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Umezu HL, Bittencourt-Silva PG, Mourão FAG, Moreira FA, Moraes MFD, Santos VR, da Silva GSF. Respiratory activity during seizures induced by pentylenetetrazole. Respir Physiol Neurobiol 2024; 323:104229. [PMID: 38307440 DOI: 10.1016/j.resp.2024.104229] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 01/27/2024] [Accepted: 01/29/2024] [Indexed: 02/04/2024]
Abstract
This study investigated the respiratory activity in adult Wistar rats across different behavioral seizure severity induced by pentylenetetrazole (PTZ). Animals underwent surgery for electrodes implantation, allowing simultaneous EEG and diaphragm EMG (DIAEMG) recordings and the respiratory frequency and DIAEMG amplitude were measured. Seizures were acutely induced through PTZ injection and classified based on a pre-established score, with absence-like seizures (spike wave discharge (SWD) events on EEG) representing the lowest score. The respiratory activity was grouped into the different seizure severities. During absence-like and myoclonic jerk seizures, the breathing frequency decreased significantly (∼50% decrease) compared to pre- and post-ictal periods. Pronounced changes occurred with more severe seizures (clonic and tonic) with periods of apnea, especially during tonic seizures. Apnea duration was significantly higher in tonic compared to clonic seizures. Notably, during PTZ-induced tonic seizures the apnea events were marked by tonic DIAEMG contraction (tonic-phase apnea). In the majority of animals (5 out of 7) this was a fatal event in which the seizure-induced respiratory arrest preceded the asystole. In conclusion, we provide an assessment of the respiratory activity in the PTZ-induced acute seizures and showed that breathing dysfunction is more pronounced in seizures with higher severity.
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Affiliation(s)
- Hanna L Umezu
- Department of Physiology and Biophysics, Institute of Biological Science, Federal University of Minas Gerais (ICB/UFMG), Belo Horizonte, Brazil
| | - Paloma G Bittencourt-Silva
- Department of Physiology and Biophysics, Institute of Biological Science, Federal University of Minas Gerais (ICB/UFMG), Belo Horizonte, Brazil
| | - Flávio A G Mourão
- Department of Physiology and Biophysics, Institute of Biological Science, Federal University of Minas Gerais (ICB/UFMG), Belo Horizonte, Brazil; Graduate Program in Neuroscience, Institute of Biological Science, Federal University of Minas Gerais (ICB/UFMG), Belo Horizonte, Brazil
| | - Fabrício A Moreira
- Department of Pharmacology, Institute of Biological Science, Federal University of Minas Gerais (ICB/UFMG), Belo Horizonte, Brazil
| | - Márcio Flávio D Moraes
- Department of Physiology and Biophysics, Institute of Biological Science, Federal University of Minas Gerais (ICB/UFMG), Belo Horizonte, Brazil; Graduate Program in Neuroscience, Institute of Biological Science, Federal University of Minas Gerais (ICB/UFMG), Belo Horizonte, Brazil
| | - Victor R Santos
- Department of Morphology, Institute of Biological Science, Federal University of Minas Gerais (ICB/UFMG), Belo Horizonte, Brazil
| | - Glauber S F da Silva
- Department of Physiology and Biophysics, Institute of Biological Science, Federal University of Minas Gerais (ICB/UFMG), Belo Horizonte, Brazil.
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2
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Nicolò A, Sacchetti M. Differential control of respiratory frequency and tidal volume during exercise. Eur J Appl Physiol 2023; 123:215-242. [PMID: 36326866 DOI: 10.1007/s00421-022-05077-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [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: 05/31/2022] [Accepted: 10/18/2022] [Indexed: 11/06/2022]
Abstract
The lack of a testable model explaining how ventilation is regulated in different exercise conditions has been repeatedly acknowledged in the field of exercise physiology. Yet, this issue contrasts with the abundance of insightful findings produced over the last century and calls for the adoption of new integrative perspectives. In this review, we provide a methodological approach supporting the importance of producing a set of evidence by evaluating different studies together-especially those conducted in 'real' exercise conditions-instead of single studies separately. We show how the collective assessment of findings from three domains and three levels of observation support the development of a simple model of ventilatory control which proves to be effective in different exercise protocols, populations and experimental interventions. The main feature of the model is the differential control of respiratory frequency (fR) and tidal volume (VT); fR is primarily modulated by central command (especially during high-intensity exercise) and muscle afferent feedback (especially during moderate exercise) whereas VT by metabolic inputs. Furthermore, VT appears to be fine-tuned based on fR levels to match alveolar ventilation with metabolic requirements in different intensity domains, and even at a breath-by-breath level. This model reconciles the classical neuro-humoral theory with apparently contrasting findings by leveraging on the emerging control properties of the behavioural (i.e. fR) and metabolic (i.e. VT) components of minute ventilation. The integrative approach presented is expected to help in the design and interpretation of future studies on the control of fR and VT during exercise.
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Affiliation(s)
- Andrea Nicolò
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro De Bosis 6, 00135, Rome, Italy.
| | - Massimo Sacchetti
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro De Bosis 6, 00135, Rome, Italy
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do Amaral-Silva L, Santin JM. A brainstem preparation allowing simultaneous access to respiratory motor output and cellular properties of motoneurons in American bullfrogs. J Exp Biol 2022; 225:jeb244079. [PMID: 35574670 PMCID: PMC9250796 DOI: 10.1242/jeb.244079] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 05/06/2022] [Indexed: 10/25/2023]
Abstract
Breathing is generated by a complex neural circuit, and the ability to monitor the activity of multiple network components simultaneously is required to uncover the cellular basis of breathing. In neonatal rodents, a single brainstem slice can be obtained to record respiratory-related motor nerve discharge along with individual rhythm-generating cells or motoneurons because of the close proximity of these neurons in the brainstem. However, most ex vivo preparations in other vertebrates can only capture respiratory motor outflow or electrophysiological properties of putative respiratory neurons in slices without relevant synaptic inputs. Here, we detail a method to horizontally slice away the dorsal portion of the brainstem to expose fluorescently labeled motoneurons for patch-clamp recordings in American bullfrogs. This 'semi-intact' preparation allows tandem recordings of motor output and single motoneurons during respiratory-related synaptic inputs. The rhythmic motor patterns are comparable to those from intact preparations and operate at physiological temperature and [K+]. Thus, this preparation provides the ability to record network and cellular outputs simultaneously and may lead to new mechanistic insights into breathing control across vertebrates.
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Affiliation(s)
- Lara do Amaral-Silva
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC 27403, USA
| | - Joseph M. Santin
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC 27403, USA
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van Kesteren Z, Veldman JK, Parkes MJ, Stevens MF, Balasupramaniam P, van den Aardweg JG, van Tienhoven G, Bel A, van Dijk IWEM. Quantifying the reduction of respiratory motion by mechanical ventilation with MRI for radiotherapy. Radiat Oncol 2022; 17:99. [PMID: 35597956 PMCID: PMC9123684 DOI: 10.1186/s13014-022-02068-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/12/2022] [Indexed: 12/13/2022] Open
Abstract
Background Due to respiratory motion, accurate radiotherapy delivery to thoracic and abdominal tumors is challenging. We aimed to quantify the ability of mechanical ventilation to reduce respiratory motion, by measuring diaphragm motion magnitudes in the same volunteers during free breathing (FB), mechanically regularized breathing (RB) at 22 breaths per minute (brpm), variation in mean diaphragm position across multiple deep inspiration breath-holds (DIBH) and diaphragm drift during single prolonged breath-holds (PBH) in two MRI sessions. Methods In two sessions, MRIs were acquired from fifteen healthy volunteers who were trained to be mechanically ventilated non-invasively We measured diaphragm motion amplitudes during FB and RB, the inter-quartile range (IQR) of the variation in average diaphragm position from one measurement over five consecutive DIBHs, and diaphragm cranial drift velocities during single PBHs from inhalation (PIBH) and exhalation (PEBH) breath-holds. Results RB significantly reduced the respiratory motion amplitude by 39%, from median (range) 20.9 (10.6–41.9) mm during FB to 12.8 (6.2–23.8) mm. The median IQR for variation in average diaphragm position over multiple DIBHs was 4.2 (1.0–23.6) mm. During single PIBHs with a median duration of 7.1 (2.0–11.1) minutes, the median diaphragm cranial drift velocity was 3.0 (0.4–6.5) mm/minute. For PEBH, the median duration was 5.8 (1.8–10.2) minutes with 4.4 (1.8–15.1) mm/minute diaphragm drift velocity. Conclusions Regularized breathing at a frequency of 22 brpm resulted in significantly smaller diaphragm motion amplitudes compared to free breathing. This would enable smaller treatment volumes in radiotherapy. Furthermore, prolonged breath-holding from inhalation and exhalation with median durations of six to seven minutes are feasible. Trial registration Medical Ethics Committee protocol NL.64693.018.18.
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Affiliation(s)
- Z van Kesteren
- Department of Radiation Oncology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
| | - J K Veldman
- Department of Radiation Oncology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - M J Parkes
- Department of Radiation Oncology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - M F Stevens
- Department of Anesthesiology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.,Department of Anesthesiology, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
| | - P Balasupramaniam
- Department of Radiation Oncology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - J G van den Aardweg
- Department of Pulmonology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - G van Tienhoven
- Department of Radiation Oncology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - A Bel
- Department of Radiation Oncology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - I W E M van Dijk
- Department of Radiation Oncology, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
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Abstract
This chapter broadly reviews cardiopulmonary sympathetic and vagal sensors and their reflex functions during physiologic and pathophysiologic processes. Mechanosensory operating mechanisms, including their central projections, are described under multiple sensor theory. In addition, ways to interpret evidence surrounding several controversial issues are provided, with detailed reasoning on how conclusions are derived. Cardiopulmonary sensory roles in breathing control and the development of symptoms and signs and pathophysiologic processes in cardiopulmonary diseases (such as cough and neuroimmune interaction) also are discussed.
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Affiliation(s)
- Jerry Yu
- Department of Medicine (Pulmonary), University of Louisville, and Robley Rex VA Medical Center, Louisville, KY, United States.
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Wu JK, Chen SH, Hsu FM, Liao SH, Wang YJ. Design of a motion simulation system to assist respiratory gating for radiation therapy. Med Dosim 2021; 46:360-363. [PMID: 33903006 DOI: 10.1016/j.meddos.2021.03.009] [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] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 02/21/2021] [Accepted: 03/22/2021] [Indexed: 11/15/2022]
Abstract
Stereotactic ablative radiotherapy (SABR) aims to deliver high doses of radiation to kill cancer cells and shrink tumors in less than or equal to 6 fractions. However, organ motion during treatment is a challenging issue for this kind of technique. We develop a control system via Bluetooth technology to simulate and correct body motion during SABR. METHODS Radiation doses were analyzed, and the radiation damage protection capability was checked by external beam therapy 3 (EBT3) films irradiated by a linear accelerator. A wireless signal test was also performed. A validation was performed with 8 previously treated patient respiratory pattern records and 8 healthy volunteers. RESULTS The homemade simulation system consisted of 2 linear actuators, one movable stage with a maximal moving distance of 6.5 cm × 12.5 cm × 5 cm to simulate the respiratory pattern of 8 patients precisely with a median error of 0.36 mm and a maximal motion difference of 1.17 mm, and 3.17 and chipset transited signals to display them as a waveform. From the test with 8 volunteers, the chip could detect deep respiratory movement up to 3 cm. The effect of the chip on a radiation dose of 400 monitor units (MUs) by 6 MV photons and 200 MUs by 10 MV photons showed high penetration rates of 98.8% and 98.6%, respectively. CONCLUSIONS We invented a tubeless and wireless respiratory gating detection chip. The chip has minimal interference with the treatment angles, good noise immunity and the capability to easily penetrate a variety of materials. The simulation system consisting of linear actuators also successfully simulates the respiratory pattern of real patients.
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Affiliation(s)
- Jian-Kuen Wu
- Division of Radiation Oncology, Departments of Oncology, National Taiwan University Hospital, Taipei, Taiwan
| | - Shih-Han Chen
- Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, Taiwan
| | - Feng-Ming Hsu
- Division of Radiation Oncology, Departments of Oncology, National Taiwan University Hospital, Taipei, Taiwan; Graduate Institute of Oncology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Shu-Hsien Liao
- Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, Taiwan
| | - Yu-Jen Wang
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 106, Taiwan; Department of Radiation Oncology, Fu Jen Catholic University Hospital, New Taipei City, Taiwan; School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan.
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Furuya WI, Dhingra RR, Gundlach AL, Hossain MA, Dutschmann M. Relaxin-3 receptor (RXFP3) activation in the nucleus of the solitary tract modulates respiratory rate and the arterial chemoreceptor reflex in rat. Respir Physiol Neurobiol 2019; 271:103310. [PMID: 31568840 DOI: 10.1016/j.resp.2019.103310] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [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: 09/23/2019] [Revised: 09/26/2019] [Accepted: 09/27/2019] [Indexed: 11/25/2022]
Abstract
The neuropeptide relaxin-3 is expressed by the pontine nucleus incertus. Relaxin-3 and synthetic agonist peptides modulate arousal and cognitive processes via activation of the relaxin-family peptide 3 receptor (RXFP3). Despite the presence of RXFP3 in the nucleus of the solitary tract (NTS), the ability of RXFP3 to modulate NTS-mediated cardiorespiratory functions has not been explored. Therefore, we examined the effects of bilateral microinjections of the selective agonist, RXFP3-A2 (40 μM, 100 nL/side), into the NTS in perfused working-heart-brainstem-preparations from rats (n = 6), while recording phrenic, vagal, and thoracic sympathetic chain activity (PNA, VNA, t-SCA) and heart rate (HR). RXFP3-A2 significantly increased respiratory rate and shortened post-inspiratory VNA. RXFP3-A2 in the NTS also significantly enhanced arterial chemoreceptor reflex (a-CR)-mediated tachypnea. However, RXFP3-A2 had no significant effect on HR and t-SCA at baseline or during the a-CR. These data represent the first evidence that RXFP3 activation in the NTS can selectively modulate respiration at baseline and during reflex behaviour.
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Affiliation(s)
- Werner I Furuya
- The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Rishi R Dhingra
- The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Andrew L Gundlach
- The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Mohammad Akhter Hossain
- The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Mathias Dutschmann
- The Florey Institute of Neuroscience and Mental Health, and Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, 3010, Australia.
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Nicolò A, Girardi M, Bazzucchi I, Felici F, Sacchetti M. Respiratory frequency and tidal volume during exercise: differential control and unbalanced interdependence. Physiol Rep 2018; 6:e13908. [PMID: 30393984 PMCID: PMC6215760 DOI: 10.14814/phy2.13908] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 10/02/2018] [Accepted: 10/03/2018] [Indexed: 01/14/2023] Open
Abstract
Differentiating between respiratory frequency (fR ) and tidal volume (VT ) may improve our understanding of exercise hyperpnoea because fR and VT seem to be regulated by different inputs. We designed a series of exercise manipulations to improve our understanding of how fR and VT are regulated during exercise. Twelve cyclists performed an incremental test and three randomized experimental sessions in separate visits. In two of the three experimental visits, participants performed a moderate-intensity sinusoidal test followed, after recovery, by a moderate-to-severe-intensity sinusoidal test. These two visits differed in the period of the sinusoid (2 min vs. 8 min). In the third experimental visit, participants performed a trapezoidal test where the workload was self-paced in order to match a predefined trapezoidal template of rating of perceived exertion (RPE). The results collectively reveal that fR changes more with RPE than with workload, gas exchange, VT or the amount of muscle activation. However, fR dissociates from RPE during moderate exercise. Both VT and minute ventilation ( V ˙ E ) showed a similar time course and a large correlation with V ˙ CO 2 in all the tests. Nevertheless, V ˙ CO 2 was associated more with V ˙ E than with VT because VT seems to adjust continuously on the basis of fR levels to match V ˙ E with V ˙ CO 2 . The present findings provide novel insight into the differential control of fR and VT - and their unbalanced interdependence - during exercise. The emerging conceptual framework is expected to guide future research on the mechanisms underlying the long-debated issue of exercise hyperpnoea.
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Affiliation(s)
- Andrea Nicolò
- Department of Movement, Human and Health SciencesUniversity of Rome “Foro Italico”RomeItaly
| | - Michele Girardi
- Department of Movement, Human and Health SciencesUniversity of Rome “Foro Italico”RomeItaly
| | - Ilenia Bazzucchi
- Department of Movement, Human and Health SciencesUniversity of Rome “Foro Italico”RomeItaly
| | - Francesco Felici
- Department of Movement, Human and Health SciencesUniversity of Rome “Foro Italico”RomeItaly
| | - Massimo Sacchetti
- Department of Movement, Human and Health SciencesUniversity of Rome “Foro Italico”RomeItaly
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