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Özalay Ö, Mediavilla T, Giacobbo BL, Pedersen R, Marcellino D, Orädd G, Rieckmann A, Sultan F. Longitudinal monitoring of the mouse brain reveals heterogenous network trajectories during aging. Commun Biol 2024; 7:210. [PMID: 38378942 PMCID: PMC10879497 DOI: 10.1038/s42003-024-05873-8] [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: 05/30/2023] [Accepted: 01/30/2024] [Indexed: 02/22/2024] Open
Abstract
The human aging brain is characterized by changes in network efficiency that are currently best captured through longitudinal resting-state functional MRI (rs-fMRI). These studies however are challenging due to the long human lifespan. Here we show that the mouse animal model with a much shorter lifespan allows us to follow the functional network organization over most of the animal's adult lifetime. We used a longitudinal study of the functional connectivity of different brain regions with rs-fMRI under anesthesia. Our analysis uncovers network modules similar to those reported in younger mice and in humans (i.e., prefrontal/default mode network (DMN), somatomotor and somatosensory networks). Statistical analysis reveals different patterns of network reorganization during aging. Female mice showed a pattern akin to human aging, with de-differentiation of the connectome, mainly due to increases in connectivity of the prefrontal/DMN cortical networks to other modules. Our male cohorts revealed heterogenous aging patterns with only one group confirming the de- differentiation, while the majority showed an increase in connectivity of the somatomotor cortex to the Nucleus accumbens. In summary, in line with human work, our analysis in mice supports the concept of de-differentiation in the aging mammalian brain and reveals additional trajectories in aging mice networks.
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Affiliation(s)
- Özgün Özalay
- Department of Medical and Translational Biology, Umeå University, 90 187, Umeå, Sweden
| | - Tomas Mediavilla
- Department of Medical and Translational Biology, Umeå University, 90 187, Umeå, Sweden
| | - Bruno Lima Giacobbo
- Department of Medical and Translational Biology, Umeå University, 90 187, Umeå, Sweden
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Hanzeplein 1, 9713 GZ, Groningen, the Netherlands
| | - Robin Pedersen
- Department of Medical and Translational Biology, Umeå University, 90 187, Umeå, Sweden
| | - Daniel Marcellino
- Department of Medical and Translational Biology, Umeå University, 90 187, Umeå, Sweden
| | - Greger Orädd
- Department of Medical and Translational Biology, Umeå University, 90 187, Umeå, Sweden
| | - Anna Rieckmann
- Department of Medical and Translational Biology, Umeå University, 90 187, Umeå, Sweden
- Department of Diagnostics and Intervention, Radiation Physics, Umeå University, 90 187, Umeå, Sweden
- Institute for Psychology, University of the Bundeswehr Munich, Neubiberg, Germany
| | - Fahad Sultan
- Department of Medical and Translational Biology, Umeå University, 90 187, Umeå, Sweden.
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Bearer EL, Medina CS, Uselman TW, Jacobs RE. Harnessing axonal transport to map reward circuitry: Differing brain-wide projections from medial prefrontal cortical domains. Front Cell Dev Biol 2023; 11:1278831. [PMID: 38099294 PMCID: PMC10720719 DOI: 10.3389/fcell.2023.1278831] [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: 08/17/2023] [Accepted: 09/25/2023] [Indexed: 12/17/2023] Open
Abstract
Neurons project long axons that contact other distant neurons. Neurons in the medial prefrontal cortex project into the limbic system to regulate responses to reward or threat. Diminished neural activity in prefrontal cortex is associated with loss of executive function leading to drug use, yet the specific circuitry that mediate these effects is unknown. Different regions within the medial prefrontal cortex may project to differing limbic system nuclei. Here, we exploited the cell biology of intracellular membrane trafficking, fast axonal transport, to map projections from two adjacent medial prefrontal cortical regions. We used Mn(II), a calcium analog, to trace medial prefrontal cortical projections in the living animal by magnetic resonance imaging (MRI). Mn(II), a contrast agent for MRI, enters neurons through voltage-activated calcium channels and relies on kinesin-1 and amyloid-precursor protein to transport out axons to distal destinations. Aqueous MnCl2 together with fluorescent dextran (3--5 nL) was stereotactically injected precisely into two adjacent regions of the medial prefrontal cortex: anterior cingulate area (ACA) or infralimbic/prelimbic (IL/PL) region. Projections were traced, first live by manganese-enhanced MRI (MEMRI) at four time points in 3D, and then after fixation by microscopy. Data-driven unbiased voxel-wise statistical maps of aligned normalized MR images after either ACA or IL/PL injections revealed statistically significant progression of Mn(II) over time into deeper brain regions: dorsal striatum, globus pallidus, amygdala, hypothalamus, substantia nigra, dorsal raphe and locus coeruleus. Quantitative comparisons of these distal accumulations at 24 h revealed dramatic differences between ACA and IL/PL injection groups throughout the limbic system, and most particularly in subdomains of the hypothalamus. ACA projections targeted dorsomedial nucleus of the hypothalamus, posterior part of the periventricular region and mammillary body nuclei as well as periaqueductal gray, while IL/PL projections accumulated in anterior hypothalamic areas and lateral hypothalamic nuclei as well as amygdala. As hypothalamic subsegments relay CNS activity to the body, our results suggest new concepts about mind-body relationships and specific roles of distinct yet adjacent medial prefrontal cortical segments. Our MR imaging strategy, when applied to follow other cell biological processes in the living organism, will undoubtedly lead to an expanded perspective on how minute details of cellular processes influence whole body health and wellbeing.
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Affiliation(s)
- Elaine L. Bearer
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Christopher S. Medina
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Taylor W. Uselman
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Russell E. Jacobs
- Zilkha Neurogenetic Institute, USC Keck School of Medicine, Los Angeles, CA, United States
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Uselman TW, Jacobs RE, Bearer EL. Reconfiguration of brain-wide neural activity after early life adversity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.10.557058. [PMID: 38328213 PMCID: PMC10849645 DOI: 10.1101/2023.09.10.557058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Early life adversity (ELA) predisposes individuals to both physical and mental disorders lifelong. How ELA affects brain function leading to this vulnerability is under intense investigation. Research has begun to shed light on ELA effects on localized brain regions within defined circuits. However, investigations into brain-wide neural activity that includes multiple localized regions, determines relationships of activity between regions and identifies shifts of activity in response to experiential conditions is necessary. Here, we performed longitudinal manganese-enhanced magnetic resonance imaging (MEMRI) to image the brain in normally reared or ELA-exposed adults. Images were captured in the freely moving home cage condition, and short- and long-term after naturalistic threat. Images were analyzed with new computational methods, including automated segmentation and fractional activation or difference volumes. We found that neural activity was increased after ELA compared to normal rearing in multiple brain regions, some of which are involved in defensive and/or reward circuitry. Widely distributed patterns of neural activity, "brain states", and their dynamics after threat were altered with ELA. Upon acute threat, ELA-mice retained heightened neural activity within many of these regions, and new hyperactive responses emerged in monoaminergic centers of the mid- and hindbrain. Nine days after acute threat, heightened neural activity remained within locus coeruleus and increased within posterior amygdala, ventral hippocampus, and dorso- and ventromedial hypothalamus, while reduced activity emerged within medial prefrontal cortical regions (prelimbic, infralimbic, anterior cingulate). These results reveal that functional imbalances arise between multiple brain-systems which are dependent upon context and cumulative experiences after ELA.
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Affiliation(s)
- Taylor W Uselman
- University of New Mexico Health Sciences Center, Albuquerque, NM 87131
| | - Russell E Jacobs
- Zilkha Neurogenetic Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033
- California Institute of Technology, Pasadena, CA 91125
| | - Elaine L Bearer
- University of New Mexico Health Sciences Center, Albuquerque, NM 87131
- California Institute of Technology, Pasadena, CA 91125
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Bearer EL, Medina CS, Uselman TW, Jacobs RE. Harnessing axonal transport to map reward circuitry: Differing brain-wide projections from medial forebrain domains. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.10.557059. [PMID: 38328063 PMCID: PMC10849663 DOI: 10.1101/2023.09.10.557059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Neurons project long axons that contact other distant neurons. Projections can be mapped by hijacking endogenous membrane trafficking machinery by introducing tracers. To witness functional connections in living animals, we developed a tracer detectible by magnetic resonance imaging (MRI), Mn(II). Mn(II) relies on kinesin-1 and amyloid-precursor protein to travel out axons. Within 24h, projection fields of cortical neurons can be mapped brain-wide with this technology. MnCl2 was stereotactically injected either into anterior cingulate area (ACA) or into infralimbic/prelimbic (IL/PL) of medial forebrain (n=10-12). Projections were imaged, first by manganese-enhanced MRI (MEMRI) live, and then after fixation by microscopy. MR images were collected at 100μm isotropic resolution (~5 neurons) in 3D at four time points: before and at successive time points after injections. Images were preprocessed by masking non-brain tissue, followed by intensity scaling and spatial alignment. Actual injection locations, measured from post-injection MR images, were found to be 0.06, 0.49 and 0.84mm apart between cohorts, in R-L, A-P, and D-V directions respectively. Mn(II) enhancements arrived in hindbrains by 24h in both cohorts, while co-injected rhodamine dextran was not detectible beyond immediate subcortical projections. Data-driven unbiased voxel-wise statistical maps after ACA injections revealed significant progression of Mn(II) distally into deeper brain regions: globus pallidus, dorsal striatum, amygdala, hypothalamus, substantia nigra, dorsal raphe and locus coeruleus. Accumulation was quantified as a fraction of total volume of each segment containing significantly enhanced voxels (fractional accumulation volumes), and results visualized in column graphs. Unpaired t-tests between groups of brain-wide voxel-wise intensity profiling by either region of interest (ROI) measurements or statistical parametric mapping highlighted distinct differences in distal accumulation between injection sites, with ACA projecting to periaqueductal gray and IL/PL to basolateral amygdala (p<0.001 FDR). Mn(II) distal accumulations differed dramatically between injection groups in subdomains of the hypothalamus, with ACA targeting dorsal medial, periventricular region and mammillary body nuclei, while IL/PL went to anterior hypothalamic areas and lateral hypothalamic nuclei. Given that these hypothalamic subsegments communicate activity in the central nervous system to the body, these observations describing distinct forebrain projection fields will undoubtedly lead to newer insights in mind-body relationships.
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Affiliation(s)
- E. L. Bearer
- Department of Pathology, Univ. of New Mexico Health Sciences Center, Albuquerque, NM
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA
| | - C. S. Medina
- Department of Pathology, Univ. of New Mexico Health Sciences Center, Albuquerque, NM
| | - T. W. Uselman
- Department of Pathology, Univ. of New Mexico Health Sciences Center, Albuquerque, NM
| | - R. E. Jacobs
- Zilkha Neurogenetic Institute, USC Keck School of Medicine, Los Angeles, CA
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Chang HH, Yeh SJ, Chiang MC, Hsieh ST. RU-Net: skull stripping in rat brain MR images after ischemic stroke with rat U-Net. BMC Med Imaging 2023; 23:44. [PMID: 36973775 PMCID: PMC10045128 DOI: 10.1186/s12880-023-00994-8] [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: 11/01/2022] [Accepted: 03/08/2023] [Indexed: 03/29/2023] Open
Abstract
BACKGROUND Experimental ischemic stroke models play a fundamental role in interpreting the mechanism of cerebral ischemia and appraising the development of pathological extent. An accurate and automatic skull stripping tool for rat brain image volumes with magnetic resonance imaging (MRI) are crucial in experimental stroke analysis. Due to the deficiency of reliable rat brain segmentation methods and motivated by the demand for preclinical studies, this paper develops a new skull stripping algorithm to extract the rat brain region in MR images after stroke, which is named Rat U-Net (RU-Net). METHODS Based on a U-shape like deep learning architecture, the proposed framework integrates batch normalization with the residual network to achieve efficient end-to-end segmentation. A pooling index transmission mechanism between the encoder and decoder is exploited to reinforce the spatial correlation. Two different modalities of diffusion-weighted imaging (DWI) and T2-weighted MRI (T2WI) corresponding to two in-house datasets with each consisting of 55 subjects were employed to evaluate the performance of the proposed RU-Net. RESULTS Extensive experiments indicated great segmentation accuracy across diversified rat brain MR images. It was suggested that our rat skull stripping network outperformed several state-of-the-art methods and achieved the highest average Dice scores of 98.04% (p < 0.001) and 97.67% (p < 0.001) in the DWI and T2WI image datasets, respectively. CONCLUSION The proposed RU-Net is believed to be potential for advancing preclinical stroke investigation and providing an efficient tool for pathological rat brain image extraction, where accurate segmentation of the rat brain region is fundamental.
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Affiliation(s)
- Herng-Hua Chang
- Computational Biomedical Engineering Laboratory (CBEL), Department of Engineering Science and Ocean Engineering, National Taiwan University, No. 1 Sec. 4 Roosevelt Road, Daan, Taipei, 10617, Taiwan.
| | - Shin-Joe Yeh
- Department of Neurology and Stroke Center, National Taiwan University Hospital, Taipei, 10002, Taiwan
| | - Ming-Chang Chiang
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, 11221, Taiwan
| | - Sung-Tsang Hsieh
- Department of Neurology and Stroke Center, National Taiwan University Hospital, Taipei, 10002, Taiwan
- Graduate Institute of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
- Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
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Xu M, Qi S, Calhoun V, Dai J, Yu B, Zhang K, Pei M, Li C, Wei Y, Jiang R, Zhi D, Huang Z, Qiu Z, Liang Z, Sui J. Aberrant brain functional and structural developments in MECP2 duplication rats. Neurobiol Dis 2022; 173:105838. [PMID: 35985556 PMCID: PMC9631682 DOI: 10.1016/j.nbd.2022.105838] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/22/2022] [Accepted: 08/11/2022] [Indexed: 12/02/2022] Open
Abstract
Transgenic animal models with homologous etiology provide a promising way to pursue the neurobiological substrates of the behavioral deficits in autism spectrum disorder (ASD). Gain-of-function mutations of MECP2 cause MECP2 duplication syndrome, a severe neurological disorder with core symptoms of ASD. However, abnormal brain developments underlying the autistic-like behavioral deficits of MECP2 duplication syndrome are rarely investigated. To this end, a human MECP2 duplication (MECP2-DP) rat model was created by the bacterial artificial chromosome transgenic method. Functional and structural magnetic resonance imaging (MRI) with high-field were performed on 16 male MECP2-DP rats and 15 male wildtype rats at postnatal 28 days, 42 days, and 56 days old. Multimodal fusion analyses guided by locomotor-relevant metrics and social novelty time separately were applied to identify abnormal brain networks associated with diverse behavioral deficits induced by MECP2 duplication. Aberrant functional developments of a core network primarily composed of the dorsal medial prefrontal cortex (dmPFC) and retrosplenial cortex (RSP) were detected to associate with diverse behavioral phenotypes in MECP2-DP rats. Altered developments of gray matter volume were detected in the hippocampus and thalamus. We conclude that gain-of-function mutations of MECP2 induce aberrant functional activities in the default-mode-like network and aberrant volumetric changes in the brain, resulting in autistic-like behavioral deficits. Our results gain critical insights into the biomarker of MECP2 duplication syndrome and the neurobiological underpinnings of the behavioral deficits in ASD.
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Affiliation(s)
- Ming Xu
- Brainnetome Center and National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Shile Qi
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China
| | - Vince Calhoun
- Tri-institutional Center for Translational Research in Neuroimaging and Data Science (TReNDS), Georgia Institute of Technology, Georgia State University, Emory University, Atlanta, GA 30303, USA
| | - Jiankun Dai
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, CAS Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Bin Yu
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, CAS Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Kaiwei Zhang
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, CAS Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Mengchao Pei
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, CAS Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Chenjian Li
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Peking University School of Life Sciences, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Yusheng Wei
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Peking University School of Life Sciences, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Rongtao Jiang
- Brainnetome Center and National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Dongmei Zhi
- Brainnetome Center and National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Zhimin Huang
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Peking University School of Life Sciences, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Peking-Tsinghua Center for Life Sciences, Beijing 100871, China
| | - Zilong Qiu
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, CAS Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Zhifeng Liang
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, CAS Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai 200031, China.
| | - Jing Sui
- IDG/McGovern Institute for Brain Research, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China.
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Uselman TW, Medina CS, Gray HB, Jacobs RE, Bearer EL. Longitudinal manganese-enhanced magnetic resonance imaging of neural projections and activity. NMR IN BIOMEDICINE 2022; 35:e4675. [PMID: 35253280 PMCID: PMC11064873 DOI: 10.1002/nbm.4675] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/19/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) holds exceptional promise for preclinical studies of brain-wide physiology in awake-behaving animals. The objectives of this review are to update the current information regarding MEMRI and to inform new investigators as to its potential. Mn(II) is a powerful contrast agent for two main reasons: (1) high signal intensity at low doses; and (2) biological interactions, such as projection tracing and neural activity mapping via entry into electrically active neurons in the living brain. High-spin Mn(II) reduces the relaxation time of water protons: at Mn(II) concentrations typically encountered in MEMRI, robust hyperintensity is obtained without adverse effects. By selectively entering neurons through voltage-gated calcium channels, Mn(II) highlights active neurons. Safe doses may be repeated over weeks to allow for longitudinal imaging of brain-wide dynamics in the same individual across time. When delivered by stereotactic intracerebral injection, Mn(II) enters active neurons at the injection site and then travels inside axons for long distances, tracing neuronal projection anatomy. Rates of axonal transport within the brain were measured for the first time in "time-lapse" MEMRI. When delivered systemically, Mn(II) enters active neurons throughout the brain via voltage-sensitive calcium channels and clears slowly. Thus behavior can be monitored during Mn(II) uptake and hyperintense signals due to Mn(II) uptake captured retrospectively, allowing pairing of behavior with neural activity maps for the first time. Here we review critical information gained from MEMRI projection mapping about human neuropsychological disorders. We then discuss results from neural activity mapping from systemic Mn(II) imaged longitudinally that have illuminated development of the tonotopic map in the inferior colliculus as well as brain-wide responses to acute threat and how it evolves over time. MEMRI posed specific challenges for image data analysis that have recently been transcended. We predict a bright future for longitudinal MEMRI in pursuit of solutions to the brain-behavior mystery.
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Affiliation(s)
- Taylor W. Uselman
- University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | | | - Harry B. Gray
- Beckman Institute, California Institute of Technology, Pasadena, California, USA
| | - Russell E. Jacobs
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Elaine L. Bearer
- University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
- Beckman Institute, California Institute of Technology, Pasadena, California, USA
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Bearer EL, Zhang X, Jacobs RE. Studying Axonal Transport in the Brain by Manganese-Enhanced Magnetic Resonance Imaging (MEMRI). METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2431:111-142. [PMID: 35412274 DOI: 10.1007/978-1-0716-1990-2_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
From the earliest notions of dynamic movements within the cell by Leeuwenhoek, intracellular transport in eukaryotes has been primarily explored by optical imaging. The giant axon of the squid became a prime experimental model for imaging transport due to its size, optical transparency, and physiological robustness. Even the biochemical basis of transport was identified using optical assays based on video microscopy of fractionated squid axoplasm. Discoveries about the dynamics and molecular components of the intracellular transport system continued in many model organisms that afforded experimental systems for optical imaging. Yet whether these experimental systems reflected a valid picture of axonal transport in the opaque mammalian brain was unknown.Magnetic resonance imaging (MRI) provides a non-destructive approach to peer into opaque tissues like the brain . The paramagnetic ion, manganese (MnII), gives a hyperintense signal in T1 weighted MRI that can serve as a marker for axonal transport. Mn(II) enters active neurons via voltage-gated calcium channels and is transported via microtubule motors down their axons by fast axonal transport. Clearance of Mn(II) is slow. Scanning live animals at successive time points reveals the dynamics of Mn(II) transport by detecting Mn(II)-induced intensity increases or accumulations along a known fiber tract, such as the optic nerve or hippocampal-forebrain projections. Mn(II)-based tract tracing also reveals projections even when not in fiber bundles, such as projections in the olfactory system or from medial prefrontal cortex into midbrain and brain stem. The rate of Mn(II) accumulation, detected as increased signal intensity by MR, serves as a proxy for transport rates. Here we describe the method for measuring transport rates and projections by mangeses-enhanced magnetic resonance imaging, MEMRI.
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Affiliation(s)
- Elaine L Bearer
- Department Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.
- Biology and Biological Engineering and the Beckman Institute, California Institute of Technology, Pasadena, CA, USA.
| | - Xiaowei Zhang
- Department of Radiology, UC San Diego School of Medicine, San Diego, CA, USA
| | - Russell E Jacobs
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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Chang HH, Yeh SJ, Chiang MC, Hsieh ST. Automatic brain extraction and hemisphere segmentation in rat brain MR images after stroke using deformable models. Med Phys 2021; 48:6036-6050. [PMID: 34388268 DOI: 10.1002/mp.15157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Experimental ischemic stroke models play an essential role in understanding the mechanisms of cerebral ischemia and evaluating the development of pathological extent. An important precursor to the investigation of ischemic strokes associated with rodents is the brain extraction and hemisphere segmentation in rat brain diffusion-weighted imaging (DWI) and T2-weighted MRI (T2WI) images. Accurate and reliable image segmentation tools for extracting the rat brain and hemispheres in the MR images are critical in subsequent processes, such as lesion identification and injury analysis. This study is an attempt to investigate rat brain extraction and hemisphere segmentation algorithms that are practicable in both DWI and T2WI images. METHODS To automatically perform brain extraction, the proposed framework is based on an efficient geometric deformable model. By introducing an additional image force in response to the rat brain characteristics into the skull stripping model, we establish a unique rat brain extraction scheme in DWI and T2WI images. For the subsequent hemisphere segmentation, we develop an efficient brain feature detection algorithm to approximately separate the rat brain. A refinement process is enforced by constructing a gradient vector flow in the proximity of the midsurface, where a parametric active contour is attracted to achieve hemisphere segmentation. RESULTS Extensive experiments with 55 DWI and T2WI subjects were executed in comparison with the state-of-the-art methods. Experimental results indicated that our rat brain extraction and hemisphere segmentation schemes outperformed the competitive methods and exhibited high performance both qualitatively and quantitatively. For rat brain extraction, the average Dice scores were 97.13% and 97.42% in DWI and T2WI image volumes, respectively. Rat hemisphere segmentation results based on the Hausdorff distance metric revealed average values of 0.17 and 0.15 mm for DWI and T2WI subjects, respectively. CONCLUSIONS We believe that the established frameworks are advantageous to facilitate preclinical stroke investigation and relevant neuroscience research that requires accurate brain extraction and hemisphere segmentation using rat DWI and T2WI images.
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Affiliation(s)
- Herng-Hua Chang
- Computational Biomedical Engineering Laboratory (CBEL), Department of Engineering Science and Ocean Engineering, National Taiwan University, Taipei, Taiwan
| | - Shin-Joe Yeh
- Graduate Institute of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Neurology and Stroke Center, National Taiwan University Hospital, Taipei, Taiwan
| | - Ming-Chang Chiang
- Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Sung-Tsang Hsieh
- Graduate Institute of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Neurology and Stroke Center, National Taiwan University Hospital, Taipei, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan.,Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
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10
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Abstract
Rodent models are increasingly important in translational neuroimaging research. In rodent neuroimaging, particularly magnetic resonance imaging (MRI) studies, brain extraction is a critical data preprocessing component. Current brain extraction methods for rodent MRI usually require manual adjustment of input parameters due to widely different image qualities and/or contrasts. Here we propose a novel method, termed SHape descriptor selected Extremal Regions after Morphologically filtering (SHERM), which only requires a brain template mask as the input and is capable of automatically and reliably extracting the brain tissue in both rat and mouse MRI images. The method identifies a set of brain mask candidates, extracted from MRI images morphologically opened and closed sequentially with multiple kernel sizes, that match the shape of the brain template. These brain mask candidates are then merged to generate the brain mask. This method, along with four other state-of-the-art rodent brain extraction methods, were benchmarked on four separate datasets including both rat and mouse MRI images. Without involving any parameter tuning, our method performed comparably to the other four methods on all datasets, and its performance was robust with stably high true positive rates and low false positive rates. Taken together, this study provides a reliable automatic brain extraction method that can contribute to the establishment of automatic pipelines for rodent neuroimaging data analysis.
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Uselman TW, Barto DR, Jacobs RE, Bearer EL. Evolution of brain-wide activity in the awake behaving mouse after acute fear by longitudinal manganese-enhanced MRI. Neuroimage 2020; 222:116975. [PMID: 32474079 PMCID: PMC7805483 DOI: 10.1016/j.neuroimage.2020.116975] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 05/19/2020] [Indexed: 01/08/2023] Open
Abstract
Life threatening fear after a single exposure evolves in a subset of vulnerable individuals to anxiety, which may persist for their lifetime. Yet neither the whole brain's response to innate acute fear nor how brain activity evolves over time is known. Sustained neuronal activity may be a factor in the development of a persistent fear response. We couple two experimental protocols to provoke acute fear leading to prolonged fear: Predator stress (PS), a naturalistic approach to induce fear in rodents; and Serotonin transporter knockout mouse (SERT-KO) that responds to PS with sustained defensive behavior. Behavior was monitored before, during and at short and long times after PS in wild type (WT) and SERT-KO mice. Both genotypes responded to PS with defensive behavior. SERT-KO retained defensive behavior for 23 days, while WT mice returned to baseline exploratory behavior by 9 days. Thus, differences in neural activity between WT and SERT-KO 9 days after PS identifies neural correlates of persistent defensive behavior, in mice. We used longitudinal manganese-enhanced magnetic resonance imaging (MEMRI) to identify brain-wide neural activity associated with different behaviors. Mn2+ accumulation in active neurons occurs in awake, behaving mice and is retrospectively imaged. Following the same two cohorts of mice, WT and SERT-KO, longitudinally allowed unbiased quantitative comparisons of brain-wide activity by statistical parametric mapping (SPM). During natural behavior in WT, only low levels of activity-induced Mn2+-accumulation were detected, while much more accumulation appeared immediately after PS in both WT and SERT-KO, and evolved at 9 days to a new activity pattern (p < 0.0001, uncorr., T = 5.4). Patterns of accumulation differed between genotypes, with more regions of the brain and larger volumes within regions involved in SERT-KO than WT. A new computational segmentation analysis, using our InVivo Atlas based on a manganese-enhanced MR image of a living mouse, revealed dynamic changes in the volume of significantly enhanced voxels within each segment that differed between genotypes across 45 of 87 segmented regions. At Day 9 after PS, the striatum and ventral pallidum were active in both genotypes but more so in the SERT-KO. SERT-KO also displayed sustained or increased volume of Mn2+ accumulations between Post-Fear and Day 9 in eight segments where activity was decreased or silenced in WT. C-fos staining, an alternative neural activity marker, of brains from the same mice fixed at conclusion of imaging sessions confirmed that MEMRI detected active neurons. Intensity measurements in 12 regions of interest (ROIs) supported the SPM results. Between group comparisons by SPM and of ROI measurements identified specific regions differing between time points and genotypes. We report brain-wide activity in response to a single exposure of acute fear, and, for the first time, its evolution to new activity patterns over time in individuals vulnerable to persistent fear. Our results show multiple regions with dynamic changes in neural activity and that the balance of activity between segments is disordered in the SERT-KO. Thus, longitudinal MEMRI represents a powerful approach to discover how brain-wide activity evolves from the natural state either after an experience or during a disease process.
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Affiliation(s)
- Taylor W Uselman
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Daniel R Barto
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Russell E Jacobs
- Zilkha Neurogenetics Institute, University of Southern California, Los Angeles, CA, USA; California Institute of Technology, Pasadena, CA, USA
| | - Elaine L Bearer
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; California Institute of Technology, Pasadena, CA, USA.
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12
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Kim JS, Lee HJ, Lee S, Lee HS, Jeong YJ, Son Y, Kim JM, Lee YJ, Park MH. Conductive Hearing Loss Aggravates Memory Decline in Alzheimer Model Mice. Front Neurosci 2020; 14:843. [PMID: 32903751 PMCID: PMC7438902 DOI: 10.3389/fnins.2020.00843] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/20/2020] [Indexed: 11/26/2022] Open
Abstract
The study of cognitive impairment associated with hearing loss has recently garnered considerable interest. Epidemiological data have demonstrated that hearing loss is a risk factor for cognitive decline as a result of aging. However, no previous study has examined the effect of hearing loss in patients with cognitive problems such as Alzheimer’s disease. Therefore, we investigated the effect of conductive hearing loss in an Alzheimer’s mouse model. Positron emission tomography (PET) and magnetic resonance imaging (MRI) were used to evaluate changes in glucose metabolism and gray matter concentrations in the 5xFAD Alzheimer’s Disease (AD) transgenic mouse model with and without conductive hearing loss (HL). Conductive hearing loss was induced using chronic perforation of the tympanic membrane. Behavioral data from the Y-maze and passive avoidance tests revealed greater memory deficits in the AD with HL (AD-HL) group than in the AD group. Following induction of hearing loss, lower cerebral glucose metabolism in the frontal association cortex was observed in the AD-HL group than in the AD group. Although lower glucose metabolism in the hippocampus and cerebellum was found in the AD-HL group than in the AD group at 3 months, the gray matter concentrations in these regions were not significantly different between the groups. Furthermore, the gray matter concentrations in the simple lobule, cingulate/retrosplenial cortex, substantia nigra, retrosigmoid nucleus, medial geniculate nucleus, and anterior pretectal nucleus at 7 months were significantly lower in the AD-HL group than in the AD group. Taken together, these results indicate that even partial hearing loss can aggravate memory impairment in Alzheimer’s disease.
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Affiliation(s)
- Jin Su Kim
- Division of RI Application, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea.,Radiological and Medico-Oncological Sciences, University of Science and Technology, Seoul, South Korea
| | - Hae-June Lee
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea
| | - Seonhwa Lee
- Division of RI Application, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea.,Department of Bio-Convergence Engineering, Korea University, Seoul, South Korea
| | - Ho Sun Lee
- Department of Otorhinolaryngology, Boramae Medical Center, Seoul Metropolitan Government-Seoul National University, Seoul, South Korea.,Department of Otorhinolaryngology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Ye Ji Jeong
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea
| | - Yeonghoon Son
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea.,National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, South Korea
| | - Jung Min Kim
- Department of Bio-Convergence Engineering, Korea University, Seoul, South Korea
| | - Yong Jin Lee
- Division of RI Application, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea
| | - Min-Hyun Park
- Department of Otorhinolaryngology, Boramae Medical Center, Seoul Metropolitan Government-Seoul National University, Seoul, South Korea.,Department of Otorhinolaryngology, College of Medicine, Seoul National University, Seoul, South Korea
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13
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Medina CS, Uselman TW, Barto DR, Cháves F, Jacobs RE, Bearer EL. Decoupling the Effects of the Amyloid Precursor Protein From Amyloid-β Plaques on Axonal Transport Dynamics in the Living Brain. Front Cell Neurosci 2019; 13:501. [PMID: 31849608 PMCID: PMC6901799 DOI: 10.3389/fncel.2019.00501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 10/22/2019] [Indexed: 11/16/2022] Open
Abstract
Amyloid precursor protein (APP) is the precursor to Aβ plaques. The cytoplasmic domain of APP mediates attachment of vesicles to molecular motors for axonal transport. In APP-KO mice, transport of Mn2+ is decreased. In old transgenic mice expressing mutated human (APPSwInd) linked to Familial Alzheimer’s Disease, with both expression of APPSwInd and plaques, the rate and destination of Mn2+ axonal transport is altered, as detected by time-lapse manganese-enhanced magnetic resonance imaging (MEMRI) of the brain in living mice. To determine the relative contribution of expression of APPSwInd versus plaque on transport dynamics, we developed a Tet-off system to decouple expression of APPSwInd from plaque, and then studied hippocampal to forebrain transport by MEMRI. Three groups of mice were compared to wild-type (WT): Mice with plaque and APPSwInd expression; mice with plaque but suppression of APPSwInd expression; and mice with APPSwInd suppressed from mating until 2 weeks before imaging with no plaque. MR images were captured before at successive time points after stereotactic injection of Mn2+ (3–5 nL) into CA3 of the hippocampus. Mice were returned to their home cage between imaging sessions so that transport would occur in the awake freely moving animal. Images of multiple mice from the three groups (suppressed or expressed) together with C57/B6J WT were aligned and processed with our automated computational pipeline, and voxel-wise statistical parametric mapping (SPM) performed. At the conclusion of MR imaging, brains were harvested for biochemistry or histopathology. Paired T-tests within-group between time points (p = 0.01 FDR corrected) support the impression that both plaque alone and APPSwInd expression alone alter transport rates and destination of Mn2+ accumulation. Expression of APPSwInd in the absence of plaque or detectable Aβ also resulted in transport defects as well as pathology of hippocampus and medial septum, suggesting two sources of pathology occur in familial Alzheimer’s disease, from toxic mutant protein as well as plaque. Alternatively mice with plaque without APPSwInd expression resemble the human condition of sporadic Alzheimer’s, and had better transport. Thus, these mice with APPSwInd expression suppressed after plaque formation will be most useful in preclinical trials.
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Affiliation(s)
- Christopher S Medina
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Taylor W Uselman
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Daniel R Barto
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Frances Cháves
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Russell E Jacobs
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.,California Institute of Technology, Pasadena, CA, United States
| | - Elaine L Bearer
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States.,California Institute of Technology, Pasadena, CA, United States
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14
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Feo R, Giove F. Towards an efficient segmentation of small rodents brain: A short critical review. J Neurosci Methods 2019; 323:82-89. [DOI: 10.1016/j.jneumeth.2019.05.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 05/09/2019] [Accepted: 05/10/2019] [Indexed: 01/27/2023]
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15
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Bearer EL, Barto D, Jacobs RE. Imaging the evolution acute fear: Longitudinal whole brain imaging in living mice of neural activity with MEMRI. PROCEEDINGS OF THE INTERNATIONAL SOCIETY FOR MAGNETIC RESONANCE IN MEDICINE ... SCIENTIFIC MEETING AND EXHIBITION. INTERNATIONAL SOCIETY FOR MAGNETIC RESONANCE IN MEDICINE. SCIENTIFIC MEETING AND EXHIBITION 2019; 27:3198. [PMID: 33442327 PMCID: PMC7803115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Elaine L Bearer
- Pathology University of New Mexico Health Sciences Center, Albuquerque, NM, United States
- California Institute of Technology, Pasadena, CA, USA
| | - Daniel Barto
- Pathology University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Russell E Jacobs
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, United States
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16
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Trastuzumab Induced Chemobrain, Atorvastatin Rescued Chemobrain with Enhanced Anticancer Effect and without Hair Loss-Side Effect. J Clin Med 2019; 8:jcm8020234. [PMID: 30754707 PMCID: PMC6406319 DOI: 10.3390/jcm8020234] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/07/2019] [Accepted: 02/08/2019] [Indexed: 12/29/2022] Open
Abstract
The authors identified that chemo-brain was induced after trastuzumab (TZB) therapy. In addition, atorvastatin (ATV) could rescue chemo-brain during trastuzumab (TZB) therapy. Enhanced therapeutic effect of TZB was confirmed after ATV therapy. We also investigated that there was no hair loss side effect due to ATV therapy. In an animal model, 150 μg TZB and five serial doses of 20 mg/kg ATV were administered. 18F-fluorodeoxyglucose Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) data were acquired. Statistical parametric mapping analysis and voxel-based morphometry analysis were performed to identify differences in glucose metabolism and gray matter concentration. The enhanced therapeutic efficacy of TZB after ATV treatment was assessed using a human epidermal growth factor receptor 2-positive gastric cancer model. We found a decrease in cerebral glucose metabolism and gray matter concentration in the frontal lobe following TZB therapy (p < 0.005). After subsequent ATV administration, glucose metabolism and regional gray matter concentration were rescued (p < 0.005). Cognitive impairment due to TZB and the rescue effect of ATV were confirmed using a passive avoidance test and quantitative real-time reverse transcription PCR. Furthermore, the penetration and accumulation of TZB in tumors increased by 100% after ATV co-administration, which resulted in an enhanced anti-cancer effect. Our study collectively demonstrates that ATV co-administration with TZB rescued the TZB-induced chemo-brain and enhances the therapeutic efficacy of TZB in tumors. We also showed that there was no hair loss during ATV therapy.
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17
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Zhang H, Mei J, Chen S, Wu X. Nondestructive prediction and visualization of plumpness in live Eriocheir sinensis using low-field 1 H magnetic resonance imaging. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2018; 98:4184-4190. [PMID: 29406600 DOI: 10.1002/jsfa.8940] [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: 11/09/2017] [Revised: 01/30/2018] [Accepted: 01/31/2018] [Indexed: 06/07/2023]
Abstract
BACKGROUND The plumpness of hepatopancreas and gonad tissues in live Chinese mitten crabs (Eriocheir sinensis) depends on the grading scale and its commercial value. In this work, a low-field T1 -weighted 1 H magnetic resonance imaging (LF-1 H MRI) technique was developed to nondestructively analyze the plumpness of hepatopancreas and gonad tissues in live E. sinensis. Both male and female E. sinensis were characterized by two-dimensional (2D) LF-1 H MRI. Moreover, a three-dimensional (3D) LF-1 H MRI model that quantitatively integrated the total volume of lipid tissues in live E. sinensis was used. RESULTS The results showed 2D LF-1 H MRI could accurately discriminate the plumpness of hepatopancreas and gonad tissues in live E. sinensis. The results of the 3D LF-1 H MRI model displayed that the lipid volume of E. sinensis could be used to quantify lipid accumulation in lipid tissues. CONCLUSION LF-1 H MRI technology was successfully developed to accurately discriminate the development of E. sinensis hepatopancreas and gonad tissues in a nondestructive manner, indicating its application potential in grading commercial live crabs or advising crab farmers on breeding and fattening processes. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Hongcai Zhang
- Laboratory of Aquatic Products Quality & Safety Risk Assessment (Shanghai) at China Ministry of Agriculture, Shanghai Ocean University, Lingang New District, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Lingang New District, Shanghai, China
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources at China Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Lingang New District, Shanghai, China
| | - Jun Mei
- Laboratory of Aquatic Products Quality & Safety Risk Assessment (Shanghai) at China Ministry of Agriculture, Shanghai Ocean University, Lingang New District, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Lingang New District, Shanghai, China
| | - Shunsheng Chen
- Laboratory of Aquatic Products Quality & Safety Risk Assessment (Shanghai) at China Ministry of Agriculture, Shanghai Ocean University, Lingang New District, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Lingang New District, Shanghai, China
| | - Xugan Wu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources at China Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Lingang New District, Shanghai, China
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18
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Bearer EL, Manifold-Wheeler BC, Medina CS, Gonzales AG, Chaves FL, Jacobs RE. Alterations of functional circuitry in aging brain and the impact of mutated APP expression. Neurobiol Aging 2018; 70:276-290. [PMID: 30055413 DOI: 10.1016/j.neurobiolaging.2018.06.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/17/2018] [Accepted: 06/18/2018] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) is a disease of aging that results in cognitive impairment, dementia, and death. Pathognomonic features of AD are amyloid plaques composed of proteolytic fragments of the amyloid precursor protein (APP) and neurofibrillary tangles composed of hyperphosphorylated tau protein. One type of familial AD occurs when mutant forms of APP are inherited. Both APP and tau are components of the microtubule-based axonal transport system, which prompts the hypothesis that axonal transport is disrupted in AD, and that such disruption impacts cognitive function. Transgenic mice expressing mutated forms of APP provide preclinical experimental systems to study AD. Here, we perform manganese-enhanced magnetic resonance imaging to study transport from hippocampus to forebrain in four cohorts of living mice: young and old wild-type and transgenic mice expressing a mutant APP with both Swedish and Indiana mutations (APPSwInd). We find that transport is decreased in normal aging and further altered in aged APPSwInd plaque-bearing mice. These findings support the hypothesis that transport deficits are a component of AD pathology and thus may contribute to cognitive deficits.
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Affiliation(s)
- Elaine L Bearer
- University of New Mexico Health Sciences Center, Albuquerque, NM, USA; Division of Biology, California Institute of Technology, Pasadena, CA, USA.
| | | | | | - Aaron G Gonzales
- University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Frances L Chaves
- University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Russell E Jacobs
- Division of Biology, California Institute of Technology, Pasadena, CA, USA; Biological Imaging Center, Beckman Institute, California Institute of Technology, Pasadena, CA, USA
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19
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Bearer EL, Barto D, Reviere ARH, Jacobs RE. Neural activation imaged by MEMRI in mouse models of PTSD: Early Life Stress and Role of the Serotonergic System in Prolonged Response to Fear. PROCEEDINGS OF THE INTERNATIONAL SOCIETY FOR MAGNETIC RESONANCE IN MEDICINE ... SCIENTIFIC MEETING AND EXHIBITION. INTERNATIONAL SOCIETY FOR MAGNETIC RESONANCE IN MEDICINE. SCIENTIFIC MEETING AND EXHIBITION 2018; 2018:2120. [PMID: 30349424 PMCID: PMC6195807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Elaine L Bearer
- Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Daniel Barto
- Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Alden R H Reviere
- Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Russell E Jacobs
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, United States
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20
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Medina CS, Manifold-Wheeler B, Gonzales A, Bearer EL. Automated Computational Processing of 3-D MR Images of Mouse Brain for Phenotyping of Living Animals. ACTA ACUST UNITED AC 2017; 119:29A.5.1-29A.5.38. [PMID: 28678440 DOI: 10.1002/cpmb.40] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Magnetic resonance (MR) imaging provides a method to obtain anatomical information from the brain in vivo that is not typically available by optical imaging because of this organ's opacity. MR is nondestructive and obtains deep tissue contrast with 100-µm3 voxel resolution or better. Manganese-enhanced MRI (MEMRI) may be used to observe axonal transport and localized neural activity in the living rodent and avian brain. Such enhancement enables researchers to investigate differences in functional circuitry or neuronal activity in images of brains of different animals. Moreover, once MR images of a number of animals are aligned into a single matrix, statistical analysis can be done comparing MR intensities between different multi-animal cohorts comprising individuals from different mouse strains or different transgenic animals, or at different time points after an experimental manipulation. Although preprocessing steps for such comparisons (including skull stripping and alignment) are automated for human imaging, no such automated processing has previously been readily available for mouse or other widely used experimental animals, and most investigators use in-house custom processing. This protocol describes a stepwise method to perform such preprocessing for mouse. © 2017 by John Wiley & Sons, Inc.
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Affiliation(s)
| | | | - Aaron Gonzales
- University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Elaine L Bearer
- University of New Mexico Health Sciences Center, Albuquerque, New Mexico.,Division of Biology, California Institute of Technology, Pasadena, California
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21
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In vivo microscopic voxel-based morphometry with a brain template to characterize strain-specific structures in the mouse brain. Sci Rep 2017; 7:85. [PMID: 28273899 PMCID: PMC5427914 DOI: 10.1038/s41598-017-00148-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 02/13/2017] [Indexed: 12/14/2022] Open
Abstract
Hundreds of inbred mouse strains are established for use in a broad spectrum of basic research fields, including genetics, neuroscience, immunology, and cancer. Inbred mice exhibit identical intra-strain genetics and divergent inter-strain phenotypes. The cognitive and behavioral divergences must be controlled by the variances of structure and function of their brains; however, the underlying morphological features of strain-to-strain difference remain obscure. Here, in vivo microscopic magnetic resonance imaging was optimized to image the mouse brains by using an isotropic resolution of 80 μm. Next, in vivo templates were created from the data from four major inbred mouse strains (C57Bl/6, BALB/cBy, C3H/He, and DBA/2). A strain-mixed brain template was also created, and the template was then employed to establish automatic voxel-based morphometry (VBM) for the mouse brain. The VBM assessment revealed strain-specific brain morphologies concerning the gray matter volume of the four strains, with a smaller volume in the primary visual cortex for the C3H/He strain, and a smaller volume in the primary auditory cortex and field CA1 of the hippocampus for the DBA/2 strain. These findings would contribute to the basis of for understanding morphological phenotype of the inbred mouse strain and may indicate a relationship between brain morphology and strain-specific cognition and behavior.
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Hippocampal to basal forebrain transport of Mn 2+ is impaired by deletion of KLC1, a subunit of the conventional kinesin microtubule-based motor. Neuroimage 2016; 145:44-57. [PMID: 27751944 DOI: 10.1016/j.neuroimage.2016.09.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 08/23/2016] [Accepted: 09/15/2016] [Indexed: 11/23/2022] Open
Abstract
Microtubule-based motors carry cargo back and forth between the synaptic region and the cell body. Defects in axonal transport result in peripheral neuropathies, some of which are caused by mutations in KIF5A, a gene encoding one of the heavy chain isoforms of conventional kinesin-1. Some mutations in KIF5A also cause severe central nervous system defects in humans. While transport dynamics in the peripheral nervous system have been well characterized experimentally, transport in the central nervous system is less experimentally accessible and until now not well described. Here we apply manganese-enhanced magnetic resonance (MEMRI) to study transport dynamics within the central nervous system, focusing on the hippocampal-forebrain circuit, and comparing kinesin-1 light chain 1 knock-out (KLC-KO) mice with age-matched wild-type littermates. We injected Mn2+ into CA3 of the posterior hippocampus and imaged axonal transport in vivo by capturing whole-brain 3D magnetic resonance images (MRI) in living mice at discrete time-points after injection. Precise placement of the injection site was monitored in both MR images and in histologic sections. Mn2+-induced intensity progressed along fiber tracts (fimbria and fornix) in both genotypes to the medial septal nuclei (MSN), correlating in location with the traditional histologic tract tracer, rhodamine dextran. Pairwise statistical parametric mapping (SPM) comparing intensities at successive time-points within genotype revealed Mn2+-enhanced MR signal as it proceeded from the injection site into the forebrain, the expected projection from CA3. By region of interest (ROI) analysis of the MSN, wide variation between individuals in each genotype was found. Despite this statistically significant intensity increases in the MSN at 6h post-injection was found in both genotypes, albeit less so in the KLC-KO. While the average accumulation at 6h was less in the KLC-KO, the difference between genotypes did not reach significance. Projections of SPM T-maps for each genotype onto the same grayscale image revealed differences in the anatomical location of significant voxels. Although KLC-KO mice had smaller brains than wild-type, the gross anatomy was normal with no apparent loss of septal cholinergic neurons. Hence anatomy alone does not explain the differences in SPM maps. We conclude that kinesin-1 defects may have only a minor effect on the rate and distribution of transported Mn2+ within the living brain. This impairment is less than expected for this abundant microtubule-based motor, yet such defects could still be functionally significant, resulting in cognitive/emotional dysfunction due to decreased replenishments of synaptic vesicles or mitochondria during synaptic activity. This study demonstrates the power of MEMRI to observe and measure vesicular transport dynamics in the central nervous system that may result from or lead to brain pathology.
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