ireland
- Tyndall National Institute, Cork T12R5CP, Ireland
| | | | - Éamonn D Murray
- Department of Physics and Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom
| | | | - Ivana Savić
- Tyndall National Institute, Cork T12R5CP, Ireland
| | - Stephen Fahy
- Department of Physics, University College Cork, Cork T12K8AF, Ireland
- Tyndall National Institute, Cork T12R5CP, Ireland
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Balta JY, Cryan JF, O'Mahony SM. The antimicrobial capacity of embalming solutions: a comparative study. J Appl Microbiol 2019; 126:764-770. [PMID: 30597684 DOI: 10.1111/jam.14191] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/12/2018] [Accepted: 12/26/2018] [Indexed: 12/26/2022]
Abstract
AIMS Infectious health risks are associated with handling human cadavers and to decrease such risks, cadavers are embalmed using different chemicals. The aim of this study is to quantify the amount of micro-organisms present in different regions of human cadavers before embalming, after embalming and over a period of 8 months. METHODS AND RESULTS Human cadavers were embalmed using Thiel, formalin, Genelyn and the Imperial College London soft-preservation (ICL-SP) solution with two cadavers per technique. Sterile swabs were used to collect samples from different regions. Samples were collected every 2 months. All cadavers had a high number of microbial colonies before embalming. While no colonies were detected on formalin and Genelyn embalmed cadavers post-embalming, the number of colonies decreased significantly in Thiel-embalmed cadavers and stayed relatively the same in ICL-SP-embalmed cadavers. CONCLUSIONS Formalin-embalmed cadavers showed the strongest disinfecting abilities followed by Thiel-embalmed cadavers, then Genelyn-embalmed cadavers and finally by ICL-SP cadavers. SIGNIFICANCE AND IMPACT OF THE STUDY This study highlights how under researched this area is and the evident variation in the antimicrobial abilities of different embalming solutions on the cadaver as a whole and within different regions of the same cadaver.
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Affiliation(s)
- J Y Balta
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - J F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - S M O'Mahony
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
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Tetel MJ, de Vries GJ, Melcangi RC, Panzica G, O'Mahony SM. Steroids, stress and the gut microbiome-brain axis. J Neuroendocrinol 2018; 30:10.1111/jne.12548. [PMID: 29024170 PMCID: PMC6314837 DOI: 10.1111/jne.12548] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 10/07/2017] [Accepted: 10/09/2017] [Indexed: 12/14/2022]
Abstract
It is becoming well established that the gut microbiome has a profound impact on human health and disease. In this review, we explore how steroids can influence the gut microbiota and, in turn, how the gut microbiota can influence hormone levels. Within the context of the gut microbiome-brain axis, we discuss how perturbations in the gut microbiota can alter the stress axis and behaviour. In addition, human studies on the possible role of gut microbiota in depression and anxiety are examined. Finally, we present some of the challenges and important questions that need to be addressed by future research in this exciting new area at the intersection of steroids, stress, gut-brain axis and human health.
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Affiliation(s)
- M J Tetel
- Neuroscience Program, Wellesley College, Wellesley, MA, USA
| | - G J de Vries
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | - R C Melcangi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - G Panzica
- Dipartimento di Neuroscienze "Rita Levi Montalcini", Neuroscience Institute Cavalieri Ottolenghi (NICO), Università degli Studi di Torino, Orbassano, Italy
| | - S M O'Mahony
- Department of Anatomy and Neuroscience, APC Microbiome Institute, University College Cork, Cork, Ireland
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O'Mahony SM, Clarke G, Dinan TG, Cryan JF. Early-life adversity and brain development: Is the microbiome a missing piece of the puzzle? Neuroscience 2015; 342:37-54. [PMID: 26432952 DOI: 10.1016/j.neuroscience.2015.09.068] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 09/23/2015] [Accepted: 09/25/2015] [Indexed: 12/12/2022]
Abstract
The prenatal and postnatal early-life periods are both dynamic and vulnerable windows for brain development. During these important neurodevelopmental phases, essential processes and structures are established. Exposure to adverse events that interfere with this critical sequence of events confers a high risk for the subsequent emergence of mental illness later in life. It is increasingly accepted that the gastrointestinal microbiota contributes substantially to shaping the development of the central nervous system. Conversely, several studies have shown that early-life events can also impact on this gut community. Due to the bidirectional communication between the gut and the brain, it is possible that aberrant situations affecting either organ in early life can impact on the other. Studies have now shown that deviations from the gold standard trajectory of gut microbiota establishment and development in early life can lead not only to disorders of the gastrointestinal tract but also complex metabolic and immune disorders. These are being extended to disorders of the central nervous system and understanding how the gut microbiome shapes brain and behavior during early life is an important new frontier in neuroscience.
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Affiliation(s)
- S M O'Mahony
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
| | - G Clarke
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - T G Dinan
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - J F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
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Hyland NP, O'Mahony SM, O'Malley D, O'Mahony CM, Dinan TG, Cryan JF. Early-life stress selectively affects gastrointestinal but not behavioral responses in a genetic model of brain-gut axis dysfunction. Neurogastroenterol Motil 2015; 27:105-13. [PMID: 25443141 DOI: 10.1111/nmo.12486] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 11/15/2014] [Indexed: 12/16/2022]
Abstract
BACKGROUND Early-life stress and a genetic predisposition to display an anxiety- and depressive-like phenotype are associated with behavioral and gastrointestinal (GI) dysfunction. Animals exposed to early-life stress, and those genetically predisposed to display anxiety or depressive behaviors, have proven useful tools in which to study stress-related GI disorders, such as irritable bowel syndrome (IBS). IBS is a heterogeneous disorder, and likely a consequence of both genetic and environmental factors. However, the combined effects of early-life stress and a genetic predisposition to display anxiety- and depression-like behaviors on GI function have not been investigated. METHODS We assessed the effect of maternal separation (MS) on behavioral and GI responses in WKY animals relative to a normo-anxious reference strain. KEY RESULTS Both non-separated (NS) WKY and WKY-MS animals displayed anxiety-like responses in the open-field test and depressive-like behaviors in the forced swim test relative to Sprague-Dawley rats. However, MS had no further influence on anxiety- and depressive-like behaviors exhibited by this stress-prone rat strain. Similarly, corticosterone levels measured after the OFT were insensitive to MS in WKY animals. However, WKY-MS displayed significantly increased colonic visceral hypersensitivity, fecal output, and altered colonic cholinergic sensitivity. CONCLUSIONS & INFERENCES Our data suggest that early-life stress, on the background of a genetic predisposition to display an anxiety- and depressive-like phenotype, selectively influences GI function rather than stress-related behaviors. Thus, our findings highlight the importance of genetic predisposition on the outcome of early-life adversity on GI function.
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Affiliation(s)
- N P Hyland
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Pharmacology & Therapeutics, University College Cork, Cork, Ireland
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O'Mahony SM, Felice VD, Nally K, Savignac HM, Claesson MJ, Scully P, Woznicki J, Hyland NP, Shanahan F, Quigley EM, Marchesi JR, O'Toole PW, Dinan TG, Cryan JF. Disturbance of the gut microbiota in early-life selectively affects visceral pain in adulthood without impacting cognitive or anxiety-related behaviors in male rats. Neuroscience 2014; 277:885-901. [PMID: 25088912 DOI: 10.1016/j.neuroscience.2014.07.054] [Citation(s) in RCA: 187] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 06/19/2014] [Accepted: 07/15/2014] [Indexed: 02/08/2023]
Abstract
Disruption of bacterial colonization during the early postnatal period is increasingly being linked to adverse health outcomes. Indeed, there is a growing appreciation that the gut microbiota plays a role in neurodevelopment. However, there is a paucity of information on the consequences of early-life manipulations of the gut microbiota on behavior. To this end we administered an antibiotic (vancomycin) from postnatal days 4-13 to male rat pups and assessed behavioral and physiological measures across all aspects of the brain-gut axis. In addition, we sought to confirm and expand the effects of early-life antibiotic treatment using a different antibiotic strategy (a cocktail of pimaricin, bacitracin, neomycin; orally) during the same time period in both female and male rat pups. Vancomycin significantly altered the microbiota, which was restored to control levels by 8 weeks of age. Notably, vancomycin-treated animals displayed visceral hypersensitivity in adulthood without any significant effect on anxiety responses as assessed in the elevated plus maze or open field tests. Moreover, cognitive performance in the Morris water maze was not affected by early-life dysbiosis. Immune and stress-related physiological responses were equally unaffected. The early-life antibiotic-induced visceral hypersensitivity was also observed in male rats given the antibiotic cocktail. Both treatments did not alter visceral pain perception in female rats. Changes in visceral pain perception in males were paralleled by distinct decreases in the transient receptor potential cation channel subfamily V member 1, the α-2A adrenergic receptor and cholecystokinin B receptor. In conclusion, a temporary disruption of the gut microbiota in early-life results in very specific and long-lasting changes in visceral sensitivity in male rats, a hallmark of stress-related functional disorders of the brain-gut axis such as irritable bowel disorder.
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Affiliation(s)
- S M O'Mahony
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - V D Felice
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - K Nally
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Biochemistry, University College Cork, Cork, Ireland
| | - H M Savignac
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - M J Claesson
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Microbiology, University College Cork, Cork, Ireland
| | - P Scully
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - J Woznicki
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - N P Hyland
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Pharmacology & Therapeutics, University College Cork, Cork, Ireland
| | - F Shanahan
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Medicine, University College Cork, Cork, Ireland
| | - E M Quigley
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - J R Marchesi
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - P W O'Toole
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Microbiology, University College Cork, Cork, Ireland
| | - T G Dinan
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Psychiatry, University College Cork, Cork, Ireland
| | - J F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
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Clarke G, O'Mahony SM, Dinan TG, Cryan JF. Priming for health: gut microbiota acquired in early life regulates physiology, brain and behaviour. Acta Paediatr 2014; 103:812-9. [PMID: 24798884 DOI: 10.1111/apa.12674] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 02/28/2014] [Accepted: 04/28/2014] [Indexed: 12/15/2022]
Abstract
UNLABELLED The infant gut microbiome is dynamic, and radical shifts in composition occur during the first 3 years of life. Disruption of these developmental patterns, and the impact of the microbial composition of our gut on brain and behaviour, has attracted much recent attention. Integrating these observations is an important new research frontier. CONCLUSION Early-life perturbations of the developing gut microbiota can impact on the central nervous system and potentially lead to adverse mental health outcomes.
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Affiliation(s)
- G Clarke
- Alimentary Pharmabiotic Centre; University College Cork; Cork Ireland
- Department of Psychiatry; University College Cork; Cork Ireland
| | - SM O'Mahony
- Alimentary Pharmabiotic Centre; University College Cork; Cork Ireland
- Department of Anatomy and Neuroscience; University College Cork; Cork Ireland
| | - TG Dinan
- Alimentary Pharmabiotic Centre; University College Cork; Cork Ireland
- Department of Psychiatry; University College Cork; Cork Ireland
| | - JF Cryan
- Alimentary Pharmabiotic Centre; University College Cork; Cork Ireland
- Department of Anatomy and Neuroscience; University College Cork; Cork Ireland
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Felice VD, Gibney SM, Gosselin RD, Dinan TG, O'Mahony SM, Cryan JF. Differential activation of the prefrontal cortex and amygdala following psychological stress and colorectal distension in the maternally separated rat. Neuroscience 2014; 267:252-62. [PMID: 24513388 DOI: 10.1016/j.neuroscience.2014.01.064] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/29/2014] [Accepted: 01/30/2014] [Indexed: 12/17/2022]
Abstract
Visceral hypersensitivity is a hallmark of many clinical conditions and remains an ongoing medical challenge. Although the central neural mechanisms that regulate visceral hypersensitivity are incompletely understood, it has been suggested that stress and anxiety often act as initiating or exacerbating factors. Dysfunctional corticolimbic structures have been implicated in disorders of visceral hypersensitivity such as irritable bowel syndrome (IBS). Moreover, the pattern of altered physiological responses to psychological and visceral stressors reported in IBS patients is also observed in the maternally separated (MS) rat model of IBS. However, the relative contribution of various divisions within the cortex to the altered stress responsivity of MS rats remains unknown. The aim of this study was to analyze the cellular activation pattern of the prefrontal cortex and amygdala in response to an acute psychological stressor (open field) and colorectal distension (CRD) using c-fos immunohistochemistry. Several corticoamygdalar structures were analyzed for the presence of c-fos-positive immunoreactivity including the prelimbic cortex, infralimbic cortex, the anterior cingulate cortex (both rostral and caudal) and the amygdala. Our data demonstrate distinct activation patterns within these corticoamygdalar regions including differential activation in basolateral versus central amygdala following exposure to CRD but not the open field stress. The identification of this neuronal activation pattern may provide further insight into the neurochemical pathways through which therapeutic strategies for IBS could be derived.
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Affiliation(s)
- V D Felice
- Department of Anatomy and Neuroscience, University College Cork, Ireland; Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Ireland
| | - S M Gibney
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Ireland
| | - R D Gosselin
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Ireland
| | - T G Dinan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; Department of Psychiatry, University College Cork, Ireland
| | - S M O'Mahony
- Department of Anatomy and Neuroscience, University College Cork, Ireland; Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Ireland.
| | - J F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Ireland
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Davey KJ, Cotter PD, O'Sullivan O, Crispie F, Dinan TG, Cryan JF, O'Mahony SM. Antipsychotics and the gut microbiome: olanzapine-induced metabolic dysfunction is attenuated by antibiotic administration in the rat. Transl Psychiatry 2013; 3:e309. [PMID: 24084940 PMCID: PMC3818006 DOI: 10.1038/tp.2013.83] [Citation(s) in RCA: 167] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 08/15/2013] [Indexed: 12/24/2022] Open
Abstract
The atypical antipsychotic olanzapine is often associated with serious metabolic side effects including weight gain and increased visceral fat. These adverse events are a considerable clinical problem and the mechanisms underlying them are multifactorial and poorly understood. Growing evidence suggests that the gut microbiota has a key role in energy regulation and disease states such as obesity. Moreover, we recently showed that chronic olanzapine altered the composition of the gut microbiome in the rat. It is thus possible that treatments that alter gut microbiota composition could ameliorate olanzapine-induced weight gain and associated metabolic syndrome. To this end, we investigated the impact of antibiotic-induced alteration of the gut microbiota on the metabolic effects associated with chronic olanzapine treatment in female rats. Animals received vehicle or olanzapine (2 mg kg(-1) per day) for 21 days, intraperitoneal injection, two times daily. Animals were also coadministered vehicle or an antibiotic cocktail consisting of neomycin (250 mg kg(-1) per day), metronidazole (50 mg kg(-1) per day) and polymyxin B (9 mg kg(-1) per day) by oral gavage, daily, beginning 5 days before olanzapine treatment. The antibiotic cocktail drastically altered the microbiota of olanzapine-treated rats, and olanzapine alone was also associated with an altered microbiota. Coadministration of the antibiotic cocktail in olanzapine-treated rats attenuated: body weight gain, uterine fat deposition, macrophage infiltration of adipose tissue, plasma free fatty acid levels, all of which were increased by olanzapine alone. These results suggest that the gut microbiome has a role in the cycle of metabolic dysfunction associated with olanzapine, and could represent a novel therapeutic target for preventing antipsychotic-induced metabolic disease.
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Affiliation(s)
- K J Davey
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland,School of Pharmacy, University College Cork, Cork, Ireland
| | - P D Cotter
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland,TeagascFood Research Centre, Moorepark, Fermoy Ireland
| | - O O'Sullivan
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland,TeagascFood Research Centre, Moorepark, Fermoy Ireland
| | - F Crispie
- TeagascFood Research Centre, Moorepark, Fermoy Ireland
| | - T G Dinan
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland,Department of Psychiatry, University College Cork, Cork, Ireland
| | - J F Cryan
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland,Department of Anatomy and Neuroscience, University College Cork, Room 386, Western Gateway Building,Western Road, Cork, NA, Ireland. E-mail:
| | - S M O'Mahony
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
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Abstract
The ability of gut microbiota to communicate with the brain and thus modulate behavior is emerging as an exciting concept in health and disease. The enteric microbiota interacts with the host to form essential relationships that govern homeostasis. Despite the unique enteric bacterial fingerprint of each individual, there appears to be a certain balance that confers health benefits. It is, therefore, reasonable to note that a decrease in the desirable gastrointestinal bacteria will lead to deterioration in gastrointestinal, neuroendocrine or immune relationships and ultimately disease. Therefore, studies focusing on the impact of enteric microbiota on the host and in particular on the central nervous system are essential to our understanding of the influence of this system. Recent studies published in this Journal demonstrate that germ-free mice display alterations in stress-responsivity, central neurochemistry and behavior indicative of a reduction in anxiety in comparison to conventional mice. Such data offer the enticing proposition that specific modulation of the enteric microbiota may be a useful strategy for stress-related disorders and for modulating the co-morbid aspects of gastrointestinal disorders such as irritable bowel syndrome and inflammatory bowel disease.
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Affiliation(s)
- J F Cryan
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
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O'Mahony SM, Bulmer DC, Coelho AM, Fitzgerald P, Bongiovanni C, Lee K, Winchester W, Dinan TG, Cryan JF. 5-HT(2B) receptors modulate visceral hypersensitivity in a stress-sensitive animal model of brain-gut axis dysfunction. Neurogastroenterol Motil 2010; 22:573-8, e124. [PMID: 20003079 DOI: 10.1111/j.1365-2982.2009.01432.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Irritable bowel syndrome (IBS) is associated with an enhanced perception to visceral stimuli and exaggerated stress response. The serotonergic neurotransmitter system has been strongly implicated as a key player in the manifestation of IBS symptomatology including visceral hypersensitivity. However the role of 5-HT(2B) receptors in visceral pain, although speculated, is currently unclear. Thus we assessed the impact of a selective 5-HT(2B) receptor antagonist, RS-127445, on visceral hypersensitivity in a model of brain gut axis dysfunction the Wistar Kyoto (WKY) rat. METHODS Colorectal distension (CRD) was used to assess the visceral sensitivity of the WKY rat compared to normosensitive Sprague Dawley (SD) rats. Once we verified the visceral sensitivity of the WKY rat we assessed the efficacy of RS-127445 in pain signalling from the colorectum. We administered the compound peripherally (i.p.) and centrally (i.c.v.) in order to ascertain the site of action of RS 127445. Behavioural responses to colorectal distention were then monitored. KEY RESULTS The WKY rats were more viscerally hypersensitive than the SD as previously shown. RS-127445 (5 mg kg(-1), i.p.) significantly reversed visceral hypersensitivity in WKY animals. Moreover, when administered intracerebroventricularly RS-127445 (100 nM) also decreased the number of pain behaviours during noxious CRD in the WKY animals. CONCLUSIONS & INFERENCES Taken together, blockade of 5-HT(2B) receptors offers an exciting novel therapeutic target for pain relief in stress-related gastrointestinal disorders such as IBS.
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Affiliation(s)
- S M O'Mahony
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
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Hyland NP, Julio-Pieper M, O'Mahony SM, Bulmer DC, Lee K, Quigley EM, Dinan TG, Cryan JF. A distinct subset of submucosal mast cells undergoes hyperplasia following neonatal maternal separation: a role in visceral hypersensitivity? Gut 2009; 58:1029-30; author reply 1030-1. [PMID: 19520896 DOI: 10.1136/gut.2008.167882] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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