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Stebbing MJ, Shafton AD, Davey CE, Di Natale MR, Furness JB, McAllen RM. A ganglionic intestinointestinal reflex activated by acute noxious challenge. Am J Physiol Gastrointest Liver Physiol 2024; 326:G360-G373. [PMID: 38226653 DOI: 10.1152/ajpgi.00145.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 12/13/2023] [Accepted: 01/07/2024] [Indexed: 01/17/2024]
Abstract
To investigate noxious stimulation-responsive neural circuits that could influence the gut, we recorded from intestinally directed (efferent) nerve filaments dissected from mesenteric nerves close to the small intestine in anesthetized rats. These exhibited baseline multiunit activity that was almost unaffected by vagotomy (VagX) and reduced only slightly by cutting the splanchnic nerves. The activity was halved by hexamethonium (Hex) treatment. When an adjacent gut segment received an intraluminal stimulus 2,4,6-trinitrobenzenesulfonate (TNBS) in 30% ethanol, mesenteric efferent nerve activity increased for more than 1 h. The increased activity was almost unaffected by bilateral vagotomy or splanchnic nerve section, indicating a lack of central nervous involvement, but it was 60% reduced by hexamethonium. Spike sorting discriminated efferent single and predominantly single-unit spike trains that responded to TNBS, were unaffected by splachnectomy but were silenced by hexamethonium. After noxious stimulation of one segment, the adjacent segment showed no evidence of suppression of gut motility or vasoconstriction. We conclude that luminal application of a noxious stimulus to the small intestine activates an entirely peripheral, intestinointestinal reflex pathway. This pathway involves enteric intestinofugal neurons that excite postganglionic sympathetic neurons via a nicotinic synapse. We suggest that the final sympathetic efferent neurons that respond to a tissue damaging stimulus are distinct from vasoconstrictor, secretomotor, and motility inhibiting neurons.NEW & NOTEWORTHY An intraluminal noxious chemical stimulus applied to one segment of small intestine increased mesenteric efferent nerve activity to an adjacent segment. This was identified as a peripheral ganglionic reflex that did not require vagal or spinal connections. Hexamethonium blocked most, but not all, ongoing and reflex mesenteric efferent activity. The prevertebral sympathetic efferent neurons that are activated likely affect inflammatory and immune functions of other gut segments.
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Affiliation(s)
- Martin J Stebbing
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Anatomy and Physiology, University of Melbourne, Parkville, Victoria, Australia
| | - Anthony D Shafton
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Catherine E Davey
- Department of Biomedical Engineering, University of Melbourne, Parkville, Victoria, Australia
| | | | - John B Furness
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Anatomy and Physiology, University of Melbourne, Parkville, Victoria, Australia
| | - Robin M McAllen
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
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Parker JE, Aristieta A, Gittis A, Rubin JE. Introducing the STReaC (Spike Train Response Classification) toolbox. J Neurosci Methods 2024; 401:110000. [PMID: 38486714 PMCID: PMC10936710 DOI: 10.1016/j.jneumeth.2023.110000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
Background This work presents a toolbox that implements methodology for automated classification of diverse neural responses to optogenetic stimulation or other changes in conditions, based on spike train recordings. New Method The toolbox implements what we call the Spike Train Response Classification algorithm (STReaC), which compares measurements of activity during a baseline period with analogous measurements during a subsequent period to identify various responses that might result from an event such as introduction of a sustained stimulus. The analyzed response types span a variety of patterns involving distinct time courses of increased firing, or excitation, decreased firing, or inhibition, or combinations of these. Excitation (inhibition) is identified from a comparative analysis of the spike density function (interspike interval function) for the baseline period relative to the corresponding function for the response period. Results The STReaC algorithm as implemented in this toolbox provides a user-friendly, tunable, objective methodology that can detect a variety of neuronal response types and associated subtleties. We demonstrate this with single-unit neural recordings of rodent substantia nigra pars reticulata (SNr) during optogenetic stimulation of the globus pallidus externa (GPe). Comparison with existing methods In several examples, we illustrate how the toolbox classifies responses in situations in which traditional methods (spike counting and visual inspection) either fail to detect a response or provide a false positive. Conclusions The STReaC toolbox provides a simple, efficient approach for classifying spike trains into a variety of response types defined relative to a period of baseline spiking.
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Affiliation(s)
- John E. Parker
- Department of Mathematics, University of Pittsburgh, Pittsburgh, PA, U.S.A
- Center for the Neural Basis of Cognition, Pittsburgh, PA, U.S.A
| | - Asier Aristieta
- Center for the Neural Basis of Cognition, Pittsburgh, PA, U.S.A
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, U.S.A
| | - Aryn Gittis
- Center for the Neural Basis of Cognition, Pittsburgh, PA, U.S.A
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, U.S.A
| | - Jonathan E. Rubin
- Department of Mathematics, University of Pittsburgh, Pittsburgh, PA, U.S.A
- Center for the Neural Basis of Cognition, Pittsburgh, PA, U.S.A
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Kutafina E, Troglio A, de Col R, Röhrig R, Rossmanith P, Namer B. Decoding Neuropathic Pain: Can We Predict Fluctuations of Propagation Speed in Stimulated Peripheral Nerve? Front Comput Neurosci 2022; 16:899584. [PMID: 35966281 PMCID: PMC9366140 DOI: 10.3389/fncom.2022.899584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/22/2022] [Indexed: 11/17/2022] Open
Abstract
To understand neural encoding of neuropathic pain, evoked and resting activity of peripheral human C-fibers are studied via microneurography experiments. Before different spiking patterns can be analyzed, spike sorting is necessary to distinguish the activity of particular fibers of a recorded bundle. Due to single-electrode measurements and high noise contamination, standard methods based on spike shapes are insufficient and need to be enhanced with additional information. Such information can be derived from the activity-dependent slowing of the fiber propagation speed, which in turn can be assessed by introducing continuous "background" 0.125-0.25 Hz electrical stimulation and recording the corresponding responses from the fibers. Each fiber's speed propagation remains almost constant in the absence of spontaneous firing or additional stimulation. This way, the responses to the "background stimulation" can be sorted by fiber. In this article, we model the changes in the propagation speed resulting from the history of fiber activity with polynomial regression. This is done to assess the feasibility of using the developed models to enhance the spike shape-based sorting. In addition to human microneurography data, we use animal in-vitro recordings with a similar stimulation protocol as higher signal-to-noise ratio data example for the models.
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Affiliation(s)
- Ekaterina Kutafina
- Institute of Medical Informatics, Medical Faculty, RWTH Aachen University, Aachen, Germany,Faculty of Applied Mathematics, AGH University of Science and Technology, Krakow, Poland,*Correspondence: Ekaterina Kutafina
| | - Alina Troglio
- Junior Research Group Neuroscience, Interdisciplinary Center for Clinical Research Within the Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | - Roberto de Col
- Junior Research Group Neuroscience, Interdisciplinary Center for Clinical Research Within the Faculty of Medicine, RWTH Aachen University, Aachen, Germany,Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Rainer Röhrig
- Institute of Medical Informatics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Peter Rossmanith
- Theoretical Computer Science, Department of Computer Science, RWTH Aachen University, Aachen, Germany
| | - Barbara Namer
- Junior Research Group Neuroscience, Interdisciplinary Center for Clinical Research Within the Faculty of Medicine, RWTH Aachen University, Aachen, Germany,Institute of Physiology, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Bod RB, Rokai J, Meszéna D, Fiáth R, Ulbert I, Márton G. From End to End: Gaining, Sorting, and Employing High-Density Neural Single Unit Recordings. Front Neuroinform 2022; 16:851024. [PMID: 35769832 PMCID: PMC9236662 DOI: 10.3389/fninf.2022.851024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 05/06/2022] [Indexed: 11/15/2022] Open
Abstract
The meaning behind neural single unit activity has constantly been a challenge, so it will persist in the foreseeable future. As one of the most sourced strategies, detecting neural activity in high-resolution neural sensor recordings and then attributing them to their corresponding source neurons correctly, namely the process of spike sorting, has been prevailing so far. Support from ever-improving recording techniques and sophisticated algorithms for extracting worthwhile information and abundance in clustering procedures turned spike sorting into an indispensable tool in electrophysiological analysis. This review attempts to illustrate that in all stages of spike sorting algorithms, the past 5 years innovations' brought about concepts, results, and questions worth sharing with even the non-expert user community. By thoroughly inspecting latest innovations in the field of neural sensors, recording procedures, and various spike sorting strategies, a skeletonization of relevant knowledge lays here, with an initiative to get one step closer to the original objective: deciphering and building in the sense of neural transcript.
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Affiliation(s)
- Réka Barbara Bod
- Laboratory of Experimental Neurophysiology, Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureş, Târgu Mureş, Romania
| | - János Rokai
- Integrative Neuroscience Group, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
- School of PhD Studies, Semmelweis University, Budapest, Hungary
| | - Domokos Meszéna
- Integrative Neuroscience Group, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Richárd Fiáth
- Integrative Neuroscience Group, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - István Ulbert
- Integrative Neuroscience Group, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Gergely Márton
- Integrative Neuroscience Group, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
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Ottaviani MM, Vallone F, Micera S, Recchia FA. Closed-Loop Vagus Nerve Stimulation for the Treatment of Cardiovascular Diseases: State of the Art and Future Directions. Front Cardiovasc Med 2022; 9:866957. [PMID: 35463766 PMCID: PMC9021417 DOI: 10.3389/fcvm.2022.866957] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/14/2022] [Indexed: 01/07/2023] Open
Abstract
The autonomic nervous system exerts a fine beat-to-beat regulation of cardiovascular functions and is consequently involved in the onset and progression of many cardiovascular diseases (CVDs). Selective neuromodulation of the brain-heart axis with advanced neurotechnologies is an emerging approach to corroborate CVDs treatment when classical pharmacological agents show limited effectiveness. The vagus nerve is a major component of the cardiac neuroaxis, and vagus nerve stimulation (VNS) is a promising application to restore autonomic function under various pathological conditions. VNS has led to encouraging results in animal models of CVDs, but its translation to clinical practice has not been equally successful, calling for more investigation to optimize this technique. Herein we reviewed the state of the art of VNS for CVDs and discuss avenues for therapeutic optimization. Firstly, we provided a succinct description of cardiac vagal innervation anatomy and physiology and principles of VNS. Then, we examined the main clinical applications of VNS in CVDs and the related open challenges. Finally, we presented preclinical studies that aim at overcoming VNS limitations through optimization of anatomical targets, development of novel neural interface technologies, and design of efficient VNS closed-loop protocols.
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Affiliation(s)
- Matteo Maria Ottaviani
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy
- Department of Excellence in Robotics and Artificial Intelligence, The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy
| | - Fabio Vallone
- Department of Excellence in Robotics and Artificial Intelligence, The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy
| | - Silvestro Micera
- Department of Excellence in Robotics and Artificial Intelligence, The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy
- Bertarelli Foundation Chair in Translational Neural Engineering, Center for Neuroprosthetics, Institute of Bioengineering, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Fabio A. Recchia
- Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy
- Fondazione Toscana Gabriele Monasterio, Pisa, Italy
- Department of Physiology, Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
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Loper H, Leinen M, Bassoff L, Sample J, Romero-Ortega M, Gustafson KJ, Taylor DM, Schiefer MA. Both high fat and high carbohydrate diets impair vagus nerve signaling of satiety. Sci Rep 2021; 11:10394. [PMID: 34001925 PMCID: PMC8128917 DOI: 10.1038/s41598-021-89465-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 04/26/2021] [Indexed: 11/23/2022] Open
Abstract
Obesity remains prevalent in the US. One potential treatment is vagus nerve stimulation (VNS), which activates the sensory afferents innervating the stomach that convey stomach volume and establish satiety. However, current VNS approaches and stimulus optimization could benefit from additional understanding of the underlying neural response to stomach distension. In this study, obesity-prone Sprague Dawley rats consumed a standard, high-carbohydrate, or high-fat diet for several months, leading to diet-induced obesity in the latter two groups. Under anesthesia, the neural activity in the vagus nerve was recorded with a penetrating microelectrode array while the stomach was distended with an implanted balloon. Vagal tone during distension was compared to baseline tone prior to distension. Responses were strongly correlated with stomach distension, but the sensitivity to distension was significantly lower in animals that had been fed the nonstandard diets. The results indicate that both high fat and high carbohydrate diets impair vagus activity.
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Affiliation(s)
- Hailley Loper
- Malcom Randall VA Medical Center, Gainesville, FL, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Monique Leinen
- Malcom Randall VA Medical Center, Gainesville, FL, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Logan Bassoff
- Malcom Randall VA Medical Center, Gainesville, FL, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Jack Sample
- Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA.,College of Medicine & Life Sciences, University of Toledo, Toledo, OH, USA
| | - Mario Romero-Ortega
- Departments of Biomedical Engineering and Biomedical Sciences, University of Houston, Houston, TX, USA
| | - Kenneth J Gustafson
- Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Dawn M Taylor
- Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.,Department of Neurosciences, The Cleveland Clinic, Cleveland, OH, USA
| | - Matthew A Schiefer
- Malcom Randall VA Medical Center, Gainesville, FL, USA. .,Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA. .,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.
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Interfacing with the Peripheral Nervous System. J Neurosci Methods 2020; 340:108745. [DOI: 10.1016/j.jneumeth.2020.108745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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