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Rivera DA, Buglione AE, Ray SE, Schaffer CB. MousePZT: A simple, reliable, low-cost device for vital sign monitoring and respiratory gating in mice under anesthesia. PLoS One 2024; 19:e0299047. [PMID: 38437201 PMCID: PMC10911610 DOI: 10.1371/journal.pone.0299047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 02/02/2024] [Indexed: 03/06/2024] Open
Abstract
Small animal studies in biomedical research often require anesthesia to reduce pain or stress experienced by research animals and to minimize motion artifact during imaging or other measurements. Anesthetized animals must be closely monitored for the safety of the animals and to prevent unintended effects of altered physiology on experimental outcomes. Many currently available monitoring devices are expensive, invasive, or interfere with experimental design. Here, we present MousePZT, a low-cost device based on a simple piezoelectric sensor, with a custom circuit and computer software that allows for measurements of both respiratory rate and heart rate in a non-invasive, minimal contact manner. We find the accuracy of the MousePZT device in measuring respiratory and heart rate matches those of commercial systems. Using the widely-used gas isoflurane and injectable ketamine/xylazine combination, we also demonstrate that changes in respiratory rate are more easily detected and can precede changes in heart rate associated with variations in anesthetic depth. Additional circuitry on the device outputs a respiration-locked trigger signal for respiratory-gating of imaging or other data acquisition and has high sensitivity and specificity for detecting respiratory cycles. We provide detailed instruction documents and all necessary microcontroller and computer software, enabling straightforward construction and utilization of this device.
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Affiliation(s)
- Daniel A. Rivera
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, United States of America
| | - Anne E. Buglione
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, United States of America
- College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Sadie E. Ray
- College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Chris B. Schaffer
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, United States of America
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Sarkar M, Perez-Liva M, Renault G, Tavitian B, Gateau J. Motion Rejection and Spectral Unmixing for Accurate Estimation of In Vivo Oxygen Saturation Using Multispectral Optoacoustic Tomography. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:1671-1681. [PMID: 37603493 DOI: 10.1109/tuffc.2023.3306592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Multispectral optoacoustic tomography (MSOT) uniquely enables spatial mapping in high resolution of oxygen saturation (SO2), with potential applications in studying pathological complications and therapy efficacy. MSOT offers seamless integration with ultrasonography, by using a common ultrasound (US) detector array. However, MSOT relies on multiple successive acquisitions of optoacoustic (OA) images at different optical wavelengths and the low frame rate of OA imaging makes the MSOT acquisition sensitive to body/respiratory motion. Moreover, the estimation of SO2 is highly sensitive to noise, and artifacts related to the respiratory motion of the animal were identified as the primary source of noise in MSOT. In this work, we propose a two-step image processing method for SO2 estimation in deep tissues. First, to mitigate motion artifacts, we propose a method of selection of OA images acquired only during the respiratory pause of the animal, using ultrafast ultrasound (US) images acquired immediately after each OA acquisition (US image acquisition duration of 1.4 ms and a total delay of 7 ms). We show that gating is more effective using US images than OA images at different optical wavelengths. Second, we propose a novel method that can estimate directly the SO2 value of a pixel and at the same time evaluate the amount of noise present in that pixel. Hence, the method can efficiently eliminate the pixels dominated by noise from the final SO2 map. Our postprocessing method is shown to outperform conventional methods for SO2 estimation, and the method was validated by in vivo oxygen challenge experiments.
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Donnelley M, Lagerquist L, Cmielewski P, Reyne N, Morgan K, Parsons D. Noncontact Respiratory Motion Detection in Anesthetized Rodents. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2023; 62:559-568. [PMID: 37816589 PMCID: PMC10772912 DOI: 10.30802/aalas-jaalas-23-000018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 05/31/2023] [Accepted: 07/17/2023] [Indexed: 10/12/2023]
Abstract
Small animal physiology studies are often complicated, but the level of complexity is greatly increased when performing live-animal X-ray imaging studies at synchrotron radiation facilities. This is because these facilities are typically not designed specifically for biomedical research, and the animals and image detectors are located away from the researchers in a radiation enclosure. In respiratory X-ray imaging studies one challenge is the detection of respiration in free-breathing anaesthetised rodents, to enable images to be acquired at specific phases of the breath and for detecting changes in respiratory rate. We have previously used a Philtec RC60 sensor interfaced to a PowerLab data acquisition system and custom-designed timing hub to perform this task. Here we evaluated the Panasonic HL-G108 for respiratory sensing. The performance of the two sensors for accurate and reliable breath detection was directly compared using a single anesthetized rat. We also assessed how an infrared heat lamp used to maintain body temperature affected sensor performance. Based on positive results from these comparisons, the HL-G108 sensor was then used for respiratory motion detection in tracheal X-ray imaging studies of 21 rats at the SPring-8 Synchrotron, including its use for gated image acquisition. The results of that test were compared to a similar imaging study that used the RC60 for respiratory detection in 19 rats. Finally, the HL-G108 sensor was tested on 5 mice to determine its effectiveness on smaller species. The results showed that the HL-G108 is much more robust and easier to configure than the RC60 sensor and produces an analog signal that is amenable to stable peak detection. Furthermore, gated image acquisition produced sequences with substantially reduced motion artefacts, enabling the additional benefit of reduced radiation dose through the application of shuttering. Finally, the mouse experiments showed that the HL-G108 is equally capable of detecting respiration in this smaller species.
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Affiliation(s)
- Martin Donnelley
- Robinson Research Institute
- Adelaide Medical School, University of Adelaide, SA, 5001, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, North Adelaide, SA, 5006, Australia
| | - Lina Lagerquist
- College of Science and Engineering, Flinders University, SA, 5042, Australia; and
| | - Patricia Cmielewski
- Robinson Research Institute
- Adelaide Medical School, University of Adelaide, SA, 5001, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, North Adelaide, SA, 5006, Australia
| | - Nikki Reyne
- Robinson Research Institute
- Adelaide Medical School, University of Adelaide, SA, 5001, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, North Adelaide, SA, 5006, Australia
| | - Kaye Morgan
- School of Physics and Astronomy, Monash University, Clayton, Vic, 3800, Australia
| | - David Parsons
- Robinson Research Institute
- Adelaide Medical School, University of Adelaide, SA, 5001, Australia
- Respiratory and Sleep Medicine, Women’s and Children’s Hospital, North Adelaide, SA, 5006, Australia
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4
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Verhaegen F, Butterworth KT, Chalmers AJ, Coppes RP, de Ruysscher D, Dobiasch S, Fenwick JD, Granton PV, Heijmans SHJ, Hill MA, Koumenis C, Lauber K, Marples B, Parodi K, Persoon LCGG, Staut N, Subiel A, Vaes RDW, van Hoof S, Verginadis IL, Wilkens JJ, Williams KJ, Wilson GD, Dubois LJ. Roadmap for precision preclinical x-ray radiation studies. Phys Med Biol 2023; 68:06RM01. [PMID: 36584393 DOI: 10.1088/1361-6560/acaf45] [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] [Received: 05/12/2022] [Accepted: 12/30/2022] [Indexed: 12/31/2022]
Abstract
This Roadmap paper covers the field of precision preclinical x-ray radiation studies in animal models. It is mostly focused on models for cancer and normal tissue response to radiation, but also discusses other disease models. The recent technological evolution in imaging, irradiation, dosimetry and monitoring that have empowered these kinds of studies is discussed, and many developments in the near future are outlined. Finally, clinical translation and reverse translation are discussed.
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Affiliation(s)
- Frank Verhaegen
- MAASTRO Clinic, Radiotherapy Division, GROW-School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
- SmART Scientific Solutions BV, Maastricht, The Netherlands
| | - Karl T Butterworth
- Patrick G. Johnston, Centre for Cancer Research, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Anthony J Chalmers
- School of Cancer Sciences, University of Glasgow, Glasgow G61 1QH, United Kingdom
| | - Rob P Coppes
- Departments of Biomedical Sciences of Cells & Systems, Section Molecular Cell Biology and Radiation Oncology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands
| | - Dirk de Ruysscher
- MAASTRO Clinic, Radiotherapy Division, GROW-School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Sophie Dobiasch
- Department of Radiation Oncology, Technical University of Munich (TUM), School of Medicine and Klinikum rechts der Isar, Germany
- Department of Medical Physics, Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, Germany
| | - John D Fenwick
- Department of Medical Physics & Biomedical Engineering University College LondonMalet Place Engineering Building, London WC1E 6BT, United Kingdom
| | | | | | - Mark A Hill
- MRC Oxford Institute for Radiation Oncology, University of Oxford, ORCRB Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Constantinos Koumenis
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kirsten Lauber
- Department of Radiation Oncology, University Hospital, LMU München, Munich, Germany
- German Cancer Consortium (DKTK), Partner site Munich, Germany
| | - Brian Marples
- Department of Radiation Oncology, University of Rochester, NY, United States of America
| | - Katia Parodi
- German Cancer Consortium (DKTK), Partner site Munich, Germany
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Garching b. Munich, Germany
| | | | - Nick Staut
- SmART Scientific Solutions BV, Maastricht, The Netherlands
| | - Anna Subiel
- National Physical Laboratory, Medical Radiation Science Hampton Road, Teddington, Middlesex, TW11 0LW, United Kingdom
| | - Rianne D W Vaes
- MAASTRO Clinic, Radiotherapy Division, GROW-School for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | | | - Ioannis L Verginadis
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jan J Wilkens
- Department of Radiation Oncology, Technical University of Munich (TUM), School of Medicine and Klinikum rechts der Isar, Germany
- Physics Department, Technical University of Munich (TUM), Germany
| | - Kaye J Williams
- Division of Pharmacy and Optometry, University of Manchester, Manchester, United Kingdom
| | - George D Wilson
- Department of Radiation Oncology, Beaumont Health, MI, United States of America
- Henry Ford Health, Detroit, MI, United States of America
| | - Ludwig J Dubois
- The M-Lab, Department of Precision Medicine, GROW-School for Oncology and Reproduction, Maastricht University, Maastricht, The Netherlands
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5
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Manser M, Jeyanathan V, Jeyanathan M, Feng X, Dolovich MB, Xing Z, Cranston ED, Thompson MR. Design Considerations for Intratracheal Delivery Devices to Achieve Proof-of-Concept Dry Powder Biopharmaceutical Delivery in Mice. Pharm Res 2023; 40:1165-1176. [PMID: 36991226 PMCID: PMC10057681 DOI: 10.1007/s11095-023-03492-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 02/26/2023] [Indexed: 03/31/2023]
Abstract
PURPOSE Intratracheal delivery and consistent dosing of dry powder vaccines is especially challenging in mice. To address this issue, device design of positive pressure dosators and actuation parameters were assessed for their impacts on powder flowability and in vivo dry powder delivery. METHODS A chamber-loading dosator assembled with stainless-steel, polypropylene or polytetrafluoroethylene needle-tips was used to determine optimal actuation parameters. Powder loading methods including tamp-loading, chamber-loading and pipette tip-loading were compared to assess performance of the dosator delivery device in mice. RESULTS Available dose was highest (45%) with a stainless-steel tip loaded with an optimal mass and syringe air volume, primarily due to the ability of this configuration to dissipate static charge. However, this tip encouraged more agglomeration along its flow path in the presence of humidity and was too rigid for intubation of mice compared to a more flexible polypropylene tip. Using optimized actuation parameters, the polypropylene pipette tip-loading dosator achieved an acceptable in vivo emitted dose of 50% in mice. After administering two doses of a spray dried adenovirus encapsulated in mannitol-dextran, high bioactivity was observed in excised mouse lung tissue three days post-infection. CONCLUSIONS This proof-of-concept study demonstrates for the first time that intratracheal delivery of a thermally stable, viral-vectored dry powder can achieve equivalent bioactivity to the same powder, reconstituted and delivered intratracheally. This work may guide the design and device selection process for murine intratracheal delivery of dry powder vaccines to help progress this promising area of inhalable therapeutics.
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Affiliation(s)
- Myla Manser
- Department of Chemical Engineering, McMaster University, Hamilton, ON, L8S 4L7, Canada
| | - Vidthiya Jeyanathan
- McMaster Immunology Research Centre and Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, L8S 4L7, Canada
| | - Mangalakumari Jeyanathan
- McMaster Immunology Research Centre and Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, L8S 4L7, Canada
| | - Xueya Feng
- McMaster Immunology Research Centre and Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, L8S 4L7, Canada
| | - Myrna B Dolovich
- Firestone Research Aerosol Laboratory, Research Institute of St Joseph's Hospital, St. Joseph's Healthcare and Faculty of Health Sciences, Department of Medicine, McMaster University, Hamilton, ON, L8N 4A6, Canada
| | - Zhou Xing
- McMaster Immunology Research Centre and Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, L8S 4L7, Canada
| | - Emily D Cranston
- Department of Chemical Engineering, McMaster University, Hamilton, ON, L8S 4L7, Canada
- Department of Wood Science, University of British Columbia, 2424 Main Mall, Vancouver, BC, V6T 1Z4, Canada
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Michael R Thompson
- Department of Chemical Engineering, McMaster University, Hamilton, ON, L8S 4L7, Canada.
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Berkane Y, Alana Shamlou A, Reyes J, Lancia HH, Filz von Reiterdank I, Bertheuil N, Uygun BE, Uygun K, Austen WG, Cetrulo CL, Randolph MA, Lellouch AG. The Superficial Inferior Epigastric Artery Axial Flap to Study Ischemic Preconditioning Effects in a Rat Model. J Vis Exp 2023:10.3791/64980. [PMID: 36779623 PMCID: PMC10910865 DOI: 10.3791/64980] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Fasciocutaneous flaps (FCF) have become the gold standard for complex defect reconstruction in plastic and reconstructive surgery. This muscle-sparing technique allows transferring vascularized tissues to cover any large defect. FCF can be used as pedicled flaps or as free flaps; however, in the literature, failure rates for pedicled FCF and free FCF are above 5%, leaving room for improvement for these techniques and further knowledge expansion in this area. Ischemic preconditioning (I.P.) has been widely studied, but the mechanisms and the optimization of the I.P. regimen are yet to be determined. This phenomenon is indeed poorly explored in plastic and reconstructive surgery. Here, a surgical model is presented to study the I.P. regimen in a rat axial fasciocutaneous flap model, describing how to safely and reliably assess the effects of I.P. on flap survival. This article describes the complete surgical procedure, including suggestions to improve the reliability of this model. The objective is to provide researchers with a reproducible and reliable model to test various ischemic preconditioning regimens and assess their effects on flap survivability.
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Affiliation(s)
- Yanis Berkane
- Vascularized Composite Allotransplantation Laboratory, Massachusetts General Hospital; Harvard Medical School; Department of Plastic, Reconstructive and Aesthetic Surgery, Rennes University Hospital Center (CHU de Rennes), University of Rennes 1; Shriners Children's Boston
| | - Austin Alana Shamlou
- Vascularized Composite Allotransplantation Laboratory, Massachusetts General Hospital; Harvard Medical School; Plastic Surgery Research Laboratory, Massachusetts General Hospital; Shriners Children's Boston
| | - Jose Reyes
- Vascularized Composite Allotransplantation Laboratory, Massachusetts General Hospital; Harvard Medical School
| | - Hyshem H Lancia
- Vascularized Composite Allotransplantation Laboratory, Massachusetts General Hospital; Harvard Medical School; Shriners Children's Boston
| | - Irina Filz von Reiterdank
- Vascularized Composite Allotransplantation Laboratory, Massachusetts General Hospital; Harvard Medical School; Shriners Children's Boston; Center for Engineering in Medicine and Surgery, Massachusetts General Hospital; Department of Plastic Surgery and Hand Surgery, University Medical Center Utrecht
| | - Nicolas Bertheuil
- Department of Plastic, Reconstructive and Aesthetic Surgery, Rennes University Hospital Center (CHU de Rennes), University of Rennes 1
| | - Basak E Uygun
- Harvard Medical School; Shriners Children's Boston; Center for Engineering in Medicine and Surgery, Massachusetts General Hospital
| | - Korkut Uygun
- Vascularized Composite Allotransplantation Laboratory, Massachusetts General Hospital; Harvard Medical School; Shriners Children's Boston; Center for Engineering in Medicine and Surgery, Massachusetts General Hospital
| | - William G Austen
- Harvard Medical School; Plastic Surgery Research Laboratory, Massachusetts General Hospital
| | - Curtis L Cetrulo
- Vascularized Composite Allotransplantation Laboratory, Massachusetts General Hospital; Harvard Medical School; Plastic Surgery Research Laboratory, Massachusetts General Hospital; Shriners Children's Boston
| | - Mark A Randolph
- Vascularized Composite Allotransplantation Laboratory, Massachusetts General Hospital; Harvard Medical School; Plastic Surgery Research Laboratory, Massachusetts General Hospital; Shriners Children's Boston
| | - Alexandre G Lellouch
- Vascularized Composite Allotransplantation Laboratory, Massachusetts General Hospital; Harvard Medical School; Shriners Children's Boston; Center for Engineering in Medicine and Surgery, Massachusetts General Hospital; Department of Plastic, Reconstructive, and Aesthetic Surgery, Groupe Almaviva Santé, Clinique de l'Alma;
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Bauer J, Devinsky O, Rothermel M, Koch H. Autonomic dysfunction in epilepsy mouse models with implications for SUDEP research. Front Neurol 2023; 13:1040648. [PMID: 36686527 PMCID: PMC9853197 DOI: 10.3389/fneur.2022.1040648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 12/12/2022] [Indexed: 01/09/2023] Open
Abstract
Epilepsy has a high prevalence and can severely impair quality of life and increase the risk of premature death. Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in drug-resistant epilepsy and most often results from respiratory and cardiac impairments due to brainstem dysfunction. Epileptic activity can spread widely, influencing neuronal activity in regions outside the epileptic network. The brainstem controls cardiorespiratory activity and arousal and reciprocally connects to cortical, diencephalic, and spinal cord areas. Epileptic activity can propagate trans-synaptically or via spreading depression (SD) to alter brainstem functions and cause cardiorespiratory dysfunction. The mechanisms by which seizures propagate to or otherwise impair brainstem function and trigger the cascading effects that cause SUDEP are poorly understood. We review insights from mouse models combined with new techniques to understand the pathophysiology of epilepsy and SUDEP. These techniques include in vivo, ex vivo, invasive and non-invasive methods in anesthetized and awake mice. Optogenetics combined with electrophysiological and optical manipulation and recording methods offer unique opportunities to study neuronal mechanisms under normal conditions, during and after non-fatal seizures, and in SUDEP. These combined approaches can advance our understanding of brainstem pathophysiology associated with seizures and SUDEP and may suggest strategies to prevent SUDEP.
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Affiliation(s)
- Jennifer Bauer
- Department of Epileptology and Neurology, RWTH Aachen University, Aachen, Germany,Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Orrin Devinsky
- Departments of Neurology, Neurosurgery and Psychiatry, NYU Langone School of Medicine, New York, NY, United States
| | - Markus Rothermel
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Henner Koch
- Department of Epileptology and Neurology, RWTH Aachen University, Aachen, Germany,*Correspondence: Henner Koch ✉
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8
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Janke E, Bhattarai JP, Ma M. Intranasal Pressure Recording for Monitoring Mouse Respiration. Methods Mol Biol 2023; 2710:49-60. [PMID: 37688723 PMCID: PMC10712686 DOI: 10.1007/978-1-0716-3425-7_4] [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: 09/11/2023]
Abstract
Respiration is a highly dynamic signal that influences voluntary behaviors including odor sampling and entrains rhythmic activity in the brain. Many techniques exist to record respiration with each exhibiting strengths and drawbacks given the ultimate goals of the respiration recording. Intranasal cannula implantation, coupled with pressure sensor recording, allows for temporal precision and detailed feature extraction of the respiratory waveform. Here we describe the implantation process and necessary recording equipment to effectively conduct intranasal pressure recording of respiration. This is an ideal method for understanding the dynamics of odor sampling in conjunction with olfactory sensory transmission.
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Affiliation(s)
- Emma Janke
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Janardhan P Bhattarai
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Minghong Ma
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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9
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Gong Y, Ye D, Chien CY, Yue Y, Chen H. Comparison of Sonication Patterns and Microbubble Administration Strategies for Focused Ultrasound-Mediated Large-Volume Drug Delivery. IEEE Trans Biomed Eng 2022; 69:3449-3459. [PMID: 35476579 PMCID: PMC9635979 DOI: 10.1109/tbme.2022.3170832] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Diffuse intrinsic pontine glioma (DIPG) is the most common and deadliest brainstem tumor in children. Focused ultrasound combined with microbubble-mediated BBB opening (FUS-BBBO) is a promising technique for overcoming the frequently intact blood-brain barrier (BBB) in DIPG to enhance therapeutic drug delivery to the brainstem. Since DIPG is highly diffusive, large-volume FUS-BBBO is needed to cover the entire tumor region. The objective of this study was to determine the optimal treatment strategy to achieve efficient and homogeneous large-volume BBBO at the brainstem for the delivery of an immune checkpoint inhibitor, anti-PD-L1 antibody (aPD-L1). METHODS Two critical parameters for large-volume FUS-BBBO, multi-point sonication pattern (interleaved vs. serial) and microbubble injection method (bolus vs. infusion), were evaluated by treating mice with four combinations of these two parameters. 2D Passive cavitation imaging (PCI) was performed for monitoring the large-volume sonication. RESULTS Interleaved sonication combined with bolus injection of microbubbles resulted in 1.29 to 2.06 folds higher efficiency than other strategies as evaluated by Evans blue extravasation. The average coefficient of variation of the Evans blue delivery was 0.66 for interleaved sonication with bolus injection, compared to 0.68-0.88 for all other strategies. Similar trend was also observed in the quantified total cavitation dose and coefficient of variance of the cavitation dose. This strategy was then applied to deliver fluorescently labeled aPD-L1 which was quantified using fluorescence imaging. A strong segmented linear correlation (R2 = 0.81) was found between the total cavitation dose and the total fluorescence intensity of aPD-L1 delivered at different sonication pressures (0.15 MPa, 0.30 MPa, and 0.45 MPa). SIGNIFICANCE Findings from this study suggest that efficient and homogeneous large-volume FUS-BBBO can be achieved by interleaved sonication combined with bolus injection of microbubbles, and the efficiency and homogeneity can be monitored by PCI.
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10
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Zak JD. Longitudinal imaging of individual olfactory sensory neurons in situ. Front Cell Neurosci 2022; 16:946816. [PMID: 35936493 PMCID: PMC9354957 DOI: 10.3389/fncel.2022.946816] [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: 05/18/2022] [Accepted: 06/30/2022] [Indexed: 12/24/2022] Open
Abstract
Olfactory sensory neurons are found deep within the nasal cavity at a spatially restricted sheet of sensory epithelium. Due to their location behind the nasal turbinates, accessing these cells for physiological measurements in living animals is challenging, and until recently, not possible. As a further complication, damage to the overlying bone on the dorsal surface of the snout disrupts the negative pressure distribution throughout the nasal cavities, which fundamentally alters how odorants are delivered to the sensory epithelium and the inherent mechanosensory properties of olfactory sensory neurons in live animals. The approach described here circumvents these limitations and allows for optical access to olfactory sensory neurons in mice across time scales ranging from days to months.
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11
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The importance of routine quality control for reproducible pulmonary measurements by in vivo micro-CT. Sci Rep 2022; 12:9695. [PMID: 35690601 PMCID: PMC9188608 DOI: 10.1038/s41598-022-13477-7] [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: 12/22/2021] [Accepted: 05/13/2022] [Indexed: 11/08/2022] Open
Abstract
Micro-computed tomography (CT) imaging provides densitometric and functional assessment of lung diseases in animal models, playing a key role either in understanding disease progression or in drug discovery studies. The generation of reliable and reproducible experimental data is strictly dependent on a system's stability. Quality controls (QC) are essential to monitor micro-CT performance but, although QC procedures are standardized and routinely employed in clinical practice, detailed guidelines for preclinical imaging are lacking. In this work, we propose a routine QC protocol for in vivo micro-CT, based on three commercial phantoms. To investigate the impact of a detected scanner drift on image post-processing, a retrospective analysis using twenty-two healthy mice was performed and lung density histograms used to compare the area under curve (AUC), the skewness and the kurtosis before and after the drift. As expected, statistically significant differences were found for all the selected parameters [AUC 532 ± 31 vs. 420 ± 38 (p < 0.001); skewness 2.3 ± 0.1 vs. 2.5 ± 0.1 (p < 0.001) and kurtosis 4.2 ± 0.3 vs. 5.1 ± 0.5 (p < 0.001)], confirming the importance of the designed QC procedure to obtain a reliable longitudinal quantification of disease progression and drug efficacy evaluation.
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12
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Liu S, Han S. Simultaneous recording of breathing and neural activity in awake behaving mice. STAR Protoc 2022; 3:101412. [PMID: 35620076 PMCID: PMC9127689 DOI: 10.1016/j.xpro.2022.101412] [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] [Indexed: 11/26/2022] Open
Abstract
This protocol provides a pipeline for simultaneous recording of breathing and neural activities in awake, behaving mice. Breathing is recorded with thermistor probes implanted in the nasal cavity, which can be easily integrated with neural activity monitoring approaches such as fiber photometry. Here, we detail the procedures of the thermistor probe assembly, surgery, recording system setup, and data analysis. This protocol can be applied to investigate respiratory physiology and breathing changes during natural behaviors. For complete details on the use and execution of this protocol, please refer to Liu et al. (2022). Protocols for constructing a simple, lightweight breathing sensor Instructions for sensor implantation surgery and behavior setup Tips on improving the signal quality and stability Flexibility to integrate with multiple recording and manipulation platforms
Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.
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Zhang Q, Turner KL, Gheres KW, Hossain MS, Drew PJ. Behavioral and physiological monitoring for awake neurovascular coupling experiments: a how-to guide. NEUROPHOTONICS 2022; 9:021905. [PMID: 35639834 PMCID: PMC8802326 DOI: 10.1117/1.nph.9.2.021905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/28/2021] [Indexed: 06/15/2023]
Abstract
Significance: Functional brain imaging in awake animal models is a popular and powerful technique that allows the investigation of neurovascular coupling (NVC) under physiological conditions. However, ubiquitous facial and body motions (fidgeting) are prime drivers of spontaneous fluctuations in neural and hemodynamic signals. During periods without movement, animals can rapidly transition into sleep, and the hemodynamic signals tied to arousal state changes can be several times larger than sensory-evoked responses. Given the outsized influence of facial and body motions and arousal signals in neural and hemodynamic signals, it is imperative to detect and monitor these events in experiments with un-anesthetized animals. Aim: To cover the importance of monitoring behavioral state in imaging experiments using un-anesthetized rodents, and describe how to incorporate detailed behavioral and physiological measurements in imaging experiments. Approach: We review the effects of movements and sleep-related signals (heart rate, respiration rate, electromyography, intracranial pressure, whisking, and other body movements) on brain hemodynamics and electrophysiological signals, with a focus on head-fixed experimental setup. We summarize the measurement methods currently used in animal models for detection of those behaviors and arousal changes. We then provide a guide on how to incorporate this measurements with functional brain imaging and electrophysiology measurements. Results: We provide a how-to guide on monitoring and interpreting a variety of physiological signals and their applications to NVC experiments in awake behaving mice. Conclusion: This guide facilitates the application of neuroimaging in awake animal models and provides neuroscientists with a standard approach for monitoring behavior and other associated physiological parameters in head-fixed animals.
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Affiliation(s)
- Qingguang Zhang
- The Pennsylvania State University, Center for Neural Engineering, Department of Engineering Science and Mechanics, University Park, Pennsylvania, United States
| | - Kevin L. Turner
- The Pennsylvania State University, Department of Biomedical Engineering, University Park, Pennsylvania, United States
| | - Kyle W. Gheres
- The Pennsylvania State University, Graduate Program in Molecular Cellular and Integrative Biosciences, University Park, Pennsylvania, United States
| | - Md Shakhawat Hossain
- The Pennsylvania State University, Department of Biomedical Engineering, University Park, Pennsylvania, United States
| | - Patrick J. Drew
- The Pennsylvania State University, Center for Neural Engineering, Department of Engineering Science and Mechanics, University Park, Pennsylvania, United States
- The Pennsylvania State University, Department of Biomedical Engineering, University Park, Pennsylvania, United States
- The Pennsylvania State University, Department of Neurosurgery, University Park, Pennsylvania, United States
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14
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The influence of the respiratory cycle on reaction times in sensory-cognitive paradigms. Sci Rep 2022; 12:2586. [PMID: 35173204 PMCID: PMC8850565 DOI: 10.1038/s41598-022-06364-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 01/25/2022] [Indexed: 11/08/2022] Open
Abstract
Behavioural and electrophysiological studies point to an apparent influence of the state of respiration, i.e., whether we inhale or exhale, on brain activity and cognitive performance. Still, the prevalence and relevance of such respiratory-behavioural relations in typical sensory-cognitive tasks remain unclear. We here used a battery of six tasks probing sensory detection, discrimination and short-term memory to address the questions of whether and by how much behaviour covaries with the respiratory cycle. Our results show that participants tend to align their respiratory cycle to the experimental paradigm, in that they tend to inhale around stimulus presentation and exhale when submitting their responses. Furthermore, their reaction times, but not so much their response accuracy, consistently and significantly covary with the respiratory cycle, differing between inhalation and exhalation. This effect is strongest when analysed contingent on the respiratory state around participants' responses. The respective effect sizes of these respiration-behaviour relations are comparable to those seen in other typical experimental manipulations in sensory-cognitive tasks, highlighting the relevance of these effects. Overall, our results support a prominent relation between respiration and sensory-cognitive function and show that sensation is intricately linked to rhythmic bodily or interoceptive functions.
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15
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Huen SC, Wang A, Feola K, Desrouleaux R, Luan HH, Hogg R, Zhang C, Zhang QJ, Liu ZP, Medzhitov R. Hepatic FGF21 preserves thermoregulation and cardiovascular function during bacterial inflammation. J Exp Med 2021; 218:e20202151. [PMID: 34406362 PMCID: PMC8374861 DOI: 10.1084/jem.20202151] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 06/22/2021] [Accepted: 08/02/2021] [Indexed: 12/16/2022] Open
Abstract
Sickness behaviors, including anorexia, are evolutionarily conserved responses to acute infections. Inflammation-induced anorexia causes dramatic metabolic changes, of which components critical to survival are unique depending on the type of inflammation. Glucose supplementation during the anorectic period induced by bacterial inflammation suppresses adaptive fasting metabolic pathways, including fibroblast growth factor 21 (FGF21), and decreases survival. Consistent with this observation, FGF21-deficient mice are more susceptible to mortality from endotoxemia and polybacterial peritonitis. Here, we report that increased circulating FGF21 during bacterial inflammation is hepatic derived and required for survival through the maintenance of thermogenesis, energy expenditure, and cardiac function. FGF21 signaling downstream of its obligate coreceptor, β-Klotho (KLB), is required in bacterial sepsis. However, FGF21 modulates thermogenesis and chronotropy independent of the adipose, forebrain, and hypothalamus, which are operative in cold adaptation, suggesting that in bacterial inflammation, either FGF21 signals through a novel, undescribed target tissue or concurrent signaling of multiple KLB-expressing tissues is required.
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Affiliation(s)
- Sarah C. Huen
- Department of Internal Medicine (Nephrology) and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Andrew Wang
- Department of Internal Medicine (Rheumatology), Yale University School of Medicine, New Haven, CT
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT
| | - Kyle Feola
- Department of Internal Medicine (Nephrology) and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Reina Desrouleaux
- Department of Internal Medicine (Rheumatology), Yale University School of Medicine, New Haven, CT
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT
| | - Harding H. Luan
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT
| | - Richard Hogg
- Department of Internal Medicine (Nephrology) and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Cuiling Zhang
- Department of Internal Medicine (Rheumatology), Yale University School of Medicine, New Haven, CT
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT
| | - Qing-Jun Zhang
- Department of Internal Medicine (Cardiology) and Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Zhi-Ping Liu
- Department of Internal Medicine (Cardiology) and Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Ruslan Medzhitov
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT
- Howard Hughes Medical Institute, Chevy Chase, MD
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16
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Reisert J, Golden GJ, Dibattista M, Gelperin A. Odor sampling strategies in mice with genetically altered olfactory responses. PLoS One 2021; 16:e0249798. [PMID: 33939692 PMCID: PMC8092659 DOI: 10.1371/journal.pone.0249798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 03/25/2021] [Indexed: 12/04/2022] Open
Abstract
Peripheral sensory cells and the central neuronal circuits that monitor environmental changes to drive behaviors should be adapted to match the behaviorally relevant kinetics of incoming stimuli, be it the detection of sound frequencies, the speed of moving objects or local temperature changes. Detection of odorants begins with the activation of olfactory receptor neurons in the nasal cavity following inhalation of air and airborne odorants carried therein. Thus, olfactory receptor neurons are stimulated in a rhythmic and repeated fashion that is determined by the breathing or sniffing frequency that can be controlled and altered by the animal. This raises the question of how the response kinetics of olfactory receptor neurons are matched to the imposed stimulation frequency and if, vice versa, the kinetics of olfactory receptor neuron responses determine the sniffing frequency. We addressed this question by using a mouse model that lacks the K+-dependent Na+/Ca2+ exchanger 4 (NCKX4), which results in markedly slowed response termination of olfactory receptor neuron responses and hence changes the temporal response kinetics of these neurons. We monitored sniffing behaviors of freely moving wildtype and NCKX4 knockout mice while they performed olfactory Go/NoGo discrimination tasks. Knockout mice performed with similar or, surprisingly, better accuracy compared to wildtype mice, but chose, depending on the task, different odorant sampling durations depending on the behavioral demands of the odorant identification task. Similarly, depending on the demands of the behavioral task, knockout mice displayed a lower basal breathing frequency prior to odorant sampling, a possible mechanism to increase the dynamic range for changes in sniffing frequency during odorant sampling. Overall, changes in sniffing behavior between wildtype and NCKX4 knockout mice were subtle, suggesting that, at least for the particular odorant-driven task we used, slowed response termination of the odorant-induced receptor neuron response either has a limited detrimental effect on odorant-driven behavior or mice are able to compensate via an as yet unknown mechanism.
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Affiliation(s)
- Johannes Reisert
- Monell Chemical Senses Center, Philadelphia, PA, United States of America
- * E-mail: (JR); (AG)
| | - Glen J. Golden
- Monell Chemical Senses Center, Philadelphia, PA, United States of America
| | - Michele Dibattista
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, University of Bari “A. Moro”, Bari, Italy
| | - Alan Gelperin
- Princeton Neuroscience Program, Princeton University, Princeton, NJ, United States of America
- * E-mail: (JR); (AG)
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17
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Eyme KM, Carvalho L, Badr CE. Intranasal delivery of experimental compounds in orthotopic brain tumor mouse models. STAR Protoc 2021; 2:100290. [PMID: 33532737 PMCID: PMC7821034 DOI: 10.1016/j.xpro.2020.100290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Effective therapeutics for malignant primary brain tumors, such as glioblastomas (GBMs), are urgently needed. To facilitate and expedite early-phase GBM therapeutic development, we describe a protocol that allows the intranasal delivery of experimental compounds in GBM orthotopic mouse models. Compounds delivered through this route can bypass the blood-brain barrier and thus help validate effective therapeutic targets for GBMs. For complete details on the use and execution of this protocol, please refer to Pinkham et al. (2019). Using patient-derived tumor cells to study and image GBM tumor growth in mice Delivery of therapeutics via the intranasal route to bypass the blood-brain barrier This delivery method can expedite early-phase testing of GBM therapeutics
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Affiliation(s)
- Katharina M Eyme
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02129, USA
| | - Litia Carvalho
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02129, USA.,Neuroscience Program, Harvard Medical School, Boston, MA, USA
| | - Christian E Badr
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02129, USA.,Neuroscience Program, Harvard Medical School, Boston, MA, USA
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18
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Mecozzi L, Mambrini M, Ruscitti F, Ferrini E, Ciccimarra R, Ravanetti F, Sverzellati N, Silva M, Ruffini L, Belenkov S, Civelli M, Villetti G, Stellari FF. In-vivo lung fibrosis staging in a bleomycin-mouse model: a new micro-CT guided densitometric approach. Sci Rep 2020; 10:18735. [PMID: 33127949 PMCID: PMC7603396 DOI: 10.1038/s41598-020-71293-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 07/28/2020] [Indexed: 02/07/2023] Open
Abstract
Although increasing used in the preclinical testing of new anti-fibrotic drugs, a thorough validation of micro-computed tomography (CT) in pulmonary fibrosis models has not been performed. Moreover, no attempts have been made so far to define density thresholds to discriminate between aeration levels in lung parenchyma. In the present study, a histogram-based analysis was performed in a mouse model of bleomycin (BLM)-induced pulmonary fibrosis by micro-CT, evaluating longitudinal density changes from 7 to 21 days after BLM challenge, a period representing the progression of fibrosis. Two discriminative densitometric indices (i.e. 40th and 70th percentiles) were extracted from Hounsfield Unit density distributions and selected for lung fibrosis staging. The strong correlation with histological findings (rSpearman = 0.76, p < 0.01) confirmed that variations in 70th percentile could reflect a pathological lung condition and estimate the effect of antifibrotic treatments. This index was therefore used to define lung aeration levels in mice distinguishing in hyper-inflated, normo-, hypo- and non-aerated pulmonary compartments. A retrospective analysis performed on a large cohort of mice confirmed the correlation between the proposed preclinical density thresholds and the histological outcomes (rSpearman = 0.6, p < 0.01), strengthening their suitability for tracking disease progression and evaluating antifibrotic drug candidates.
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Affiliation(s)
- Laura Mecozzi
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Martina Mambrini
- Department of Veterinary Science, University of Parma, Parma, Italy
| | - Francesca Ruscitti
- Phamacology and Toxicology Department, Chiesi Farmaceutici S.P.A., Corporate Pre-Clinical R&D, Largo Belloli, 11/A 43122, Parma, Italy
| | - Erica Ferrini
- Department of Veterinary Science, University of Parma, Parma, Italy
| | | | | | | | - Mario Silva
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Livia Ruffini
- Department Nuclear Medicine, Academic Hospital of Parma, Parma, Italy
| | | | - Maurizio Civelli
- Phamacology and Toxicology Department, Chiesi Farmaceutici S.P.A., Corporate Pre-Clinical R&D, Largo Belloli, 11/A 43122, Parma, Italy
| | - Gino Villetti
- Phamacology and Toxicology Department, Chiesi Farmaceutici S.P.A., Corporate Pre-Clinical R&D, Largo Belloli, 11/A 43122, Parma, Italy
| | - Fabio Franco Stellari
- Phamacology and Toxicology Department, Chiesi Farmaceutici S.P.A., Corporate Pre-Clinical R&D, Largo Belloli, 11/A 43122, Parma, Italy.
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19
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Reisert J, Golden GJ, Dibattista M, Gelperin A. Dynamics of odor sampling strategies in mice. PLoS One 2020; 15:e0237756. [PMID: 32797072 PMCID: PMC7428156 DOI: 10.1371/journal.pone.0237756] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/31/2020] [Indexed: 11/18/2022] Open
Abstract
Mammalian olfactory receptor neurons in the nasal cavity are stimulated by odorants carried by the inhaled air and their activation is therefore tied to and driven by the breathing or sniffing frequency. Sniffing frequency can be deliberately modulated to alter how odorants stimulate olfactory receptor neurons, giving the animal control over the frequency of odorant exposure to potentially aid odorant detection and discrimination. We monitored sniffing behaviors and odorant discrimination ability of freely-moving mice while they sampled either decreasing concentrations of target odorants or sampled a fixed target odorant concentration in the presence of a background of increasing odorant concentrations, using a Go-NoGo behavioral paradigm. This allowed us to ask how mice alter their odorant sampling duration and sampling (sniffing) frequency depending on the demands of the task and its difficulty. Mice showed an anticipatory increase in sniffing rate prior to odorant exposure and chose to sample for longer durations when exposed to odorants as compared to the solvent control odorant. Similarly, mice also took more odorant sampling sniffs when exposed to target odorants compared to the solvent control odorant. In general, odorant sampling strategies became more similar the more difficult the task was, e.g. the lower the target odorant concentration or the lower the target odorant contrast relative to the background odorant, suggesting that sniffing patterns are not preset, but are dynamically modulated by the particular task and its difficulty.
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Affiliation(s)
- Johannes Reisert
- Monell Chemical Senses Center, Philadelphia, PA, United States of America
| | - Glen J. Golden
- Monell Chemical Senses Center, Philadelphia, PA, United States of America
| | - Michele Dibattista
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, University of Bari “A. Moro”, Bari, Italy
| | - Alan Gelperin
- Department of Neuroscience, Princeton University, Princeton, NJ, United States of America
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20
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Wallace J, Lord J, Dissing-Olesen L, Stevens B, Murthy VN. Microglial depletion disrupts normal functional development of adult-born neurons in the olfactory bulb. eLife 2020; 9:e50531. [PMID: 32150529 PMCID: PMC7062469 DOI: 10.7554/elife.50531] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 01/13/2020] [Indexed: 12/11/2022] Open
Abstract
Microglia play key roles in regulating synapse development and refinement in the developing brain, but it is unknown whether they are similarly involved during adult neurogenesis. By transiently depleting microglia from the healthy adult mouse brain, we show that microglia are necessary for the normal functional development of adult-born granule cells (abGCs) in the olfactory bulb. Microglial depletion reduces the odor responses of developing, but not preexisting GCs in vivo in both awake and anesthetized mice. Microglia preferentially target their motile processes to interact with mushroom spines on abGCs, and when microglia are absent, abGCs develop smaller spines and receive weaker excitatory synaptic inputs. These results suggest that microglia promote the development of excitatory synapses onto developing abGCs, which may impact the function of these cells in the olfactory circuit.
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Affiliation(s)
- Jenelle Wallace
- Molecules, Cells, and Organisms Training Program, Harvard UniversityCambridgeUnited States
- Center for Brain Science, Harvard UniversityCambridgeUnited States
- Department of Molecular and Cellular Biology, Harvard UniversityCambridgeUnited States
- FM Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
| | - Julia Lord
- Department of Molecular and Cellular Biology, Harvard UniversityCambridgeUnited States
| | - Lasse Dissing-Olesen
- FM Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
- Harvard Medical SchoolBostonUnited States
| | - Beth Stevens
- FM Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
- Harvard Medical SchoolBostonUnited States
- Stanley Center for Psychiatric Research, Broad Institute of MIT and HarvardCambridgeUnited States
- Howard Hughes Medical Institute, Boston Children’s HospitalBostonUnited States
| | - Venkatesh N Murthy
- Molecules, Cells, and Organisms Training Program, Harvard UniversityCambridgeUnited States
- Center for Brain Science, Harvard UniversityCambridgeUnited States
- Department of Molecular and Cellular Biology, Harvard UniversityCambridgeUnited States
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21
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Smith TM, Lee D, Bradley K, McMahon SB. Methodology for quantifying excitability of identified projection neurons in the dorsal horn of the spinal cord, specifically to study spinal cord stimulation paradigms. J Neurosci Methods 2020; 330:108479. [DOI: 10.1016/j.jneumeth.2019.108479] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 10/22/2019] [Indexed: 11/28/2022]
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22
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Narrowly Confined and Glomerulus-Specific Onset Latencies of Odor-Evoked Calcium Transients in the Juxtaglomerular Cells of the Mouse Main Olfactory Bulb. eNeuro 2019; 6:eN-NWR-0387-18. [PMID: 30834302 PMCID: PMC6397951 DOI: 10.1523/eneuro.0387-18.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 02/01/2019] [Accepted: 02/05/2019] [Indexed: 12/04/2022] Open
Abstract
Odor information is transmitted from olfactory sensory neurons to principal neurons at the glomeruli of the olfactory bulb. The intraglomerular neuronal circuit also includes hundreds of interneurons referred to as juxtaglomerular (JG) cells. Stimulus selectivity is well correlated among many JG cells that are associated with the same glomerulus, consistent with their highly homogeneous sensory inputs. However, much less is known about the temporal aspects of their activity, including the temporal coordination of their odor-evoked responses. As many JG cells within a glomerular module respond to the same stimulus, the extent to which their activity is temporally aligned will affect the temporal profile of their population inhibitory inputs. Using random-access high-speed two-photon microscopy, we recorded the odor-evoked calcium transients of mouse JG cells and compared the onset latency and rise time among neurons putatively associated with the same and different glomeruli. Whereas the overall onset latencies of odor-evoked transients were distributed across a ∼150 ms time window, those from cells putatively associated with the same glomerulus were confined to a much narrower window of several tens of milliseconds. This result suggests that onset latency primarily depends on the associated glomerulus. We also observed glomerular specificity in the rise time. The glomerulus-specific temporal pattern of odor-evoked activity implies that the temporal patterns of inputs from the intraglomerular circuit are unique to individual glomerulus–odor pairs, which may contribute to efficient shaping of the temporal pattern of activity in the principal neurons.
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