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Oldroyd P, Oldroyd S, Meng M, Makwana R, Sanger G, Bulmer D, Malliaras GG, Owens RM. Stretchable Device for Simultaneous Measurements of Contractility and Electrophysiology of Neuromuscular Tissue in the Gastrointestinal Tract. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2312735. [PMID: 38290128 DOI: 10.1002/adma.202312735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 01/15/2024] [Indexed: 02/01/2024]
Abstract
Devices interfacing with biological tissues can provide valuable insights into function, disease, and metabolism through electrical and mechanical signals. However, certain neuromuscular tissues, like those in the gastrointestinal tract, undergo significant strains of up to 40%. Conventional inextensible devices cannot capture the dynamic responses in these tissues. This study introduces electrodes made from poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and polydimethylsiloxane (PDMS) that enable simultaneous monitoring of electrical and mechanical responses of gut tissue. The soft PDMS layers conform to tissue surfaces during gastrointestinal movement. Dopants, including Capstone FS-30 and polyethylene glycol, are explored to enhance the conductivity, electrical sensitivity to strain, and stability of the PEDOT:PSS. The devices are fabricated using shadow masks and solution-processing techniques, providing a faster and simpler process than traditional clean-room-based lithography. Tested on ex vivo mouse colon and human stomach, the device recorded voltage changes of up to 300 µV during contraction and distension consistent with muscle activity, while simultaneously recording resistance changes of up to 150% due to mechanical strain. These devices detect and respond to chemical stimulants and blockers, and can induce contractions through electrical stimulation. They hold great potential for studying and treating complex disorders like irritable bowel syndrome and gastroparesis.
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Affiliation(s)
- Poppy Oldroyd
- Electrical Engineering Division, Department of Engineering, University of Cambridge, Cambridge, CB3 0FA, UK
| | - Sophie Oldroyd
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
| | - Michelle Meng
- Department of Pharmacology, Tennis Ct Rd, University of Cambridge, Cambridge, CB2 1PD, UK
| | - Rajesh Makwana
- Blizard Institute, Queen Mary University of London, Cambridge, E1 2AT, UK
| | - Gareth Sanger
- Blizard Institute, Queen Mary University of London, Cambridge, E1 2AT, UK
| | - David Bulmer
- Department of Pharmacology, Tennis Ct Rd, University of Cambridge, Cambridge, CB2 1PD, UK
| | - George G Malliaras
- Electrical Engineering Division, Department of Engineering, University of Cambridge, Cambridge, CB3 0FA, UK
| | - Róisín M Owens
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK
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2
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Sasidharan A, Peethambar BA, Kumar KS, Kumar AV, Hiregange A, Fawkes N, Collins JF, Grosche A, Vidyasagar S. Advancing peristalsis deciphering in mouse small intestine by multi-parameter tracking. Commun Biol 2023; 6:1237. [PMID: 38062160 PMCID: PMC10703907 DOI: 10.1038/s42003-023-05631-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
Assessing gastrointestinal motility lacks simultaneous evaluation of intraluminal pressure (ILP), circular muscle (CM) and longitudinal muscle (LM) contraction, and lumen emptying. In this study, a sophisticated machine was developed that synchronized real-time recordings to quantify the intricate interplay between CM and LM contractions, and their timings for volume changes using high-resolution cameras with machine learning capability, the ILP using pressure transducers and droplet discharge (DD) using droplet counters. Results revealed four distinct phases, BPhase, NPhase, DPhase, and APhase, distinguished by pressure wave amplitudes. Fluid filling impacted LM strength and contraction frequency initially, followed by CM contraction affecting ILP, volume, and the extent of anterograde, retrograde, and segmental contractions during these phases that result in short or long duration DD. This comprehensive analysis sheds light on peristalsis mechanisms, understand their sequence and how one parameter influenced the other, offering insights for managing peristalsis by regulating smooth muscle contractions.
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Affiliation(s)
- Anusree Sasidharan
- Department of Radiation Oncology, University of Florida, Gainesville, FL, USA
| | | | | | - Ashok V Kumar
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL, USA
| | | | | | - James F Collins
- Food Science and Human Nutrition Department, University of Florida, Gainesville, FL, USA
| | - Astrid Grosche
- Department of Radiation Oncology, University of Florida, Gainesville, FL, USA
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3
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Cassidy RM, Flores EM, Trinh Nguyen AK, Cheruvu SS, Uribe RA, Krachler AM, Odem MA. Systematic analysis of proximal midgut- and anorectal-originating contractions in larval zebrafish using event feature detection and supervised machine learning algorithms. Neurogastroenterol Motil 2023; 35:e14675. [PMID: 37743702 PMCID: PMC10841157 DOI: 10.1111/nmo.14675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 07/16/2023] [Accepted: 08/28/2023] [Indexed: 09/26/2023]
Abstract
BACKGROUND Zebrafish larvae are translucent, allowing in vivo analysis of gut development and physiology, including gut motility. While recent progress has been made in measuring gut motility in larvae, challenges remain which can influence results, such as how data are interpreted, opportunities for technical user error, and inconsistencies in methods. METHODS To overcome these challenges, we noninvasively introduced Nile Red fluorescent dye to fill the intraluminal gut space in zebrafish larvae and collected serial confocal microscopic images of gut fluorescence. We automated the detection of fluorescent-contrasted contraction events against the median-subtracted signal and compared it to manually annotated gut contraction events across anatomically defined gut regions. Supervised machine learning (multiple logistic regression) was then used to discriminate between true contraction events and noise. To demonstrate, we analyzed motility in larvae under control and reserpine-treated conditions. We also used automated event detection analysis to compare unfed and fed larvae. KEY RESULTS Automated analysis retained event features for proximal midgut-originating retrograde and anterograde contractions and anorectal-originating retrograde contractions. While manual annotation showed reserpine disrupted gut motility, machine learning only achieved equivalent contraction discrimination in controls and failed to accurately identify contractions after reserpine due to insufficient intraluminal fluorescence. Automated analysis also showed feeding had no effect on the frequency of anorectal-originating contractions. CONCLUSIONS & INFERENCES Automated event detection analysis rapidly and accurately annotated contraction events, including the previously neglected phenomenon of anorectal contractions. However, challenges remain to discriminate contraction events based on intraluminal fluorescence under treatment conditions that disrupt functional motility.
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Affiliation(s)
- Ryan M. Cassidy
- Brown Foundation Institute of Molecular Medicine, McGovern
Medical School at UTHealth, Houston, TX 77030, USA
| | - Erika M. Flores
- Department of Microbiology and Molecular Genetics, McGovern
Medical School at UTHealth, Houston, TX 77030, USA
| | - Anh K. Trinh Nguyen
- Department of Microbiology and Molecular Genetics, McGovern
Medical School at UTHealth, Houston, TX 77030, USA
| | - Sai S. Cheruvu
- Department of Integrative Biology and Pharmacology,
McGovern Medical School at UTHealth, Houston, TX 77030, USA
| | - Rosa A. Uribe
- Department of Biosciences, Rice University, Houston, TX
77005, USA
| | - Anne Marie Krachler
- Department of Microbiology and Molecular Genetics, McGovern
Medical School at UTHealth, Houston, TX 77030, USA
| | - Max A. Odem
- Department of Microbiology and Molecular Genetics, McGovern
Medical School at UTHealth, Houston, TX 77030, USA
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4
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Avvari RK. Role of segmental contraction in the small intestinal digestion: A computational approach to study the physics behind the luminal mixing and transport. J Theor Biol 2023; 561:111418. [PMID: 36682409 DOI: 10.1016/j.jtbi.2023.111418] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023]
Abstract
Segmentation is well known to digest the food rich in proteins, starch, and lipids; however, the mechanism leading to the digestion remains unclear. In this study, a theoretical model for segmental contractions of the small intestine is developed using lubrication method to explore the mechanisms involved. Here, the nonlinear partial differential equations governing the fluid flow were normalized in viscous regime and solved semi-analytically for a power law fluid under long wavelength approximation on a MatlabTM platform. Study indicates that shearing is highest at the 1st and 4th mid-occlusion in comparison to 2nd and 3rd mid-occlusion. Parametric study indicates that the flow is sensitive to - the span of segmentation or wavelength of the wave, occlusion of the wave and frequency of the contraction; with shearing being highest for dilatants. Shearing is more prominent at higher occlusion (>50 %) and frequency (>6Hz). Further, mixing is more prominent at the steep regions of the wave; having intensity of mixing highest for the outer waves in comparison to waves at mid-region of the segmentation. The power demand is found to be greater in segmentation and has the following precedence - frequency, wavelength, flow behavior index, and occlusion (up to 80 %). Further, multiplicity of the wave gives rise to multiple zones of mixing which increases the rate of mixing of the contents. Suggesting that, the segmentation primarily serves the purpose of mixing. The study will be useful to explore novel therapeutic strategies of managing patients suffering from various motility-associated disorders of the small intestine.
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Affiliation(s)
- Ravi Kant Avvari
- Department of Biotechnology and Medical Engineering, NIT Rourkela, Odisha 769008, India.
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5
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Du P, Joshi V, Beyder A. Tracking Gut Motility in Organ and Cultures. Methods Mol Biol 2023; 2644:449-466. [PMID: 37142940 DOI: 10.1007/978-1-0716-3052-5_29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Gastrointestinal (GI) motility is a key component of digestive health, and it is complex, involving a multitude of cell types and mechanisms to drive both rhythmic and arrhythmic activity. Tracking GI motility in organ and tissue cultures across multiple temporal (seconds, minutes, hours, days) scales can provide valuable information regarding dysmotility and to evaluate treatment options. Here, the chapter describes a simple method to monitor GI motility in organotypic cultures, using a single video camera is placed perpendicularly to the surface of the tissue. A cross-correlational analysis is used to track the relative movements of tissues between subsequent frames and subsequent fitting procedures to fit finite element functions to the deformed tissue to calculate the strain fields. Additional motility index measures from the displacement information are used to further quantify the behaviors of the tissues that are maintained in organotypic culture over days. The protocols presented in this chapter can be adapted to study organotypic cultures from other organs.
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Affiliation(s)
- Peng Du
- Auckland Bioengineering Institute, Department of Engineering Science and Biomedical Engineering, University of Auckland, Auckland, New Zealand.
| | - Vikram Joshi
- Department of Physiology and Biomedical Engineering, Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Arthur Beyder
- Department of Physiology and Biomedical Engineering, Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
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6
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Andrews PLR, Ponte G, Rosas C. Methodological considerations in studying digestive system physiology in octopus: limitations, lacunae and lessons learnt. Front Physiol 2022; 13:928013. [PMID: 36160859 PMCID: PMC9501996 DOI: 10.3389/fphys.2022.928013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 08/01/2022] [Indexed: 11/13/2022] Open
Abstract
Current understanding of cephalopod digestive tract physiology is based on relatively “old” literature and a “mosaic of data” from multiple species. To provide a background to the discussion of methodologies for investigating physiology we first review the anatomy of the cephalopod digestive tract with a focus on Octopus vulgaris, highlighting structure-function relationships and species differences with potential functional consequences (e.g., absence of a crop in cuttlefish and squid; presence of a caecal sac in squid). We caution about extrapolation of data on the digestive system physiology from one cephalopod species to another because of the anatomical differences. The contribution of anatomical and histological techniques (e.g., digestive enzyme histochemistry and neurotransmitter immunohistochemistry) to understanding physiological processes is discussed. For each major digestive tract function we briefly review current knowledge, and then discuss techniques and their limitations for the following parameters: 1) Measuring motility in vitro (e.g., spatiotemporal mapping, tension and pressure), in vivo (labelled food, high resolution ultrasound) and aspects of pharmacology; 2) Measuring food ingestion and the time course of digestion with an emphasis on understanding enzyme function in each gut region with respect to time; 3) Assessing transepithelial transport of nutrients; 4) Measuring the energetic cost of food processing, impact of environmental temperature and metabolic rate (flow-through/intermittent respirometry); 4) Investigating neural (brain, gastric ganglion, enteric) and endocrine control processes with an emphasis on application of molecular techniques to identify receptors and their ligands. A number of major knowledge lacunae are identified where available techniques need to be applied to cephalopods, these include: 1) What is the physiological function of the caecal leaflets and intestinal typhlosoles in octopus? 2) What role does the transepithelial transport in the caecum and intestine play in ion, water and nutrient transport? 3) What information is signalled from the digestive tract to the brain regarding the food ingested and the progress of digestion? It is hoped that by combining discussion of the physiology of the cephalopod digestive system with an overview of techniques and identification of key knowledge gaps that this will encourage a more systematic approach to research in this area.
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Affiliation(s)
- Paul L. R. Andrews
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
- *Correspondence: Paul L. R. Andrews,
| | - Giovanna Ponte
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Carlos Rosas
- Unidad Multidisciplinaria de Docencia e Investigación, Facultad de Ciencias, Universidad Nacional Autónoma de México, Sisal, Yucatán, Mexico
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Kamran SA, Hossain KF, Moghnieh H, Riar S, Bartlett A, Tavakkoli A, Sanders KM, Baker SA. New open-source software for subcellular segmentation and analysis of spatiotemporal fluorescence signals using deep learning. iScience 2022; 25:104277. [PMID: 35573197 PMCID: PMC9095751 DOI: 10.1016/j.isci.2022.104277] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 04/04/2022] [Accepted: 04/18/2022] [Indexed: 11/20/2022] Open
Abstract
Cellular imaging instrumentation advancements as well as readily available optogenetic and fluorescence sensors have yielded a profound need for fast, accurate, and standardized analysis. Deep-learning architectures have revolutionized the field of biomedical image analysis and have achieved state-of-the-art accuracy. Despite these advancements, deep learning architectures for the segmentation of subcellular fluorescence signals is lacking. Cellular dynamic fluorescence signals can be plotted and visualized using spatiotemporal maps (STMaps), and currently their segmentation and quantification are hindered by slow workflow speed and lack of accuracy, especially for large datasets. In this study, we provide a software tool that utilizes a deep-learning methodology to fundamentally overcome signal segmentation challenges. The software framework demonstrates highly optimized and accurate calcium signal segmentation and provides a fast analysis pipeline that can accommodate different patterns of signals across multiple cell types. The software allows seamless data accessibility, quantification, and graphical visualization and enables large dataset analysis throughput.
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Affiliation(s)
- Sharif Amit Kamran
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Anderson Medical Building MS352, Reno, NV 89557, USA
- Department of Computer Science and Engineering, University of Nevada, Reno, NV 89557, USA
| | | | - Hussein Moghnieh
- Department of Electrical and Computer Engineering], McGill University, Montréal, QC H3A 0E9, Canada
| | - Sarah Riar
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Anderson Medical Building MS352, Reno, NV 89557, USA
| | - Allison Bartlett
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Anderson Medical Building MS352, Reno, NV 89557, USA
| | - Alireza Tavakkoli
- Department of Computer Science and Engineering, University of Nevada, Reno, NV 89557, USA
| | - Kenton M. Sanders
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Anderson Medical Building MS352, Reno, NV 89557, USA
| | - Salah A. Baker
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Anderson Medical Building MS352, Reno, NV 89557, USA
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8
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Waclawiková B, Codutti A, Alim K, El Aidy S. Gut microbiota-motility interregulation: insights from in vivo, ex vivo and in silico studies. Gut Microbes 2022; 14:1997296. [PMID: 34978524 PMCID: PMC8741295 DOI: 10.1080/19490976.2021.1997296] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/30/2021] [Accepted: 10/19/2021] [Indexed: 02/06/2023] Open
Abstract
The human gastrointestinal tract is home to trillions of microbes. Gut microbial communities have a significant regulatory role in the intestinal physiology, such as gut motility. Microbial effect on gut motility is often evoked by bioactive molecules from various sources, including microbial break down of carbohydrates, fibers or proteins. In turn, gut motility regulates the colonization within the microbial ecosystem. However, the underlying mechanisms of such regulation remain obscure. Deciphering the inter-regulatory mechanisms of the microbiota and bowel function is crucial for the prevention and treatment of gut dysmotility, a comorbidity associated with many diseases. In this review, we present an overview of the current knowledge on the impact of gut microbiota and its products on bowel motility. We discuss the currently available techniques employed to assess the changes in the intestinal motility. Further, we highlight the open challenges, and incorporate biophysical elements of microbes-motility interplay, in an attempt to lay the foundation for describing long-term impacts of microbial metabolite-induced changes in gut motility.
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Affiliation(s)
- Barbora Waclawiková
- Host-Microbe Interactions, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
| | - Agnese Codutti
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
| | - Karen Alim
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- Physics Department and Center for Protein Assemblies (CPA), Technische Universität München, Garching, Germany
| | - Sahar El Aidy
- Host-Microbe Interactions, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands
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9
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Costa M, Wiklendt L, Hibberd T, Dinning P, Spencer NJ, Brookes S. Analysis of Intestinal Movements with Spatiotemporal Maps: Beyond Anatomy and Physiology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1383:271-294. [PMID: 36587166 DOI: 10.1007/978-3-031-05843-1_26] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Over 150 years ago, methods for quantitative analysis of gastrointestinal motor patterns first appeared. Graphic representations of physiological variables were recorded with the kymograph after the mid-1800s. Changes in force or length of intestinal muscles could be quantified, however most recordings were limited to a single point along the digestive tract.In parallel, photography and cinematography with X-Rays visualised changes in intestinal shape, but were hard to quantify. More recently, the ability to record physiological events at many sites along the gut in combination with computer processing allowed construction of spatiotemporal maps. These included diameter maps (DMaps), constructed from video recordings of intestinal movements and pressure maps (PMaps), constructed using data from high-resolution manometry catheters. Combining different kinds of spatiotemporal maps revealed additional details about gut wall status, including compliance, which relates forces to changes in length. Plotting compliance values along the intestine enabled combined DPMaps to be constructed, which can distinguish active contractions and relaxations from passive changes. From combinations of spatiotemporal maps, it is possible to deduce the role of enteric circuits and pacemaker cells in the generation of complex motor patterns. Development and application of spatiotemporal methods to normal and abnormal motor patterns in animals and humans is ongoing, with further technical improvements arising from their combination with impedance manometry, magnetic resonance imaging, electrophysiology, and ultrasonography.
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Affiliation(s)
- Marcello Costa
- College of Medicine and Public Health, Department of Human Physiology, Flinders University, Bedford Park, SA, Australia.
| | - Luke Wiklendt
- Department of Gastroenterology and Surgery, Flinders Medical Centre, Bedford Park, SA, Australia
| | - Tim Hibberd
- College of Medicine and Public Health, Department of Human Physiology, Flinders University, Bedford Park, SA, Australia
| | - Phil Dinning
- Department of Gastroenterology and Surgery, Flinders Medical Centre, Bedford Park, SA, Australia
| | - Nick J Spencer
- College of Medicine and Public Health, Department of Human Physiology, Flinders University, Bedford Park, SA, Australia
| | - Simon Brookes
- College of Medicine and Public Health, Department of Human Physiology, Flinders University, Bedford Park, SA, Australia
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10
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Loppini A, Erhardt J, Fenton FH, Filippi S, Hörning M, Gizzi A. Optical Ultrastructure of Large Mammalian Hearts Recovers Discordant Alternans by In Silico Data Assimilation. FRONTIERS IN NETWORK PHYSIOLOGY 2022; 2:866101. [PMID: 36926104 PMCID: PMC10012998 DOI: 10.3389/fnetp.2022.866101] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/04/2022] [Indexed: 12/12/2022]
Abstract
Understanding and predicting the mechanisms promoting the onset and sustainability of cardiac arrhythmias represent a primary concern in the scientific and medical communities still today. Despite the long-lasting effort in clinical and physico-mathematical research, a critical aspect to be fully characterized and unveiled is represented by spatiotemporal alternans patterns of cardiac excitation. The identification of discordant alternans and higher-order alternating rhythms by advanced data analyses as well as their prediction by reliable mathematical models represents a major avenue of research for a broad and multidisciplinary scientific community. Current limitations concern two primary aspects: 1) robust and general-purpose feature extraction techniques and 2) in silico data assimilation within reliable and predictive mathematical models. Here, we address both aspects. At first, we extend our previous works on Fourier transformation imaging (FFI), applying the technique to whole-ventricle fluorescence optical mapping. Overall, we identify complex spatial patterns of voltage alternans and characterize higher-order rhythms by a frequency-series analysis. Then, we integrate the optical ultrastructure obtained by FFI analysis within a fine-tuned electrophysiological mathematical model of the cardiac action potential. We build up a novel data assimilation procedure demonstrating its reliability in reproducing complex alternans patterns in two-dimensional computational domains. Finally, we prove that the FFI approach applied to both experimental and simulated signals recovers the same information, thus closing the loop between the experiment, data analysis, and numerical simulations.
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Affiliation(s)
- Alessandro Loppini
- Nonlinear Physics and Mathematical Modeling Laboratory, University Campus Bio-Medico of Rome, Rome, Italy
| | - Julia Erhardt
- Biobased Materials Laboratory, Institute of Biomaterials and Biomolecular Systems, Faculty of Energy, Process and Biotechnology, University of Stuttgart, Stuttgart, Germany
| | - Flavio H Fenton
- School of Physics, Georgia Institute of Technology, Atlanta, GA, United States
| | - Simonetta Filippi
- Nonlinear Physics and Mathematical Modeling Laboratory, University Campus Bio-Medico of Rome, Rome, Italy
| | - Marcel Hörning
- Biobased Materials Laboratory, Institute of Biomaterials and Biomolecular Systems, Faculty of Energy, Process and Biotechnology, University of Stuttgart, Stuttgart, Germany
| | - Alessio Gizzi
- Nonlinear Physics and Mathematical Modeling Laboratory, University Campus Bio-Medico of Rome, Rome, Italy
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11
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Kuruppu S, Cheng LK, Nielsen PMF, Gamage TPB, Avci R, Angeli TR, Paskaranandavadivel N. High-Resolution Spatiotemporal Quantification of Intestinal Motility with Free-Form Deformation. IEEE Trans Biomed Eng 2021; 69:2077-2086. [PMID: 34910629 DOI: 10.1109/tbme.2021.3135855] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To develop a method to quantify strain fields from in vivo intestinal motility recordings that mitigate accumulation of tracking error. METHODS The deforming geometry of the intestine in video sequences was modeled by a biquadratic B-spline mesh. Green-Lagrange strain fields were computed to quantify the surface deformations from motility. A nonlinear optimization scheme was applied to mitigate the accumulation of tracking error associated with image registration. RESULTS The optimization scheme maintained the RMS strain error under 1% and reduced the rate of strain error by 97% during synthetic tests. The algorithm was applied to map 64 segmental, 12 longitudinal, and 23 propagating circular contractions in the jejunum. Coordinated activity of the two muscle layers could be identified and the strain fields were able to map and quantify the anisotropic contractions of the intestine. Frequency and velocity were also quantified, from which two types of propagating circular contractions were identified: (i) -0:360:04 strain contractions that originated spontaneously and propagated at 31 mm/s in two pigs, and (ii) cyclic propagating contractions of -0:170:02 strain occurred at 11:00:6 cpm and propagated at 164 mm/s in a rabbit. CONCLUSION The algorithm simultaneously mapped the circular, longitudinal activity of the intestine with high spatial resolution and quantified anisotropic contractions and relaxations. SIGNIFICANCE The proposed algorithm can now be used to define the interactions of muscle layers during motility patterns. It can be integrated with high-resolution bioelectrical recordings to investigate the regulatory mechanisms of motility.
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12
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Ibrahim HMM, El-Ashker MR. Reference Values and Repeatability of Transabdominal Ultrasonographic Gastrointestinal Tract Thickness and Motility in Healthy Donkeys (Equus asinus). J Equine Vet Sci 2020; 92:103153. [PMID: 32797781 DOI: 10.1016/j.jevs.2020.103153] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/30/2020] [Accepted: 06/01/2020] [Indexed: 01/03/2023]
Abstract
The present study aimed to provide reference ranges for the wall thickness and motility pattern of the gastrointestinal tract from a sample of donkeys (Equus asinus) population using B-mode ultrasonography. In the present study, 30 clinically healthy donkeys (Equus asinus) (15 males and 15 females), aged 2-20 year old and weighed 100-280 kg were randomly selected for B-mode ultrasonographic scanning of the abdomen. The wall thickness of the stomach, duodenum, jejunum, left colon, right colon, and cecum was assessed. Moreover, the motility pattern of the duodenum, jejunum, left colon, right colon, and cecum was evaluated over a period of 3 minutes. Abdominal ultrasonographic scanning of the gastrointestinal tract of healthy donkeys explored that the stomach, duodenum, jejunum, left colon, right colon, and cecum could be visualized easily. The wall thickness of the stomach, duodenum, jejunum, left colon, right colon, and cecum was 7.0 ± 0.9 mm, 3.3 ± 1.0 mm, 5.4 ± 0.6 mm, 5.1 ± 0.5 mm, 5.4 ± 0.5 mm, and 5.4 ± 0.6 mm, respectively. The thickest part of the gastrointestinal tract is the stomach, whereas the thinnest part is the duodenum. The motility pattern of the duodenum, jejunum, left colon, right colon, and cecum was 7.7 ± 1.3 contractions/3 minutes, 6.9 ± 1.1 contractions/3 minutes, 4.1 ± 1.2 contractions/3 minutes, 5.5 ± 1.3 contractions/3 minutes, and 4.0 ± 0.8 contractions/3 minutes, respectively. Both the duodenum and jejunum contractions were significantly higher than that of the left colon, right colon, and cecum. This is the first study reporting the reference values for both the wall thickness and motility pattern of the gastrointestinal tract in healthy donkeys (Equus asinus) in Egypt. Good knowledge of these standard and reference values of the wall thickness and motility pattern of gastrointestinal tract structures represents a step in the early diagnosis of the gastrointestinal disorders, including colic in such animal species.
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Affiliation(s)
- Hussam M M Ibrahim
- Department of Internal Medicine, Infectious and Fish Diseases, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
| | - Maged R El-Ashker
- Department of Internal Medicine, Infectious and Fish Diseases, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
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Chevalier NR, Dacher N, Jacques C, Langlois L, Guedj C, Faklaris O. Embryogenesis of the peristaltic reflex. J Physiol 2019; 597:2785-2801. [PMID: 30924929 DOI: 10.1113/jp277746] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 03/28/2019] [Indexed: 12/31/2022] Open
Abstract
KEY POINTS Neurogenic gut movements start after longitudinal smooth muscle differentiation in three species (mouse, zebrafish, chicken), and at E16 in the chicken embryo. The first activity of the chicken enteric nervous system is dominated by inhibitory neurons. The embryonic enteric nervous system electromechanically couples circular and longitudinal spontaneous myogenic contractions, thereby producing a new, rostro-caudally directed bolus transport pattern: the migrating motor complex. The response of the embryonic gut to mechanical stimulation evolves from a symmetric, myogenic response at E12, to a neurally mediated, polarized, descending inhibitory, 'law of the intestine'-like response at E16. High resolution, whole-mount 3D reconstructions are presented of the enteric nervous system of the chicken embryo at the neural-control stage E16 with the iDISCO+ tissue clarification technique. ABSTRACT Gut motility is a complex transport phenomenon involving smooth muscle, enteric neurons, glia and interstitial cells of Cajal. Because these different cells differentiate and become active at different times during embryo development, studying the ontogenesis of motility offers a unique opportunity to 'time-reverse-engineer' the peristaltic reflex. Working on chicken embryo intestinal explants in vitro, we found by spatio-temporal mapping and signal processing of diameter and position changes that motility follows a characteristic sequence of increasing complexity: (1) myogenic circular smooth muscle contractions from E6 to E12 that propagate as waves along the intestine, (2) overlapping and independent, myogenic, low-frequency, bulk longitudinal smooth muscle contractions around E14, and (3) tetrodotoxin-sensitive coupling of longitudinal and circular contractions by the enteric nervous system as from E16. Inhibition of nitric oxide synthase neurons shows that the coupling consists in nitric oxide-mediated relaxation of circular smooth muscle when the longitudinal muscle layer is contracted. This mechanosensitive coupling gives rise to a directional, cyclical, propagating bolus transport pattern: the migrating motor complex. We further reveal a transition to a polarized, descending, inhibitory reflex response to mechanical stimulation after neuronal activity sets in at E16. This asymmetric response is the elementary mechanism responsible for peristaltic transport. We finally present unique high-resolution 3D reconstructions of the chicken enteric nervous system at the neural-control stage based on confocal imaging of iDISCO+ clarified tissues. Our study shows that the enteric nervous system gives rise to new peristaltic transport patterns during development by coupling spontaneous circular and longitudinal smooth muscle contraction waves.
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Affiliation(s)
- Nicolas R Chevalier
- Laboratoire Matière et Systèmes Complexes, Université Paris Diderot/CNRS UMR 7057, Sorbonne Paris Cité, 10 rue Alice Domon et Léonie Duquet, 75013, Paris, France
| | - Nicolas Dacher
- Laboratoire Matière et Systèmes Complexes, Université Paris Diderot/CNRS UMR 7057, Sorbonne Paris Cité, 10 rue Alice Domon et Léonie Duquet, 75013, Paris, France
| | - Cécile Jacques
- Laboratoire Matière et Systèmes Complexes, Université Paris Diderot/CNRS UMR 7057, Sorbonne Paris Cité, 10 rue Alice Domon et Léonie Duquet, 75013, Paris, France
| | - Lucas Langlois
- Laboratoire Matière et Systèmes Complexes, Université Paris Diderot/CNRS UMR 7057, Sorbonne Paris Cité, 10 rue Alice Domon et Léonie Duquet, 75013, Paris, France
| | - Chloé Guedj
- Imagoseine Core Facility, Institut Jacques Monod, Université Paris Diderot/CNRS UMR7592, 15 rue Hélène Brion, 75013, Paris, France
| | - Orestis Faklaris
- Imagoseine Core Facility, Institut Jacques Monod, Université Paris Diderot/CNRS UMR7592, 15 rue Hélène Brion, 75013, Paris, France.,MRI Core facility, Biocampus, UMS 3426 CNRS - Université Montpellier, 141 rue de la Cardonille, 34094 Montpellier Cedex 5, France
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