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Gutiérrez-Jiménez E, Rasmussen PM, Mikkelsen IK, Kura S, Fruekilde SK, Hansen B, Bordoni L, Carlsen J, Palmfeldt J, Boas DA, Sakadžić S, Vinogradov S, Khatib ME, Ramos-Cejudo J, Wied B, Leduc-Galindo D, Canepa E, Mar AC, Gamallo-Lana B, Fossati S, Østergaard L. Carbonic anhydrase inhibitors prevent presymptomatic capillary flow disturbances in a model of cerebral amyloidosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.22.609091. [PMID: 39229198 PMCID: PMC11370441 DOI: 10.1101/2024.08.22.609091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
INTRODUCTION Disturbances in microvascular flow dynamics are hypothesized to precede the symptomatic phase of Alzheimer's disease (AD). However, evidence in presymptomatic AD remains elusive, underscoring the need for therapies targeting these early vascular changes. METHODS We employed a multimodal approach, combining in vivo optical imaging, molecular techniques, and ex vivo MRI, to investigate early capillary dysfunction in Tg-SwDI mice without memory impairment. We also assessed the efficacy of carbonic anhydrase inhibitors (CAIs) in preventing capillary flow disturbances. RESULTS Our study revealed capillary flow disturbances associated with alterations in capillary morphology, adhesion molecule expression, and Amyloid-β (Aβ) load in 9-10-month-old Tg-SwDI mice without memory impairment. CAI treatment ameliorated these capillary flow disturbances, enhanced oxygen availability, and reduced Aβ load. DISCUSSION These findings underscore the importance of capillary flow disturbances as early biomarkers in presymptomatic AD and highlight the potential of CAIs for preserving vascular integrity in the early stages of AD.
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Wei Z, Roh SE, Yang X, Wang W, Wang J, Chen L, Li Y, Bibic A, Lu H. The impact of isoflurane anesthesia on brain metabolism in mice: An MRI and electroencephalography study. NMR IN BIOMEDICINE 2024; 37:e5260. [PMID: 39254055 PMCID: PMC11563868 DOI: 10.1002/nbm.5260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 08/15/2024] [Accepted: 08/31/2024] [Indexed: 09/11/2024]
Abstract
Isoflurane is one of the most widely used anesthetic agents in rodent imaging studies. However, the impact of isoflurane on brain metabolism has not been fully characterized to date, primarily due to a scarcity of noninvasive technologies to quantitatively measure the brain's metabolic rate in vivo. In this study, using noncontrast MRI techniques, we dynamically measured cerebral metabolic rate of oxygen (CMRO2) under varying doses of isoflurane anesthesia in mice. Concurrently, systemic parameters of heart and respiration rates were recorded alongside CMRO2. Additionally, electroencephalogram (EEG) recording was used to identify changes in neuronal activities under the same anesthetic regimen employed in the MRI experiments. We found suppression of the CMRO2 by isoflurane in a dose-dependent manner, concomitant with a diminished high-frequency EEG activity. The degree of metabolic suppression by isoflurane was strongly correlated with the respiration rate, which offers a potential approach to calibrate CMRO2 measurements. Furthermore, the metabolic level associated with neural responses of the somatosensory and motor cortices in mice was estimated as 308.2 μmol/100 g/min. These findings may facilitate the integration of metabolic parameters into future studies involving animal disease models and anesthesia usage.
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Affiliation(s)
- Zhiliang Wei
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Seung-Eon Roh
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Xiuli Yang
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Wenshen Wang
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Jiekang Wang
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Lin Chen
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Yuguo Li
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Adnan Bibic
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Hanzhang Lu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Darevsky D, Kim J, Ganguly K. Coupling of Slow Oscillations in the Prefrontal and Motor Cortex Predicts Onset of Spindle Trains and Persistent Memory Reactivations. J Neurosci 2024; 44:e0621242024. [PMID: 39168655 PMCID: PMC11502226 DOI: 10.1523/jneurosci.0621-24.2024] [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: 04/02/2024] [Revised: 07/12/2024] [Accepted: 08/10/2024] [Indexed: 08/23/2024] Open
Abstract
Sleep is known to drive the consolidation of motor memories. During nonrapid eye movement (NREM) sleep, the close temporal proximity between slow oscillations (SOs) and spindles ("nesting" of SO-spindles) is known to be essential for consolidation, likely because it is closely associated with the reactivation of awake task activity. Interestingly, recent work has found that spindles can occur in temporal clusters or "trains." However, it remains unclear how spindle trains are related to the nesting phenomenon. Here, we hypothesized that spindle trains are more likely when SOs co-occur in the prefrontal and motor cortex. We conducted simultaneous neural recordings in the medial prefrontal cortex (mPFC) and primary motor cortex (M1) of male rats training on the reach-to-grasp motor task. We found that intracortically recorded M1 spindles are organized into distinct temporal clusters. Notably, the occurrence of temporally precise SOs between mPFC and M1 was a strong predictor of spindle trains. Moreover, reactivation of awake task patterns is much more persistent during spindle trains in comparison with that during isolated spindles. Together, our work suggests that the precise coupling of SOs across mPFC and M1 may be a potential driver of spindle trains and persistent reactivation of motor memory during NREM sleep.
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Affiliation(s)
- David Darevsky
- Bioengineering Graduate Program, University of California San Francisco, San Francisco, California 94143
- Medical Scientist Training Program, University of California San Francisco, San Francisco, California 94143
- Neurology Service, San Francisco Veterans Affairs Medical Center, San Francisco, California 94121
- Department of Neurology, University of California San Francisco, San Francisco, California 94143
| | - Jaekyung Kim
- Neurology Service, San Francisco Veterans Affairs Medical Center, San Francisco, California 94121
- Department of Neurology, University of California San Francisco, San Francisco, California 94143
| | - Karunesh Ganguly
- Neurology Service, San Francisco Veterans Affairs Medical Center, San Francisco, California 94121
- Department of Neurology, University of California San Francisco, San Francisco, California 94143
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4
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Zvolanek KM, Moore JE, Jarvis K, Moum SJ, Bright MG. Macrovascular blood flow and microvascular cerebrovascular reactivity are regionally coupled in adolescence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.26.590312. [PMID: 38746187 PMCID: PMC11092525 DOI: 10.1101/2024.04.26.590312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Cerebrovascular imaging assessments are particularly challenging in adolescent cohorts, where not all modalities are appropriate, and rapid brain maturation alters hemodynamics at both macro- and microvascular scales. In a preliminary sample of healthy adolescents (n=12, 8-25 years), we investigated relationships between 4D flow MRI-derived blood velocity and blood flow in bilateral anterior, middle, and posterior cerebral arteries and BOLD cerebrovascular reactivity in associated vascular territories. As hypothesized, higher velocities in large arteries are associated with an earlier response to a vasodilatory stimulus (cerebrovascular reactivity delay) in the downstream territory. Higher blood flow through these arteries is associated with a larger BOLD response to a vasodilatory stimulus (cerebrovascular reactivity amplitude) in the associated territory. These trends are consistent in a case study of adult moyamoya disease. In our small adolescent cohort, macrovascular-microvascular relationships for velocity/delay and flow/CVR change with age, though underlying mechanisms are unclear. Our work emphasizes the need to better characterize this key stage of human brain development, when cerebrovascular hemodynamics are changing, and standard imaging methods offer limited insight into these processes. We provide important normative data for future comparisons in pathology, where combining macro- and microvascular assessments may better help us prevent, stratify, and treat cerebrovascular disease.
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Affiliation(s)
- Kristina M. Zvolanek
- Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Biomedical Engineering, McCormick School of Engineering and Applied Sciences, Northwestern University, Evanston, IL, USA
| | - Jackson E. Moore
- Biomedical Engineering, McCormick School of Engineering and Applied Sciences, Northwestern University, Evanston, IL, USA
- Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Kelly Jarvis
- Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Sarah J. Moum
- Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Medical Imaging, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL, USA
| | - Molly G. Bright
- Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Biomedical Engineering, McCormick School of Engineering and Applied Sciences, Northwestern University, Evanston, IL, USA
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5
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Bourne JA, Cichy RM, Kiorpes L, Morrone MC, Arcaro MJ, Nielsen KJ. Development of Higher-Level Vision: A Network Perspective. J Neurosci 2024; 44:e1291242024. [PMID: 39358020 PMCID: PMC11450542 DOI: 10.1523/jneurosci.1291-24.2024] [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: 07/07/2024] [Revised: 07/27/2024] [Accepted: 07/29/2024] [Indexed: 10/04/2024] Open
Abstract
Most studies on the development of the visual system have focused on the mechanisms shaping early visual stages up to the level of primary visual cortex (V1). Much less is known about the development of the stages after V1 that handle the higher visual functions fundamental to everyday life. The standard model for the maturation of these areas is that it occurs sequentially, according to the positions of areas in the adult hierarchy. Yet, the existing literature reviewed here paints a different picture, one in which the adult configuration emerges through a sequence of unique network configurations that are not mere partial versions of the adult hierarchy. In addition to studying higher visual development per se to fill major gaps in knowledge, it will be crucial to adopt a network-level perspective in future investigations to unravel normal developmental mechanisms, identify vulnerabilities to developmental disorders, and eventually devise treatments for these disorders.
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Affiliation(s)
- James A Bourne
- Section on Cellular and Cognitive Neurodevelopment, Systems Neurodevelopment Laboratory, National Institute of Mental Health, Bethesda, Maryland 20814
| | - Radoslaw M Cichy
- Department of Education and Psychology, Freie Universität Berlin, Berlin 14195, Germany
- Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin 10099, Germany
- Einstein Center for Neurosciences Berlin, Charite-Universitätsmedizin Berlin, Berlin 10117, Germany
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Berlin 10099, Germany
| | - Lynne Kiorpes
- Center for Neural Science, New York University, New York, New York 10003
| | - Maria Concetta Morrone
- IRCCS Fondazione Stella Maris, Pisa 56128, Italy
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa 56126, Italy
| | - Michael J Arcaro
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Kristina J Nielsen
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland 21218
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Solano A, Lerner G, Griffa G, Deleglise A, Caffaro P, Riquelme L, Perez-Chada D, Della-Maggiore V. Sleep Consolidation Potentiates Sensorimotor Adaptation. J Neurosci 2024; 44:e0325242024. [PMID: 39074983 PMCID: PMC11376339 DOI: 10.1523/jneurosci.0325-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 05/23/2024] [Accepted: 06/12/2024] [Indexed: 07/31/2024] Open
Abstract
Contrary to its well-established role in declarative learning, the impact of sleep on motor memory consolidation remains a subject of debate. Current literature suggests that while motor skill learning benefits from sleep, consolidation of sensorimotor adaptation (SMA) depends solely on the passage of time. This has led to the proposal that SMA may be an exception to other types of memories. Here, we addressed this ongoing controversy in humans through three comprehensive experiments using the visuomotor adaptation paradigm (N = 290, 150 females). In Experiment 1, we investigated the impact of sleep on memory retention when the temporal gap between training and sleep was not controlled. In line with the previous literature, we found that memory consolidates with the passage of time. In Experiment 2, we used an anterograde interference protocol to determine the time window during which SMA memory is most fragile and, thus, potentially most sensitive to sleep intervention. Our results show that memory is most vulnerable during the initial hour post-training. Building on this insight, in Experiment 3, we investigated the impact of sleep when it coincided with the critical first hour of memory consolidation. This manipulation unveiled a benefit of sleep (30% memory enhancement) alongside an increase in spindle density and spindle-SO coupling during NREM sleep, two well-established neural markers of sleep consolidation. Our findings reconcile seemingly conflicting perspectives on the active role of sleep in motor learning and point to common mechanisms at the basis of memory formation.
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Affiliation(s)
- Agustin Solano
- Universidad de Buenos Aires-CONICET. Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Facultad de Medicina, Departamento de Ciencias Fisiológicas, Ciudad de Buenos Aires C1121ABG, Argentina
| | - Gonzalo Lerner
- Universidad de Buenos Aires-CONICET. Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Facultad de Medicina, Departamento de Ciencias Fisiológicas, Ciudad de Buenos Aires C1121ABG, Argentina
| | - Guillermina Griffa
- Universidad de Buenos Aires-CONICET. Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Facultad de Medicina, Departamento de Ciencias Fisiológicas, Ciudad de Buenos Aires C1121ABG, Argentina
| | - Alvaro Deleglise
- Universidad de Buenos Aires-CONICET. Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Facultad de Medicina, Departamento de Ciencias Fisiológicas, Ciudad de Buenos Aires C1121ABG, Argentina
| | - Pedro Caffaro
- Universidad de Buenos Aires-CONICET. Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Facultad de Medicina, Departamento de Ciencias Fisiológicas, Ciudad de Buenos Aires C1121ABG, Argentina
| | - Luis Riquelme
- Universidad de Buenos Aires-CONICET. Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Facultad de Medicina, Departamento de Ciencias Fisiológicas, Ciudad de Buenos Aires C1121ABG, Argentina
| | - Daniel Perez-Chada
- Departamento de Medicina Interna, Servicio de Medicina Pulmonar y Sueño, Hospital Universitario Austral, Pilar, Buenos Aires B1629AHJ, Argentina
| | - Valeria Della-Maggiore
- Universidad de Buenos Aires-CONICET. Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay), Facultad de Medicina, Departamento de Ciencias Fisiológicas, Ciudad de Buenos Aires C1121ABG, Argentina
- Department of Neurology and Neurosurgery, McGill University Montreal, Quebec H3A2B4, Canada
- Escuela de Ciencia y Tecnología (ECyT), Universidad Nacional de San Martin, San Martin, Buenos Aires, CP 1650, Argentina
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Riegel J, Schüller A, Reichenbach T. No Evidence of Musical Training Influencing the Cortical Contribution to the Speech-Frequency-Following Response and Its Modulation through Selective Attention. eNeuro 2024; 11:ENEURO.0127-24.2024. [PMID: 39160069 PMCID: PMC11382759 DOI: 10.1523/eneuro.0127-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 07/23/2024] [Accepted: 07/24/2024] [Indexed: 08/21/2024] Open
Abstract
Musicians can have better abilities to understand speech in adverse condition such as background noise than non-musicians. However, the neural mechanisms behind such enhanced behavioral performances remain largely unclear. Studies have found that the subcortical frequency-following response to the fundamental frequency of speech and its higher harmonics (speech-FFR) may be involved since it is larger in people with musical training than in those without. Recent research has shown that the speech-FFR consists of a cortical contribution in addition to the subcortical sources. Both the subcortical and the cortical contribution are modulated by selective attention to one of two competing speakers. However, it is unknown whether the strength of the cortical contribution to the speech-FFR, or its attention modulation, is influenced by musical training. Here we investigate these issues through magnetoencephalographic (MEG) recordings of 52 subjects (18 musicians, 25 non-musicians, and 9 neutral participants) listening to two competing male speakers while selectively attending one of them. The speech-in-noise comprehension abilities of the participants were not assessed. We find that musicians and non-musicians display comparable cortical speech-FFRs and additionally exhibit similar subject-to-subject variability in the response. Furthermore, we also do not observe a difference in the modulation of the neural response through selective attention between musicians and non-musicians. Moreover, when assessing whether the cortical speech-FFRs are influenced by particular aspects of musical training, no significant effects emerged. Taken together, we did not find any effect of musical training on the cortical speech-FFR.
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Affiliation(s)
- Jasmin Riegel
- Department Artificial Intelligence in Biomedical Engineering (AIBE), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91052 Erlangen, Germany
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Wong AL, Eyssalenne AN, Carter L, Therrien AS. Different Sensory Information Is Used for State Estimation when Stationary or Moving. eNeuro 2024; 11:ENEURO.0357-23.2024. [PMID: 39147580 PMCID: PMC11376429 DOI: 10.1523/eneuro.0357-23.2024] [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: 09/14/2023] [Revised: 07/19/2024] [Accepted: 08/08/2024] [Indexed: 08/17/2024] Open
Abstract
The accurate estimation of limb state is necessary for movement planning and execution. While state estimation requires both feedforward and feedback information, we focus here on the latter. Prior literature has shown that integrating visual and proprioceptive feedback improves estimates of static limb position. However, differences in visual and proprioceptive feedback delays suggest that multisensory integration could be disadvantageous when the limb is moving. We formalized this hypothesis by modeling feedback-based state estimation using the long-standing maximum likelihood estimation model of multisensory integration, which we updated to account for sensory delays. Our model predicted that the benefit of multisensory integration was largely lost when the limb was passively moving. We tested this hypothesis in a series of experiments in human subjects that compared the degree of interference created by discrepant visual or proprioceptive feedback when estimating limb position either statically at the end of the movement or dynamically at movement midpoint. In the static case, we observed significant interference: discrepant feedback in one modality systematically biased sensory estimates based on the other modality. However, no interference was seen in the dynamic case: participants could ignore sensory feedback from one modality and accurately reproduce the motion indicated by the other modality. Together, these findings suggest that the sensory feedback used to compute a state estimate differs depending on whether the limb is stationary or moving. While the former may tend toward multimodal integration, the latter is more likely to be based on feedback from a single sensory modality.
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Affiliation(s)
- Aaron L Wong
- Moss Rehabilitation Research Institute, Thomas Jefferson University, Elkins Park, Pennsylvania 19027
- Department of Rehabilitation Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Alyssa N Eyssalenne
- Moss Rehabilitation Research Institute, Thomas Jefferson University, Elkins Park, Pennsylvania 19027
| | - Luke Carter
- Moss Rehabilitation Research Institute, Thomas Jefferson University, Elkins Park, Pennsylvania 19027
| | - Amanda S Therrien
- Moss Rehabilitation Research Institute, Thomas Jefferson University, Elkins Park, Pennsylvania 19027
- Department of Rehabilitation Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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Lindhardt TB, Skoven CS, Bordoni L, Østergaard L, Liang Z, Hansen B. Anesthesia-related brain microstructure modulations detected by diffusion magnetic resonance imaging. NMR IN BIOMEDICINE 2024; 37:e5033. [PMID: 37712335 DOI: 10.1002/nbm.5033] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 07/06/2023] [Accepted: 08/09/2023] [Indexed: 09/16/2023]
Abstract
Recent studies have shown significant changes to brain microstructure during sleep and anesthesia. In vivo optical microscopy and magnetic resonance imaging (MRI) studies have attributed these changes to anesthesia and sleep-related modulation of the brain's extracellular space (ECS). Isoflurane anesthesia is widely used in preclinical diffusion MRI (dMRI) and it is therefore important to investigate if the brain's microstructure is affected by anesthesia to an extent detectable with dMRI. Here, we employ diffusion kurtosis imaging (DKI) to assess brain microstructure in the awake and anesthetized mouse brain (n = 22). We find both mean diffusivity (MD) and mean kurtosis (MK) to be significantly decreased in the anesthetized mouse brain compared with the awake state (p < 0.001 for both). This effect is observed in both gray matter and white matter. To further investigate the time course of these changes we introduce a method for time-resolved fast DKI. With this, we show the time course of the microstructural alterations in mice (n = 5) as they transition between states in an awake-anesthesia-awake paradigm. We find that the decrease in MD and MK occurs rapidly after delivery of gas isoflurane anesthesia and that values normalize only slowly when the animals return to the awake state. Finally, time-resolved fast DKI is employed in an experimental mouse model of brain edema (n = 4), where cell swelling causes the ECS volume to decrease. Our results show that isoflurane affects DKI parameters and metrics of brain microstructure and point to isoflurane causing a reduction in the ECS volume. The demonstrated DKI methods are suitable for in-bore perturbation studies, for example, for investigating microstructural modulations related to sleep/wake-dependent functions of the glymphatic system. Importantly, our study shows an effect of isoflurane anesthesia on rodent brain microstructure that has broad relevance to preclinical dMRI.
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Affiliation(s)
- Thomas Beck Lindhardt
- Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Sino-Danish Center for Education and Research, Aarhus, Denmark
- University of the Chinese Academy of Sciences, Beijing, China
| | - Christian Stald Skoven
- Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Luca Bordoni
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Letten Center, University of Oslo, Oslo, Norway
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Radiology, Neuroradiology Research Unit, Aarhus University Hospital, Aarhus, Denmark
| | - Zhifeng Liang
- CAS Center for Excellence in Brain Sciences and Intelligence Technology, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China
| | - Brian Hansen
- Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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Chaomulige, Matsuo T, Sugimoto K, Miyaji M, Hosoya O, Ueda M, Kobayashi R, Horii T, Hatada I. Morphometric Analysis of the Eye by Magnetic Resonance Imaging in MGST2-Gene-Deficient Mice. Biomedicines 2024; 12:370. [PMID: 38397974 PMCID: PMC10887158 DOI: 10.3390/biomedicines12020370] [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: 12/13/2023] [Revised: 01/23/2024] [Accepted: 02/01/2024] [Indexed: 02/25/2024] Open
Abstract
Strabismus, a neuro-ophthalmological condition characterized by misalignment of the eyes, is a common ophthalmic disorder affecting both children and adults. In our previous study, we identified the microsomal glutathione S-transferase 2 (MGST2) gene as one of the potential candidates for comitant strabismus susceptibility in a Japanese population. The MGST2 gene belongs to the membrane-associated protein involved in the generation of pro-inflammatory mediators, and it is also found in the protection against oxidative stress by decreasing the reactivity of oxidized lipids. To look for the roles of the MGST2 gene in the development, eye alignment, and overall morphology of the eye as the possible background of strabismus, MGST2 gene knockout (KO) mice were generated by CRISPR/Cas9-mediated gene editing with guide RNAs targeting the MGST2 exon 2. The ocular morphology of the KO mice was analyzed through high-resolution images obtained by a magnetic resonance imaging (MRI) machine for small animals. The morphometric analyses showed that the height, width, and volume of the eyeballs in MGST2 KO homozygous mice were significantly greater than those of wild-type mice, indicating that the eyes of MGST2 KO homozygous mice were significantly enlarged. There were no significant differences in the axis length and axis angle. These morphological changes may potentially contribute to the development of a subgroup of strabismus.
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Affiliation(s)
- Chaomulige
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama 700-8558, Japan;
| | - Toshihiko Matsuo
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama 700-8558, Japan;
- Department of Ophthalmology, Okayama University Hospital, Okayama 700-8558, Japan
| | - Kohei Sugimoto
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama 700-8558, Japan;
| | - Mary Miyaji
- Department of Medical Neurobiology, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan; (M.M.); (O.H.)
| | - Osamu Hosoya
- Department of Medical Neurobiology, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan; (M.M.); (O.H.)
| | - Masashi Ueda
- Department of Biofunctional Imaging Analysis, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan;
| | - Ryosuke Kobayashi
- Biosignal Genome Resource Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512, Japan; (R.K.); (T.H.); (I.H.)
| | - Takuro Horii
- Biosignal Genome Resource Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512, Japan; (R.K.); (T.H.); (I.H.)
| | - Izuho Hatada
- Biosignal Genome Resource Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512, Japan; (R.K.); (T.H.); (I.H.)
- Viral Vector Core, Gunma University Initiative for Advanced Research (GIAR), Maebashi 371-8511, Japan
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11
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Ben Youss Z, Arefin TM, Qayyum S, Yi R, Zhang J, Zaim Wadghiri Y, Alon L, Yaghmazadeh O. Open-source versatile 3D-print animal conditioning platform design for in vivo preclinical brain imaging in awake mice and anesthetized mice and rats. Lab Anim (NY) 2024; 53:33-42. [PMID: 38279029 PMCID: PMC11095950 DOI: 10.1038/s41684-023-01320-z] [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: 11/20/2022] [Accepted: 12/14/2023] [Indexed: 01/28/2024]
Abstract
Proper animal conditioning is a key factor in the quality and success of preclinical neuroimaging applications. Here, we introduce an open-source easy-to-modify multimodal 3D printable design for rodent conditioning for magnetic resonance imaging (MRI) or other imaging modalities. Our design can be used for brain imaging in anesthetized or awake mice, and in anesthetized rats. We show ease of use and reproducibility of subject conditioning with anatomical T2-weighted imaging for both mice and rats. We also demonstrate the application of our design for awake functional MRI in mice using both visual evoked potential and olfactory stimulation paradigms. In addition, using a combined MRI, positron emission tomography and X-ray computed tomography experiment, we demonstrate that our proposed cradle design can be utilized for multiple imaging modalities.
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Affiliation(s)
- Zakia Ben Youss
- Bernard and Irene Schwartz Center for Biomedical Imaging (CBI), Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Tanzil Mahmud Arefin
- Center for Neurotechnology in Mental Health Research, Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Sawwal Qayyum
- Department of Radiology, Weill Cornell Medical College, New York, NY, USA
| | - Runjie Yi
- Neuroscience Institute, New York University School of Medicine, New York, NY, USA
| | - Jiangyang Zhang
- Bernard and Irene Schwartz Center for Biomedical Imaging (CBI), Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Youssef Zaim Wadghiri
- Bernard and Irene Schwartz Center for Biomedical Imaging (CBI), Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA.
| | - Leeor Alon
- Bernard and Irene Schwartz Center for Biomedical Imaging (CBI), Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA.
| | - Omid Yaghmazadeh
- Neuroscience Institute, New York University School of Medicine, New York, NY, USA.
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12
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Kozlova EV, Bishay AE, Denys ME, Chinthirla BD, Valdez MC, Spurgin KA, Krum JM, Basappa KR, Currás-Collazo MC. Gene deletion of the PACAP/VIP receptor, VPAC2R, alters glycemic responses during metabolic and psychogenic stress in adult female mice. J Neuroendocrinol 2023; 35:e13354. [PMID: 37946684 DOI: 10.1111/jne.13354] [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: 05/03/2023] [Revised: 09/28/2023] [Accepted: 09/28/2023] [Indexed: 11/12/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) and the homologous peptide, vasoactive intestinal peptide (VIP), participate in glucose homeostasis using insulinotropic and counterregulatory processes. The role of VIP receptor 2 (VPAC2R) in these opposing actions needs further characterization. In this study, we examined the participation of VPAC2R on basal glycemia, fasted levels of glucoregulatory hormones and on glycemia responses during metabolic and psychogenic stress using gene-deleted (Vipr2-/- ) female mice. The mean basal glycemia was significantly greater in Vipr2-/- in the fed state and after an 8-h overnight fast as compared to wild-type (WT) mice. Insulin tolerance testing following a 5-h fast (morning fast, 0.38 U/kg insulin) indicated no effect of genotype. However, during a more intense metabolic challenge (8 h, ON fast, 0.25 U/kg insulin), Vipr2-/- females displayed significantly impaired insulin hypoglycemia. During immobilization stress, the hyperglycemic response and plasma epinephrine levels were significantly elevated above basal in Vipr2-/- , but not WT mice, in spite of similar stress levels of plasma corticosterone. Together, these results implicate participation of VPAC2R in upregulated counterregulatory processes influenced by enhanced sympathoexcitation. Moreover, the suppression of plasma GLP-1 levels in Vipr2-/- mice may have removed the inhibition on hepatic glucose production and the promotion of glucose disposal by GLP-1. qPCR analysis indicated deregulation of central gene markers of PACAP/VIP signaling in Vipr2-/- , upregulated medulla tyrosine hydroxylase (Th) and downregulated hypothalamic Vip transcripts. These results demonstrate a physiological role for VPAC2R in glucose metabolism, especially during insulin challenge and psychogenic stress, likely involving the participation of sympathoadrenal activity and/or metabolic hormones.
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Affiliation(s)
- Elena V Kozlova
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, USA
- Neuroscience Graduate Program, University of California, Riverside, California, USA
| | - Anthony E Bishay
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, USA
| | - Maximilian E Denys
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, USA
| | - Bhuvaneswari D Chinthirla
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, USA
| | - Matthew C Valdez
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, USA
- Neuroscience Graduate Program, University of California, Riverside, California, USA
| | - Kurt A Spurgin
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, USA
- Neuroscience Graduate Program, University of California, Riverside, California, USA
| | - Julia M Krum
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, USA
| | - Karthik R Basappa
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, California, USA
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13
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Ghosh S, Ghosh R, Sawoo R, Dutta P, Bishayi B. Impact of dual neutralization of TNF-α and IL-1β along with Gentamicin treatment on the functions of blood and splenic neutrophils and its role on improvement of S. aureus induced septic arthritis. Int Immunopharmacol 2023; 123:110766. [PMID: 37572502 DOI: 10.1016/j.intimp.2023.110766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 07/27/2023] [Accepted: 08/02/2023] [Indexed: 08/14/2023]
Abstract
Researches of recent past years have emphasized potential of antibiotics to improve septic arthritis but as multi-drug resistant strains like MRSA are emerging fast, new alternative therapeutic advances are high in demand. This study aims to figure out the role of neutrophils in regulating inflammatory responses of S. aureus induced septic arthritis while using TNF-α Ab or IL-1β Ab along with antibiotic gentamicin or both in combination. In this study, role of anti-oxidant enzymes were investigated and correlated with generated ROS level. While expression of TLR2, TNFR2, MMP2, RANKL, SAPK/JNK in the spleen were evaluated through western blot. Serum activity of IL-8, IL-10, IL-12, OPG, OPN, CRP was assessed using ELISA. Flow cytometry study evaluated inflamed neutrophil population. Results have shown TNF-α neutralization along with gentamicin was able to reduce arthritic swelling prominently. While combination therapy effectively reduced blood neutrophil ROS activity, arginase activity, MPO activity along with spleen bacterial burden. Serum OPG, CRP, IL-10 level got reduced while serum OPN, IL-8 and IL-12 level enhanced in treatment groups, showing mitigation of inflammatory damage. Overall, it is a novel work that observed how antibiotic and antibody therapy enhanced neutrophil function positively to combat sepsis. This study may not be fully applicable in clinical trials as it is performed with animal model. Clinical trials include crystalline and inflammatory arthritides, trauma, neoplasm. Interdisciplinary collaboration between radiology, orthopaedic surgery and knowledge of animal system responses may give better idea to find proper therapeutic approach in future research works.
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Affiliation(s)
- Sharmistha Ghosh
- Department of Physiology, Immunology Laboratory, University of Calcutta, University Colleges of Science and Technology, 92 APC Road, Calcutta 700009, West Bengal, India
| | - Rituparna Ghosh
- Department of Physiology, Immunology Laboratory, University of Calcutta, University Colleges of Science and Technology, 92 APC Road, Calcutta 700009, West Bengal, India
| | - Ritasha Sawoo
- Department of Physiology, Immunology Laboratory, University of Calcutta, University Colleges of Science and Technology, 92 APC Road, Calcutta 700009, West Bengal, India
| | - Puja Dutta
- Department of Physiology, Immunology Laboratory, University of Calcutta, University Colleges of Science and Technology, 92 APC Road, Calcutta 700009, West Bengal, India
| | - Biswadev Bishayi
- Department of Physiology, Immunology Laboratory, University of Calcutta, University Colleges of Science and Technology, 92 APC Road, Calcutta 700009, West Bengal, India.
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14
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Poplawsky AJ, Cover C, Reddy S, Chishti HB, Vazquez A, Fukuda M. Odor-evoked layer-specific fMRI activities in the awake mouse olfactory bulb. Neuroimage 2023; 274:120121. [PMID: 37080347 PMCID: PMC10240534 DOI: 10.1016/j.neuroimage.2023.120121] [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: 01/05/2023] [Revised: 03/22/2023] [Accepted: 04/17/2023] [Indexed: 04/22/2023] Open
Abstract
Awake rodent fMRI is increasingly common over the use of anesthesia since it permits behavioral paradigms and does not confound normal brain function or neurovascular coupling. It is well established that adequate acclimation to the loud fMRI environment and head fixation reduces stress in the rodents and allows for whole brain imaging with little contamination from motion. However, it is unknown whether high-resolution fMRI with increased susceptibility to motion and lower sensitivity can measure small, but spatially discrete, activations in awake mice. To examine this, we used contrast-enhanced cerebral blood volume-weighted (CBVw) fMRI in the mouse olfactory bulb for its enhanced sensitivity and neural specificity. We determined that activation patterns in the glomerular layer to four different odors were spatially distinct and were consistent with previously established histological patterns. In addition, odor-evoked laminar activations were greatest in superficial layers that decreased with laminar depth, similar to previous observations. Interestingly, the fMRI response strengths in the granule cell layer were greater in awake mice than our previous anesthetized rat studies, suggesting that feedback neural activities were intact with wakefulness. We finally determined that fMRI signal changes to repeated odor exposure (i.e., olfactory adaptation) attenuated relatively more in the feedback granule cell layer compared to the input glomerular layer, which is consistent with prior observations. We, therefore, conclude that high-resolution CBVw fMRI can measure odor-specific activation patterns and distinguish changes in laminar activity of head and body restrained awake mice.
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Affiliation(s)
- Alexander John Poplawsky
- Department of Radiology, University of Pittsburgh, McGowan Institute for Regenerative Medicine Building, 3025 E. Carson St., rm. 159, Pittsburgh, PA, 15203, United States.
| | - Christopher Cover
- Department of Radiology, University of Pittsburgh, McGowan Institute for Regenerative Medicine Building, 3025 E. Carson St., rm. 159, Pittsburgh, PA, 15203, United States; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sujatha Reddy
- Department of Radiology, University of Pittsburgh, McGowan Institute for Regenerative Medicine Building, 3025 E. Carson St., rm. 159, Pittsburgh, PA, 15203, United States
| | - Harris B Chishti
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Alberto Vazquez
- Department of Radiology, University of Pittsburgh, McGowan Institute for Regenerative Medicine Building, 3025 E. Carson St., rm. 159, Pittsburgh, PA, 15203, United States; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Mitsuhiro Fukuda
- Department of Radiology, University of Pittsburgh, McGowan Institute for Regenerative Medicine Building, 3025 E. Carson St., rm. 159, Pittsburgh, PA, 15203, United States
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15
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Brems BM, Sullivan EE, Connolly JG, Zhang J, Chang A, Ortiz R, Cantwell L, Kulkarni P, Thakur GA, Ferris CF. Dose-dependent effects of GAT107, a novel allosteric agonist-positive allosteric modulator (ago-PAM) for the α7 nicotinic cholinergic receptor: a BOLD phMRI and connectivity study on awake rats. Front Neurosci 2023; 17:1196786. [PMID: 37424993 PMCID: PMC10326388 DOI: 10.3389/fnins.2023.1196786] [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: 03/30/2023] [Accepted: 06/06/2023] [Indexed: 07/11/2023] Open
Abstract
Background Alpha 7 nicotinic acetylcholine receptor (α7nAChR) agonists have been developed to treat schizophrenia but failed in clinical trials due to rapid desensitization. GAT107, a type 2 allosteric agonist-positive allosteric modulator (ago-PAM) to the α7 nAChR was designed to activate the α7 nAChR while reducing desensitization. We hypothesized GAT107 would alter the activity of thalamocortical neural circuitry associated with cognition, emotion, and sensory perception. Methods The present study used pharmacological magnetic resonance imaging (phMRI) to evaluate the dose-dependent effect of GAT107 on brain activity in awake male rats. Rats were given a vehicle or one of three different doses of GAT107 (1, 3, and 10 mg/kg) during a 35 min scanning session. Changes in BOLD signal and resting state functional connectivity were evaluated and analyzed using a rat 3D MRI atlas with 173 brain areas. Results GAT107 presented with an inverted-U dose response curve with the 3 mg/kg dose having the greatest effect on the positive BOLD volume of activation. The primary somatosensory cortex, prefrontal cortex, thalamus, and basal ganglia, particularly areas with efferent connections from the midbrain dopaminergic system were activated as compared to vehicle. The hippocampus, hypothalamus, amygdala, brainstem, and cerebellum showed little activation. Forty-five min post treatment with GAT107, data for resting state functional connectivity were acquired and showed a global decrease in connectivity as compared to vehicle. Discussion GAT107 activated specific brain regions involved in cognitive control, motivation, and sensory perception using a BOLD provocation imaging protocol. However, when analyzed for resting state functional connectivity there was an inexplicable, general decrease in connectivity across all brain areas.
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Affiliation(s)
- Brittany M. Brems
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, United States
| | - Erin E. Sullivan
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, United States
| | - Jenna G. Connolly
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, United States
| | - Jingchun Zhang
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, United States
| | - Arnold Chang
- Center for Translational Neuroimaging, Northeastern University, Boston, MA, United States
| | - Richard Ortiz
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM, United States
| | - Lucas Cantwell
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, United States
| | - Praveen Kulkarni
- Center for Translational Neuroimaging, Northeastern University, Boston, MA, United States
| | - Ganesh A. Thakur
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, United States
| | - Craig F. Ferris
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, United States
- Center for Translational Neuroimaging, Northeastern University, Boston, MA, United States
- Department of Psychology, Northeastern University, Boston, MA, United States
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16
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Markussen NB, Knopper RW, Hasselholt S, Skoven CS, Nyengaard JR, Østergaard L, Hansen B. Locus coeruleus ablation in mice: protocol optimization, stereology and behavioral impact. Front Cell Neurosci 2023; 17:1138624. [PMID: 37180952 PMCID: PMC10172584 DOI: 10.3389/fncel.2023.1138624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 04/05/2023] [Indexed: 05/16/2023] Open
Abstract
The Locus Coeruleus (LC) is in the brainstem and supplies key brain structures with noradrenaline, including the forebrain and hippocampus. The LC impacts specific behaviors such as anxiety, fear, and motivation, as well as physiological phenomena that impact brain functions in general, including sleep, blood flow regulation, and capillary permeability. Nevertheless, the short- and long-term consequences of LC dysfunction remain unclear. The LC is among the brain structures first affected in patients suffering from neurodegenerative diseases such as Parkinson's disease and Alzheimer's Disease, hinting that LC dysfunction may play a central role in disease development and progression. Animal models with modified or disrupted LC function are essential to further our understanding of LC function in the normal brain, the consequences of LC dysfunction, and its putative roles in disease development. For this, well-characterized animal models of LC dysfunction are needed. Here, we establish the optimal dose of selective neurotoxin N-(2-chloroethyl)-N-ethyl-bromo-benzylamine (DSP-4) for LC ablation. Using histology and stereology, we compare LC volume and neuron number in LC ablated (LCA) mice and controls to assess the efficacy of LC ablation with different numbers of DSP-4 injections. All LCA groups show a consistent decrease in LC cell count and LC volume. We then proceed to characterize the behavior of LCA mice using a light-dark box test, Barnes maze test, and non-invasive sleep-wakefulness monitoring. Behaviorally, LCA mice differ subtly from control mice, with LCA mice generally being more curious and less anxious compared to controls consistent with known LC function and projections. We note an interesting contrast in that control mice have varying LC size and neuron count but consistent behavior whereas LCA mice (as expected) have consistently sized LC but erratic behavior. Our study provides a thorough characterization of an LC ablation model, firmly consolidating it as a valid model system for the study of LC dysfunction.
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Affiliation(s)
- Nanna Bertin Markussen
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Rasmus West Knopper
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Sino-Danish Center for Education and Research, University of Chinese Academy of Sciences, Beijing, China
| | - Stine Hasselholt
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Christian Stald Skoven
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jens Randel Nyengaard
- Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Brian Hansen
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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17
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Swan J, Boyer S, Westlund K, Bengtsson C, Nordahl G, Törnqvist E. Decreased levels of discomfort in repeatedly handled mice during experimental procedures, assessed by facial expressions. Front Behav Neurosci 2023; 17:1109886. [PMID: 36873771 PMCID: PMC9978997 DOI: 10.3389/fnbeh.2023.1109886] [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: 11/28/2022] [Accepted: 01/16/2023] [Indexed: 02/05/2023] Open
Abstract
Mice are the most commonly used laboratory animal, yet there are limited studies which investigate the effects of repeated handling on their welfare and scientific outcomes. Furthermore, simple methods to evaluate distress in mice are lacking, and specialized behavioral or biochemical tests are often required. Here, two groups of CD1 mice were exposed to either traditional laboratory handling methods or a training protocol with cup lifting for 3 and 5 weeks. The training protocol was designed to habituate the mice to the procedures involved in subcutaneous injection, e.g., removal from the cage, skin pinch. This protocol was followed by two common research procedures: subcutaneous injection and tail vein blood sampling. Two training sessions and the procedures (subcutaneous injection and blood sampling) were video recorded. The mouse facial expressions were then scored, focusing on the ear and eye categories of the mouse grimace scale. Using this assessment method, trained mice expressed less distress than the control mice during subcutaneous injection. Mice trained for subcutaneous injection also had reduced facial scores during blood sampling. We found a clear sex difference as female mice responded to training faster than the male mice, they also had lower facial scores than the male mice when trained. The ear score appeared to be a more sensitive measure of distress than the eye score, which may be more indicative of pain. In conclusion, training is an important refinement method to reduce distress in mice during common laboratory procedures and this can best be assessed using the ear score of the mouse grimace scale.
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Affiliation(s)
- Julia Swan
- Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Scott Boyer
- Chemotargets SL, Barcelona, Spain.,Global Safety Assessment, AstraZeneca R&D, Södertälje, Sweden
| | | | - Camilla Bengtsson
- Global Safety Assessment, AstraZeneca R&D, Södertälje, Sweden.,Independant Consultant, Strömsund, Sweden
| | | | - Elin Törnqvist
- Global Safety Assessment, AstraZeneca R&D, Södertälje, Sweden.,Department of Animal Health and Antimicrobial Strategies, Swedish National Veterinary Institute (SVA), Uppsala, Sweden.,Institute of Environmental Medicine, Karolinska Institutet, Solna, Sweden
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18
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Barkus C, Bergmann C, Branco T, Carandini M, Chadderton PT, Galiñanes GL, Gilmour G, Huber D, Huxter JR, Khan AG, King AJ, Maravall M, O'Mahony T, Ragan CI, Robinson ESJ, Schaefer AT, Schultz SR, Sengpiel F, Prescott MJ. Refinements to rodent head fixation and fluid/food control for neuroscience. J Neurosci Methods 2022; 381:109705. [PMID: 36096238 DOI: 10.1016/j.jneumeth.2022.109705] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 09/01/2022] [Accepted: 09/03/2022] [Indexed: 12/14/2022]
Abstract
The use of head fixation in mice is increasingly common in research, its use having initially been restricted to the field of sensory neuroscience. Head restraint has often been combined with fluid control, rather than food restriction, to motivate behaviour, but this too is now in use for both restrained and non-restrained animals. Despite this, there is little guidance on how best to employ these techniques to optimise both scientific outcomes and animal welfare. This article summarises current practices and provides recommendations to improve animal wellbeing and data quality, based on a survey of the community, literature reviews, and the expert opinion and practical experience of an international working group convened by the UK's National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs). Topics covered include head fixation surgery and post-operative care, habituation to restraint, and the use of fluid/food control to motivate performance. We also discuss some recent developments that may offer alternative ways to collect data from large numbers of behavioural trials without the need for restraint. The aim is to provide support for researchers at all levels, animal care staff, and ethics committees to refine procedures and practices in line with the refinement principle of the 3Rs.
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Affiliation(s)
- Chris Barkus
- National Centre for Replacement, Refinement and Reduction of Animals in Research (NC3Rs), London, UK.
| | | | - Tiago Branco
- Sainsbury Wellcome Centre, University College London, London, UK
| | - Matteo Carandini
- Institute of Ophthalmology, University College London, London, UK
| | - Paul T Chadderton
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | | | | | - Daniel Huber
- Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
| | | | - Adil G Khan
- Centre for Developmental Neurobiology, King's College London, London, UK
| | - Andrew J King
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Miguel Maravall
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, UK
| | - Tina O'Mahony
- Sainsbury Wellcome Centre, University College London, London, UK
| | - C Ian Ragan
- National Centre for Replacement, Refinement and Reduction of Animals in Research (NC3Rs), London, UK
| | - Emma S J Robinson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Andreas T Schaefer
- Sensory Circuits and Neurotechnology Laboratory, The Francis Crick Institute, London, UK; Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Simon R Schultz
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, UK
| | | | - Mark J Prescott
- National Centre for Replacement, Refinement and Reduction of Animals in Research (NC3Rs), London, UK
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19
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Mikkelsen SH, Wied B, Dashkovskyi V, Lindhardt TB, Hirschler L, Warnking JM, Barbier EL, Postnov D, Hansen B, Gutiérrez-Jiménez E. Head holder and cranial window design for sequential magnetic resonance imaging and optical imaging in awake mice. Front Neurosci 2022; 16:926828. [PMID: 36051645 PMCID: PMC9425635 DOI: 10.3389/fnins.2022.926828] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 07/14/2022] [Indexed: 11/28/2022] Open
Abstract
Medical imaging techniques are widely used in preclinical research as diagnostic tools to detect physiological abnormalities and assess the progression of neurovascular disease in animal models. Despite the wealth of imaging options in magnetic resonance imaging (MRI), interpretation of imaging-derived parameters regarding underlying tissue properties is difficult due to technical limitations or lack of parameter specificity. To address the challenge of interpretation, we present an animal preparation protocol to achieve quantitative measures from both MRI and advanced optical techniques, including laser speckle contrast imaging and two-photon microscopy, in murine models. In this manner, non-translatable methods support and improve interpretation of less specific, translatable methods, i.e., MRI. Combining modalities for improved clinical interpretation involves satisfying the requirements of various methods. Furthermore, physiology unperturbed by anesthetics is a prerequisite for the strategy to succeed. Awake animal imaging with restraint provides an alternative to anesthesia and facilitates translatability of cerebral measurements. The method outlines design requirements for the setup and a corresponding reproducible surgical procedure for implanting a 3D printed head holder and cranial window to enable repeated multimodal imaging. We document the development, application, and validation of the method and provide examples confirming the usefulness of the design in acquiring high quality data from multiple modalities for quantification of a wide range of metrics of cerebral physiology in the same animal. The method contributes to preclinical small animal imaging, enabling sequential imaging of previously mutually exclusive techniques.
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Affiliation(s)
- Signe H. Mikkelsen
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Boris Wied
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Vitalii Dashkovskyi
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | | | | | - Jan M. Warnking
- Univ. Grenoble Alpes, Inserm, U1216, GIN, Grenoble Institut des Neurosciences, La Tronche, France
| | - Emmanuel L. Barbier
- Univ. Grenoble Alpes, Inserm, U1216, GIN, Grenoble Institut des Neurosciences, La Tronche, France
| | - Dmitry Postnov
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Brian Hansen
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- *Correspondence: Brian Hansen,
| | - Eugenio Gutiérrez-Jiménez
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- Eugenio Gutiérrez-Jiménez,
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