1
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Kawana Y, Imai J, Morizawa YM, Ikoma Y, Kohata M, Komamura H, Sato T, Izumi T, Yamamoto J, Endo A, Sugawara H, Kubo H, Hosaka S, Munakata Y, Asai Y, Kodama S, Takahashi K, Kaneko K, Sawada S, Yamada T, Ito A, Niizuma K, Tominaga T, Yamanaka A, Matsui K, Katagiri H. Optogenetic stimulation of vagal nerves for enhanced glucose-stimulated insulin secretion and β cell proliferation. Nat Biomed Eng 2024; 8:808-822. [PMID: 37945752 PMCID: PMC11310082 DOI: 10.1038/s41551-023-01113-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 09/26/2023] [Indexed: 11/12/2023]
Abstract
The enhancement of insulin secretion and of the proliferation of pancreatic β cells are promising therapeutic options for diabetes. Signals from the vagal nerve regulate both processes, yet the effectiveness of stimulating the nerve is unclear, owing to a lack of techniques for doing it so selectively and prolongedly. Here we report two optogenetic methods for vagal-nerve stimulation that led to enhanced glucose-stimulated insulin secretion and to β cell proliferation in mice expressing choline acetyltransferase-channelrhodopsin 2. One method involves subdiaphragmatic implantation of an optical fibre for the photostimulation of cholinergic neurons expressing a blue-light-sensitive opsin. The other method, which suppressed streptozotocin-induced hyperglycaemia in the mice, involves the selective activation of vagal fibres by placing blue-light-emitting lanthanide microparticles in the pancreatic ducts of opsin-expressing mice, followed by near-infrared illumination. The two methods show that signals from the vagal nerve, especially from nerve fibres innervating the pancreas, are sufficient to regulate insulin secretion and β cell proliferation.
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Affiliation(s)
- Yohei Kawana
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Junta Imai
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan.
| | - Yosuke M Morizawa
- Super-network Brain Physiology, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Yoko Ikoma
- Super-network Brain Physiology, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Masato Kohata
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroshi Komamura
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Toshihiro Sato
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Tomohito Izumi
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Junpei Yamamoto
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Akira Endo
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroto Sugawara
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Haremaru Kubo
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | | | - Yuichiro Munakata
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yoichiro Asai
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Shinjiro Kodama
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kei Takahashi
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Keizo Kaneko
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Shojiro Sawada
- Division of Metabolism and Diabetes, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Tetsuya Yamada
- Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Akira Ito
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kuniyasu Niizuma
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Neurosurgical Engineering and Translational Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Neurosurgical Engineering and Translational Neuroscience, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan
| | - Teiji Tominaga
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Ko Matsui
- Super-network Brain Physiology, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Hideki Katagiri
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai, Japan
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2
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Jonaitis J, Hibbard KL, McCafferty Layte K, Hiramoto A, Cardona A, Truman JW, Nose A, Zwart MF, Pulver SR. STEERING FROM THE REAR: COORDINATION OF CENTRAL PATTERN GENERATORS UNDERLYING NAVIGATION BY ASCENDING INTERNEURONS. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.17.598162. [PMID: 38948859 PMCID: PMC11212907 DOI: 10.1101/2024.06.17.598162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Understanding how animals coordinate movements to achieve goals is a fundamental pursuit in neuroscience. Here we explore how neurons that reside in posterior lower-order regions of a locomotor system project to anterior higher-order regions to influence steering and navigation. We characterized the anatomy and functional role of a population of ascending interneurons in the ventral nerve cord of Drosophila larvae. Through electron microscopy reconstructions and light microscopy, we determined that the cholinergic 19f cells receive input primarily from premotor interneurons and synapse upon a diverse array of postsynaptic targets within the anterior segments including other 19f cells. Calcium imaging of 19f activity in isolated central nervous system (CNS) preparations in relation to motor neurons revealed that 19f neurons are recruited into most larval motor programmes. 19f activity lags behind motor neuron activity and as a population, the cells encode spatio-temporal patterns of locomotor activity in the larval CNS. Optogenetic manipulations of 19f cell activity in isolated CNS preparations revealed that they coordinate the activity of central pattern generators underlying exploratory headsweeps and forward locomotion in a context and location specific manner. In behaving animals, activating 19f cells suppressed exploratory headsweeps and slowed forward locomotion, while inhibition of 19f activity potentiated headsweeps, slowing forward movement. Inhibiting activity in 19f cells ultimately affected the ability of larvae to remain in the vicinity of an odor source during an olfactory navigation task. Overall, our findings provide insights into how ascending interneurons monitor motor activity and shape interactions amongst rhythm generators underlying complex navigational tasks.
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Affiliation(s)
- Julius Jonaitis
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | | | | | - Atsuki Hiramoto
- Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Albert Cardona
- HHMI Janelia Research Campus, Ashburn, VA, USA
- Department of Physiology, Development, and Neuroscience, University of Cambridge, Cambridge, UK
- MRC Laboratory of Molecular Biology, Cambridge UK
| | - James W. Truman
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA, USA
| | - Akinao Nose
- Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
- Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Maarten F. Zwart
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
- Centre of Biophotonics, University of St Andrews, St Andrews, UK
- Institute for Behavioural and Neural Sciences, University of St Andrews, St Andrews, UK
| | - Stefan R. Pulver
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
- Centre of Biophotonics, University of St Andrews, St Andrews, UK
- Institute for Behavioural and Neural Sciences, University of St Andrews, St Andrews, UK
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3
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Ryczko D. The Mesencephalic Locomotor Region: Multiple Cell Types, Multiple Behavioral Roles, and Multiple Implications for Disease. Neuroscientist 2024; 30:347-366. [PMID: 36575956 PMCID: PMC11107129 DOI: 10.1177/10738584221139136] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The mesencephalic locomotor region (MLR) controls locomotion in vertebrates. In humans with Parkinson disease, locomotor deficits are increasingly associated with decreased activity in the MLR. This brainstem region, commonly considered to include the cuneiform and pedunculopontine nuclei, has been explored as a target for deep brain stimulation to improve locomotor function, but the results are variable, from modest to promising. However, the MLR is a heterogeneous structure, and identification of the best cell type to target is only beginning. Here, I review the studies that uncovered the role of genetically defined MLR cell types, and I highlight the cells whose activation improves locomotor function in animal models of Parkinson disease. The promising cell types to activate comprise some glutamatergic neurons in the cuneiform and caudal pedunculopontine nuclei, as well as some cholinergic neurons of the pedunculopontine nucleus. Activation of MLR GABAergic neurons should be avoided, since they stop locomotion or evoke bouts flanked with numerous stops. MLR is also considered a potential target in spinal cord injury, supranuclear palsy, primary progressive freezing of gait, or stroke. Better targeting of the MLR cell types should be achieved through optimized deep brain stimulation protocols, pharmacotherapy, or the development of optogenetics for human use.
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Affiliation(s)
- Dimitri Ryczko
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Canada
- Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Canada
- Neurosciences Sherbrooke, Sherbrooke, Canada
- Institut de Pharmacologie de Sherbrooke, Sherbrooke, Canada
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4
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Sharma S, Badenhorst CA, Ashby DM, Di Vito SA, Tran MA, Ghavasieh Z, Grewal GK, Belway CR, McGirr A, Whelan PJ. Inhibitory medial zona incerta pathway drives exploratory behavior by inhibiting glutamatergic cuneiform neurons. Nat Commun 2024; 15:1160. [PMID: 38326327 PMCID: PMC10850156 DOI: 10.1038/s41467-024-45288-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 01/19/2024] [Indexed: 02/09/2024] Open
Abstract
The cuneiform nucleus (CnF) regulates locomotor activity, which is canonically viewed as being primarily involved in initiating locomotion and regulating speed. Recent research shows greater context dependency in the locomotor functions of this nucleus. Glutamatergic neurons, which contain vesicular glutamate transporter 2 (vGLUT2), regulate context-dependent locomotor speed in the CnF and play a role in defensive behavior. Here, we identify projections from the medial zona incerta (mZI) to CnF vGLUT2 neurons that promote exploratory behavior. Using fiber photometry recordings in male mice, we find that mZI gamma-aminobutyric acid (GABA) neurons increase activity during periods of exploration. Activation of mZI GABAergic neurons is associated with reduced spiking of CnF neurons. Additionally, activating both retrogradely labeled mZI-CnF GABAergic projection neurons and their terminals in the CnF increase exploratory behavior. Inhibiting CnF vGLUT2 neuronal activity also increases exploratory behavior. These findings provide evidence for the context-dependent dynamic regulation of CnF vGLUT2 neurons, with the mZI-CnF circuit shaping exploratory behavior.
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Affiliation(s)
- Sandeep Sharma
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Cecilia A Badenhorst
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Donovan M Ashby
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Psychiatry, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Stephanie A Di Vito
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Michelle A Tran
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Zahra Ghavasieh
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Gurleen K Grewal
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Cole R Belway
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Alexander McGirr
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Psychiatry, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Patrick J Whelan
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.
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5
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Morgenstern NA, Esposito MS. The Basal Ganglia and Mesencephalic Locomotor Region Connectivity Matrix. Curr Neuropharmacol 2024; 22:1454-1472. [PMID: 37559244 PMCID: PMC11097982 DOI: 10.2174/1570159x21666230809112840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/16/2023] [Accepted: 02/23/2023] [Indexed: 08/11/2023] Open
Abstract
Although classically considered a relay station for basal ganglia (BG) output, the anatomy, connectivity, and function of the mesencephalic locomotor region (MLR) were redefined during the last two decades. In striking opposition to what was initially thought, MLR and BG are actually reciprocally and intimately interconnected. New viral-based, optogenetic, and mapping technologies revealed that cholinergic, glutamatergic, and GABAergic neurons coexist in this structure, which, in addition to extending descending projections, send long-range ascending fibers to the BG. These MLR projections to the BG convey motor and non-motor information to specific synaptic targets throughout different nuclei. Moreover, MLR efferent fibers originate from precise neuronal subpopulations located in particular MLR subregions, defining independent anatomo-functional subcircuits involved in particular aspects of animal behavior such as fast locomotion, explorative locomotion, posture, forelimb- related movements, speed, reinforcement, among others. In this review, we revised the literature produced during the last decade linking MLR and BG. We conclude that the classic framework considering the MLR as a homogeneous output structure passively receiving input from the BG needs to be revisited. We propose instead that the multiple subcircuits embedded in this region should be taken as independent entities that convey relevant and specific ascending information to the BG and, thus, actively participate in the execution and tuning of behavior.
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Affiliation(s)
- Nicolás A. Morgenstern
- Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal
- Faculty of Medicine, University of Lisbon, Instituto De Medicina Molecular João Lobo Antunes, Lisbon, Portugal
| | - Maria S. Esposito
- Department of Medical Physics, Centro Atomico Bariloche, CNEA, CONICET, Av. Bustillo 9500, San Carlos de Bariloche, Rio Negro, Argentina
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6
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Braine A, Georges F. Emotion in action: When emotions meet motor circuits. Neurosci Biobehav Rev 2023; 155:105475. [PMID: 37996047 DOI: 10.1016/j.neubiorev.2023.105475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 11/25/2023]
Abstract
The brain is a remarkably complex organ responsible for a wide range of functions, including the modulation of emotional states and movement. Neuronal circuits are believed to play a crucial role in integrating sensory, cognitive, and emotional information to ultimately guide motor behavior. Over the years, numerous studies employing diverse techniques such as electrophysiology, imaging, and optogenetics have revealed a complex network of neural circuits involved in the regulation of emotional or motor processes. Emotions can exert a substantial influence on motor performance, encompassing both everyday activities and pathological conditions. The aim of this review is to explore how emotional states can shape movements by connecting the neural circuits for emotional processing to motor neural circuits. We first provide a comprehensive overview of the impact of different emotional states on motor control in humans and rodents. In line with behavioral studies, we set out to identify emotion-related structures capable of modulating motor output, behaviorally and anatomically. Neuronal circuits involved in emotional processing are extensively connected to the motor system. These circuits can drive emotional behavior, essential for survival, but can also continuously shape ongoing movement. In summary, the investigation of the intricate relationship between emotion and movement offers valuable insights into human behavior, including opportunities to enhance performance, and holds promise for improving mental and physical health. This review integrates findings from multiple scientific approaches, including anatomical tracing, circuit-based dissection, and behavioral studies, conducted in both animal and human subjects. By incorporating these different methodologies, we aim to present a comprehensive overview of the current understanding of the emotional modulation of movement in both physiological and pathological conditions.
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Affiliation(s)
- Anaelle Braine
- Univ. Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
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7
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Meindl JN, Ivy JW. A Neurobiological-Behavioral Approach to Predicting and Influencing Private Events. Perspect Behav Sci 2023; 46:409-429. [PMID: 38144550 PMCID: PMC10733245 DOI: 10.1007/s40614-023-00390-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2023] [Indexed: 12/26/2023] Open
Abstract
The primary goals of behavior analysis are the prediction and influence of behavior. These goals are largely achieved through the identification of functional relations between behaviors and the stimulating environment. Behavior-behavior relations are insufficient to meet these goals. Although this environment-behavior approach has been highly successful when applied to public behaviors, extensions to private events have been limited. This article discusses technical and conceptual challenges to the study of private events. We introduce a neurobiological-behavioral approach which seeks to understand private behavior as environmentally controlled in part by private neurobiological stimuli. These stimuli may enter into functional relations with both public and private behaviors. The analysis builds upon several current approaches to private events, delineates private behaviors and private stimulation, and emphasizes the reciprocal interaction between the two. By doing so, this approach can improve treatment and assessment of behavior and advance understanding of concepts such as motivating operations. We then describe the array of stimulus functions that neurobiological stimuli may acquire, including eliciting, discriminative, motivating, reinforcing, and punishing effects, and describe how the overall approach expands the concept of contextual influence. Finally, we describe how advances in behavioral neuroscience that enable the measurement and analysis of private behaviors and stimuli are allowing these once private events to affect the public world. Applications in the area of human-computer interfaces are discussed.
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Affiliation(s)
- James N. Meindl
- University of Memphis, 400B Ball Hall, Memphis, TN 38152 USA
| | - Jonathan W. Ivy
- The Pennsylvania State University – Harrisburg, Middletown, PA USA
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8
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Aiken J, Holzbaur ELF. Spastin locally amplifies microtubule dynamics to pattern the axon for presynaptic cargo delivery. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.08.552320. [PMID: 37609249 PMCID: PMC10441300 DOI: 10.1101/2023.08.08.552320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Neurons rely on long-range trafficking of synaptic components to form and maintain the complex neural networks that encode the human experience. With a single neuron capable of forming thousands of distinct en passant synapses along its axon, spatially precise delivery of the necessary synaptic components is paramount. How these synapses are patterned, and how efficient delivery of synaptic components is regulated, remains largely unknown. Here, we reveal a novel role for the microtubule severing enzyme spastin in locally enhancing microtubule polymerization to influence presynaptic cargo pausing and retention along the axon. In human neurons derived from induced pluripotent stem cells (iPSCs), we identify sites stably enriched for presynaptic components, termed 'protosynapses', which are distributed along the axon prior to the robust assembly of mature presynapses apposed by postsynaptic contacts. These sites are capable of cycling synaptic vesicles, are enriched with spastin, and are hotspots for new microtubule growth and synaptic vesicle precursor (SVP) pausing/retention. Disruption of neuronal spastin, either by CRISPRi-mediated depletion or transient overexpression, interrupts the localized enrichment of dynamic microtubule plus ends and diminishes SVP accumulation. Using an innovative human heterologous synapse model, where microfluidically isolated human axons recognize and form presynaptic connections with neuroligin-expressing non-neuronal cells, we reveal that neurons deficient for spastin do not achieve the same level of presynaptic component accumulation as control neurons. We propose a model where spastin acts locally as an amplifier of microtubule polymerization to pattern specific regions of the axon for synaptogenesis and guide synaptic cargo delivery.
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Affiliation(s)
- Jayne Aiken
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Erika L F Holzbaur
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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9
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Dubuc R, Cabelguen JM, Ryczko D. Locomotor pattern generation and descending control: a historical perspective. J Neurophysiol 2023; 130:401-416. [PMID: 37465884 DOI: 10.1152/jn.00204.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/20/2023] Open
Abstract
The ability to generate and control locomotor movements depends on complex interactions between many areas of the nervous system, the musculoskeletal system, and the environment. How the nervous system manages to accomplish this task has been the subject of investigation for more than a century. In vertebrates, locomotion is generated by neural networks located in the spinal cord referred to as central pattern generators. Descending inputs from the brain stem initiate, maintain, and stop locomotion as well as control speed and direction. Sensory inputs adapt locomotor programs to the environmental conditions. This review presents a comparative and historical overview of some of the neural mechanisms underlying the control of locomotion in vertebrates. We have put an emphasis on spinal mechanisms and descending control.
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Affiliation(s)
- Réjean Dubuc
- Groupe de Recherche en Activité Physique Adaptée, Département des Sciences de l'Activité Physique, Université du Québec à Montréal, Montreal, Quebec, Canada
- Groupe de Recherche sur le Système Nerveux Central, Département de Neurosciences, Université de Montréal, Montreal, Quebec, Canada
| | - Jean-Marie Cabelguen
- Institut National de la Santé et de la Recherche Médicale (INSERM) U 1215-Neurocentre Magendie, Université de Bordeaux, Bordeaux Cedex, France
| | - Dimitri Ryczko
- Département de Pharmacologie-Physiologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada
- Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Quebec, Canada
- Neurosciences Sherbrooke, Sherbrooke, Quebec, Canada
- Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada
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10
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Hérent C, Diem S, Usseglio G, Fortin G, Bouvier J. Upregulation of breathing rate during running exercise by central locomotor circuits in mice. Nat Commun 2023; 14:2939. [PMID: 37217517 DOI: 10.1038/s41467-023-38583-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 05/02/2023] [Indexed: 05/24/2023] Open
Abstract
While respiratory adaptation to exercise is compulsory to cope with the increased metabolic demand, the neural signals at stake remain poorly identified. Using neural circuit tracing and activity interference strategies in mice, we uncover here two systems by which the central locomotor network can enable respiratory augmentation in relation to running activity. One originates in the mesencephalic locomotor region (MLR), a conserved locomotor controller. Through direct projections onto the neurons of the preBötzinger complex that generate the inspiratory rhythm, the MLR can trigger a moderate increase of respiratory frequency, prior to, or even in the absence of, locomotion. The other is the lumbar enlargement of the spinal cord containing the hindlimb motor circuits. When activated, and through projections onto the retrotrapezoid nucleus (RTN), it also potently upregulates breathing rate. On top of identifying critical underpinnings for respiratory hyperpnea, these data also expand the functional implication of cell types and pathways that are typically regarded as "locomotor" or "respiratory" related.
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Affiliation(s)
- Coralie Hérent
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400, Saclay, France
- Champalimaud Research, Champalimaud Foundation, 1400-038, Lisbon, Portugal
| | - Séverine Diem
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400, Saclay, France
- Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, 34094, Montpellier, France
| | - Giovanni Usseglio
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400, Saclay, France
| | - Gilles Fortin
- Institut de Biologie de l'École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, PSL Research University, 75005, Paris, France
| | - Julien Bouvier
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91400, Saclay, France.
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11
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Lacroix-Ouellette P, Dubuc R. Brainstem neural mechanisms controlling locomotion with special reference to basal vertebrates. Front Neural Circuits 2023; 17:910207. [PMID: 37063386 PMCID: PMC10098025 DOI: 10.3389/fncir.2023.910207] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Over the last 60 years, the basic neural circuitry responsible for the supraspinal control of locomotion has progressively been uncovered. Initially, significant progress was made in identifying the different supraspinal structures controlling locomotion in mammals as well as some of the underlying mechanisms. It became clear, however, that the complexity of the mammalian central nervous system (CNS) prevented researchers from characterizing the detailed cellular mechanisms involved and that animal models with a simpler nervous system were needed. Basal vertebrate species such as lampreys, xenopus embryos, and zebrafish became models of choice. More recently, optogenetic approaches have considerably revived interest in mammalian models. The mesencephalic locomotor region (MLR) is an important brainstem region known to control locomotion in all vertebrate species examined to date. It controls locomotion through intermediary cells in the hindbrain, the reticulospinal neurons (RSNs). The MLR comprises populations of cholinergic and glutamatergic neurons and their specific contribution to the control of locomotion is not fully resolved yet. Moreover, the downward projections from the MLR to RSNs is still not fully understood. Reporting on discoveries made in different animal models, this review article focuses on the MLR, its projections to RSNs, and the contribution of these neural elements to the control of locomotion. Excellent and detailed reviews on the brainstem control of locomotion have been recently published with emphasis on mammalian species. The present review article focuses on findings made in basal vertebrates such as the lamprey, to help direct new research in mammals, including humans.
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Affiliation(s)
| | - Réjean Dubuc
- Department of Neurosciences, Université de Montréal, Montréal, QC, Canada
- Department of Physical Activity Sciences, Université du Québec à Montréal, Montréal, QC, Canada
- Research Group for Adapted Physical Activity, Université du Québec à Montréal, Montréal, QC, Canada
- *Correspondence: Réjean Dubuc,
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12
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Roussel M, Lafrance-Zoubga D, Josset N, Lemieux M, Bretzner F. Functional contribution of mesencephalic locomotor region nuclei to locomotor recovery after spinal cord injury. Cell Rep Med 2023; 4:100946. [PMID: 36812893 PMCID: PMC9975330 DOI: 10.1016/j.xcrm.2023.100946] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 12/09/2022] [Accepted: 01/23/2023] [Indexed: 02/23/2023]
Abstract
Spinal cord injury (SCI) results in a disruption of information between the brain and the spinal circuit. Electrical stimulation of the mesencephalic locomotor region (MLR) can promote locomotor recovery in acute and chronic SCI rodent models. Although clinical trials are currently under way, there is still debate about the organization of this supraspinal center and which anatomic correlate of the MLR should be targeted to promote recovery. Combining kinematics, electromyographic recordings, anatomic analysis, and mouse genetics, our study reveals that glutamatergic neurons of the cuneiform nucleus contribute to locomotor recovery by enhancing motor efficacy in hindlimb muscles, and by increasing locomotor rhythm and speed on a treadmill, over ground, and during swimming in chronic SCI mice. In contrast, glutamatergic neurons of the pedunculopontine nucleus slow down locomotion. Therefore, our study identifies the cuneiform nucleus and its glutamatergic neurons as a therapeutical target to improve locomotor recovery in patients living with SCI.
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Affiliation(s)
- Marie Roussel
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC G1V 4G2, Canada
| | - David Lafrance-Zoubga
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC G1V 4G2, Canada
| | - Nicolas Josset
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC G1V 4G2, Canada
| | - Maxime Lemieux
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC G1V 4G2, Canada
| | - Frederic Bretzner
- Centre de Recherche du CHU de Québec, CHUL-Neurosciences, 2705 Boul. Laurier, Québec, QC G1V 4G2, Canada; Faculty of Medicine, Department of Psychiatry and Neurosciences, Université Laval, Québec, QC G1V 4G2, Canada.
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13
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Hofer AS, Scheuber MI, Sartori AM, Good N, Stalder SA, Hammer N, Fricke K, Schalbetter SM, Engmann AK, Weber RZ, Rust R, Schneider MP, Russi N, Favre G, Schwab ME. Stimulation of the cuneiform nucleus enables training and boosts recovery after spinal cord injury. Brain 2022; 145:3681-3697. [PMID: 35583160 PMCID: PMC9586551 DOI: 10.1093/brain/awac184] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 04/07/2022] [Accepted: 05/04/2022] [Indexed: 11/15/2022] Open
Abstract
Severe spinal cord injuries result in permanent paraparesis in spite of the frequent sparing of small portions of white matter. Spared fibre tracts are often incapable of maintaining and modulating the activity of lower spinal motor centres. Effects of rehabilitative training thus remain limited. Here, we activated spared descending brainstem fibres by electrical deep brain stimulation of the cuneiform nucleus of the mesencephalic locomotor region, the main control centre for locomotion in the brainstem, in adult female Lewis rats. We show that deep brain stimulation of the cuneiform nucleus enhances the weak remaining motor drive in highly paraparetic rats with severe, incomplete spinal cord injuries and enables high-intensity locomotor training. Stimulation of the cuneiform nucleus during rehabilitative aquatraining after subchronic (n = 8 stimulated versus n = 7 unstimulated versus n = 7 untrained rats) and chronic (n = 14 stimulated versus n = 9 unstimulated versus n = 9 untrained rats) spinal cord injury re-established substantial locomotion and improved long-term recovery of motor function. We additionally identified a safety window of stimulation parameters ensuring context-specific locomotor control in intact rats (n = 18) and illustrate the importance of timing of treatment initiation after spinal cord injury (n = 14). This study highlights stimulation of the cuneiform nucleus as a highly promising therapeutic strategy to enhance motor recovery after subchronic and chronic incomplete spinal cord injury with direct clinical applicability.
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Affiliation(s)
- Anna-Sophie Hofer
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Myriam I Scheuber
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Andrea M Sartori
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Nicolas Good
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Stephanie A Stalder
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Nicole Hammer
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Kai Fricke
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Sina M Schalbetter
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Anne K Engmann
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Rebecca Z Weber
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Ruslan Rust
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Marc P Schneider
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Natalie Russi
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Giacomin Favre
- Department of Economics, University of Zurich, 8032 Zurich, Switzerland
| | - Martin E Schwab
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
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14
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Le Ray D, Bertrand SS, Dubuc R. Cholinergic Modulation of Locomotor Circuits in Vertebrates. Int J Mol Sci 2022; 23:ijms231810738. [PMID: 36142651 PMCID: PMC9501616 DOI: 10.3390/ijms231810738] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 11/24/2022] Open
Abstract
Locomotion is a basic motor act essential for survival. Amongst other things, it allows animals to move in their environment to seek food, escape predators, or seek mates for reproduction. The neural mechanisms involved in the control of locomotion have been examined in many vertebrate species and a clearer picture is progressively emerging. The basic muscle synergies responsible for propulsion are generated by neural networks located in the spinal cord. In turn, descending supraspinal inputs are responsible for starting, maintaining, and stopping locomotion as well as for steering and controlling speed. Several neurotransmitter systems play a crucial role in modulating the neural activity during locomotion. For instance, cholinergic inputs act both at the spinal and supraspinal levels and the underlying mechanisms are the focus of the present review. Much information gained on supraspinal cholinergic modulation of locomotion was obtained from the lamprey model. Nicotinic cholinergic inputs increase the level of excitation of brainstem descending command neurons, the reticulospinal neurons (RSNs), whereas muscarinic inputs activate a select group of hindbrain neurons that project to the RSNs to boost their level of excitation. Muscarinic inputs also reduce the transmission of sensory inputs in the brainstem, a phenomenon that could help in sustaining goal directed locomotion. In the spinal cord, intrinsic cholinergic inputs strongly modulate the activity of interneurons and motoneurons to control the locomotor output. Altogether, the present review underlines the importance of the cholinergic inputs in the modulation of locomotor activity in vertebrates.
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Affiliation(s)
- Didier Le Ray
- Institut des Neurosciences Cognitives et Intégratives d’Aquitaine (INCIA), UMR 5287, Université de Bordeaux-CNRS, F-33076 Bordeaux, France
- Correspondence: (D.L.R.); (R.D.)
| | - Sandrine S. Bertrand
- Institut des Neurosciences Cognitives et Intégratives d’Aquitaine (INCIA), UMR 5287, Université de Bordeaux-CNRS, F-33076 Bordeaux, France
| | - Réjean Dubuc
- Department of Neurosciences, Université de Montréal, Montréal, QC H3C 3J7, Canada
- Department of Physical Activity Sciences and Research Group in Adapted Physical Activity, Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada
- Correspondence: (D.L.R.); (R.D.)
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15
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Flaive A, Ryczko D. From retina to motoneurons: A substrate for visuomotor transformation in salamanders. J Comp Neurol 2022; 530:2518-2536. [PMID: 35662021 PMCID: PMC9545292 DOI: 10.1002/cne.25348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 05/02/2022] [Accepted: 05/04/2022] [Indexed: 11/18/2022]
Abstract
The transformation of visual input into motor output is essential to approach a target or avoid a predator. In salamanders, visually guided orientation behaviors have been extensively studied during prey capture. However, the neural circuitry involved is not resolved. Using salamander brain preparations, calcium imaging and tracing experiments, we describe a neural substrate through which retinal input is transformed into spinal motor output. We found that retina stimulation evoked responses in reticulospinal neurons of the middle reticular nucleus, known to control steering movements in salamanders. Microinjection of glutamatergic antagonists in the optic tectum (superior colliculus in mammals) decreased the reticulospinal responses. Using tracing, we found that retina projected to the dorsal layers of the contralateral tectum, where the dendrites of neurons projecting to the middle reticular nucleus were located. In slices, stimulation of the tectal dorsal layers evoked glutamatergic responses in deep tectal neurons retrogradely labeled from the middle reticular nucleus. We then examined how tectum activation translated into spinal motor output. Tectum stimulation evoked motoneuronal responses, which were decreased by microinjections of glutamatergic antagonists in the contralateral middle reticular nucleus. Reticulospinal fibers anterogradely labeled from tracer injection in the middle reticular nucleus were preferentially distributed in proximity with the dendrites of ipsilateral motoneurons. Our work establishes a neural substrate linking visual and motor centers in salamanders. This retino‐tecto‐reticulo‐spinal circuitry is well positioned to control orienting behaviors. Our study bridges the gap between the behavioral studies and the neural mechanisms involved in the transformation of visual input into motor output in salamanders.
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Affiliation(s)
- Aurélie Flaive
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Dimitri Ryczko
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Quebec, Canada.,Centre d'excellence en neurosciences de l'Université de Sherbrooke, Sherbrooke, Quebec, Canada.,Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada
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16
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Networking brainstem and basal ganglia circuits for movement. Nat Rev Neurosci 2022; 23:342-360. [DOI: 10.1038/s41583-022-00581-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2022] [Indexed: 12/14/2022]
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17
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Suryanarayana SM, Robertson B, Grillner S. The neural bases of vertebrate motor behaviour through the lens of evolution. Philos Trans R Soc Lond B Biol Sci 2022; 377:20200521. [PMID: 34957847 PMCID: PMC8710883 DOI: 10.1098/rstb.2020.0521] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/27/2021] [Indexed: 12/23/2022] Open
Abstract
The primary driver of the evolution of the vertebrate nervous system has been the necessity to move, along with the requirement of controlling the plethora of motor behavioural repertoires seen among the vast and diverse vertebrate species. Understanding the neural basis of motor control through the perspective of evolution, mandates thorough examinations of the nervous systems of species in critical phylogenetic positions. We present here, a broad review of studies on the neural motor infrastructure of the lamprey, a basal and ancient vertebrate, which enjoys a unique phylogenetic position as being an extant representative of the earliest group of vertebrates. From the central pattern generators in the spinal cord to the microcircuits of the pallial cortex, work on the lamprey brain over the years, has provided detailed insights into the basic organization (a bauplan) of the ancestral vertebrate brain, and narrates a compelling account of common ancestry of fundamental aspects of the neural bases for motion control, maintained through half a billion years of vertebrate evolution. This article is part of the theme issue 'Systems neuroscience through the lens of evolutionary theory'.
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Affiliation(s)
- Shreyas M. Suryanarayana
- Department of Neuroscience, Karolinska institutet, 17177 Stockholm, Sweden
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Brita Robertson
- Department of Neuroscience, Karolinska institutet, 17177 Stockholm, Sweden
| | - Sten Grillner
- Department of Neuroscience, Karolinska institutet, 17177 Stockholm, Sweden
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18
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Masini D, Kiehn O. Targeted activation of midbrain neurons restores locomotor function in mouse models of parkinsonism. Nat Commun 2022; 13:504. [PMID: 35082287 PMCID: PMC8791953 DOI: 10.1038/s41467-022-28075-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 01/07/2022] [Indexed: 12/26/2022] Open
Abstract
The pedunculopontine nucleus (PPN) is a locomotor command area containing glutamatergic neurons that control locomotor initiation and maintenance. These motor actions are deficient in Parkinson’s disease (PD), where dopaminergic neurodegeneration alters basal ganglia activity. Being downstream of the basal ganglia, the PPN may be a suitable target for ameliorating parkinsonian motor symptoms. Here, we use in vivo cell-type specific PPN activation to restore motor function in two mouse models of parkinsonism made by acute pharmacological blockage of dopamine transmission. With a combination of chemo- and opto-genetics, we show that excitation of caudal glutamatergic PPN neurons can normalize the otherwise severe locomotor deficit in PD, whereas targeting the local GABAergic population only leads to recovery of slow locomotion. The motor rescue driven by glutamatergic PPN activation is independent of activity in nearby locomotor promoting glutamatergic Cuneiform neurons. Our observations point to caudal glutamatergic PPN neurons as a potential target for neuromodulatory restoration of locomotor function in PD. Here, the authors use cell-type specific stimulation of brainstem neurons within the caudal pedunculopontine nucleus to show that activation of excitatory neurons can normalize severe locomotor deficit in mouse models of parkinsonism. The study defines a potential target for neuromodulatory restoration of locomotor function in Parkinson’s disease.
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Affiliation(s)
- Débora Masini
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Ole Kiehn
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark. .,Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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19
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Isa K, Tokuoka K, Ikeda S, Karimi S, Kobayashi K, Sooksawate T, Isa T. Amygdala Underlies the Environment Dependency of Defense Responses Induced via Superior Colliculus. Front Neural Circuits 2022; 15:768647. [PMID: 35069122 PMCID: PMC8776830 DOI: 10.3389/fncir.2021.768647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/30/2021] [Indexed: 11/13/2022] Open
Abstract
In our previous study, we showed that the defense responses induced by the selective optogenetic activation of the uncrossed output pathway from the deeper layer of the superior colliculus were environment dependent in the mouse. In a small closed box, the stimulus frequently induced flight (fast forward run away) responses, while in a large open field, the stimulus tended to induce backward retreat responses. We tested a hypothesis that the amygdala is involved in such environment dependency of the innate defense responses. For this purpose, we made a bilateral lesion of the amygdala induced by the ibotenic acid injections in male mice. As a result, in the mice with lesions of substantial portions of the basolateral and basomedial complex, the flight responses in the closed box disappeared and retreat responses were mainly induced. The retreat responses on the open platform were unchanged. Classically, the amygdala has been considered to be involved in the memory-dependent contextual modulation of the fear responses. In contrast, the present results suggest a novel view on the role of the amygdala in which the amygdala plays a key role in sensing the current environmental setting for making a quick decision of action upon emergency, which is critical for survival in the natural environment.
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Affiliation(s)
- Kaoru Isa
- Department of Neuroscience, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kota Tokuoka
- Department of Neuroscience, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Sakura Ikeda
- Department of Neuroscience, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Sara Karimi
- Department of Neuroscience, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Physiology Research Center, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki, Japan
| | - Thongchai Sooksawate
- Department of Neuroscience, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Department of Pharmacology and Physiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, Thailand
- *Correspondence: Tadashi Isa
| | - Tadashi Isa
- Department of Neuroscience, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Human Brain Research Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto, Japan
- Thongchai Sooksawate
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20
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Abstract
Locomotion is a universal motor behavior that is expressed as the output of many integrated brain functions. Locomotion is organized at several levels of the nervous system, with brainstem circuits acting as the gate between brain areas regulating innate, emotional, or motivational locomotion and executive spinal circuits. Here we review recent advances on brainstem circuits involved in controlling locomotion. We describe how delineated command circuits govern the start, speed, stop, and steering of locomotion. We also discuss how these pathways interface between executive circuits in the spinal cord and diverse brain areas important for context-specific selection of locomotion. A recurrent theme is the need to establish a functional connectome to and from brainstem command circuits. Finally, we point to unresolved issues concerning the integrated function of locomotor control. Expected final online publication date for the Annual Review of Neuroscience, Volume 45 is July 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Roberto Leiras
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jared M. Cregg
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ole Kiehn
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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21
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Abstract
When animals walk overground, mechanical stimuli activate various receptors located in muscles, joints, and skin. Afferents from these mechanoreceptors project to neuronal networks controlling locomotion in the spinal cord and brain. The dynamic interactions between the control systems at different levels of the neuraxis ensure that locomotion adjusts to its environment and meets task demands. In this article, we describe and discuss the essential contribution of somatosensory feedback to locomotion. We start with a discussion of how biomechanical properties of the body affect somatosensory feedback. We follow with the different types of mechanoreceptors and somatosensory afferents and their activity during locomotion. We then describe central projections to locomotor networks and the modulation of somatosensory feedback during locomotion and its mechanisms. We then discuss experimental approaches and animal models used to investigate the control of locomotion by somatosensory feedback before providing an overview of the different functional roles of somatosensory feedback for locomotion. Lastly, we briefly describe the role of somatosensory feedback in the recovery of locomotion after neurological injury. We highlight the fact that somatosensory feedback is an essential component of a highly integrated system for locomotor control. © 2021 American Physiological Society. Compr Physiol 11:1-71, 2021.
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Affiliation(s)
- Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Quebec, Canada
| | - Turgay Akay
- Department of Medical Neuroscience, Atlantic Mobility Action Project, Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Boris I Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
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22
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Noga BR, Guest JD. Combined neuromodulatory approaches in the central nervous system for treatment of spinal cord injury. Curr Opin Neurol 2021; 34:804-811. [PMID: 34593718 PMCID: PMC8595808 DOI: 10.1097/wco.0000000000000999] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW To report progress in neuromodulation following spinal cord injury (SCI) using combined brain and spinal neuromodulation.Neuromodulation refers to alterations in neuronal activity for therapeutic purposes. Beneficial effects are established in disease states such as Parkinson's Disease (PD), chronic pain, epilepsy, and SCI. The repertoire of neuromodulation and bioelectric medicine is rapidly expanding. After SCI, cohort studies have reported the benefits of epidural stimulation (ES) combined with training. Recently, we have explored combining ES with deep brain stimulation (DBS) to increase activation of descending motor systems to address limitations of ES in severe SCI. In this review, we describe the types of applied neuromodulation that could be combined in SCI to amplify efficacy to enable movement. These include ES, mesencephalic locomotor region (MLR) - DBS, noninvasive transcutaneous stimulation, transcranial magnetic stimulation, paired-pulse paradigms, and neuromodulatory drugs. We examine immediate and longer-term effects and what is known about: (1) induced neuroplastic changes, (2) potential safety concerns; (3) relevant outcome measures; (4) optimization of stimulation; (5) therapeutic limitations and prospects to overcome these. RECENT FINDINGS DBS of the mesencephalic locomotor region is emerging as a potential clinical target to amplify supraspinal command circuits for locomotion. SUMMARY Combinations of neuromodulatory methods may have additive value for restoration of function after spinal cord injury.
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Affiliation(s)
- Brian R Noga
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
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23
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Zhang H, Liu Y, Zhou K, Wei W, Liu Y. Restoring Sensorimotor Function Through Neuromodulation After Spinal Cord Injury: Progress and Remaining Challenges. Front Neurosci 2021; 15:749465. [PMID: 34720867 PMCID: PMC8551759 DOI: 10.3389/fnins.2021.749465] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/13/2021] [Indexed: 12/27/2022] Open
Abstract
Spinal cord injury (SCI) is a major disability that results in motor and sensory impairment and extensive complications for the affected individuals which not only affect the quality of life of the patients but also result in a heavy burden for their families and the health care system. Although there are few clinically effective treatments for SCI, research over the past few decades has resulted in several novel treatment strategies which are related to neuromodulation. Neuromodulation-the use of neuromodulators, electrical stimulation or optogenetics to modulate neuronal activity-can substantially promote the recovery of sensorimotor function after SCI. Recent studies have shown that neuromodulation, in combination with other technologies, can allow paralyzed patients to carry out intentional, controlled movement, and promote sensory recovery. Although such treatments hold promise for completely overcoming SCI, the mechanisms by which neuromodulation has this effect have been difficult to determine. Here we review recent progress relative to electrical neuromodulation and optogenetics neuromodulation. We also examine potential mechanisms by which these methods may restore sensorimotor function. We then highlight the strengths of these approaches and remaining challenges with respect to its application.
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Affiliation(s)
- Hui Zhang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Yaping Liu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Kai Zhou
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Wei Wei
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Yaobo Liu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
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24
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Optogenetic stimulation of glutamatergic neurons in the cuneiform nucleus controls locomotion in a mouse model of Parkinson's disease. Proc Natl Acad Sci U S A 2021; 118:2110934118. [PMID: 34670837 DOI: 10.1073/pnas.2110934118] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2021] [Indexed: 01/22/2023] Open
Abstract
In Parkinson's disease (PD), the loss of midbrain dopaminergic cells results in severe locomotor deficits, such as gait freezing and akinesia. Growing evidence indicates that these deficits can be attributed to the decreased activity in the mesencephalic locomotor region (MLR), a brainstem region controlling locomotion. Clinicians are exploring the deep brain stimulation of the MLR as a treatment option to improve locomotor function. The results are variable, from modest to promising. However, within the MLR, clinicians have targeted the pedunculopontine nucleus exclusively, while leaving the cuneiform nucleus unexplored. To our knowledge, the effects of cuneiform nucleus stimulation have never been determined in parkinsonian conditions in any animal model. Here, we addressed this issue in a mouse model of PD, based on the bilateral striatal injection of 6-hydroxydopamine, which damaged the nigrostriatal pathway and decreased locomotor activity. We show that selective optogenetic stimulation of glutamatergic neurons in the cuneiform nucleus in mice expressing channelrhodopsin in a Cre-dependent manner in Vglut2-positive neurons (Vglut2-ChR2-EYFP mice) increased the number of locomotor initiations, increased the time spent in locomotion, and controlled locomotor speed. Using deep learning-based movement analysis, we found that the limb kinematics of optogenetic-evoked locomotion in pathological conditions were largely similar to those recorded in intact animals. Our work identifies the glutamatergic neurons of the cuneiform nucleus as a potentially clinically relevant target to improve locomotor activity in parkinsonian conditions. Our study should open avenues to develop the targeted stimulation of these neurons using deep brain stimulation, pharmacotherapy, or optogenetics.
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Computational Modeling of Spinal Locomotor Circuitry in the Age of Molecular Genetics. Int J Mol Sci 2021; 22:ijms22136835. [PMID: 34202085 PMCID: PMC8267724 DOI: 10.3390/ijms22136835] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 12/13/2022] Open
Abstract
Neuronal circuits in the spinal cord are essential for the control of locomotion. They integrate supraspinal commands and afferent feedback signals to produce coordinated rhythmic muscle activations necessary for stable locomotion. For several decades, computational modeling has complemented experimental studies by providing a mechanistic rationale for experimental observations and by deriving experimentally testable predictions. This symbiotic relationship between experimental and computational approaches has resulted in numerous fundamental insights. With recent advances in molecular and genetic methods, it has become possible to manipulate specific constituent elements of the spinal circuitry and relate them to locomotor behavior. This has led to computational modeling studies investigating mechanisms at the level of genetically defined neuronal populations and their interactions. We review literature on the spinal locomotor circuitry from a computational perspective. By reviewing examples leading up to and in the age of molecular genetics, we demonstrate the importance of computational modeling and its interactions with experiments. Moving forward, neuromechanical models with neuronal circuitry modeled at the level of genetically defined neuronal populations will be required to further unravel the mechanisms by which neuronal interactions lead to locomotor behavior.
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Hausmann SB, Vargas AM, Mathis A, Mathis MW. Measuring and modeling the motor system with machine learning. Curr Opin Neurobiol 2021; 70:11-23. [PMID: 34116423 DOI: 10.1016/j.conb.2021.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 03/23/2021] [Accepted: 04/18/2021] [Indexed: 12/11/2022]
Abstract
The utility of machine learning in understanding the motor system is promising a revolution in how to collect, measure, and analyze data. The field of movement science already elegantly incorporates theory and engineering principles to guide experimental work, and in this review we discuss the growing use of machine learning: from pose estimation, kinematic analyses, dimensionality reduction, and closed-loop feedback, to its use in understanding neural correlates and untangling sensorimotor systems. We also give our perspective on new avenues, where markerless motion capture combined with biomechanical modeling and neural networks could be a new platform for hypothesis-driven research.
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Affiliation(s)
| | | | - Alexander Mathis
- EPFL, Swiss Federal Institute of Technology, Lausanne, Switzerland.
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