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Cao Y, Cheung NA, Giustini D, LeDue J, Murphy TH. Scholar Metrics Scraper (SMS): automated retrieval of citation and author data. Front Res Metr Anal 2024; 9:1335454. [PMID: 38456123 PMCID: PMC10917922 DOI: 10.3389/frma.2024.1335454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 02/06/2024] [Indexed: 03/09/2024] Open
Abstract
Academic departments, research clusters and evaluators analyze author and citation data to measure research impact and to support strategic planning. We created Scholar Metrics Scraper (SMS) to automate the retrieval of bibliometric data for a group of researchers. The project contains Jupyter notebooks that take a list of researchers as an input and exports a CSV file of citation metrics from Google Scholar (GS) to visualize the group's impact and collaboration. A series of graph outputs are also available. SMS is an open solution for automating the retrieval and visualization of citation data.
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Affiliation(s)
- Yutong Cao
- Department of Psychiatry, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Nicole A. Cheung
- Department of Psychiatry, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Dean Giustini
- Biomedical Branch Library, University of British Columbia, Vancouver, BC, Canada
| | - Jeffrey LeDue
- Department of Psychiatry, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Timothy H. Murphy
- Department of Psychiatry, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
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2
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Michelson NJ, Bolaños F, Bolaños LA, Balbi M, LeDue JM, Murphy TH. Meso-Py: Dual Brain Cortical Calcium Imaging in Mice during Head-Fixed Social Stimulus Presentation. eNeuro 2023; 10:ENEURO.0096-23.2023. [PMID: 38053472 PMCID: PMC10731520 DOI: 10.1523/eneuro.0096-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 11/06/2023] [Accepted: 11/14/2023] [Indexed: 12/07/2023] Open
Abstract
We present a cost-effective, compact foot-print, and open-source Raspberry Pi-based widefield imaging system. The compact nature allows the system to be used for close-proximity dual-brain cortical mesoscale functional-imaging to simultaneously observe activity in two head-fixed animals in a staged social touch-like interaction. We provide all schematics, code, and protocols for a rail system where head-fixed mice are brought together to a distance where the macrovibrissae of each mouse make contact. Cortical neuronal functional signals (GCaMP6s; genetically encoded Ca2+ sensor) were recorded from both mice simultaneously before, during, and after the social contact period. When the mice were together, we observed bouts of mutual whisking and cross-mouse correlated cortical activity across the cortex. Correlations were not observed in trial-shuffled mouse pairs, suggesting that correlated activity was specific to individual interactions. Whisking-related cortical signals were observed during the period where mice were together (closest contact). The effects of social stimulus presentation extend outside of regions associated with mutual touch and have global synchronizing effects on cortical activity.
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Affiliation(s)
- Nicholas J Michelson
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Federico Bolaños
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Luis A Bolaños
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Matilde Balbi
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Jeffrey M LeDue
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Timothy H Murphy
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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Xiao D, Yan Y, Murphy TH. Mesotrode chronic simultaneous mesoscale cortical imaging and subcortical or peripheral nerve spiking activity recording in mice. eLife 2023; 12:RP87691. [PMID: 37962180 PMCID: PMC10645427 DOI: 10.7554/elife.87691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023] Open
Abstract
Brain function originates from hierarchical spatial-temporal neural dynamics distributed across cortical and subcortical networks. However, techniques available to assess large-scale brain network activity with single-neuron resolution in behaving animals remain limited. Here, we present Mesotrode that integrates chronic wide-field mesoscale cortical imaging and compact multi-site cortical/subcortical cellular electrophysiology in head-fixed mice that undergo self-initiated running or orofacial movements. Specifically, we harnessed the flexibility of chronic multi-site tetrode recordings to monitor single-neuron activity in multiple subcortical structures while simultaneously imaging the mesoscale activity of the entire dorsal cortex. A mesoscale spike-triggered averaging procedure allowed the identification of cortical activity motifs preferentially associated with single-neuron spiking. Using this approach, we were able to characterize chronic single-neuron-related functional connectivity maps for up to 60 days post-implantation. Neurons recorded from distinct subcortical structures display diverse but segregated cortical maps, suggesting that neurons of different origins participate in distinct cortico-subcortical pathways. We extended the capability of Mesotrode by implanting the micro-electrode at the facial motor nerve and found that facial nerve spiking is functionally associated with the PTA, RSP, and M2 network, and optogenetic inhibition of the PTA area significantly reduced the facial movement of the mice. These findings demonstrate that Mesotrode can be used to sample different combinations of cortico-subcortical networks over prolonged periods, generating multimodal and multi-scale network activity from a single implant, offering new insights into the neural mechanisms underlying specific behaviors.
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Affiliation(s)
- Dongsheng Xiao
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological ResearchVancouverCanada
- Djavad Mowafaghian Centre for Brain Health, University of British ColumbiaVancouverCanada
| | - Yuhao Yan
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological ResearchVancouverCanada
- Djavad Mowafaghian Centre for Brain Health, University of British ColumbiaVancouverCanada
| | - Timothy H Murphy
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological ResearchVancouverCanada
- Djavad Mowafaghian Centre for Brain Health, University of British ColumbiaVancouverCanada
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Hu H, Zhang R, Fong T, Rhodin H, Murphy TH. Standardized 3D test object for multi-camera calibration during animal pose capture. Neurophotonics 2023; 10:046602. [PMID: 37942210 PMCID: PMC10629347 DOI: 10.1117/1.nph.10.4.046602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 10/05/2023] [Accepted: 10/10/2023] [Indexed: 11/10/2023]
Abstract
Accurate capture of animal behavior and posture requires the use of multiple cameras to reconstruct three-dimensional (3D) representations. Typically, a paper ChArUco (or checker) board works well for correcting distortion and calibrating for 3D reconstruction in stereo vision. However, measuring the error in two-dimensional (2D) is also prone to bias related to the placement of the 2D board in 3D. We proposed a procedure as a visual way of validating camera placement, and it also can provide some guidance about the positioning of cameras and potential advantages of using multiple cameras. We propose the use of a 3D printable test object for validating multi-camera surround-view calibration in small animal video capture arenas. The proposed 3D printed object has no bias to a particular dimension and is designed to minimize occlusions. The use of the calibrated test object provided an estimate of 3D reconstruction accuracy. The approach reveals that for complex specimens such as mice, some view angles will be more important for accurate capture of keypoints. Our method ensures accurate 3D camera calibration for surround image capture of laboratory mice and other specimens.
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Affiliation(s)
- Hao Hu
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
| | - Roark Zhang
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
| | - Tony Fong
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
| | - Helge Rhodin
- University of British Columbia, Department of Computer Science, Vancouver, British Columbia, Canada
| | - Timothy H. Murphy
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
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Fong T, Hu H, Gupta P, Jury B, Murphy TH. PyMouseTracks: Flexible Computer Vision and RFID-Based System for Multiple Mouse Tracking and Behavioral Assessment. eNeuro 2023; 10:ENEURO.0127-22.2023. [PMID: 37185293 PMCID: PMC10198609 DOI: 10.1523/eneuro.0127-22.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/13/2023] [Accepted: 04/19/2023] [Indexed: 05/17/2023] Open
Abstract
PyMouseTracks (PMT) is a scalable and customizable computer vision and radio frequency identification (RFID)-based system for multiple rodent tracking and behavior assessment that can be set up within minutes in any user-defined arena at minimal cost. PMT is composed of the online Raspberry Pi (RPi)-based video and RFID acquisition with subsequent offline analysis tools. The system is capable of tracking up to six mice in experiments ranging from minutes to days. PMT maintained a minimum of 88% detections tracked with an overall accuracy >85% when compared with manual validation of videos containing one to four mice in a modified home-cage. As expected, chronic recording in home-cage revealed diurnal activity patterns. In open-field, it was observed that novel noncagemate mouse pairs exhibit more similarity in travel trajectory patterns than cagemate pairs over a 10-min period. Therefore, shared features within travel trajectories between animals may be a measure of sociability that has not been previously reported. Moreover, PMT can interface with open-source packages such as DeepLabCut and Traja for pose estimation and travel trajectory analysis, respectively. In combination with Traja, PMT resolved motor deficits exhibited in stroke animals. Overall, we present an affordable, open-sourced, and customizable/scalable mouse behavior recording and analysis system.
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Affiliation(s)
- Tony Fong
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia Canada V6T 1Z3
| | - Hao Hu
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia Canada V6T 1Z3
| | - Pankaj Gupta
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia Canada V6T 1Z3
| | - Braeden Jury
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia Canada V6T 1Z3
| | - Timothy H Murphy
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia Canada V6T 1Z3
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Ramandi D, Michelson NJ, Raymond LA, Murphy TH. Chronic multiscale resolution of mouse brain networks using combined mesoscale cortical imaging and subcortical fiber photometry. Neurophotonics 2023; 10:015001. [PMID: 36694618 PMCID: PMC9867602 DOI: 10.1117/1.nph.10.1.015001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
SIGNIFICANCE Genetically encoded optical probes to image calcium levels in neurons in vivo are used widely as a real-time measure of neuronal activity in the brain. Mesoscale calcium imaging through a cranial window provides a method of studying the interaction of circuit activity between cortical areas but lacks access to subcortical regions. AIM We have developed an optical and surgical preparation that preserves wide-field imaging of the cortical surface while also permitting access to specific subcortical networks. APPROACH This was achieved using an optical fiber implanted in the striatum, along with a bilateral widefield cranial window, enabling simultaneous mesoscale cortical imaging and subcortical fiber photometry recording of calcium signals in a transgenic animal expressing GCaMP. Subcortical signals were collected from the dorsal regions of the striatum. We combined this approach with multiple sensory-motor tasks, including specific auditory and visual stimulation, and video monitoring of animal movements and pupillometry during head-fixed behaviors. RESULTS We found high correlations between cortical and striatal activity in response to sensory stimulation or movement. Furthermore, spontaneous activity recordings revealed that specific motifs of cortical activity are correlated with presynaptic activity recorded in the striatum, enabling us to select for corticostriatal activity motifs. CONCLUSION We believe that this method can be utilized to reveal not only global patterns but also cell-specific connectivity that provides insight into corticobasal ganglia circuit organization.
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Affiliation(s)
- Daniel Ramandi
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Department of Psychiatry, Vancouver, British Columbia, Canada
| | - Nicholas J. Michelson
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Department of Psychiatry, Vancouver, British Columbia, Canada
| | - Lynn A. Raymond
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Department of Psychiatry, Vancouver, British Columbia, Canada
| | - Timothy H. Murphy
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Department of Psychiatry, Vancouver, British Columbia, Canada
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Wang Y, LeDue JM, Murphy TH. Multiscale imaging informs translational mouse modeling of neurological disease. Neuron 2022; 110:3688-3710. [PMID: 36198319 DOI: 10.1016/j.neuron.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/26/2022] [Accepted: 09/06/2022] [Indexed: 11/05/2022]
Abstract
Multiscale neurophysiology reveals that simple motor actions are associated with changes in neuronal firing in virtually every brain region studied. Accordingly, the assessment of focal pathology such as stroke or progressive neurodegenerative diseases must also extend widely across brain areas. To derive mechanistic information through imaging, multiple resolution scales and multimodal factors must be included, such as the structure and function of specific neurons and glial cells and the dynamics of specific neurotransmitters. Emerging multiscale methods in preclinical animal studies that span micro- to macroscale examinations fill this gap, allowing a circuit-based understanding of pathophysiological mechanisms. Combined with high-performance computation and open-source data repositories, these emerging multiscale and large field-of-view techniques include live functional ultrasound, multi- and single-photon wide-scale light microscopy, video-based miniscopes, and tissue-penetrating fiber photometry, as well as variants of post-mortem expansion microscopy. We present these technologies and outline use cases and data pipelines to uncover new knowledge within animal models of stroke, Alzheimer's disease, and movement disorders.
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Affiliation(s)
- Yundi Wang
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Jeffrey M LeDue
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Timothy H Murphy
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada.
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Mitelut C, Zhang Y, Sekino Y, Boyd JD, Bollanos F, Swindale NV, Silasi G, Saxena S, Murphy TH. Mesoscale cortex-wide neural dynamics predict goal-directed, but not random actions in mice several seconds prior to movement. eLife 2022; 11:76506. [PMID: 36326239 PMCID: PMC9671502 DOI: 10.7554/elife.76506] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 11/02/2022] [Indexed: 11/06/2022] Open
Abstract
Volition – the sense of control or agency over one’s voluntary actions – is widely recognized as the basis of both human subjective experience and natural behavior in nonhuman animals. Several human studies have found peaks in neural activity preceding voluntary actions, for example the readiness potential (RP), and some have shown upcoming actions could be decoded even before awareness. Others propose that random processes underlie and explain pre-movement neural activity. Here, we seek to address these issues by evaluating whether pre-movement neural activity in mice contains structure beyond that present in random neural activity. Implementing a self-initiated water-rewarded lever-pull paradigm in mice while recording widefield [Ca++] neural activity we find that cortical activity changes in variance seconds prior to movement and that upcoming lever pulls could be predicted between 3 and 5 s (or more in some cases) prior to movement. We found inhibition of motor cortex starting at approximately 5 s prior to lever pulls and activation of motor cortex starting at approximately 2 s prior to a random unrewarded left limb movement. We show that mice, like humans, are biased toward commencing self-initiated actions during specific phases of neural activity but that the pre-movement neural code changes over time in some mice and is widely distributed as behavior prediction improved when using all vs. single cortical areas. These findings support the presence of structured multi-second neural dynamics preceding self-initiated action beyond that expected from random processes. Our results also suggest that neural mechanisms underlying self-initiated action could be preserved between mice and humans.
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Affiliation(s)
| | - Yongxu Zhang
- Department of Engineering, University of Florida
| | - Yuki Sekino
- Department of Psychiatry, University of British Columbia
| | - Jamie D Boyd
- Department of Psychiatry, University of British Columbia
| | | | - Nicholas V Swindale
- Department of Ophthalmology and Visual Sciences, University of British Columbia
| | - Greg Silasi
- Department of Cellular and Molecular Medicine, University of Ottawa
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Hu H, Xiao D, Rhodin H, Murphy TH. Towards a Visualizable, De-identified Synthetic Biomarker of Human Movement Disorders. J Parkinsons Dis 2022; 1:2085-2096. [PMID: 36057831 PMCID: PMC10473142 DOI: 10.3233/jpd-223351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/10/2022] [Indexed: 12/15/2022]
Abstract
Human motion analysis has been a common thread across modern and early medicine. While medicine evolves, analysis of movement disorders is mostly based on clinical presentation and trained observers making subjective assessments using clinical rating scales. Currently, the field of computer vision has seen exponential growth and successful medical applications. While this has been the case, neurology, for the most part, has not embraced digital movement analysis. There are many reasons for this including: the limited size of labeled datasets, accuracy and nontransparent nature of neural networks, and potential legal and ethical concerns. We hypothesize that a number of opportunities are made available by advancements in computer vision that will enable digitization of human form, movements, and will represent them synthetically in 3D. Representing human movements within synthetic body models will potentially pave the way towards objective standardized digital movement disorder diagnosis and building sharable open-source datasets from such processed videos. We provide a perspective of this emerging field and describe how clinicians and computer scientists can navigate this new space. Such digital movement capturing methods will be important for both machine learning-based diagnosis and computer vision-aided clinical assessment. It would also supplement face-to-face clinical visits and be used for longitudinal monitoring and remote diagnosis.
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Affiliation(s)
- Hao Hu
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Dongsheng Xiao
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Helge Rhodin
- Department of Computer Science, University of British Columbia, Vancouver, BC, Canada
| | - Timothy H. Murphy
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
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Sepers MD, Mackay JP, Koch E, Xiao D, Mohajerani MH, Chan AW, Smith-Dijak AI, Ramandi D, Murphy TH, Raymond LA. Altered cortical processing of sensory input in Huntington disease mouse models. Neurobiol Dis 2022; 169:105740. [PMID: 35460870 DOI: 10.1016/j.nbd.2022.105740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 04/10/2022] [Accepted: 04/16/2022] [Indexed: 11/24/2022] Open
Abstract
Huntington disease (HD), a hereditary neurodegenerative disorder, manifests as progressively impaired movement and cognition. Although early abnormalities of neuronal activity in striatum are well established in HD models, there are fewer in vivo studies of the cortex. Here, we record local field potentials (LFPs) in YAC128 HD model mice versus wild-type mice. In multiple cortical areas, limb sensory stimulation evokes a greater change in LFP power in YAC128 mice. Mesoscopic imaging using voltage-sensitive dyes reveals more extensive spread of evoked sensory signals across the cortical surface in YAC128 mice. YAC128 layer 2/3 sensory cortical neurons ex vivo show increased excitatory events, which could contribute to enhanced sensory responses in vivo. Cortical LFP responses to limb stimulation, visual and auditory input are also significantly increased in zQ175 HD mice. Results presented here extend knowledge of HD beyond ex vivo studies of individual neurons to the intact cortical network.
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Affiliation(s)
- Marja D Sepers
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - James P Mackay
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Ellen Koch
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Dongsheng Xiao
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Majid H Mohajerani
- Canadian Center for Behavioural Neuroscience, University of Lethbridge, Lethbridge T1K 3M4, Canada
| | - Allan W Chan
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
| | - Amy I Smith-Dijak
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Daniel Ramandi
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Timothy H Murphy
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Lynn A Raymond
- Department of Psychiatry and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T1Z3, Canada.
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Xiao D, Forys BJ, Vanni MP, Murphy TH. MesoNet allows automated scaling and segmentation of mouse mesoscale cortical maps using machine learning. Nat Commun 2021; 12:5992. [PMID: 34645817 PMCID: PMC8514445 DOI: 10.1038/s41467-021-26255-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 09/23/2021] [Indexed: 01/17/2023] Open
Abstract
Understanding the basis of brain function requires knowledge of cortical operations over wide spatial scales and the quantitative analysis of brain activity in well-defined brain regions. Matching an anatomical atlas to brain functional data requires substantial labor and expertise. Here, we developed an automated machine learning-based registration and segmentation approach for quantitative analysis of mouse mesoscale cortical images. A deep learning model identifies nine cortical landmarks using only a single raw fluorescent image. Another fully convolutional network was adapted to delimit brain boundaries. This anatomical alignment approach was extended by adding three functional alignment approaches that use sensory maps or spatial-temporal activity motifs. We present this methodology as MesoNet, a robust and user-friendly analysis pipeline using pre-trained models to segment brain regions as defined in the Allen Mouse Brain Atlas. This Python-based toolbox can also be combined with existing methods to facilitate high-throughput data analysis.
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Affiliation(s)
- Dongsheng Xiao
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, V6T 1Z3, British Columbia, Canada
| | - Brandon J Forys
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, V6T 1Z3, British Columbia, Canada
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Matthieu P Vanni
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, V6T 1Z3, British Columbia, Canada
- Université de Montréal, École d'Optométrie, 3744 Jean Brillant H3T 1P1, Montréal, Québec, Canada
| | - Timothy H Murphy
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, V6T 1Z3, British Columbia, Canada.
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Bolaños LA, Xiao D, Ford NL, LeDue JM, Gupta PK, Doebeli C, Hu H, Rhodin H, Murphy TH. A three-dimensional virtual mouse generates synthetic training data for behavioral analysis. Nat Methods 2021; 18:378-381. [PMID: 33820989 PMCID: PMC8034498 DOI: 10.1038/s41592-021-01103-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 02/25/2021] [Indexed: 11/24/2022]
Abstract
We developed a three-dimensional (3D) synthetic animated mouse based on computed tomography scans that is actuated using animation and semirandom, joint-constrained movements to generate synthetic behavioral data with ground-truth label locations. Image-domain translation produced realistic synthetic videos used to train two-dimensional (2D) and 3D pose estimation models with accuracy similar to typical manual training datasets. The outputs from the 3D model-based pose estimation yielded better definition of behavioral clusters than 2D videos and may facilitate automated ethological classification.
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Affiliation(s)
- Luis A Bolaños
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dongsheng Xiao
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nancy L Ford
- Centre for High-Throughput Phenogenomics, Department of Oral Biological and Medical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jeff M LeDue
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Pankaj K Gupta
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Carlos Doebeli
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hao Hu
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Helge Rhodin
- Department of Computer Science, University of British Columbia, Vancouver, British Columbia, Canada
| | - Timothy H Murphy
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada.
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada.
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13
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Murphy TH, Michelson NJ, Boyd JD, Fong T, Bolanos LA, Bierbrauer D, Siu T, Balbi M, Bolanos F, Vanni M, LeDue JM. Automated task training and longitudinal monitoring of mouse mesoscale cortical circuits using home cages. eLife 2020; 9:55964. [PMID: 32412409 PMCID: PMC7332290 DOI: 10.7554/elife.55964] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 05/07/2020] [Indexed: 12/12/2022] Open
Abstract
We report improved automated open-source methodology for head-fixed mesoscale cortical imaging and/or behavioral training of home cage mice using Raspberry Pi-based hardware. Staged partial and probabilistic restraint allows mice to adjust to self-initiated headfixation over 3 weeks' time with ~50% participation rate. We support a cue-based behavioral licking task monitored by a capacitive touch-sensor water spout. While automatically head-fixed, we acquire spontaneous, movement-triggered, or licking task-evoked GCaMP6 cortical signals. An analysis pipeline marked both behavioral events, as well as analyzed brain fluorescence signals as they relate to spontaneous and/or task-evoked behavioral activity. Mice were trained to suppress licking and wait for cues that marked the delivery of water. Correct rewarded go-trials were associated with widespread activation of midline and lateral barrel cortex areas following a vibration cue and delayed frontal and lateral motor cortex activation. Cortical GCaMP signals predicted trial success and correlated strongly with trial-outcome dependent body movements.
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Affiliation(s)
- Timothy H Murphy
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Nicholas J Michelson
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Jamie D Boyd
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Tony Fong
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Luis A Bolanos
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - David Bierbrauer
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Teri Siu
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Matilde Balbi
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Federico Bolanos
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Matthieu Vanni
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Jeff M LeDue
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
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14
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McGirr A, LeDue J, Chan AW, Boyd JD, Metzak PD, Murphy TH. Stress impacts sensory variability through cortical sensory activity motifs. Transl Psychiatry 2020; 10:20. [PMID: 32066714 PMCID: PMC7026117 DOI: 10.1038/s41398-020-0713-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 12/19/2019] [Accepted: 01/02/2020] [Indexed: 12/26/2022] Open
Abstract
Medically unexplained symptoms in depression are common. These individual-specific complaints are often considered an 'idiom of distress', yet animal studies suggest that cortical sensory representations are flexible and influenced by spontaneous cortical activity. We hypothesized that stress would reveal activity dynamics in somatosensory cortex resulting in greater sensory-evoked response variability. Using millisecond resolution in vivo voltage sensitive dye (VSD) imaging in mouse neocortex, we characterized spontaneous regional depolarizations within limb and barrel regions of somatosensory cortex, or spontaneous sensory motifs, and their influence on sensory variability. Stress revealed an idiosyncratic increase in spontaneous sensory motifs that is normalized by selective serotonin reuptake inhibitor treatment. Spontaneous motif frequency is associated with increased variability in sensory-evoked responses, and we optogenetically demonstrate that regional depolarization in somatosensory cortex increases sensory-evoked variability for seconds. This reveals a putative circuit level target for changes in sensory processing and for unexplained physical complaints in stress-related psychopathology.
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Affiliation(s)
- Alexander McGirr
- Department of Psychiatry, University of Calgary, Calgary, AB, Canada. .,Hotchkiss Brain Institute & The Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB, Canada.
| | - Jeffrey LeDue
- grid.17091.3e0000 0001 2288 9830Department of Psychiatry, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Djavad Mowafaghian Brain Research Centre, University of British Columbia, Vancouver, BC Canada
| | - Allen W. Chan
- grid.17089.37Department of Psychiatry, University of Alberta, Edmonton, AB Canada
| | - James D. Boyd
- grid.17091.3e0000 0001 2288 9830Department of Psychiatry, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Djavad Mowafaghian Brain Research Centre, University of British Columbia, Vancouver, BC Canada
| | - Paul D. Metzak
- grid.22072.350000 0004 1936 7697Department of Psychiatry, University of Calgary, Calgary, AB Canada ,grid.22072.350000 0004 1936 7697Hotchkiss Brain Institute & The Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB Canada
| | - Timothy H. Murphy
- grid.17091.3e0000 0001 2288 9830Department of Psychiatry, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830Djavad Mowafaghian Brain Research Centre, University of British Columbia, Vancouver, BC Canada
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15
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Ashby DM, LeDue J, Murphy TH, McGirr A. Peripheral Nerve Ligation Elicits Widespread Alterations in Cortical Sensory Evoked and Spontaneous Activity. Sci Rep 2019; 9:15341. [PMID: 31653941 PMCID: PMC6814845 DOI: 10.1038/s41598-019-51811-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/08/2019] [Indexed: 12/31/2022] Open
Abstract
Peripheral neuropathies result in adaptation in primary sensory and other regions of cortex, and provide a framework for understanding the localized and widespread adaptations that arise from altered sensation. Mesoscale cortical imaging achieves high temporal resolution of activity using optical sensors of neuronal activity to simultaneously image across a wide expanse of cortex and capture this adaptation using sensory-evoked and spontaneous cortical activity. Saphenous nerve ligation in mouse is an animal model of peripheral neuropathy that produces hyperalgesia circumscribed to the hindlimb. We performed saphenous nerve ligation or sham, followed by mesoscale cortical imaging using voltage sensitive dye (VSD) after ten days. We utilized subcutaneous electrical stimulation at multiple stimulus intensities to characterize sensory responses after ligation or sham, and acquired spontaneous activity to characterize functional connectivity and large scale cortical network reorganization. Relative to sham animals, the primary sensory-evoked response to hindlimb stimulation in ligated animals was unaffected in magnitude at all stimulus intensities. However, we observed a diminished propagating wave of cortical activity at lower stimulus intensities in ligated animals after hindlimb, but not forelimb, sensory stimulation. We simultaneously observed a widespread decrease in cortical functional connectivity, where midline association regions appeared most affected. These results are consistent with localized and broad alterations in intracortical connections in response to a peripheral insult, with implications for novel circuit level understanding and intervention for peripheral neuropathies and other conditions affecting sensation.
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Affiliation(s)
- Donovan M Ashby
- Hotchkiss Brain Institute, University of Calgary, Calgary, Canada
| | - Jeffrey LeDue
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Timothy H Murphy
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada.,Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Alexander McGirr
- Hotchkiss Brain Institute, University of Calgary, Calgary, Canada. .,Department of Psychiatry, Cumming School of Medicine, University of Calgary, Calgary, Canada. .,Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, Canada.
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16
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Balbi M, Vanni MP, Vega MJ, Silasi G, Sekino Y, Boyd JD, LeDue JM, Murphy TH. Longitudinal monitoring of mesoscopic cortical activity in a mouse model of microinfarcts reveals dissociations with behavioral and motor function. J Cereb Blood Flow Metab 2019; 39:1486-1500. [PMID: 29521138 PMCID: PMC6681536 DOI: 10.1177/0271678x18763428] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 01/29/2018] [Accepted: 02/01/2018] [Indexed: 12/14/2022]
Abstract
Small vessel disease is characterized by sporadic obstruction of small vessels leading to neuronal cell death. These microinfarcts often escape detection by conventional magnetic resonance imaging and are identified only upon postmortem examination. Our work explores a brain-wide microinfarct model in awake head-fixed mice, where occlusions of small penetrating arterioles are reproduced by endovascular injection of fluorescent microspheres. Mesoscopic functional connectivity was mapped longitudinally in awake GCaMP6 mice using genetically encoded calcium indicators for transcranial wide-field calcium imaging. Microsphere occlusions were quantified and changes in cerebral blood flow were measured with laser speckle imaging. The neurodeficit score in microinfarct mice was significantly higher than in sham, indicating impairment in motor function. The novel object recognition test showed a reduction in the discrimination index in microinfarct mice compared to sham. Graph-theoretic analysis of functional connectivity did not reveal significant differences in functional connectivity between sham and microinfarct mice. While behavioral tasks revealed impairments following microinfarct induction, the absence of measurable functional alterations in cortical activity has a less straightforward interpretation. The behavioral alterations produced by this model are consistent with alterations observed in human patients suffering from microinfarcts and support the validity of microsphere injection as a microinfarct model.
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Affiliation(s)
- Matilde Balbi
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Matthieu P Vanni
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Max J Vega
- Department of Psychology, Motivated
Cognition Lab, University of British Columbia, Vancouver, British Columbia,
Canada
| | - Gergely Silasi
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Yuki Sekino
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Jamie D Boyd
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
| | - Jeffrey M LeDue
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
- Djavad Mowafaghian Center for Brain
Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Timothy H Murphy
- Department of Psychiatry, Kinsmen
Laboratory of Neurological Research, University of British Columbia, Vancouver,
British Columbia, Canada
- Djavad Mowafaghian Center for Brain
Health, University of British Columbia, Vancouver, British Columbia, Canada
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17
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Michelson NJ, Vanni MP, Murphy TH. Comparison between transgenic and AAV-PHP.eB-mediated expression of GCaMP6s using in vivo wide-field functional imaging of brain activity. Neurophotonics 2019; 6:025014. [PMID: 31763351 PMCID: PMC6864505 DOI: 10.1117/1.nph.6.2.025014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/22/2019] [Indexed: 05/13/2023]
Abstract
We employ transcranial wide-field single-photon imaging to compare genetically encoded calcium sensors under transgenic or viral vector expression strategies. Awake, head-fixed animals and brief visual flash stimuli are used to assess function. The use of awake transcranial imaging may reduce confounds attributed to cranial window implantation or anesthesia states. We report differences in wide-field epifluorescence brightness and peak Δ F / F 0 response to visual stimulation between expression strategies. Other metrics for indicator performance include fluctuation analysis (standard deviation) and regional correlation maps made from spontaneous activity. We suggest that multiple measures, such as stimulus-evoked signal-to-noise ratio, brightness, and averaged visual Δ F / F 0 response, may be necessary to characterize indicator sensitivity and methods of expression. Furthermore, we show that strategies using blood brain barrier-permeable viruses, such as PHP.eB, yield comparable expression and function as those derived from transgenic mice. We suggest that testing of new genetically engineered activity sensors could employ a single-photon, wide-field imaging pipeline involving visual stimulation in awake mice that have been intravenously injected with PHP.eB.
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Affiliation(s)
- Nicholas J. Michelson
- Kinsmen Laboratory of Neurological Research, Department of Psychiatry, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
| | - Matthieu P. Vanni
- Kinsmen Laboratory of Neurological Research, Department of Psychiatry, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
- Université de Montréal, School of Optometry, Montréal, Québec, Canada
| | - Timothy H. Murphy
- Kinsmen Laboratory of Neurological Research, Department of Psychiatry, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
- Address all correspondence to Timothy H. Murphy E-mail:
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18
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Langdon KD, Cordova CA, Granter-Button S, Boyd JD, Peeling J, Murphy TH, Corbett D. Executive dysfunction and blockage of brain microvessels in a rat model of vascular cognitive impairment. J Cereb Blood Flow Metab 2018; 38:1727-1740. [PMID: 29083274 PMCID: PMC6168916 DOI: 10.1177/0271678x17739219] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Most research focuses on overt stroke caused by blockage of major blood vessels. Less attention has been paid to small vessel disease which gives rise to covert stroke that often leads to vascular cognitive impairment (VCI). One reason for this may be the relative lack of relevant animal models. Herein, we describe, a model of VCI induced in middle-aged Sprague-Dawley rats exposed to a diet high in saturated fats, salt and refined sugar (HFSS). In Experiment 1, rats were fed HFSS and subjected to a small mediodorsal (MD) thalamic stroke with or without concomitant permanent bilateral carotid artery occlusion. MD lesions produce significant executive dysfunction in an attention set-shift task ( p = 0.012). In Experiment 2, rats were exposed to either HFSS or control diet and functional effects assessed. We found significant hypertension ( p = 0.013), blockage of brain microvessels ( p = 0.018) and white matter atrophy ( p = 0.039) in HFSS diet animals. As in Experiment 1, profound, specific set-shifting executive dysfunction was noted ( p = 0.003) following both small MD infarcts (0.332 mm3) and the HFSS diet. In summary, these data describe a middle-aged animal model of VCI that includes clinically relevant metabolic disturbances and small vessel disease and as such may be helpful in developing new cognitive therapies.
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Affiliation(s)
- Kristopher D Langdon
- 1 BioMedical Sciences, Memorial University, St. John's, NL, Canada.,2 Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
| | - Chris A Cordova
- 1 BioMedical Sciences, Memorial University, St. John's, NL, Canada
| | | | - Jamie D Boyd
- 3 Department of Psychiatry, Brain Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - James Peeling
- 4 Department of Radiology, University of Manitoba, Winnipeg, MB, Canada.,5 Department of Chemistry, University of Winnipeg, Winnipeg, MB, Canada
| | - Timothy H Murphy
- 3 Department of Psychiatry, Brain Research Centre, University of British Columbia, Vancouver, BC, Canada.,6 Canadian Partnership for Stroke Recovery, Ottawa, ON, Canada.,7 Kinsmen Laboratory, Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.,8 Department of Cellular & Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Dale Corbett
- 1 BioMedical Sciences, Memorial University, St. John's, NL, Canada.,6 Canadian Partnership for Stroke Recovery, Ottawa, ON, Canada.,9 Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,10 Department of Medicine, University of Toronto, Toronto, ON, Canada
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19
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Silasi G, Boyd JD, Bolanos F, LeDue JM, Scott SH, Murphy TH. Individualized tracking of self-directed motor learning in group-housed mice performing a skilled lever positioning task in the home cage. J Neurophysiol 2017; 119:337-346. [PMID: 29070625 DOI: 10.1152/jn.00115.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Skilled forelimb function in mice is traditionally studied through behavioral paradigms that require extensive training by investigators and are limited by the number of trials individual animals are able to perform within a supervised session. We developed a skilled lever positioning task that mice can perform within their home cage. The task requires mice to use their forelimb to precisely hold a lever mounted on a rotary encoder within a rewarded position to dispense a water reward. A Raspberry Pi microcomputer is used to record lever position during trials and to control task parameters, thus making this low-footprint apparatus ideal for use within animal housing facilities. Custom Python software automatically increments task difficulty by requiring a longer hold duration, or a more accurate hold position, to dispense a reward. The performance of individual animals within group-housed mice is tracked through radio-frequency identification implants, and data stored on the microcomputer may be accessed remotely through an active internet connection. Mice continuously engage in the task for over 2.5 mo and perform ~500 trials/24 h. Mice required ~15,000 trials to learn to hold the lever within a 10° range for 1.5 s and were able to further refine movement accuracy by limiting their error to a 5° range within each trial. These results demonstrate the feasibility of autonomously training group-housed mice on a forelimb motor task. This paradigm may be used in the future to assess functional recovery after injury or cortical reorganization induced by self-directed motor learning. NEW & NOTEWORTHY We developed a low-cost system for fully autonomous training of group-housed mice on a forelimb motor task. We demonstrate the feasibility of tracking both end-point, as well as kinematic performance of individual mice, with each performing thousands of trials over 2.5 mo. The task is run and controlled by a Raspberry Pi microcomputer, which allows for cages to be monitored remotely through an active internet connection.
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Affiliation(s)
- Gergely Silasi
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa , Ottawa, Ontario , Canada
| | - Jamie D Boyd
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada
| | - Federico Bolanos
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jeff M LeDue
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stephen H Scott
- Centre for Neuroscience Studies, Queen's University , Kingston, Ontario , Canada
| | - Timothy H Murphy
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
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20
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McGirr A, LeDue J, Chan AW, Xie Y, Murphy TH. Cortical functional hyperconnectivity in a mouse model of depression and selective network effects of ketamine. Brain 2017; 140:2210-2225. [PMID: 28899017 DOI: 10.1093/brain/awx142] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 04/26/2017] [Indexed: 12/28/2022] Open
Abstract
See Huang and Liston (doi:10.1093/awx166) for a scientific commentary on this article.Human depression is associated with glutamatergic dysfunction and alterations in resting state network activity. However, the indirect nature of human in vivo glutamate and activity assessments obscures mechanistic details. Using the chronic social defeat mouse model of depression, we determine how mesoscale glutamatergic networks are altered after chronic stress, and in response to the rapid acting antidepressant, ketamine. Transgenic mice (Ai85) expressing iGluSnFR (a recombinant protein sensor) permitted real-time in vivo selective characterization of extracellular glutamate and longitudinal imaging of mesoscale cortical glutamatergic functional circuits. Mice underwent chronic social defeat or a control condition, while spontaneous cortical activity was longitudinally sampled. After chronic social defeat, we observed network-wide glutamate functional hyperconnectivity in defeated animals, which was confirmed with voltage sensitive dye imaging in an independent cohort. Subanaesthetic ketamine has unique effects in defeated animals. Acutely, subanaesthetic ketamine induces large global cortical glutamate transients in defeated animals, and an elevated subanaesthetic dose resulted in sustained global increase in cortical glutamate. Local cortical inhibition of glutamate transporters in naïve mice given ketamine produced a similar extracellular glutamate phenotype, with both glutamate transients and a dose-dependent accumulation of glutamate. Twenty-four hours after ketamine, normalization of depressive-like behaviour in defeated animals was accompanied by reduced glutamate functional connectivity strength. Altered glutamate functional connectivity in this animal model confirms the central role of glutamate dynamics as well as network-wide changes after chronic stress and in response to ketamine.
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Affiliation(s)
- Alexander McGirr
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Jeffrey LeDue
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Allen W Chan
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Yicheng Xie
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Timothy H Murphy
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
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21
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Corbett D, Carmichael ST, Murphy TH, Jones TA, Schwab ME, Jolkkonen J, Clarkson AN, Dancause N, Weiloch T, Johansen-Berg H, Nilsson M, McCullough LD, Joy MT. Enhancing the Alignment of the Preclinical and Clinical Stroke Recovery Research Pipeline: Consensus-Based Core Recommendations From the Stroke Recovery and Rehabilitation Roundtable Translational Working Group. Neurorehabil Neural Repair 2017; 31:699-707. [DOI: 10.1177/1545968317724285] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Stroke recovery research involves distinct biological and clinical targets compared to the study of acute stroke. Guidelines are proposed for the pre-clinical modeling of stroke recovery and for the alignment of pre-clinical studies to clinical trials in stroke recovery.
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Affiliation(s)
- Dale Corbett
- Department of Cellular and Molecular Medicine, University of Ottawa, Canadian Partnership for Stroke Recovery, Ottawa, Canada
| | - S. Thomas Carmichael
- Department of Neurology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, USA
| | - Timothy H. Murphy
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Theresa A. Jones
- Department of Psychology and Neuroscience Institute, University of Texas at Austin, Austin, TX, USA
| | - Martin E. Schwab
- Institute for Brain Research, University of Zurich, Zurich, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Jukka Jolkkonen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland and Neurocenter, Neurology, University Hospital of Kuopio, Kuopio, Finland
| | - Andrew N. Clarkson
- Department of Anatomy, Brain Health Research Center, and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
- Faculty of Pharmacy, The University of Sydney, Sydney, Australia
| | - Numa Dancause
- Groupe de Recherche sur le Système Nerveux Central (GRSNC), Département de Neurosciences, Université de Montréal, Montréal, Canada
| | - Tadeusz Weiloch
- Department of Clinical Sciences, Laboratory for Experimental Brain Research, Lund, Sweden
| | - Heidi Johansen-Berg
- Oxford Centre for Functional MRI of the Brain, John Radcliffe Hospital, Headington, Oxford, UK
| | - Michael Nilsson
- Hunter Medical Research Institute, University of Newcastle, New Lambton, Australia
| | - Louise D. McCullough
- Department of Neurology, University of Texas Health Sciences Center at Houston, Houston, TX, USA
| | - Mary T. Joy
- Department of Neurology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, USA
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Corbett D, Carmichael ST, Murphy TH, Jones TA, Schwab ME, Jolkkonen J, Clarkson AN, Dancause N, Weiloch T, Johansen-Berg H, Nilsson M, McCullough LD, Joy MT. Enhancing the alignment of the preclinical and clinical stroke recovery research pipeline: Consensus-based core recommendations from the Stroke Recovery and Rehabilitation Roundtable translational working group. Int J Stroke 2017; 12:462-471. [DOI: 10.1177/1747493017711814] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Stroke recovery research involves distinct biological and clinical targets compared to the study of acute stroke. Guidelines are proposed for the pre-clinical modeling of stroke recovery and for the alignment of pre-clinical studies to clinical trials in stroke recovery.
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Affiliation(s)
- Dale Corbett
- Department of Cellular and Molecular Medicine, University of Ottawa, Canadian Partnership for Stroke Recovery, Ottawa, Canada
| | - S Thomas Carmichael
- Department of Neurology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, USA
| | - Timothy H Murphy
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Theresa A Jones
- Department of Psychology and Neuroscience Institute, University of Texas at Austin, Austin, TX, USA
| | - Martin E Schwab
- Institute for Brain Research, University of Zurich
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Jukka Jolkkonen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland and Neurocenter, Neurology, University Hospital of Kuopio, Kuopio, Finland
| | - Andrew N Clarkson
- Department of Anatomy, Brain Health Research Center, and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
- Faculty of Pharmacy, The University of Sydney, Sydney, Australia
| | - Numa Dancause
- Groupe de Recherche sur le Système Nerveux central (GRSNC), Département de Neurosciences, Université de Montréal, Montréal, Canada
| | - Tadeusz Weiloch
- Department of Clinical Sciences, Laboratory for Experimental Brain Research, Lund, Sweden
| | - Heidi Johansen-Berg
- Oxford Centre for Functional MRI of the Brain, John Radcliffe Hospital, Headington, Oxford, UK
| | - Michael Nilsson
- Hunter Medical Research Institute, University of Newcastle, New Lambton, Australia
| | - Louise D McCullough
- Department of Neurology, University of Texas Health Sciences Center at Houston, Houston, TX, USA
| | - Mary T Joy
- Department of Neurology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, USA
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Balbi M, Vanni MP, Silasi G, Sekino Y, Bolanos L, LeDue JM, Murphy TH. Targeted ischemic stroke induction and mesoscopic imaging assessment of blood flow and ischemic depolarization in awake mice. Neurophotonics 2017; 4:035001. [PMID: 28721356 PMCID: PMC5512458 DOI: 10.1117/1.nph.4.3.035001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 06/16/2017] [Indexed: 05/24/2023]
Abstract
Despite advances in experimental stroke models, confounding factors such as anesthetics used during stroke induction remain. Furthermore, imaging of blood flow during stroke is not routinely done. We take advantage of in vivo bihemispheric transcranial windows for longitudinal mesoscopic imaging of cortical function to establish a protocol for focal ischemic stroke induction in target brain regions using photothrombosis in awake head-fixed mice. Our protocol does not require any surgical steps at the time of stroke induction or anesthetics during either head fixation or photoactivation. In addition, we performed laser speckle contrast imaging and wide-field calcium imaging to reveal the effect of cortical spreading ischemic depolarization after stroke in both anesthetized and awake animals over a spatial scale encompassing both hemispheres. With our combined approach, we observed ischemic depolarizing waves (3 to [Formula: see text]) propagating across the cortex 1 to 5 min after stroke induction in genetically encoded calcium indicator mice. Measures of blood flow by laser speckle were correlated with neurological impairment and lesion volume, suggesting a metric for reducing experimental variability. The ability to follow brain dynamics immediately after stroke as well as during recovery may provide a valuable guide to develop activity-dependent therapeutic interventions to be performed shortly after stroke induction.
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Affiliation(s)
- Matilde Balbi
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavillion, Vancouver, British Columbia, Canada
| | - Matthieu P. Vanni
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavillion, Vancouver, British Columbia, Canada
| | - Gergely Silasi
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavillion, Vancouver, British Columbia, Canada
| | - Yuki Sekino
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavillion, Vancouver, British Columbia, Canada
| | - Luis Bolanos
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavillion, Vancouver, British Columbia, Canada
| | - Jeffrey M. LeDue
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavillion, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Center for Brain Health, Vancouver, British Columbia, Canada
| | - Timothy H. Murphy
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavillion, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Center for Brain Health, Vancouver, British Columbia, Canada
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24
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Noorshams O, Boyd JD, Murphy TH. Automating mouse weighing in group homecages with Raspberry Pi micro-computers. J Neurosci Methods 2017; 285:1-5. [PMID: 28476590 DOI: 10.1016/j.jneumeth.2017.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/29/2017] [Accepted: 05/01/2017] [Indexed: 11/17/2022]
Abstract
BACKGROUND Operant training systems make use of water or food restriction and make it necessary to weigh animals to ensure compliance with experimental endpoints. In other applications periodic weighing is necessary to assess drug side-effects, or as an endpoint in feeding experiments. Periodic weighing while essential can disrupt animal circadian rhythms and social structure. NEW METHOD Automatic weighing system within paired mouse homecages. Up to 10 mice freely move between two cages (28×18×9cm) which were connected by a weighing chamber mounted on a load cell. Each mouse was identified using an RFID tag placed under the skin of the neck. A single-board computer (Raspberry Pi; RPi) controls the task, logging RFID tag, load cell weights, and time stamps from each RFID detection until the animal leaves the chamber. Collected data were statistically analyzed to estimate mouse weights. We anticipate integration with tasks where automated imaging or behaviour is assessed in homecages. RESULTS Mice frequently move between the two cages, an average of 42+-16 times/day/mouse at which time we obtained weights. We report accurate determination of mouse weight and long term monitoring over 53days. Comparison with existing methods Although commercial systems are available for automatically weighing rodents, they only work with single animals, or are not open source nor cost effective for specific custom application. CONCLUSIONS This automated system permits automated weighing of mice ∼40 times per day. The system employs inexpensive hardware and open-source Python code.
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Affiliation(s)
- Omid Noorshams
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Jamie D Boyd
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Timothy H Murphy
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
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Abstract
Few stand-alone software applications are available for sorting spikes from recordings made with multi-electrode arrays. Ideally, an application should be user friendly with a graphical user interface, able to read data files in a variety of formats, and provide users with a flexible set of tools giving them the ability to detect and sort extracellular voltage waveforms from different units with some degree of reliability. Previously published spike sorting methods are now available in a software program, SpikeSorter, intended to provide electrophysiologists with a complete set of tools for sorting, starting from raw recorded data file and ending with the export of sorted spikes times. Procedures are automated to the extent this is currently possible. The article explains and illustrates the use of the program. A representative data file is opened, extracellular traces are filtered, events are detected and then clustered. A number of problems that commonly occur during sorting are illustrated, including the artefactual over-splitting of units due to the tendency of some units to fire spikes in pairs where the second spike is significantly smaller than the first, and over-splitting caused by slow variation in spike height over time encountered in some units. The accuracy of SpikeSorter's performance has been tested with surrogate ground truth data and found to be comparable to that of other algorithms in current development.
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Affiliation(s)
| | - Catalin Mitelut
- Ophthalmology and Visual Sciences, University of British Columbia
| | | | - Martin A Spacek
- Ophthalmology and Visual Sciences, University of British Columbia; Neurobiology, Biology II, LMU München
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26
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Xiao D, Vanni MP, Mitelut CC, Chan AW, LeDue JM, Xie Y, Chen AC, Swindale NV, Murphy TH. Mapping cortical mesoscopic networks of single spiking cortical or sub-cortical neurons. eLife 2017; 6. [PMID: 28160463 PMCID: PMC5328594 DOI: 10.7554/elife.19976] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 02/02/2017] [Indexed: 12/13/2022] Open
Abstract
Understanding the basis of brain function requires knowledge of cortical operations over wide-spatial scales, but also within the context of single neurons. In vivo, wide-field GCaMP imaging and sub-cortical/cortical cellular electrophysiology were used in mice to investigate relationships between spontaneous single neuron spiking and mesoscopic cortical activity. We make use of a rich set of cortical activity motifs that are present in spontaneous activity in anesthetized and awake animals. A mesoscale spike-triggered averaging procedure allowed the identification of motifs that are preferentially linked to individual spiking neurons by employing genetically targeted indicators of neuronal activity. Thalamic neurons predicted and reported specific cycles of wide-scale cortical inhibition/excitation. In contrast, spike-triggered maps derived from single cortical neurons yielded spatio-temporal maps expected for regional cortical consensus function. This approach can define network relationships between any point source of neuronal spiking and mesoscale cortical maps. DOI:http://dx.doi.org/10.7554/eLife.19976.001
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Affiliation(s)
- Dongsheng Xiao
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Matthieu P Vanni
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Catalin C Mitelut
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Allen W Chan
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Jeffrey M LeDue
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Yicheng Xie
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Andrew Cn Chen
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Nicholas V Swindale
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada
| | - Timothy H Murphy
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
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27
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Bolaños F, LeDue JM, Murphy TH. Cost effective raspberry pi-based radio frequency identification tagging of mice suitable for automated in vivo imaging. J Neurosci Methods 2017; 276:79-83. [DOI: 10.1016/j.jneumeth.2016.11.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 11/23/2016] [Accepted: 11/24/2016] [Indexed: 01/30/2023]
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28
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McVea DA, Murphy TH, Mohajerani MH. Large Scale Cortical Functional Networks Associated with Slow-Wave and Spindle-Burst-Related Spontaneous Activity. Front Neural Circuits 2016; 10:103. [PMID: 28066190 PMCID: PMC5174115 DOI: 10.3389/fncir.2016.00103] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 11/30/2016] [Indexed: 11/13/2022] Open
Abstract
Cortical sensory systems are active with rich patterns of activity during sleep and under light anesthesia. Remarkably, this activity shares many characteristics with those present when the awake brain responds to sensory stimuli. We review two specific forms of such activity: slow-wave activity (SWA) in the adult brain and spindle bursts in developing brain. SWA is composed of 0.5-4 Hz resting potential fluctuations. Although these fluctuations synchronize wide regions of cortex, recent large-scale imaging has shown spatial details of their distribution that reflect underlying cortical structural projections and networks. These networks are regulated, as prior awake experiences alter both the spatial and temporal features of SWA in subsequent sleep. Activity patterns of the immature brain, however, are very different from those of the adult. SWA is absent, and the dominant pattern is spindle bursts, intermittent high frequency oscillations superimposed on slower depolarizations within sensory cortices. These bursts are driven by intrinsic brain activity, which act to generate peripheral inputs, for example via limb twitches. They are present within developing sensory cortex before they are mature enough to exhibit directed movements and respond to external stimuli. Like in the adult, these patterns resemble those evoked by sensory stimulation when awake. It is suggested that spindle-burst activity is generated purposefully by the developing nervous system as a proxy for true external stimuli. While the sleep-related functions of both slow-wave and spindle-burst activity may not be entirely clear, they reflect robust regulated phenomena which can engage select wide-spread cortical circuits. These circuits are similar to those activated during sensory processing and volitional events. We highlight these two patterns of brain activity because both are prominent and well-studied forms of spontaneous activity that will yield valuable insights into brain function in the coming years.
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Affiliation(s)
- David A. McVea
- Department of Psychiatry, University of British ColumbiaVancouver, BC, Canada
- Brain Research Centre, University of British ColumbiaVancouver, BC, Canada
| | - Timothy H. Murphy
- Department of Psychiatry, University of British ColumbiaVancouver, BC, Canada
- Brain Research Centre, University of British ColumbiaVancouver, BC, Canada
| | - Majid H. Mohajerani
- Canadian Center for Behavioural Neuroscience, University of LethbridgeLethbridge, AB, Canada
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29
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Hefendehl JK, LeDue J, Ko RWY, Mahler J, Murphy TH, MacVicar BA. Mapping synaptic glutamate transporter dysfunction in vivo to regions surrounding Aβ plaques by iGluSnFR two-photon imaging. Nat Commun 2016; 7:13441. [PMID: 27834383 PMCID: PMC5114608 DOI: 10.1038/ncomms13441] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 10/04/2016] [Indexed: 12/22/2022] Open
Abstract
Amyloid-β (Aβ) plaques, a hallmark of Alzheimer's disease (AD), are surrounded by regions of neuronal and glial hyperactivity. We use in vivo two-photon and wide-field imaging of the glutamate sensor iGluSnFR to determine whether pathological changes in glutamate dynamics in the immediate vicinity of Aβ deposits in APPPS1 transgenic mice could alter neuronal activity in this microenvironment. In regions close to Aβ plaques chronic states of high spontaneous glutamate fluctuations are observed and the timing of glutamate responses evoked by sensory stimulation exhibit slower decay rates in two cortical brain areas. GLT-1 expression is reduced around Aβ plaques and upregulation of GLT-1 expression and activity by ceftriaxone partially restores glutamate dynamics to values in control regions. We conclude that the toxic microenvironment surrounding Aβ plaques results, at least partially, from enhanced glutamate levels and that pharmacologically increasing GLT-1 expression and activity may be a new target for early therapeutic intervention. In Alzheimer's disease (AD), neural hyperactivity has been shown to occur in the regions surrounding Aβ plaques. Here, the authors use in vivo two-photon imaging in mouse models of AD and report abnormal glutamate dynamics in the vicinity of plaques which can be partially restored via GLT-1 upregulation through Ceftriaxone treatment.
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Affiliation(s)
- J K Hefendehl
- Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3
| | - J LeDue
- Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3
| | - R W Y Ko
- Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3
| | - J Mahler
- Hertie-Institut für klinische Hirnforschung, Otfried-Müller-Strasse 27, 72076 Tübingen, Germany
| | - T H Murphy
- Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3
| | - B A MacVicar
- Djavad Mowafaghian Centre for Brain Health, Faculty of Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z3
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30
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Murphy TH, Boyd JD, Bolaños F, Vanni MP, Silasi G, Haupt D, LeDue JM. High-throughput automated home-cage mesoscopic functional imaging of mouse cortex. Nat Commun 2016; 7:11611. [PMID: 27291514 PMCID: PMC4909937 DOI: 10.1038/ncomms11611] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 04/12/2016] [Indexed: 12/14/2022] Open
Abstract
Mouse head-fixed behaviour coupled with functional imaging has become a powerful technique in rodent systems neuroscience. However, training mice can be time consuming and is potentially stressful for animals. Here we report a fully automated, open source, self-initiated head-fixation system for mesoscopic functional imaging in mice. The system supports five mice at a time and requires minimal investigator intervention. Using genetically encoded calcium indicator transgenic mice, we longitudinally monitor cortical functional connectivity up to 24 h per day in >7,000 self-initiated and unsupervised imaging sessions up to 90 days. The procedure provides robust assessment of functional cortical maps on the basis of both spontaneous activity and brief sensory stimuli such as light flashes. The approach is scalable to a number of remotely controlled cages that can be assessed within the controlled conditions of dedicated animal facilities. We anticipate that home-cage brain imaging will permit flexible and chronic assessment of mesoscale cortical function. Functional imaging in awake head-fixed mice is a widely used technique to study neural responses. Here the authors report on an open source, fully automated unsupervised system for training mice to self initiate head fixation to enable stable mesoscopic functional imaging of cortical functional connectivity.
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Affiliation(s)
- Timothy H Murphy
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Jamie D Boyd
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Federico Bolaños
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Matthieu P Vanni
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Gergely Silasi
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Dirk Haupt
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Jeff M LeDue
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
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31
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Silasi G, Xiao D, Vanni MP, Chen ACN, Murphy TH. Intact skull chronic windows for mesoscopic wide-field imaging in awake mice. J Neurosci Methods 2016; 267:141-9. [PMID: 27102043 DOI: 10.1016/j.jneumeth.2016.04.012] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 04/09/2016] [Accepted: 04/16/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND Craniotomy-based window implants are commonly used for microscopic imaging, in head-fixed rodents, however their field of view is typically small and incompatible with mesoscopic functional mapping of cortex. NEW METHOD We describe a reproducible and simple procedure for chronic through-bone wide-field imaging in awake head-fixed mice providing stable optical access for chronic imaging over large areas of the cortex for months. RESULTS The preparation is produced by applying clear-drying dental cement to the intact mouse skull, followed by a glass coverslip to create a partially transparent imaging surface. Surgery time takes about 30min. A single set-screw provides a stable means of attachment (in relation to the measured lateral and axial resolution) for mesoscale assessment without obscuring the cortical field of view. COMPARISON WITH EXISTING METHODS We demonstrate the utility of this method by showing seed-pixel functional connectivity maps generated from spontaneous cortical activity of GCAMP6 signals in both awake and anesthetized mice in longitudinal studies of up to 2 months in duration. CONCLUSIONS We propose that the intact skull preparation described here may be used for most longitudinal studies that do not require micron scale resolution and where cortical neural or vascular signals are recorded with intrinsic sensors or in transgenic mice expressing genetically encoded sensors of activity.
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Affiliation(s)
- Gergely Silasi
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Dongsheng Xiao
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada; Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Matthieu P Vanni
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Andrew C N Chen
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.
| | - Timothy H Murphy
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
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32
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Lim DH, LeDue JM, Murphy TH. Network analysis of mesoscale optical recordings to assess regional, functional connectivity. Neurophotonics 2015; 2:041405. [PMID: 26158019 PMCID: PMC4478876 DOI: 10.1117/1.nph.2.4.041405] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 05/19/2015] [Indexed: 05/29/2023]
Abstract
With modern optical imaging methods, it is possible to map structural and functional connectivity. Optical imaging studies that aim to describe large-scale neural connectivity often need to handle large and complex datasets. In order to interpret these datasets, new methods for analyzing structural and functional connectivity are being developed. Recently, network analysis, based on graph theory, has been used to describe and quantify brain connectivity in both experimental and clinical studies. We outline how to apply regional, functional network analysis to mesoscale optical imaging using voltage-sensitive-dye imaging and channelrhodopsin-2 stimulation in a mouse model. We include links to sample datasets and an analysis script. The analyses we employ can be applied to other types of fluorescence wide-field imaging, including genetically encoded calcium indicators, to assess network properties. We discuss the benefits and limitations of using network analysis for interpreting optical imaging data and define network properties that may be used to compare across preparations or other manipulations such as animal models of disease.
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Affiliation(s)
- Diana H. Lim
- University of British Columbia at Vancouver, Department of Psychiatry, 4N1-2255 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Jeffrey M. LeDue
- University of British Columbia at Vancouver, Department of Psychiatry, 4N1-2255 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Timothy H. Murphy
- University of British Columbia at Vancouver, Department of Psychiatry, 4N1-2255 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
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33
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Zeng S, Murphy TH. Special Section Guest Editorial:Special Section on Light Microscopy of Connectivity. Neurophotonics 2015; 2:041401. [PMID: 26705538 PMCID: PMC4689102 DOI: 10.1117/1.nph.2.4.041401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Shaoqun Zeng
- Huazhong University of Science and Technology, Britton Chance Center for Biomedical Photonics, Department of Biomedical Engineering, 1037 Luoyu Road, Wuhan, 430074 China
| | - Timothy H. Murphy
- University of British Columbia at Vancouver, Department of Psychiatry, British Columbia V6T 1Z3, Canada
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34
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Funayama K, Minamisawa G, Matsumoto N, Ban H, Chan AW, Matsuki N, Murphy TH, Ikegaya Y. Neocortical Rebound Depolarization Enhances Visual Perception. PLoS Biol 2015; 13:e1002231. [PMID: 26274866 PMCID: PMC4537103 DOI: 10.1371/journal.pbio.1002231] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 07/22/2015] [Indexed: 01/24/2023] Open
Abstract
Animals are constantly exposed to the time-varying visual world. Because visual perception is modulated by immediately prior visual experience, visual cortical neurons may register recent visual history into a specific form of offline activity and link it to later visual input. To examine how preceding visual inputs interact with upcoming information at the single neuron level, we designed a simple stimulation protocol in which a brief, orientated flashing stimulus was subsequently coupled to visual stimuli with identical or different features. Using in vivo whole-cell patch-clamp recording and functional two-photon calcium imaging from the primary visual cortex (V1) of awake mice, we discovered that a flash of sinusoidal grating per se induces an early, transient activation as well as a long-delayed reactivation in V1 neurons. This late response, which started hundreds of milliseconds after the flash and persisted for approximately 2 s, was also observed in human V1 electroencephalogram. When another drifting grating stimulus arrived during the late response, the V1 neurons exhibited a sublinear, but apparently increased response, especially to the same grating orientation. In behavioral tests of mice and humans, the flashing stimulation enhanced the detection power of the identically orientated visual stimulation only when the second stimulation was presented during the time window of the late response. Therefore, V1 late responses likely provide a neural basis for admixing temporally separated stimuli and extracting identical features in time-varying visual environments. A study of mice and humans shows that prior activity in the visual cortex induces a long-delayed depolarization that enhances perception of subsequent visual stimuli if these are identical to the previous one, thereby extracting invariant visual features from the constantly changing visual world. Animals are constantly exposed to a visual world that varies over time. To examine how the visual cortex integrates visual information that is temporally spaced, we monitored neuronal activity of the primary visual cortex (V1) using single- and multicell recording techniques. We discovered that a brief visual stimulus induced an early, transient activation as well as a delayed reactivation of V1 neurons in mice and humans. Notably, this reactivation of visual cortex conveyed information about stimulus orientation: presentation of a second visual stimulus during this reactivation enhanced the V1 response specifically when the orientations of the two stimuli were identical. Behavioral tests in mice and humans revealed that the ability to detect visual stimuli was also enhanced when the second stimulus was presented during the time window of V1 reactivation. Because animals extract visual information from an environment in constant change, the modulation of visual responses through cortical reactivation might be a strategy commonly used in the visual system.
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Affiliation(s)
- Kenta Funayama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Genki Minamisawa
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Nobuyoshi Matsumoto
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Hiroshi Ban
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita City, Osaka, Japan
- Graduate School of Frontier Biosciences, Osaka University, Suita City, Osaka, Japan
| | - Allen W. Chan
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Norio Matsuki
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Timothy H. Murphy
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita City, Osaka, Japan
- * E-mail:
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35
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Abstract
To gain insight into the dendritic structural changes that occur within minutes of ischemia, as well as circuit-level plasticity that occurs over days to weeks, it is necessary to devise stroke models for anesthetized transgenic mice that are compatible with in vivo imaging methods. In particular, we are interested in examining events during the first few minutes of ischemia that are associated with a wave of ischemic depolarization. Given the short latency to ischemic depolarization (∼2 min), we have found it necessary to develop ischemia models that can be initiated while the animal is within the two-photon microscope for in vivo imaging. We describe both a global ischemia model and a targeted photothrombotic ischemia model in green fluorescent protein- and yellow fluorescent protein-expressing transgenic mice in which in vivo imaging of dendritic structure can be performed. The advantage of the global model is the speed with which ischemia can be induced and reversed, whereas the focal model lacks precise temporal control but can be targeted to a select region.
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Silasi G, She J, Boyd JD, Xue S, Murphy TH. A mouse model of small-vessel disease that produces brain-wide-identified microocclusions and regionally selective neuronal injury. J Cereb Blood Flow Metab 2015; 35:734-8. [PMID: 25690472 PMCID: PMC4420872 DOI: 10.1038/jcbfm.2015.8] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 01/06/2015] [Accepted: 01/07/2015] [Indexed: 11/09/2022]
Abstract
We developed a mouse model of small-vessel disease where occlusions are produced through endovascular injection of fluorescent microspheres that target ~12 μm diameter penetrating arterioles and can be localized in histology. Using Thy1-GFP transgenic mice, we visualized the impact of microocclusions on neuronal structure. Microocclusions in the hippocampus produce cell loss or neuronal atrophy (~7% of lodged microspheres led to microinfarcts), while axons within white matter tracts, as well as the striatum and thalamus became blebbed or disrupted. Although the neocortex contained more occlusions than other structures, labeled layer 5 neurons were relatively resistant to structural damage, with <2% of the lodged microspheres producing obvious neuronal damage.
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Affiliation(s)
- Gergely Silasi
- 1] Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada [2] Brain Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jennifer She
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada
| | - Jamie D Boyd
- 1] Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada [2] Brain Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Songchao Xue
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada
| | - Timothy H Murphy
- 1] Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Vancouver, British Columbia, Canada [2] Brain Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
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37
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Abstract
Connections between neurons are affected within 3 min of stroke onset by massive ischemic depolarization and then delayed cell death. Some connections can recover with prompt reperfusion; others associated with the dying infarct do not. Disruption in functional connectivity is due to direct tissue loss and indirect disconnections of remote areas known as diaschisis. Stroke is devastating, yet given the brain's redundant design, collateral surviving networks and their connections are well-positioned to compensate. Our perspective is that new treatments for stroke may involve a rational functional and structural connections-based approach. Surviving, affected, and at-risk networks can be identified and targeted with scenario-specific treatments. Strategies for recovery may include functional inhibition of the intact hemisphere, rerouting of connections, or setpoint-mediated network plasticity. These approaches may be guided by brain imaging and enabled by patient- and injury-specific brain stimulation, rehabilitation, and potential molecule-based strategies to enable new connections.
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Affiliation(s)
- Gergely Silasi
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada; Brain Research Centre, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Timothy H Murphy
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada; Brain Research Centre, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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Reimers MA, Mohajerani M, Murphy TH. A dynamic model for delta rhythm fit to high-frequency cortical activity data shows discrete functional connectivity in mouse cortex. BMC Neurosci 2014. [PMCID: PMC4126567 DOI: 10.1186/1471-2202-15-s1-p82] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Silasi G, Murphy TH. Removing the brakes on post-stroke plasticity drives recovery from the intact hemisphere and spinal cord. ACTA ACUST UNITED AC 2014; 137:648-50. [PMID: 24549809 DOI: 10.1093/brain/awu016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Gergely Silasi
- Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, B.C. Canada V6T 1Z3
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Anenberg E, Arstikaitis P, Niitsu Y, Harrison TC, Boyd JD, Hilton BJ, Tetzlaff W, Murphy TH. Ministrokes in channelrhodopsin-2 transgenic mice reveal widespread deficits in motor output despite maintenance of cortical neuronal excitability. J Neurosci 2014; 34:1094-104. [PMID: 24453302 PMCID: PMC6705317 DOI: 10.1523/jneurosci.1442-13.2014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 11/28/2013] [Accepted: 12/04/2013] [Indexed: 11/21/2022] Open
Abstract
We evaluated the effects of ministrokes targeted to individual pial arterioles on motor function in Thy-1 line 18 channelrhodopsin-2 (ChR2) transgenic mice within the first hours after ischemia. Using optogenetics, we directly assessed both the excitability and motor output of cortical neurons in a manner independent of behavioral state or training. Occlusion of individual arterioles within the motor cortex led to a ministroke that was verified using laser speckle contrast imaging. Surprisingly, ministrokes targeted to a relatively small region of the forelimb motor map, with an ischemic core of 0.07 ± 0.03 mm(2), impaired motor responses evoked from points across widespread areas of motor cortex even 1.5 mm away. Contrasting averaged ChR2-evoked electroencephalographic, spinal (ChR2 evoked potential), and electromyographic responses revealed a mismatch between measures of cortical excitability and motor output within 60 min after stroke. This mismatch suggests that apparently excitable cortical neurons (even >1 mm into peri-infarct areas, away from the infarct core) were impaired in their capacity to generate spinal potentials leading to even more severe deficits in motor output at muscles. We suggest that ischemia, targeted to a subset of motor cortex, leads to relatively small reductions in excitability within motor cortex, and cumulative depression of both descending spinal circuits and motor output in response to the activation of widespread cortical territories even outside of the area directly affected by the ischemia.
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Affiliation(s)
| | | | | | | | | | - Brett J. Hilton
- Department of Zoology, and
- International Collaboration on Repair Discoveries, University of British Columbia at Vancouver, Vancouver, British Columbia V6T 1Z3, Canada
| | - Wolfram Tetzlaff
- Department of Zoology, and
- International Collaboration on Repair Discoveries, University of British Columbia at Vancouver, Vancouver, British Columbia V6T 1Z3, Canada
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Abstract
The brain's cortical maps serve as a macroscopic framework upon which additional levels of detail can be overlaid. Unlike sensory maps generated by measuring the brain's responses to incoming stimuli, motor maps are made by directly stimulating the brain itself. To understand the significance of motor maps and the functions they represent, it is necessary to consider the relationship between the natural operation of the motor system and the pattern of activity evoked in it by artificial stimulation. We review recent findings from the study of the cortical motor system and new insights into the control of movement based on its mapping within cortical space.
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Affiliation(s)
- Thomas C Harrison
- Department of Psychiatry and Brain Research Centre, University of British Columbia, 2255 Wesbrook Mall, Vancouver BC Canada V6T1Z3
| | - Timothy H Murphy
- Department of Psychiatry and Brain Research Centre, University of British Columbia, 2255 Wesbrook Mall, Vancouver BC Canada V6T1Z3.
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Mohajerani MH, Chan AW, Mohsenvand M, LeDue J, Liu R, McVea DA, Boyd JD, Wang YT, Reimers M, Murphy TH. Spontaneous cortical activity alternates between motifs defined by regional axonal projections. Nat Neurosci 2013; 16:1426-35. [PMID: 23974708 DOI: 10.1038/nn.3499] [Citation(s) in RCA: 254] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 07/17/2013] [Indexed: 12/20/2022]
Abstract
Using millisecond-timescale voltage-sensitive dye imaging in lightly anesthetized or awake adult mice, we show that a palette of sensory-evoked and hemisphere-wide activity motifs are represented in spontaneous activity. These motifs can reflect multiple modes of sensory processing, including vision, audition and touch. We found similar cortical networks with direct cortical activation using channelrhodopsin-2. Regional analysis of activity spread indicated modality-specific sources, such as primary sensory areas, a common posterior-medial cortical sink where sensory activity was extinguished within the parietal association area and a secondary anterior medial sink within the cingulate and secondary motor cortices for visual stimuli. Correlation analysis between functional circuits and intracortical axonal projections indicated a common framework corresponding to long-range monosynaptic connections between cortical regions. Maps of intracortical monosynaptic structural connections predicted hemisphere-wide patterns of spontaneous and sensory-evoked depolarization. We suggest that an intracortical monosynaptic connectome shapes the ebb and flow of spontaneous cortical activity.
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Affiliation(s)
- Majid H Mohajerani
- 1] Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada. [2] Brain Research Centre, University of British Columbia, Vancouver, British Columbia, Canada. [3] [4]
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Xie Y, Chen S, Anenberg E, Murphy TH. Resistance of optogenetically evoked motor function to global ischemia and reperfusion in mouse in vivo. J Cereb Blood Flow Metab 2013; 33:1148-52. [PMID: 23736644 PMCID: PMC3734785 DOI: 10.1038/jcbfm.2013.89] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 04/22/2013] [Accepted: 04/28/2013] [Indexed: 11/09/2022]
Abstract
Recently we have shown that despite reperfusion, sensory processing exhibits persistent deficits after global ischemia in a mouse in vivo model. We now address how motor output, specifically cortically evoked muscle activity, stimulated by channelrhodopsin-2 is affected by global ischemia and reperfusion. We find that the light-based optogenetic motor map recovers to 80% within an hour. Moreover, motor output recovers relatively faster and more completely than the sensory processing after 5-minute period of global ischemia. Our results suggest a differential sensitivity of sensory and motor systems to the effects of global ischemia and reperfusion that may have implications for rehabilitation.
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Affiliation(s)
- Yicheng Xie
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia, Canada
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Silasi G, Boyd JD, Ledue J, Murphy TH. Improved methods for chronic light-based motor mapping in mice: automated movement tracking with accelerometers, and chronic EEG recording in a bilateral thin-skull preparation. Front Neural Circuits 2013; 7:123. [PMID: 23966910 PMCID: PMC3722499 DOI: 10.3389/fncir.2013.00123] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 07/03/2013] [Indexed: 01/07/2023] Open
Abstract
Optogenetic stimulation of the mouse cortex can be used to generate motor maps that are similar to maps derived from electrode-based stimulation. Here we present a refined set of procedures for repeated light-based motor mapping in ChR2-expressing mice implanted with a bilateral thinned-skull chronic window and a chronically implanted electroencephalogram (EEG) electrode. Light stimulation is delivered sequentially to over 400 points across the cortex, and evoked movements are quantified on-line with a three-axis accelerometer attached to each forelimb. Bilateral maps of forelimb movement amplitude and movement direction were generated at weekly intervals after recovery from cranial window implantation. We found that light pulses of ~2 mW produced well-defined maps that were centered approximately 0.7 mm anterior and 1.6 mm lateral from bregma. Map borders were defined by sites where light stimulation evoked EEG deflections, but not movements. Motor maps were similar in size and location between mice, and maps were stable over weeks in terms of the number of responsive sites, and the direction of evoked movements. We suggest that our method may be used to chronically assess evoked motor output in mice, and may be combined with other imaging tools to assess cortical reorganization or sensory-motor integration.
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Affiliation(s)
- Gergely Silasi
- Department of Psychiatry, University of British Columbia Vancouver, BC, Canada ; Brain Research Centre, University of British Columbia Vancouver, BC, Canada
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Reimers M, Mohajerani M, Murphy TH. A model for delta rhythm fit to high-frequency cortical activity data. BMC Neurosci 2013. [PMCID: PMC3704529 DOI: 10.1186/1471-2202-14-s1-p287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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46
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Abstract
BACKGROUND AND PURPOSE Recovery from stroke is hypothesized to involve the reorganization of surviving cortical areas. To study the functional organization of sensorimotor cortex at multiple time points before and after stroke, we performed longitudinal light-based motor mapping of transgenic mice expressing light-sensitive channelrhodopsin-2 in layer 5 cortical neurons. METHODS Pulses of light stimulation were targeted to an array of cortical points, whereas evoked forelimb motor activity was recorded using noninvasive motion sensors. Intrinsic optical signal imaging produced maps of the forelimb somatosensory cortex. The resulting motor and sensory maps were repeatedly generated for weeks before and after small (0.2 mm3) photothrombotic infarcts were targeted to forelimb motor or sensory cortex. RESULTS Infarcts targeted to forelimb sensory or motor areas caused decreased motor output in the infarct area and spatial displacement of sensory and motor maps. Strokes in sensory cortex caused the sensory map to move into motor cortex, which adopted a more diffuse structure. Stroke in motor cortex caused a compensatory increase in peri-infarct motor output, but did not affect the position or excitability of sensory maps. CONCLUSIONS After stroke in motor cortex, decreased motor output from the infarcted area was offset by peri-infarct excitability. Sensory stroke caused a new sensory map to form in motor cortex, which maintained its center position, despite becoming more diffuse. These data suggest that surviving regions of cortex are able to assume functions from stroke-damaged areas, although this may come at the cost of alterations in map structure.
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Affiliation(s)
- Thomas C Harrison
- Department of Psychiatry, Brain Research Centre, University of British Columbia, Vancouver, BC, Canada
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Lim DH, Ledue J, Mohajerani MH, Vanni MP, Murphy TH. Optogenetic approaches for functional mouse brain mapping. Front Neurosci 2013; 7:54. [PMID: 23596383 PMCID: PMC3622058 DOI: 10.3389/fnins.2013.00054] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 03/24/2013] [Indexed: 12/20/2022] Open
Abstract
To better understand the connectivity of the brain, it is important to map both structural and functional connections between neurons and cortical regions. In recent years, a set of optogenetic tools have been developed that permit selective manipulation and investigation of neural systems. These tools have enabled the mapping of functional connections between stimulated cortical targets and other brain regions. Advantages of the approach include the ability to arbitrarily stimulate brain regions that express opsins, allowing for brain mapping independent of behavior or sensory processing. The ability of opsins to be rapidly and locally activated allows for investigation of connectivity with spatial resolution on the order of single neurons and temporal resolution on the order of milliseconds. Optogenetic methods for functional mapping have been applied in experiments ranging from in vitro investigation of microcircuits, to in vivo probing of inter-regional cortical connections, to examination of global connections within the whole brain. We review recently developed functional mapping methods that use optogenetic single-point stimulation in the rodent brain and employ cellular electrophysiology, evoked motor movements, voltage sensitive dyes (VSDs), calcium indicators, or functional magnetic resonance imaging (fMRI) to assess activity. In particular we highlight results using red-shifted organic VSDs that permit high temporal resolution imaging in a manner spectrally separated from Channelrhodopsin-2 (ChR2) activation. VSD maps stimulated by ChR2 were dependent on intracortical synaptic activity and were able to reflect circuits used for sensory processing. Although the methods reviewed are powerful, challenges remain with respect to finding approaches that permit selective high temporal resolution assessment of stimulated activity in animals that can be followed longitudinally.
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Affiliation(s)
- Diana H Lim
- Department of Psychiatry, University of British Columbia at Vancouver Vancouver, BC, Canada
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48
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Abstract
The firing rates of neurons in primate motor cortex have been related to multiple parameters of voluntary movement. This finding has been corroborated by stimulation-based studies that have mapped complex movements in rodent and primate motor cortex. However, it has been difficult to link the movement tuning of a neuron with its role within the cortical microcircuit. In sensory cortex, neuronal tuning is largely established by afferents delivering information from tuned receptors in the periphery. Motor cortex, which lacks the granular input layer, may be better understood by analyzing its efferent projections. As a primary source of cortical output, layer 5 neurons represent an ideal starting point for this line of experimentation. It is in these deep output layers that movements can most effectively be evoked by intracortical microstimulation and recordings can obtain the most useful signals for the control of motor prostheses. Studies focused on layer 5 output neurons have revealed that projection identity is a fundamental property related to the laminar position, receptive field and ion channel complement of these cells. Given the variety of brain areas targeted by layer 5 output neurons, knowledge of a neuron's downstream connectivity may provide insight into its movement tuning. Future experiments that relate motor behavior to the activity of neurons with a known projection identity will yield a more detailed understanding of the function of cortical microcircuits.
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Affiliation(s)
- Thomas C Harrison
- Department of Psychiatry, University of British Columbia Vancouver, BC, Canada
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Chen S, Mohajerani MH, Xie Y, Murphy TH. Optogenetic analysis of neuronal excitability during global ischemia reveals selective deficits in sensory processing following reperfusion in mouse cortex. J Neurosci 2012; 32:13510-9. [PMID: 23015440 PMCID: PMC6621379 DOI: 10.1523/jneurosci.1439-12.2012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 06/26/2012] [Accepted: 07/21/2012] [Indexed: 12/30/2022] Open
Abstract
We have developed an approach to directly probe neuronal excitability during the period beginning with induction of global ischemia and extending after reperfusion using transgenic mice expressing channelrhodopsin-2 (ChR2) to activate deep layer cortical neurons independent of synaptic or sensory stimulation. Spontaneous, ChR2, or forepaw stimulation-evoked electroencephalogram (EEG) or local field potential (LFP) records were collected from the somatosensory cortex. Within 20 s of ischemia, a >90% depression of spontaneous 0.3-3 Hz EEG and LFP power was detected. Ischemic depolarization followed EEG depression with a ∼2 min delay. Surprisingly, neuronal excitability, as assessed by the ChR2-mediated EEG response, was intact during the period of strong spontaneous EEG suppression and actually increased before ischemic depolarization. In contrast, a decrease in the somatosensory-evoked potential (forepaw-evoked potential, reflecting cortical synaptic transmission) was coincident with the EEG suppression. After 5 min of ischemia, the animal was reperfused, and the ChR2-mediated response mostly recovered within 30 min (>80% of preischemia value). However, the recovery of the somatosensory-evoked potential was significantly delayed compared with the ChR2-mediated response (<40% of preischemia value at 60 min). By assessing intrinsic optical signals in combination with EEG, we found that neuronal excitability approached minimal values when the spreading ischemic depolarization wave propagated to the ChR2-stimulated cortex. Our results indicate that the ChR2-mediated EEG/LFP response recovers much faster than sensory-evoked EEG/LFP activity in vivo following ischemia and reperfusion, defining a period where excitable but synaptically silent neurons are present.
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Affiliation(s)
- Shangbin Chen
- Department of Psychiatry, Brain Research Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Majid H. Mohajerani
- Department of Psychiatry, Brain Research Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Yicheng Xie
- Department of Psychiatry, Brain Research Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Timothy H. Murphy
- Department of Psychiatry, Brain Research Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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Harrison TC, Ayling OGS, Murphy TH. Distinct cortical circuit mechanisms for complex forelimb movement and motor map topography. Neuron 2012; 74:397-409. [PMID: 22542191 DOI: 10.1016/j.neuron.2012.02.028] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2012] [Indexed: 11/27/2022]
Abstract
Cortical motor maps are the basis of voluntary movement, but they have proven difficult to understand in the context of their underlying neuronal circuits. We applied light-based motor mapping of Channelrhodopsin-2 mice to reveal a functional subdivision of the forelimb motor cortex based on the direction of movement evoked by brief (10 ms) pulses. Prolonged trains of electrical or optogenetic stimulation (100-500 ms) targeted to anterior or posterior subregions of motor cortex evoked reproducible complex movements of the forelimb to distinct positions in space. Blocking excitatory cortical synaptic transmission did not abolish basic motor map topography, but the site-specific expression of complex movements was lost. Our data suggest that the topography of movement maps arises from their segregated output projections, whereas complex movements evoked by prolonged stimulation require intracortical synaptic transmission.
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Affiliation(s)
- Thomas C Harrison
- Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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