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Perales-López L, Sanz-Esteban I, Jiménez-Antona C, Serrano JI, San-Martín-Gómez A, Vives-Gelabert X, Cano-de-la-Cuerda R. Automatic gait evoking in healthy adults through Vojta's peripheric somatosensory stimulation: a double-blind randomized controlled trial. J Neuroeng Rehabil 2024; 21:174. [PMID: 39354570 DOI: 10.1186/s12984-024-01470-2] [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: 10/10/2023] [Accepted: 09/11/2024] [Indexed: 10/03/2024] Open
Abstract
BACKGROUND To study the effects of different interventions on automatic gait processing in contrast with voluntary gait processing in healthy subjects. METHODS A double-blind randomised controlled trial was designed (120 able-body persons between 18 and 65 years old entered and completed the study), with pre-intervention and post-intervention assessments using the 6-Minute Walk Test (6MWT). The participants were randomly distributed into four groups. Prior to intervention, all participants performed voluntary gait on the ground (VoG) in a calibrated circuit following the 6MWT. The presence of automatic gait (AG) was explored post-intervention without a voluntary demand in the same circuit following the 6MWT. Each group received a different intervention for 30 min: Vojta stimulation, MOTOMED® at no less than 60 revolutions/minute, treadmill walking at 3 km/h, and resting in a chair (control). The main assessment, conducted by a blinded rater, was the difference in distance covered (in meters) during the 6MWT between pre- and post-intervention. Surface electromyography (sEMG) average root mean square (RMS) signals in the right tibialis anterior, right soleus, right rectus femoris, and right biceps femoris were also considered outcome measures. RESULTS The Vojta group was the only one that initiated AG after the intervention (476.4 m ± 57.1 in VoG versus 9.0 m ± 8.9 in AG, p < 0.001) with comparable kinematics and EMG parameters during voluntary gait, except for ankle dorsal flexion. Within the Vojta group, high variability in kinematics, sEMG activity, and distance covered was observed. CONCLUSIONS AG isolation is approachable through Vojta at only one session measurable with the 6MWT without any voluntary gait demand. No automatic gait effects were observed post-intervention in the other groups. TRIAL REGISTRATION NCT04689841 (ClinicalTrials.gov).
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Affiliation(s)
| | - Ismael Sanz-Esteban
- Department of Physiotherapy. Physical Therapy and Health Research Group, Faculty of Sport Sciences, Universidad Europea de Madrid, Madrid, Spain
| | - Camen Jiménez-Antona
- Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Faculty of Health Sciences, Universidad Rey Juan Carlos (URJC), Alcorcón, Madrid, Spain.
| | - J Ignacio Serrano
- Neural and Cognitive Engineering Group (gNeC), Center for Automation and Robotics CSIC- UPM (CAR CSIC-UPM), Madrid, Spain.
| | - Ana San-Martín-Gómez
- Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Faculty of Health Sciences, Universidad Rey Juan Carlos (URJC), Alcorcón, Madrid, Spain
| | | | - Roberto Cano-de-la-Cuerda
- Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Faculty of Health Sciences, Universidad Rey Juan Carlos (URJC), Alcorcón, Madrid, Spain
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Klishko AN, Harnie J, Hanson CE, Rahmati SM, Rybak IA, Frigon A, Prilutsky BI. EFFECTS OF SPINAL TRANSECTION AND LOCOMOTOR SPEED ON MUSCLE SYNERGIES OF THE CAT HINDLIMB. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.19.613891. [PMID: 39345603 PMCID: PMC11429932 DOI: 10.1101/2024.09.19.613891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
It was suggested that during locomotion, the nervous system controls movement by activating groups of muscles, or muscle synergies. Analysis of muscle synergies can reveal the organization of spinal locomotor networks and how it depends on the state of the nervous system, such as before and after spinal cord injury, and on different locomotor conditions, including a change in speed. The goal of this study was to investigate the effects of spinal transection and locomotor speed on hindlimb muscle synergies and their time-dependent activity patterns in adult cats. EMG activities of 15 hindlimb muscles were recorded in 9 adult cats of either sex during tied-belt treadmill locomotion at speeds of 0.4, 0.7, and 1.0 m/s before and after recovery from a low thoracic spinal transection. We determined EMG burst groups using cluster analysis of EMG burst onset and offset times and muscle synergies using non-negative matrix factorization. We found five major EMG burst groups and five muscle synergies in each of six experimental conditions (2 states x 3 speeds). In each case, the synergies accounted for at least 90% of muscle EMG variance. Both spinal transection and locomotion speed modified subgroups of EMG burst groups and the composition and activation patterns of selected synergies. However, these changes did not modify the general organization of muscle synergies. Based on the obtained results, we propose an organization for a pattern formation network of a two-level central pattern generator that can be tested in neuromechanical simulations of spinal circuits controlling cat locomotion.
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Agha MA, Kishore S, McLean DL. Cell-type-specific origins of locomotor rhythmicity at different speeds in larval zebrafish. eLife 2024; 13:RP94349. [PMID: 39287613 PMCID: PMC11407768 DOI: 10.7554/elife.94349] [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] [Indexed: 09/19/2024] Open
Abstract
Different speeds of locomotion require heterogeneous spinal populations, but a common mode of rhythm generation is presumed to exist. Here, we explore the cellular versus synaptic origins of spinal rhythmicity at different speeds by performing electrophysiological recordings from premotor excitatory interneurons in larval zebrafish. Chx10-labeled V2a neurons are divided into at least two morphological subtypes proposed to play distinct roles in timing and intensity control. Consistent with distinct rhythm generating and output patterning functions within the spinal V2a population, we find that descending subtypes are recruited exclusively at slow or fast speeds and exhibit intrinsic cellular properties suitable for rhythmogenesis at those speeds, while bifurcating subtypes are recruited more reliably at all speeds and lack appropriate rhythmogenic cellular properties. Unexpectedly, however, phasic firing patterns during locomotion in rhythmogenic and non-rhythmogenic V2a neurons alike are best explained by distinct modes of synaptic inhibition linked to cell type and speed. At fast speeds reciprocal inhibition in descending V2a neurons supports phasic firing, while recurrent inhibition in bifurcating V2a neurons helps pattern motor output. In contrast, at slow speeds recurrent inhibition in descending V2a neurons supports phasic firing, while bifurcating V2a neurons rely on reciprocal inhibition alone to pattern output. Our findings suggest cell-type-specific, not common, modes of rhythmogenesis generate and coordinate different speeds of locomotion.
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Affiliation(s)
- Moneeza A Agha
- Department of Neurobiology, Northwestern UniversityEvanstonUnited States
- Interdisciplinary Biological Sciences Graduate Program, Northwestern UniversityEvanstonUnited States
| | - Sandeep Kishore
- Department of Neurobiology, Northwestern UniversityEvanstonUnited States
| | - David L McLean
- Department of Neurobiology, Northwestern UniversityEvanstonUnited States
- Interdisciplinary Biological Sciences Graduate Program, Northwestern UniversityEvanstonUnited States
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Rybak IA, Shevtsova NA, Audet J, Yassine S, Markin SN, Prilutsky BI, Frigon A. Operation of spinal sensorimotor circuits controlling phase durations during tied-belt and split-belt locomotion after a lateral thoracic hemisection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.10.612376. [PMID: 39314446 PMCID: PMC11419089 DOI: 10.1101/2024.09.10.612376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
Locomotion is controlled by spinal circuits that interact with supraspinal drives and sensory feedback from the limbs. These sensorimotor interactions are disrupted following spinal cord injury. The thoracic lateral hemisection represents an experimental model of an incomplete spinal cord injury, where connections between the brain and spinal cord are abolished on one side of the cord. To investigate the effects of such an injury on the operation of the spinal locomotor network, we used our computational model of cat locomotion recently published in eLife (Rybak et al., 2024) to investigate and predict changes in cycle and phase durations following a thoracic lateral hemisection during treadmill locomotion in tied-belt (equal left-right speeds) and split-belt (unequal left-right speeds) conditions. In our simulations, the "hemisection" was always applied to the right side. Based on our model, we hypothesized that following hemisection, the contralesional ("intact", left) side of the spinal network is mostly controlled by supraspinal drives, whereas the ipsilesional ("hemisected", right) side is mostly controlled by somatosensory feedback. We then compared the simulated results with those obtained during experiments in adult cats before and after a mid-thoracic lateral hemisection on the right side in the same locomotor conditions. Our experimental results confirmed many effects of hemisection on cat locomotion predicted by our simulations. We show that having the ipsilesional hindlimb step on the slow belt, but not the fast belt, during split-belt locomotion substantially reduces the effects of lateral hemisection. The model provides explanations for changes in temporal characteristics of hindlimb locomotion following hemisection based on altered interactions between spinal circuits, supraspinal drives, and somatosensory feedback.
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Affiliation(s)
- Ilya A Rybak
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19129, USA
| | - Natalia A Shevtsova
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19129, USA
| | - Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Sirine Yassine
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Sergey N Markin
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19129, USA
| | - Boris I Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
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Schapiro KA, Rittenberg JD, Kenngott M, Marder E. I h Block Reveals Separation of Timescales in Pyloric Rhythm Response to Temperature Changes in Cancer borealis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.04.592541. [PMID: 38766157 PMCID: PMC11100622 DOI: 10.1101/2024.05.04.592541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Motor systems operate over a range of frequencies and relative timing (phase). We studied the contribution of the hyperpolarization-activated inward current (Ih) to frequency and phase in the pyloric rhythm of the stomatogastric ganglion (STG) of the crab, Cancer borealis as temperature was altered from 11°C to 21°C. Under control conditions, the frequency of the rhythm increased monotonically with temperature, while the phases of the pyloric dilator (PD), lateral pyloric (LP), and pyloric (PY) neurons remained constant. When we blocked Ih with cesium (Cs+) PD offset, LP onset, and LP offset were all phase advanced in Cs+ at 11°C, and the latter two further advanced as temperature increased. In Cs+ the steady state increase in pyloric frequency with temperature diminished and the Q10 of the pyloric frequency dropped from ~1.75 to ~1.35. Unexpectedly in Cs+, the frequency displayed non-monotonic dynamics during temperature transitions; the frequency initially dropped as temperature increased, then rose once temperature stabilized, creating a characteristic "jag". Interestingly, these jags were still present during temperature transitions in Cs+ when the pacemaker was isolated by picrotoxin, although the temperature-induced change in frequency recovered to control levels. Overall, these data suggest that Ih plays an important role in the ability of this circuit to produce smooth transitory responses and persistent frequency increases by different mechanisms during temperature fluctuations.
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Affiliation(s)
- Kyra A Schapiro
- Volen Center and Biology Department, Brandeis University, Waltham, MA 02454 USA
| | - J D Rittenberg
- Volen Center and Biology Department, Brandeis University, Waltham, MA 02454 USA
| | - Max Kenngott
- Volen Center and Biology Department, Brandeis University, Waltham, MA 02454 USA
| | - Eve Marder
- Volen Center and Biology Department, Brandeis University, Waltham, MA 02454 USA
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Rybak IA, Shevtsova NA, Markin SN, Prilutsky BI, Frigon A. Operation regimes of spinal circuits controlling locomotion and role of supraspinal drives and sensory feedback. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.21.586122. [PMID: 38585778 PMCID: PMC10996463 DOI: 10.1101/2024.03.21.586122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Locomotion in mammals is directly controlled by the spinal neuronal network, operating under the control of supraspinal signals and somatosensory feedback that interact with each other. However, the functional architecture of the spinal locomotor network, its operation regimes, and the role of supraspinal and sensory feedback in different locomotor behaviors, including at different speeds, remain unclear. We developed a computational model of spinal locomotor circuits receiving supraspinal drives and limb sensory feedback that could reproduce multiple experimental data obtained in intact and spinal-transected cats during tied-belt and split-belt treadmill locomotion. We provide evidence that the spinal locomotor network operates in different regimes depending on locomotor speed. In an intact system, at slow speeds (< 0.4 m/s), the spinal network operates in a non-oscillating state-machine regime and requires sensory feedback or external inputs for phase transitions. Removing sensory feedback related to limb extension prevents locomotor oscillations at slow speeds. With increasing speed and supraspinal drives, the spinal network switches to a flexor-driven oscillatory regime and then to a classical half-center regime. Following spinal transection, the model predicts that the spinal network can only operate in the state-machine regime. Our results suggest that the spinal network operates in different regimes for slow exploratory and fast escape locomotor behaviors, making use of different control mechanisms.
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Agha MA, Kishore S, McLean DL. Cell-type-specific origins of locomotor rhythmicity at different speeds in larval zebrafish. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.11.575271. [PMID: 38260357 PMCID: PMC10802601 DOI: 10.1101/2024.01.11.575271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Different speeds of locomotion require heterogeneous spinal populations, but a common mode of rhythm generation is presumed to exist. Here, we explore the cellular versus synaptic origins of spinal rhythmicity at different speeds by performing electrophysiological recordings from premotor excitatory interneurons in larval zebrafish. Chx10-labeled V2a neurons are divided into at least two morphological subtypes proposed to play distinct roles in timing and intensity control. Consistent with distinct rhythm generating and output patterning functions within the spinal V2a population, we find that descending subtypes are recruited exclusively at slow or fast speeds and exhibit intrinsic cellular properties suitable for rhythmogenesis at those speeds, while bifurcating subtypes are recruited more reliably at all speeds and lack appropriate rhythmogenic cellular properties. Unexpectedly, however, phasic firing patterns during locomotion in rhythmogenic and non-rhythmogenic V2a neurons alike are best explained by distinct modes of synaptic inhibition linked to cell-type and speed. At fast speeds reciprocal inhibition in descending V2a neurons supports phasic firing, while recurrent inhibition in bifurcating V2a neurons helps pattern motor output. In contrast, at slow speeds recurrent inhibition in descending V2a neurons supports phasic firing, while bifurcating V2a neurons rely on reciprocal inhibition alone to pattern output. Our findings suggest cell-type-specific, not common, modes of rhythmogenesis generate and coordinate different speeds of locomotion.
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Audet J, Lecomte CG, Harnie J, Yassine S, Al Arab R, Soucy F, Morency C, Mari S, Jéhannin P, Merlet AN, Frigon A. Simultaneous control of forward and backward locomotion by spinal sensorimotor circuits. J Physiol 2024; 602:183-204. [PMID: 38016922 DOI: 10.1113/jp285473] [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: 08/12/2023] [Accepted: 11/01/2023] [Indexed: 11/30/2023] Open
Abstract
Mammals walk in different directions, such as forward and backward. In human infants/adults and decerebrate cats, one leg can walk forward and the other backward simultaneously on a split-belt treadmill, termed hybrid or bidirectional locomotion. The purpose of the present study was to determine if spinal sensorimotor circuits generate hybrid locomotion and if so, how the limbs remain coordinated. We tested hybrid locomotion in 11 intact cats and in five following complete spinal thoracic transection (spinal cats) at three treadmill speeds with the hindlimbs moving forward, backward or bidirectionally. All intact cats generated hybrid locomotion with the forelimbs on a stationary platform. Four of five spinal cats generated hybrid locomotion, also with the forelimbs on a stationary platform, but required perineal stimulation. During hybrid locomotion, intact and spinal cats positioned their forward and backward moving hindlimbs caudal and rostral to the hip, respectively. The hindlimbs maintained consistent left-right out-of-phase alternation in the different stepping directions. Our results suggest that spinal locomotor networks generate hybrid locomotion by following certain rules at phase transitions. We also found that stance duration determined cycle duration in the different locomotor directions/conditions, consistent with a common rhythm-generating mechanism for different locomotor directions. Our findings provide additional insight on how left-right spinal networks and sensory feedback from the limbs interact to coordinate the hindlimbs and provide stability during locomotion in different directions. KEY POINTS: Terrestrial mammals can walk forward and backward, which is controlled in part by spinal sensorimotor circuits. Humans and cats also perform bidirectional or hybrid locomotion on a split-belt treadmill with one leg going forward and the other going backward. We show that cats with a spinal transection can perform hybrid locomotion and maintain left-right out-of-phase coordination, indicating that spinal sensorimotor circuits can perform simultaneous forward and backward locomotion. We also show that the regulation of cycle duration and phase duration is conserved across stepping direction, consistent with a common rhythm-generating mechanism for different stepping directions. The results help us better understand how spinal networks controlling the left and right legs enable locomotion in different directions.
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Affiliation(s)
- Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Charly G Lecomte
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Sirine Yassine
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Rasha Al Arab
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Félix Soucy
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Caroline Morency
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Stephen Mari
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Pierre Jéhannin
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Angèle N Merlet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du Centre Hospitalier de l'Université de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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Lanthier F, Laforge J, Pflieger JF. Influence of the vestibular system on the neonatal motor behaviors in the gray short-tailed opossum ( Monodelphis domestica). IBRO Neurosci Rep 2023; 15:42-49. [PMID: 37415730 PMCID: PMC10320520 DOI: 10.1016/j.ibneur.2023.06.004] [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: 04/30/2023] [Accepted: 06/15/2023] [Indexed: 07/08/2023] Open
Abstract
Marsupials are born very immature yet must be sufficiently autonomous to crawl on the mother's belly, find a teat and attach to it to pursue their development. Sensory inputs are necessary to guide the newborn to a teat and induce attachment. The vestibular system, which perceives gravity and head movements, is one of the senses proposed to guide newborns towards the teats but there are conflicting observations about its functionality at birth (postnatal day (P) 0). To test if the vestibular system of opossum newborns is functional and can influence locomotion, we used two approaches. First, we stimulated the vestibular apparatus in in vitro preparations from opossums aged from P1 to P12 and recorded motor responses: at all ages studied, mechanical pressures applied on the vestibular organs induced spinal roots activity whereas head tilts did not induce forelimb muscle contractions. Second, using immunofluorescence, we assessed the presence of Piezo2, a protein involved in mechanotransduction in vestibular hair cells. Piezo2 labeling was scant in the utricular macula at birth, but observed in all vestibular organs at P7, its intensity increasing up to P14; it seemed to stay the same at P21. Our results indicate that neural pathways from the labyrinth to the spinal cord are already in place around birth but that the vestibular organs are too immature to influence motor activity before the end of the second postnatal week in the opossum. It may be the rule in marsupial species that the vestibular system becomes functional only after birth.
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Affiliation(s)
| | | | - Jean-François Pflieger
- Correspondence to: Département de Sciences biologiques, Université de Montréal, C.P. 6128, Succursale centre-ville, Montréal, QC H3C 3J7, Canada.
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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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Wilson AC, Sweeney LB. Spinal cords: Symphonies of interneurons across species. Front Neural Circuits 2023; 17:1146449. [PMID: 37180760 PMCID: PMC10169611 DOI: 10.3389/fncir.2023.1146449] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 03/23/2023] [Indexed: 05/16/2023] Open
Abstract
Vertebrate movement is orchestrated by spinal inter- and motor neurons that, together with sensory and cognitive input, produce dynamic motor behaviors. These behaviors vary from the simple undulatory swimming of fish and larval aquatic species to the highly coordinated running, reaching and grasping of mice, humans and other mammals. This variation raises the fundamental question of how spinal circuits have changed in register with motor behavior. In simple, undulatory fish, exemplified by the lamprey, two broad classes of interneurons shape motor neuron output: ipsilateral-projecting excitatory neurons, and commissural-projecting inhibitory neurons. An additional class of ipsilateral inhibitory neurons is required to generate escape swim behavior in larval zebrafish and tadpoles. In limbed vertebrates, a more complex spinal neuron composition is observed. In this review, we provide evidence that movement elaboration correlates with an increase and specialization of these three basic interneuron types into molecularly, anatomically, and functionally distinct subpopulations. We summarize recent work linking neuron types to movement-pattern generation across fish, amphibians, reptiles, birds and mammals.
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Affiliation(s)
| | - Lora B. Sweeney
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Lower Austria, Austria
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Li WY, Deng LX, Zhai FG, Wang XY, Li ZG, Wang Y. Chx10+V2a interneurons in spinal motor regulation and spinal cord injury. Neural Regen Res 2022; 18:933-939. [PMID: 36254971 PMCID: PMC9827767 DOI: 10.4103/1673-5374.355746] [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] [Indexed: 11/05/2022] Open
Abstract
Chx10-expressing V2a (Chx10+V2a) spinal interneurons play a large role in the excitatory drive of motoneurons. Chemogenetic ablation studies have demonstrated the essential nature of Chx10+V2a interneurons in the regulation of locomotor initiation, maintenance, alternation, speed, and rhythmicity. The role of Chx10+V2a interneurons in locomotion and autonomic nervous system regulation is thought to be robust, but their precise role in spinal motor regulation and spinal cord injury have not been fully explored. The present paper reviews the origin, characteristics, and functional roles of Chx10+V2a interneurons with an emphasis on their involvement in the pathogenesis of spinal cord injury. The diverse functional properties of these cells have only been substantiated by and are due in large part to their integration in a variety of diverse spinal circuits. Chx10+V2a interneurons play an integral role in conferring locomotion, which integrates various corticospinal, mechanosensory, and interneuron pathways. Moreover, accumulating evidence suggests that Chx10+V2a interneurons also play an important role in rhythmic patterning maintenance, left-right alternation of central pattern generation, and locomotor pattern generation in higher order mammals, likely conferring complex locomotion. Consequently, the latest research has focused on postinjury transplantation and noninvasive stimulation of Chx10+V2a interneurons as a therapeutic strategy, particularly in spinal cord injury. Finally, we review the latest preclinical study advances in laboratory derivation and stimulation/transplantation of these cells as a strategy for the treatment of spinal cord injury. The evidence supports that the Chx10+V2a interneurons act as a new therapeutic target for spinal cord injury. Future optimization strategies should focus on the viability, maturity, and functional integration of Chx10+V2a interneurons transplanted in spinal cord injury foci.
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Affiliation(s)
- Wen-Yuan Li
- Institute of Neural Tissue Engineering, Mudanjiang College of Medicine, Mudanjiang, Heilongjiang Province, China
| | - Ling-Xiao Deng
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Feng-Guo Zhai
- Department of Pharmacy, Mudanjiang College of Medicine, Mudanjiang, Heilongjiang Province, China
| | - Xiao-Yu Wang
- Institute of Neural Tissue Engineering, Mudanjiang College of Medicine, Mudanjiang, Heilongjiang Province, China
| | - Zhi-Gang Li
- Department of General Surgery, Hongqi Hospital, Mudanjiang College of Medicine, Mudanjiang, Heilongjiang Province, China,Correspondence to: Ying Wang, ; Zhi-Gang Li, .
| | - Ying Wang
- Institute of Neural Tissue Engineering, Mudanjiang College of Medicine, Mudanjiang, Heilongjiang Province, China,Correspondence to: Ying Wang, ; Zhi-Gang Li, .
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13
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Merkulyeva N, Lyakhovetskii V, Gorskii O, Musienko P. Differences in backward and forward treadmill locomotion in decerebrated cats. J Exp Biol 2022; 225:jeb244210. [PMID: 35438747 PMCID: PMC9163443 DOI: 10.1242/jeb.244210] [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: 02/28/2022] [Accepted: 04/12/2022] [Indexed: 11/20/2022]
Abstract
Locomotion in different directions is vital for animal life and requires fine-adjusted neural activity of spinal networks. To compare the levels of recruitability of the locomotor circuitry responsible for forward and backward stepping, several electromyographic and kinematic characteristics of the two locomotor modes were analysed in decerebrated cats. Electrical epidural spinal cord stimulation was used to evoke forward and backward locomotion on a treadmill belt. The functional state of the bilateral spinal networks was tuned by symmetrical and asymmetrical epidural stimulation. A significant deficit in the backward but not forward stepping was observed when laterally shifted epidural stimulation was used but was not observed with central stimulation: only half of the cats were able to perform bilateral stepping, but all the cats performed forward stepping. This difference was in accordance with the features of stepping during central epidural stimulation. Both the recruitability and stability of the EMG signals as well as inter-limb coordination during backward stepping were significantly decreased compared with those during forward stepping. The possible underlying neural mechanisms of the obtained functional differences of backward and forward locomotion (spinal network organisation, commissural communication and supraspinal influence) are discussed.
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Affiliation(s)
| | | | - Oleg Gorskii
- Pavlov Institute of Physiology, 199034 St Petersburg, Russia
- Institute of Translational Biomedicine, St Petersburg State University, 199034 St Petersburg, Russia
| | - Pavel Musienko
- Pavlov Institute of Physiology, 199034 St Petersburg, Russia
- Institute of Translational Biomedicine, St Petersburg State University, 199034 St Petersburg, Russia
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14
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Pithapuram MV, Raghavan M. Automatic rule-based generation of spinal cord connectome model for a neuro-musculoskeletal limb in-silico. IOP SCINOTES 2022. [DOI: 10.1088/2633-1357/ac585e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Abstract
Studying spinal interactions with muscles has been of great importance for over a century. However, with surging spinal-related movement pathologies, the need for computational models to study spinal pathways is increasing. Although spinal cord connectome models have been developed, anatomically relevant spinal neuromotor models are rare. However, building and maintaining such models is time consuming. In this study, the concept of the rule-based generation of a spinal connectome was introduced and lumbosacral connectome generation was demonstrated as an example. Furthermore, the rule-based autogenerated connectome models were synchronized with lower-limb musculoskeletal models to create an in-silico test bed. Using this setup, the role of the autogenic Ia-excitatory pathway in controlling the ankle angle was tested.
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15
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Mirkiani S, Roszko DA, O'Sullivan C, Faridi P, Hu DS, Fang D, Everaert DG, Toossi A, Konrad PE, Robinson K, Mushahwar VK. Overground gait kinematics and muscle activation patterns in the Yucatan mini pig. J Neural Eng 2022; 19. [PMID: 35172283 DOI: 10.1088/1741-2552/ac55ac] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/16/2022] [Indexed: 11/12/2022]
Abstract
Objective The objectives of this study were to assess gait biomechanics and the effect of overground walking speed on gait parameters, kinematics, and electromyographic (EMG) activity in the hindlimb muscles of Yucatan Minipigs (YMPs). Approach Nine neurologically-intact, adult YMPs were trained to walk overground in a straight line. Whole-body kinematics and EMG activity of hindlimb muscles were recorded and analyzed at 6 different speed ranges (0.4-0.59, 0.6-0.79, 0.8-0.99, 1.0-1.19, 1.2-1.39, and 1.4-1.6 m/s). A MATLAB program was developed to detect strides and gait events automatically from motion-captured data. The kinematics and EMG activity were analyzed for each stride based on the detected events. Main results Significant decreases in stride duration, stance and swing times and an increase in stride length were observed with increasing speed. A transition in gait pattern occurred at the 1.0m/s walking speed. Significant increases in the range of motion of the knee and ankle joints were observed at higher speeds. Also, the points of minimum and maximum joint angles occurred earlier in the gait cycle as the walking speed increased. The onset of EMG activity in the biceps femoris muscle occurred significantly earlier in the gait cycle with increasing speed. Significance YMPs are becoming frequently used as large animal models for preclinical testing and translation of novel interventions to humans. A comprehensive characterization of overground walking in neurologically-intact YMPs is provided in this study. These normative measures set the basis against which the effects of future interventions on locomotor capacity in YMPs can be compared.
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Affiliation(s)
- Soroush Mirkiani
- Neuroscience & Mental Health Institute and Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, 5005 Katz Building, University of Alberta, Edmonton, Alberta, T6G 2R3, CANADA
| | - David A Roszko
- Neuroscience & Mental Health Institute and Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, 5005 Katz Building, Edmonton, Alberta, T6G 2R3, CANADA
| | - Carly O'Sullivan
- Neuroscience & Mental Health Institute and Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, 5005 Katz, Building, Edmonton, Alberta, T6G 2R3, CANADA
| | - Pouria Faridi
- Neuroscience & Mental Health Institute and Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, 5005 Katz Building, Edmonton, Alberta, T6G 2R3, CANADA
| | - David S Hu
- Department of Medicine and Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, 5005 Katz Building, Edmonton, Alberta, T6G 2R3, CANADA
| | - Daniel Fang
- Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, 5005 Katz Building, Edmonton, Alberta, T6G 2R3, CANADA
| | - Dirk G Everaert
- Department of Medicine and Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, 5005 Katz Building, Edmonton, Alberta, T6G 2R3, CANADA
| | - Amirali Toossi
- Neuroscience & Mental Health Institute and Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, 5005 Katz Building, Edmonton, Alberta, T6G 2R3, CANADA
| | - Peter E Konrad
- Department of Neurosurgery, West Virginia University, PO Box 9183, Morgantown, West Virginia, 26506, UNITED STATES
| | - Kevin Robinson
- School of Physical Therapy, Belmont University, 341 McWhorter Hall, Nashville, Tennessee, 37212, UNITED STATES
| | - Vivian K Mushahwar
- Department of Medicine and Sensory Motor Adaptive Rehabilitation Technology (SMART) Network, University of Alberta, 5005 Katz Building, University of Alberta, Edmonton, Alberta, T6G 2R3, CANADA
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16
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Samadzadeh S, Hefter H, Tezayak O, Rosenthal D. Analysis of Running in Wilson's Disease. Sports (Basel) 2022; 10:sports10010011. [PMID: 35050976 PMCID: PMC8822897 DOI: 10.3390/sports10010011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/30/2021] [Accepted: 01/05/2022] [Indexed: 02/04/2023] Open
Abstract
Aim of the study was to analyze the ability of long-term treated patients with Wilson’s disease (WD) to run a distance of 40 m. 30 WD-patients from a single center were consecutively recruited. All patients were able to walk a distance of 40 m without walking aids. Vertical ground reaction forces (GRF-curves) were analyzed by means of an Infotronic® gait analysis system (CDG®) and correlated with clinical and laboratory findings. Results of the WD-patients were compared to those of an age-and sex-matched control group. 25 of the 30 WD-patients were able to run. Patients being unable to run had a significantly (p < 0.03) higher non-motor score. In comparison to the controls speed of running was significantly (p < 0.02) reduced in WD-patients. Their duration of foot contact on the ground lasted significantly (p < 0.05) longer. Running was more irregular in WD and the variability of times to peak of the GRF-curves was significantly (p < 0.05) increased. All running parameters extracted from the GRF-curves of the CDG® did not correlate with severity of WD. Cadence of running was significantly (p < 0.03) negatively correlated with serum liver enzyme levels. Running appears to be rather unimpaired in long-term treated WD, only 16% of the 30 WD-patients were unable to run. This knowledge is highly relevant for the patient management, but because of the missing correlation with severity of WD, analysis of running is of minor importance for monitoring WD-therapy.
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Affiliation(s)
- Sara Samadzadeh
- Department of Neurology, University of Düsseldorf, 40225 Düsseldorf, Germany; (S.S.); (O.T.); (D.R.)
| | - Harald Hefter
- Department of Neurology, University of Düsseldorf, 40225 Düsseldorf, Germany; (S.S.); (O.T.); (D.R.)
- Correspondence: ; Tel.: +49-211-811-7025; Fax: +49-211-810-4903
| | - Osman Tezayak
- Department of Neurology, University of Düsseldorf, 40225 Düsseldorf, Germany; (S.S.); (O.T.); (D.R.)
- Department of Psychiatry, Psychiatriezentrum Kreuzlingen, 8280 Kreuzlingen, Switzerland
| | - Dietmar Rosenthal
- Department of Neurology, University of Düsseldorf, 40225 Düsseldorf, Germany; (S.S.); (O.T.); (D.R.)
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17
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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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18
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Hachmann JT, Yousak A, Wallner JJ, Gad PN, Edgerton VR, Gorgey AS. Epidural spinal cord stimulation as an intervention for motor recovery after motor complete spinal cord injury. J Neurophysiol 2021; 126:1843-1859. [PMID: 34669485 DOI: 10.1152/jn.00020.2021] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 10/12/2021] [Indexed: 12/19/2022] Open
Abstract
Spinal cord injury (SCI) commonly results in permanent loss of motor, sensory, and autonomic function. Recent clinical studies have shown that epidural spinal cord stimulation may provide a beneficial adjunct for restoring lower extremity and other neurological functions. Herein, we review the recent clinical advances of lumbosacral epidural stimulation for restoration of sensorimotor function in individuals with motor complete SCI and we discuss the putative neural pathways involved in this promising neurorehabilitative approach. We focus on three main sections: review recent clinical results for locomotor restoration in complete SCI; discuss the contemporary understanding of electrical neuromodulation and signal transduction pathways involved in spinal locomotor networks; and review current challenges of motor system modulation and future directions toward integrative neurorestoration. The current understanding is that initial depolarization occurs at the level of large diameter dorsal root proprioceptive afferents that when integrated with interneuronal and latent residual supraspinal translesional connections can recruit locomotor centers and augment downstream motor units. Spinal epidural stimulation can initiate excitability changes in spinal networks and supraspinal networks. Different stimulation parameters can facilitate standing or stepping, and it may also have potential for augmenting myriad other sensorimotor and autonomic functions. More comprehensive investigation of the mechanisms that mediate the transformation of dysfunctional spinal networks to higher functional states with a greater focus on integrated systems-based control system may reveal the key mechanisms underlying neurological augmentation and motor restoration after severe paralysis.
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Affiliation(s)
- Jan T Hachmann
- Department of Neurological Surgery, Virginia Commonwealth University, Richmond, Virginia
| | - Andrew Yousak
- Spinal Cord Injury and Disorders Center, Hunter Holmes McGuire VAMC, Richmond, Virginia
| | - Josephine J Wallner
- Spinal Cord Injury and Disorders Center, Hunter Holmes McGuire VAMC, Richmond, Virginia
| | - Parag N Gad
- Department of Neurobiology, University of California, Los Angeles, California
| | - V Reggie Edgerton
- Department of Neurobiology, University of California, Los Angeles, California
- Fundación Institut Guttmann, Institut Universitari de Neurorehabilitació Badalona, Barcelona, Spain
| | - Ashraf S Gorgey
- Spinal Cord Injury and Disorders Center, Hunter Holmes McGuire VAMC, Richmond, Virginia
- Physical Medicine and Rehabilitation, Virginia Commonwealth University, Richmond, Virginia
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19
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Abstract
The olfactory system allows animals to navigate in their environment to feed, mate, and escape predators. It is well established that odorant exposure or electrical stimulation of the olfactory system induces stereotyped motor responses in fishes. However, the neural circuitry responsible for the olfactomotor transformations is only beginning to be unraveled. A neural substrate eliciting motor responses to olfactory inputs was identified in the lamprey, a basal vertebrate used extensively to examine the neural mechanisms underlying sensorimotor transformations. Two pathways were discovered from the olfactory organ in the periphery to the brainstem motor nuclei responsible for controlling swimming. The first pathway originates from sensory neurons located in the accessory olfactory organ and reaches a single population of projection neurons in the medial olfactory bulb, which, in turn, transmit the olfactory signals to the posterior tuberculum and then to downstream brainstem locomotor centers. A second pathway originates from the main olfactory epithelium and reaches the main olfactory bulb, the neurons of which project to the pallium/cortex. The olfactory signals are then conveyed to the posterior tuberculum and then to brainstem locomotor centers. Olfactomotor behavior can adapt, and studies were aimed at defining the underlying neural mechanisms. Modulation of bulbar neural activity by GABAergic, dopaminergic, and serotoninergic inputs is likely to provide strong control over the hardwired circuits to produce appropriate motor behavior in response to olfactory cues. This review summarizes current knowledge relative to the neural circuitry producing olfactomotor behavior in lampreys and their modulatory mechanisms.
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20
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Boulain M, Khsime I, Sourioux M, Thoby-Brisson M, Barrière G, Simmers J, Morin D, Juvin L. Synergistic interaction between sensory inputs and propriospinal signalling underlying quadrupedal locomotion. J Physiol 2021; 599:4477-4496. [PMID: 34412148 DOI: 10.1113/jp281861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 08/05/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Stimulation of hindlimb afferent fibres can both stabilize and increase the activity of fore- and hindlimb motoneurons during fictive locomotion. The increase in motoneuron activity is at least partially due to the production of doublets of action potentials in a subpopulation of motoneurons. These results were obtained using an in vitro brainstem/spinal cord preparation of neonatal rat. ABSTRACT Quadrupedal locomotion relies on a dynamic coordination between central pattern generators (CPGs) located in the cervical and lumbar spinal cord, and controlling the fore- and hindlimbs, respectively. It is assumed that this CPG interaction is achieved through separate closed-loop processes involving propriospinal and sensory pathways. However, the functional consequences of a concomitant involvement of these different influences on the degree of coordination between the fore- and hindlimb CPGs is still largely unknown. Using an in vitro brainstem/spinal cord preparation of neonatal rat, we found that rhythmic, bilaterally alternating stimulation of hindlimb sensory input pathways elicited coordinated hindlimb and forelimb CPG activity. During pharmacologically induced fictive locomotion, lumbar dorsal root (DR) stimulation entrained and stabilized an ongoing cervico-lumbar locomotor-like rhythm and increased the amplitude of both lumbar and cervical ventral root bursting. The increase in cervical burst amplitudes was correlated with the occurrence of doublet action potential firing in a subpopulation of motoneurons, enabling the latter to transition between low and high frequency discharge according to the intensity of DR stimulation. Moreover, our data revealed that propriospinal and sensory pathways act synergistically to strengthen cervico-lumbar interactions. Indeed, split-bath experiments showed that fully coordinated cervico-lumbar fictive locomotion was induced by combining pharmacological stimulation of either the lumbar or cervical CPGs with lumbar DR stimulation. This study thus highlights the powerful interactions between sensory and propriospinal pathways which serve to ensure the coupling of the fore- and hindlimb CPGs for effective quadrupedal locomotion.
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Affiliation(s)
- Marie Boulain
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, CNRS, Université de Bordeaux, CNRS, EPHE, INCIA, UMR5287 F-33000, Bordeaux, France
| | - Inès Khsime
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, CNRS, Université de Bordeaux, CNRS, EPHE, INCIA, UMR5287 F-33000, Bordeaux, France
| | - Mélissa Sourioux
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, CNRS, Université de Bordeaux, CNRS, EPHE, INCIA, UMR5287 F-33000, Bordeaux, France
| | - Muriel Thoby-Brisson
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, CNRS, Université de Bordeaux, CNRS, EPHE, INCIA, UMR5287 F-33000, Bordeaux, France
| | - Grégory Barrière
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, CNRS, Université de Bordeaux, CNRS, EPHE, INCIA, UMR5287 F-33000, Bordeaux, France
| | - John Simmers
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, CNRS, Université de Bordeaux, CNRS, EPHE, INCIA, UMR5287 F-33000, Bordeaux, France
| | - Didier Morin
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, CNRS, Université de Bordeaux, CNRS, EPHE, INCIA, UMR5287 F-33000, Bordeaux, France
| | - Laurent Juvin
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Unité Mixte de Recherche 5287, CNRS, Université de Bordeaux, CNRS, EPHE, INCIA, UMR5287 F-33000, Bordeaux, France
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21
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Merlet AN, Harnie J, Frigon A. Inhibition and Facilitation of the Spinal Locomotor Central Pattern Generator and Reflex Circuits by Somatosensory Feedback From the Lumbar and Perineal Regions After Spinal Cord Injury. Front Neurosci 2021; 15:720542. [PMID: 34393721 PMCID: PMC8355562 DOI: 10.3389/fnins.2021.720542] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 07/08/2021] [Indexed: 02/03/2023] Open
Abstract
Somatosensory feedback from peripheral receptors dynamically interacts with networks located in the spinal cord and brain to control mammalian locomotion. Although somatosensory feedback from the limbs plays a major role in regulating locomotor output, those from other regions, such as lumbar and perineal areas also shape locomotor activity. In mammals with a complete spinal cord injury, inputs from the lumbar region powerfully inhibit hindlimb locomotion, while those from the perineal region facilitate it. Our recent work in cats with a complete spinal cord injury shows that they also have opposite effects on cutaneous reflexes from the foot. Lumbar inputs increase the gain of reflexes while those from the perineal region decrease it. The purpose of this review is to discuss how somatosensory feedback from the lumbar and perineal regions modulate the spinal locomotor central pattern generator and reflex circuits after spinal cord injury and the possible mechanisms involved. We also discuss how spinal cord injury can lead to a loss of functional specificity through the abnormal activation of functions by somatosensory feedback, such as the concurrent activation of locomotion and micturition. Lastly, we discuss the potential functions of somatosensory feedback from the lumbar and perineal regions and their potential for promoting motor recovery after spinal cord injury.
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Affiliation(s)
- Angèle N Merlet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, QC, Canada
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22
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Chambers V, Artemiadis P. A Model-Based Analysis of Supraspinal Mechanisms of Inter-Leg Coordination in Human Gait: Toward Model-Informed Robot-Assisted Rehabilitation. IEEE Trans Neural Syst Rehabil Eng 2021; 29:740-749. [PMID: 33844630 DOI: 10.1109/tnsre.2021.3072771] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Stroke survivors are often left suffering from gait instability due to hemiparesis. This gait dysfunction can lead to higher fall rates and an overall decrease in quality of life. Though there are many post-stroke gait rehabilitation methods in use currently, none of them allow patients to regain complete functionality. Interlimb coordination is one of the main mechanisms of walking and is usually overlooked in most post-stroke gait rehabilitation protocols. This work attempts to help further understand the mechanism of interlimb coordination and how the brain is involved in it, studying the contralateral response to unilateral stiffness perturbations. A unique robotic device, the Variable Stiffness Treadmill (VST), is used in conjunction with a pre-established neuromuscular gait model to analyze for the first time the supraspinal control mechanisms involved in inter-leg coordination induced after unilateral perturbations. The attempt to explain the observed kinematic and muscular activation data via the gait model results in the identification of two control variables that seem to play an important role in gait stability and recovery after perturbations: the target angle of attack and target hip to ankle span. This is significant because these two parameters are directly related to longer stride length and larger foot clearance during swing phase. Both variables work toward correcting common issues with hemiparetic gait, such as a shorter stride and toe drag during swing phase of the paretic leg. The results of this work could aid in the design of future model-based stroke rehabilitation methods that would perturb the subject in a systematic way and allow targeted interventions with specific functional outcomes on gait. Additionally, this work-along with future studies-could assist in improving controllers for robust bipedal robots as well as our understanding of how the brain controls balance during perturbed walking.
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23
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Ramalingasetty ST, Danner SM, Arreguit J, Markin SN, Rodarie D, Kathe C, Courtine G, Rybak IA, Ijspeert AJ. A Whole-Body Musculoskeletal Model of the Mouse. IEEE ACCESS : PRACTICAL INNOVATIONS, OPEN SOLUTIONS 2021; 9:163861-163881. [PMID: 35211364 PMCID: PMC8865483 DOI: 10.1109/access.2021.3133078] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Neural control of movement cannot be fully understood without careful consideration of interactions between the neural and biomechanical components. Recent advancements in mouse molecular genetics allow for the identification and manipulation of constituent elements underlying the neural control of movement. To complement experimental studies and investigate the mechanisms by which the neural circuitry interacts with the body and the environment, computational studies modeling motor behaviors in mice need to incorporate a model of the mouse musculoskeletal system. Here, we present the first fully articulated musculoskeletal model of the mouse. The mouse skeletal system has been developed from anatomical references and includes the sets of bones in all body compartments, including four limbs, spine, head and tail. Joints between all bones allow for simulation of full 3D mouse kinematics and kinetics. Hindlimb and forelimb musculature has been implemented using Hill-type muscle models. We analyzed the mouse whole-body model and described the moment-arms for different hindlimb and forelimb muscles, the moments applied by these muscles on the joints, and their involvement in limb movements at different limb/body configurations. The model represents a necessary step for the subsequent development of a comprehensive neuro-biomechanical model of freely behaving mice; this will close the loop between the neural control and the physical interactions between the body and the environment.
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Affiliation(s)
- Shravan Tata Ramalingasetty
- Biorobotic Laboratory (BioRob), School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Simon M. Danner
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA 19104, USA
| | - Jonathan Arreguit
- Biorobotic Laboratory (BioRob), School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Sergey N. Markin
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA 19104, USA
| | - Dimitri Rodarie
- BBP-CORE, Campus Biotech, École Polytechnique Fédérale de Lausanne, 1202 Geneva, Switzerland
| | - Claudia Kathe
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Grégoire Courtine
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Ilya A. Rybak
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA 19104, USA
| | - Auke Jan Ijspeert
- Biorobotic Laboratory (BioRob), School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
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24
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Gordon JC, Holt NC, Biewener A, Daley MA. Tuning of feedforward control enables stable muscle force-length dynamics after loss of autogenic proprioceptive feedback. eLife 2020; 9:53908. [PMID: 32573432 PMCID: PMC7334023 DOI: 10.7554/elife.53908] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 06/12/2020] [Indexed: 12/11/2022] Open
Abstract
Animals must integrate feedforward, feedback and intrinsic mechanical control mechanisms to maintain stable locomotion. Recent studies of guinea fowl (Numida meleagris) revealed that the distal leg muscles rapidly modulate force and work output to minimize perturbations in uneven terrain. Here we probe the role of reflexes in the rapid perturbation responses of muscle by studying the effects of proprioceptive loss. We induced bilateral loss of autogenic proprioception in the lateral gastrocnemius muscle (LG) using self-reinnervation. We compared in vivo muscle dynamics and ankle kinematics in birds with reinnervated and intact LG. Reinnervated and intact LG exhibit similar steady state mechanical function and similar work modulation in response to obstacle encounters. Reinnervated LG exhibits 23ms earlier steady-state activation, consistent with feedforward tuning of activation phase to compensate for lost proprioception. Modulation of activity duration is impaired in rLG, confirming the role of reflex feedback in regulating force duration in intact muscle.
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Affiliation(s)
- Joanne C Gordon
- Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, United Kingdom
| | - Natalie C Holt
- Evolution, Ecology & Organismal Biology, University of California, Riverside, Riverside, United States
| | - Andrew Biewener
- Organismic and Evolutionary Biology, Harvard University, Cambridge, Cambridge, United States
| | - Monica A Daley
- Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, United Kingdom.,Ecology and Evolutionary Biology, University of California, Irvine, Irvine, United States
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25
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Akay T. Sensory Feedback Control of Locomotor Pattern Generation in Cats and Mice. Neuroscience 2020; 450:161-167. [PMID: 32422335 DOI: 10.1016/j.neuroscience.2020.05.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/31/2020] [Accepted: 05/05/2020] [Indexed: 01/02/2023]
Abstract
Traditionally, research aimed at the understanding of the sensory control of terrestrial mammalian locomotion has focused on cats as the animal model. But advances in molecular genetics and new methods to record movement in small animals have moved mice into the forefront of locomotor research. In this review article, I will first give an overview of what is known about sensory feedback control of locomotion, mainly emerged from experiments performed on cats. This overview will not be an exhaustive overview, but will rather aim to give a broad picture of what has been learned about the sensory control of locomotion using cats as the animal model. I will then give a brief summary of how the mouse is adding to these insights.
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Affiliation(s)
- Turgay Akay
- Dalhousie University, Dept. of Medical Neuroscience, Atlantic Mobility Action Project, Brain Repair Center, Halifax, NS, Canada.
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26
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Asymmetric Control of Coexisting Slow and Fast Rhythms in a Multifunctional Central Pattern Generator: A Model Study. NEUROPHYSIOLOGY+ 2020. [DOI: 10.1007/s11062-020-09834-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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27
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Pearcey GEP, Zehr EP. We Are Upright-Walking Cats: Human Limbs as Sensory Antennae During Locomotion. Physiology (Bethesda) 2020; 34:354-364. [PMID: 31389772 DOI: 10.1152/physiol.00008.2019] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Humans and cats share many characteristics pertaining to the neural control of locomotion, which has enabled the comprehensive study of cutaneous feedback during locomotion. Feedback from discrete skin regions on both surfaces of the human foot has revealed that neuromechanical responses are highly topographically organized and contribute to "sensory guidance" of our limbs during locomotion.
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Affiliation(s)
- Gregory E P Pearcey
- Rehabilitation Neuroscience Laboratory, University of Victoria, Victoria, British Columbia, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, British Columbia, Canada.,Centre for Biomedical Research, University of Victoria, Victoria, British Columbia, Canada
| | - E Paul Zehr
- Rehabilitation Neuroscience Laboratory, University of Victoria, Victoria, British Columbia, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, British Columbia, Canada.,Centre for Biomedical Research, University of Victoria, Victoria, British Columbia, Canada.,Division of Medical Sciences, University of Victoria, British Columbia, Canada.,Zanshin Consulting, Inc., Victoria, British Columbia, Canada
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28
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Schmitz J, Gruhn M, Büschges A. Body side-specific changes in sensorimotor processing of movement feedback in a walking insect. J Neurophysiol 2019; 122:2173-2186. [PMID: 31553676 PMCID: PMC6879953 DOI: 10.1152/jn.00436.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/29/2019] [Accepted: 09/14/2019] [Indexed: 01/19/2023] Open
Abstract
Feedback from load and movement sensors can modify timing and magnitude of the motor output in the stepping stick insect. One source of feedback is stretch reception by the femoral chordotonal organ (fCO), which encodes such parameters as the femorotibial (FTi) joint angle, the angular velocity, and its acceleration. Stimulation of the fCO causes a postural resistance reflex, during quiescence, and can elicit the opposite, so-called active reaction (AR), which assists ongoing flexion during active movements. In the present study, we investigated the role of fCO feedback for the difference in likelihood of generating ARs on the inside vs. the outside during curve stepping. We analyzed the effects of fCO stimulation on the motor output to the FTi and the neighboring coxa-trochanter and thorax-coxa joints of the middle leg. In inside and outside turns, the probability for ARs increases with increasing starting angle and decreasing stimulus velocity; furthermore, it is independent of the total angular excursion. However, the transition between stance and swing motor activity always occurs after a specific angular excursion, independent of the turning direction. Feedback from the fCO also has an excitatory influence on levator trochanteris motoneurons (MNs) during inside and outside turns, whereas the same feedback affects protractor coxae MNs only during outside steps. Our results suggest joint- and body side-dependent processing of fCO feedback. A shift in gain may be responsible for different AR probabilities between inside and outside turning, whereas the general control mechanism for ARs is unchanged.NEW & NOTEWORTHY We show that parameters of movement feedback from the tibia in an insect during curve walking are processed in a body side-specific manner, and how. From our results it is highly conceivable that the difference in motor response to the feedback supports the body side-specific leg kinematics during turning. Future studies will need to determine the source for the inputs that determine the local changes in sensory-motor processing.
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Affiliation(s)
- Joscha Schmitz
- Department for Animal Physiology, Institute for Zoology, Biocenter Cologne, University of Cologne, Cologne, Germany
| | - Matthias Gruhn
- Department for Animal Physiology, Institute for Zoology, Biocenter Cologne, University of Cologne, Cologne, Germany
| | - Ansgar Büschges
- Department for Animal Physiology, Institute for Zoology, Biocenter Cologne, University of Cologne, Cologne, Germany
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29
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Li EZ, Garcia-Ramirez DL, Dougherty KJ. Flexor and Extensor Ankle Afferents Broadly Innervate Locomotor Spinal Shox2 Neurons and Induce Similar Effects in Neonatal Mice. Front Cell Neurosci 2019; 13:452. [PMID: 31649510 PMCID: PMC6794418 DOI: 10.3389/fncel.2019.00452] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 09/20/2019] [Indexed: 01/03/2023] Open
Abstract
Central pattern generators (CPGs) in the thoracolumbar spinal cord generate the basic hindlimb locomotor pattern. The locomotor CPG integrates descending commands and sensory information from the periphery to activate, modulate and halt the rhythmic program. General CPG function and response to sensory perturbations are well described in cat and rat models. In mouse, roles for many genetically identified spinal interneurons have been inferred from locomotor alterations following population deletion or modulation. However, the organization of afferent input to specific genetically identified populations of spinal CPG interneurons in mouse remains comparatively less resolved. Here, we focused on a population of CPG neurons marked by the transcription factor Shox2. To directly test integration of afferent signaling by Shox2 neurons, sensory afferents were stimulated during patch clamp recordings of Shox2 neurons in isolated spinal cord preparations from neonatal mice. Shox2 neurons broadly displayed afferent-evoked currents at multiple segmental levels, particularly from caudal dorsal roots innervating distal hindlimb joints. As dorsal root stimulation may activate both flexor- and extensor-related afferents, preparations preserving peripheral nerves were used to provide more specific activation of ankle afferents. We found that both flexor- and extensor-related afferent stimulation were likely to evoke similar currents in a given Shox2 neuron, as assessed by response polarity, latency, duration and amplitude. It has been proposed that Shox2 neurons can be divided into neurons which contribute to rhythm generation and neurons that are premotor by the absence and presence of the V2a marker Chx10, respectively. Response to afferent stimulation did not differ based on Chx10 expression. Although currents evoked in response to flexor and extensor afferent activation did not follow expected functional antagonism, they were consistent with the observation that stimulation of flexor- and extensor-related afferents both reset the phase of ongoing fictive locomotion to flexion in neonatal mice. Together, the data suggest that Shox2 neurons are interposed in multiple sensory pathways and low threshold proprioceptive input reinforces sensory perturbation of ongoing locomotion by similarly activating or inhibiting both the rhythm and patterning layers of the CPG.
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Affiliation(s)
- Erik Z Li
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
| | - D Leonardo Garcia-Ramirez
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Kimberly J Dougherty
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
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30
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Hierarchical control of locomotion by distinct types of spinal V2a interneurons in zebrafish. Nat Commun 2019; 10:4197. [PMID: 31519892 PMCID: PMC6744451 DOI: 10.1038/s41467-019-12240-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/29/2019] [Indexed: 12/15/2022] Open
Abstract
In all vertebrates, excitatory spinal interneurons execute dynamic adjustments in the timing and amplitude of locomotor movements. Currently, it is unclear whether interneurons responsible for timing control are distinct from those involved in amplitude control. Here, we show that in larval zebrafish, molecularly, morphologically and electrophysiologically distinct types of V2a neurons exhibit complementary patterns of connectivity. Stronger higher-order connections from type I neurons to other excitatory V2a and inhibitory V0d interneurons provide timing control, while stronger last-order connections from type II neurons to motor neurons provide amplitude control. Thus, timing and amplitude are coordinated by distinct interneurons distinguished not by their occupation of hierarchically-arranged anatomical layers, but rather by differences in the reliability and probability of higher-order and last-order connections that ultimately form a single anatomical layer. These findings contribute to our understanding of the origins of timing and amplitude control in the spinal cord. V2a excitatory interneurons in the spinal cord are important for coordinating locomotion. Here the authors describe two types of V2a neuron with differences in higher order and lower order connectivity in larval zebrafish.
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31
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Dewolf AH, Ivanenko YP, Zelik KE, Lacquaniti F, Willems PA. Differential activation of lumbar and sacral motor pools during walking at different speeds and slopes. J Neurophysiol 2019; 122:872-887. [PMID: 31291150 DOI: 10.1152/jn.00167.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Organization of spinal motor output has become of interest for investigating differential activation of lumbar and sacral motor pools during locomotor tasks. Motor pools are associated with functional grouping of motoneurons of the lower limb muscles. Here we examined how the spatiotemporal organization of lumbar and sacral motor pool activity during walking is orchestrated with slope of terrain and speed of progression. Ten subjects walked on an instrumented treadmill at different slopes and imposed speeds. Kinetics, kinematics, and electromyography of 16 lower limb muscles were recorded. The spinal locomotor output was assessed by decomposing the coordinated muscle activation profiles into a small set of common factors and by mapping them onto the rostrocaudal location of the motoneuron pools. Our results show that lumbar and sacral motor pool activity depend on slope and speed. Compared with level walking, sacral motor pools decrease their activity at negative slopes and increase at positive slopes, whereas lumbar motor pools increase their engagement when both positive and negative slope increase. These findings are consistent with a differential involvement of the lumbar and the sacral motor pools in relation to changes in positive and negative center of body mass mechanical power production due to slope and speed.NEW & NOTEWORTHY In this study, the spatiotemporal maps of motoneuron activity in the spinal cord were assessed during walking at different slopes and speeds. We found differential involvement of lumbar and sacral motor pools in relation to changes in positive and negative center of body mass power production due to slope and speed. The results are consistent with recent findings about the specialization of neuronal networks located at different segments of the spinal cord for performing specific locomotor tasks.
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Affiliation(s)
- A H Dewolf
- Laboratory of Biomechanics and Physiology of Locomotion, Institute of NeuroScience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Y P Ivanenko
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
| | - K E Zelik
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee.,Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee.,Department of Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, Tennessee
| | - F Lacquaniti
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Systems Medicine and Center of Space Biomedicine, University of Rome Tor Vergata, Rome, Italy
| | - P A Willems
- Laboratory of Biomechanics and Physiology of Locomotion, Institute of NeuroScience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
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32
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Chatterjee SA, Fox EJ, Daly JJ, Rose DK, Wu SS, Christou EA, Hawkins KA, Otzel DM, Butera KA, Skinner JW, Clark DJ. Interpreting Prefrontal Recruitment During Walking After Stroke: Influence of Individual Differences in Mobility and Cognitive Function. Front Hum Neurosci 2019; 13:194. [PMID: 31316360 PMCID: PMC6611435 DOI: 10.3389/fnhum.2019.00194] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 05/23/2019] [Indexed: 11/13/2022] Open
Abstract
Background: Functional near-infrared spectroscopy (fNIRS) is a valuable neuroimaging approach for studying cortical contributions to walking function. Recruitment of prefrontal cortex during walking has been a particular area of focus in the literature. The present study investigated whether task-related change in prefrontal recruitment measured by fNIRS is affected by individual differences in people post-stroke. The primary hypotheses were that poor mobility function would contribute to prefrontal over-recruitment during typical walking, and that poor cognitive function would contribute to a ceiling in prefrontal recruitment during dual-task walking (i.e., walking with a cognitive task). Methods: Thirty-three adults with chronic post-stroke hemiparesis performed three tasks: typical walking at preferred speed (Walk), serial-7 subtraction (Serial7), and walking combined with serial-7 subtraction (Dual-Task). Prefrontal recruitment was measured with fNIRS and quantified as the change in oxygenated hemoglobin concentration (ΔO2Hb) between resting and active periods for each task. Spatiotemporal gait parameters were measured on an electronic walkway. Stepwise regression was used to assess how prefrontal recruitment was affected by individual differences including age, sex, stroke region, injured hemisphere, stroke chronicity, 10-meter walking speed, balance confidence measured by Activities-specific Balance Confidence (ABC) Scale, sensorimotor impairment measured by Fugl-Meyer Assessment, and cognitive function measured by Mini-Mental State Examination (MMSE). Results: For Walk, poor balance confidence (ABC Scale score) significantly predicted greater prefrontal recruitment (ΔO2Hb; R 2 = 0.25, p = 0.003). For Dual-Task, poor cognitive function (MMSE score) significantly predicted lower prefrontal recruitment (ΔO2Hb; R 2 = 0.25, p = 0.002). Conclusions: Poor mobility function predicted higher prefrontal recruitment during typical walking, consistent with compensatory over-recruitment. Poor cognitive function predicted lower prefrontal recruitment during dual-task walking, consistent with a recruitment ceiling effect. These findings indicate that interpretation of prefrontal recruitment should carefully consider the characteristics of the person and demands of the task.
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Affiliation(s)
- Sudeshna A. Chatterjee
- Brain Rehabilitation Research Center (BRRC), Malcom Randall VA Medical Center, Gainesville, FL, United States
- Department of Physical Therapy, University of Florida, Gainesville, FL, United States
| | - Emily J. Fox
- Department of Physical Therapy, University of Florida, Gainesville, FL, United States
- Brooks Rehabilitation, Jacksonville, FL, United States
| | - Janis J. Daly
- Brain Rehabilitation Research Center (BRRC), Malcom Randall VA Medical Center, Gainesville, FL, United States
- Department of Neurology, University of Florida, Gainesville, FL, United States
| | - Dorian K. Rose
- Brain Rehabilitation Research Center (BRRC), Malcom Randall VA Medical Center, Gainesville, FL, United States
- Department of Physical Therapy, University of Florida, Gainesville, FL, United States
| | - Samuel S. Wu
- Department of Biostatistics, University of Florida, Gainesville, FL, United States
| | - Evangelos A. Christou
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States
| | - Kelly A. Hawkins
- Department of Physical Therapy, University of Florida, Gainesville, FL, United States
| | - Dana M. Otzel
- Brain Rehabilitation Research Center (BRRC), Malcom Randall VA Medical Center, Gainesville, FL, United States
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL, United States
| | - Katie A. Butera
- Brain Rehabilitation Research Center (BRRC), Malcom Randall VA Medical Center, Gainesville, FL, United States
- Department of Physical Therapy, University of Florida, Gainesville, FL, United States
| | - Jared W. Skinner
- Geriatric Research, Education and Clinical Center, Malcom Randall VA Medical Center, Gainesville, FL, United States
| | - David J. Clark
- Brain Rehabilitation Research Center (BRRC), Malcom Randall VA Medical Center, Gainesville, FL, United States
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL, United States
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33
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Alcock LR, Spence AJ, Lockyer EJ, Button DC, Power KE. Short-interval intracortical inhibition to the biceps brachii is present during arm cycling but is not different than a position- and intensity-matched tonic contraction. Exp Brain Res 2019; 237:2145-2154. [DOI: 10.1007/s00221-019-05579-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/08/2019] [Indexed: 10/26/2022]
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34
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Hassan M, Kadone H, Ueno T, Hada Y, Sankai Y, Suzuki K. Feasibility of Synergy-Based Exoskeleton Robot Control in Hemiplegia. IEEE Trans Neural Syst Rehabil Eng 2019; 26:1233-1242. [PMID: 29877848 DOI: 10.1109/tnsre.2018.2832657] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Here, we present a study on exoskeleton robot control based on inter-limb locomotor synergies using a robot control method developed to target hemiparesis. The robot control is based on inter-limb locomotor synergies and kinesiological information from the non-paretic leg and a walking aid cane to generate motion patterns for the assisted leg. The developed synergy-based system was tested against an autonomous robot control system in five patients with hemiparesis and varying locomotor abilities. Three of the participants were able to walk using the robot. Results from these participants showed an improved spatial symmetry ratio and more consistent step length with the synergy-based method compared with that for the autonomous method, while the increase in the range of motion for the assisted joints was larger with the autonomous system. The kinematic synergy distribution of the participants walking without the robot suggests a relationship between each participant's synergy distribution and his/her ability to control the robot: participants with two independent synergies accounting for approximately 80% of the data variability were able to walk with the robot. This observation was not consistently apparent with conventional clinical measures such as the Brunnstrom stages. This paper contributes to the field of robot-assisted locomotion therapy by introducing the concept of inter-limb synergies, demonstrating performance differences between synergy-based and autonomous robot control, and investigating the range of disability in which the system is usable.
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35
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Meyer C, Killeen T, Easthope CS, Curt A, Bolliger M, Linnebank M, Zörner B, Filli L. Familiarization with treadmill walking: How much is enough? Sci Rep 2019; 9:5232. [PMID: 30914746 PMCID: PMC6435738 DOI: 10.1038/s41598-019-41721-0] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/12/2019] [Indexed: 11/21/2022] Open
Abstract
Treadmill-based gait analysis is widely used to investigate walking pathologies and quantify treatment effects on locomotion. Differential sensorimotor conditions during overground vs. treadmill walking necessitate initial familiarization to treadmill walking. Currently, there is no standardized treadmill acclimatization protocol and insufficient familiarization potentially confounds analyses. We monitored initial adaptations to treadmill walking in 40 healthy adults. Twenty-six walking parameters were assessed over 10 minutes with marker-based kinematic analysis and acclimatization profiles were generated. While 16 walking parameters demonstrated initial acclimatization followed by plateau performance, ten parameters remained stable. Distal lower limb control including ankle range of motion, toe trajectory and foot clearance underwent substantial adaptations. Moreover, intralimb coordination and gait variability also demonstrated acclimatization, while measures of symmetry and interlimb coordination did not. All parameters exhibiting a plateau after acclimatization did so within 6–7 minutes (425 strides). Older participants and those naïve to treadmill walking showed adaptations with higher amplitudes but over similar timescales. Our results suggest a minimum of 6 minutes treadmill acclimatization is required to reach a stable performance, and that this should suffice for both older and naïve healthy adults. The presented data aids in optimizing treadmill-based gait analysis and contributes to improving locomotor assessments in research and clinical settings.
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Affiliation(s)
- Christian Meyer
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, Zurich, Switzerland. .,Department of Neurology, University Hospital and University of Zurich, Frauenklinikstrasse 26, Zurich, Switzerland.
| | - Tim Killeen
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, Zurich, Switzerland
| | - Christopher S Easthope
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, Zurich, Switzerland
| | - Armin Curt
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, Zurich, Switzerland
| | - Marc Bolliger
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, Zurich, Switzerland
| | - Michael Linnebank
- Department of Neurology, University Hospital and University of Zurich, Frauenklinikstrasse 26, Zurich, Switzerland.,Department of Neurology, Helios-Klinik Hagen-Ambrock, Witten/Herdecke University, Ambrocker Weg 60, 58091, Hagen, Germany
| | - Björn Zörner
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, Zurich, Switzerland.,Department of Neurology, University Hospital and University of Zurich, Frauenklinikstrasse 26, Zurich, Switzerland
| | - Linard Filli
- Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, Zurich, Switzerland.,Department of Neurology, University Hospital and University of Zurich, Frauenklinikstrasse 26, Zurich, Switzerland
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36
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Corticospinal Excitability to the Biceps Brachii is Not Different When Arm Cycling at a Self-Selected or Fixed Cadence. Brain Sci 2019; 9:brainsci9020041. [PMID: 30769825 PMCID: PMC6406314 DOI: 10.3390/brainsci9020041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/11/2019] [Accepted: 02/12/2019] [Indexed: 11/17/2022] Open
Abstract
Background: The present study compared corticospinal excitability to the biceps brachii muscle during arm cycling at a self-selected and a fixed cadence (SSC and FC, respectively). We hypothesized that corticospinal excitability would not be different between the two conditions. Methods: The SSC was initially performed and the cycling cadence was recorded every 5 s for one minute. The average cadence of the SSC cycling trial was then used as a target for the FC of cycling that the participants were instructed to maintain. The motor evoked potentials (MEPs) elicited via transcranial magnetic stimulation (TMS) of the motor cortex were recorded from the biceps brachii during each trial of SSC and FC arm cycling. Results: Corticospinal excitability, as assessed via normalized MEP amplitudes (MEPs were made relative to a maximal compound muscle action potential), was not different between groups. Conclusions: Focusing on maintaining a fixed cadence during arm cycling does not influence corticospinal excitability, as assessed via TMS-evoked MEPs.
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37
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Desrochers E, Harnie J, Doelman A, Hurteau MF, Frigon A. Spinal control of muscle synergies for adult mammalian locomotion. J Physiol 2018; 597:333-350. [PMID: 30334575 DOI: 10.1113/jp277018] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 10/09/2018] [Indexed: 01/08/2023] Open
Abstract
KEY POINTS The control of locomotion is thought to be generated by activating groups of muscles that perform similar actions, which are termed muscle synergies. Here, we investigated if muscle synergies are controlled at the level of the spinal cord. We did this by comparing muscle activity in the legs of cats during stepping on a treadmill before and after a complete spinal transection that abolishes commands from the brain. We show that muscle synergies were maintained following spinal transection, validating the concept that muscle synergies for locomotion are primarily controlled by circuits of neurons within the spinal cord. ABSTRACT Locomotion is thought to involve the sequential activation of functional modules or muscle synergies. Here, we tested the hypothesis that muscle synergies for locomotion are organized within the spinal cord. We recorded bursts of muscle activity in the same cats (n = 7) before and after spinal transection during tied-belt locomotion at three speeds and split-belt locomotion at three left-right speed differences. We identified seven muscles synergies before (intact state) and after (spinal state) spinal transection. The muscles comprising the different synergies were the same in the intact and spinal states as well as at different speeds or left-right speed differences. However, there were some significant shifts in the onsets and offsets of certain synergies as a function of state, speed and left-right speed differences. The most notable difference between the intact and spinal states was a change in the timing between the knee flexor and hip flexor muscle synergies. In the intact state, the knee flexor synergy preceded the hip flexor synergy, whereas in the spinal state both synergies occurred concurrently. Afferent inputs also appear important for the expression of some muscle synergies, specifically those involving biphasic patterns of muscle activity. We propose that muscle synergies for locomotion are primarily organized within the spinal cord, although their full expression and proper timing requires inputs from supraspinal structures and/or limb afferents.
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Affiliation(s)
- Etienne Desrochers
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, J1H 5N4, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, J1H 5N4, Canada
| | - Adam Doelman
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, J1H 5N4, Canada
| | - Marie-France Hurteau
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, J1H 5N4, Canada
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, J1H 5N4, Canada
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38
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Power KE, Lockyer EJ, Forman DA, Button DC. Modulation of motoneurone excitability during rhythmic motor outputs. Appl Physiol Nutr Metab 2018. [DOI: 10.1139/apnm-2018-0077] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In quadrupeds, special circuity located within the spinal cord, referred to as central pattern generators (CPGs), is capable of producing complex patterns of activity such as locomotion in the absence of descending input. During these motor outputs, the electrical properties of spinal motoneurones are modulated such that the motoneurone is more easily activated. Indirect evidence suggests that like quadrupeds, humans also have spinally located CPGs capable of producing locomotor outputs, albeit descending input is considered to be of greater importance. Whether motoneurone properties are reconfigured in a similar manner to those of quadrupeds is unclear. The purpose of this review is to summarize our current state of knowledge regarding the modulation of motoneurone excitability during CPG-mediated motor outputs using animal models. This will be followed by more recent work initially aimed at understanding changes in motoneurone excitability during CPG-mediated motor outputs in humans, which quickly expanded to also include supraspinal excitability.
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Affiliation(s)
- Kevin E. Power
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
- Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
| | - Evan J. Lockyer
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
| | - Davis A. Forman
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
- Faculty of Science, University of Ontario Institute of Technology, Oshawa, ON L1H 7K4, Canada
| | - Duane C. Button
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
- Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
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Berg EM, Björnfors ER, Pallucchi I, Picton LD, El Manira A. Principles Governing Locomotion in Vertebrates: Lessons From Zebrafish. Front Neural Circuits 2018; 12:73. [PMID: 30271327 PMCID: PMC6146226 DOI: 10.3389/fncir.2018.00073] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 08/27/2018] [Indexed: 11/24/2022] Open
Abstract
Locomotor behaviors are critical for survival and enable animals to navigate their environment, find food and evade predators. The circuits in the brain and spinal cord that initiate and maintain such different modes of locomotion in vertebrates have been studied in numerous species for over a century. In recent decades, the zebrafish has emerged as one of the main model systems for the study of locomotion, owing to its experimental amenability, and work in zebrafish has revealed numerous new insights into locomotor circuit function. Here, we review the literature that has led to our current understanding of the neural circuits controlling swimming and escape in zebrafish. We highlight recent studies that have enriched our comprehension of key topics, such as the interactions between premotor excitatory interneurons (INs) and motoneurons (MNs), supraspinal and spinal circuits that coordinate escape maneuvers, and developmental changes in overall circuit composition. We also discuss roles for neuromodulators and sensory inputs in modifying the relative strengths of constituent circuit components to provide flexibility in zebrafish behavior, allowing the animal to accommodate changes in the environment. We aim to provide a coherent framework for understanding the circuitry in the brain and spinal cord of zebrafish that allows the animal to flexibly transition between different speeds, and modes, of locomotion.
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Affiliation(s)
- Eva M Berg
- Department of Neuroscience, Karolinska Institute (KI), Stockholm, Sweden
| | | | - Irene Pallucchi
- Department of Neuroscience, Karolinska Institute (KI), Stockholm, Sweden
| | - Laurence D Picton
- Department of Neuroscience, Karolinska Institute (KI), Stockholm, Sweden
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Duysens J, Forner-Cordero A. Walking with perturbations: a guide for biped humans and robots. BIOINSPIRATION & BIOMIMETICS 2018; 13:061001. [PMID: 30109860 DOI: 10.1088/1748-3190/aada54] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This paper provides an update on the neural control of bipedal walking in relation to bioinspired models and robots. It is argued that most current models or robots are based on the construct of a symmetrical central pattern generator (CPG). However, new evidence suggests that CPG functioning is basically asymmetrical with its flexor half linked more tightly to the rhythm generator. The stability of bipedal gait, which is an important problem for robots and biological systems, is also addressed. While it is not possible to determine how biological biped systems guarantee stability, robot solutions can be useful to propose new hypotheses for biology. In the second part of this review, the focus is on gait perturbations, which is an important topic in robotics in view of the frequent falls of robots when faced with perturbations. From the human physiology it is known that the initial reaction often consists of a brief interruption followed by an adequate response. For instance, the successful recovery from a trip is achieved using some basic reactions (termed elevating and lowering strategies), that depend on the phase of the step cycle of the trip occurrence. Reactions to stepping unexpectedly in a hole depend on comparing expected and real feedback. Implementation of these ideas in models and robotics starts to emerge, with the most advanced robots being able to learn how to fall safely and how to deal with complicated disturbances such as provided by walking on a split-belt.
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Affiliation(s)
- Jacques Duysens
- Biomechatronics Lab., Mechatronics Department, Escola Politécnica da Universidade de São Paulo, Av. Prof. Mello Moraes, 2231, Cidade Universitária 05508-030, São Paulo-SP, Brasil. Department of Kinesiology, FaBeR, Katholieke Universiteit Leuven, Leuven, Belgium
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41
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Mayer WP, Murray AJ, Brenner-Morton S, Jessell TM, Tourtellotte WG, Akay T. Role of muscle spindle feedback in regulating muscle activity strength during walking at different speed in mice. J Neurophysiol 2018; 120:2484-2497. [PMID: 30133381 DOI: 10.1152/jn.00250.2018] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Terrestrial animals increase their walking speed by increasing the activity of the extensor muscles. However, the mechanism underlying how this speed-dependent amplitude modulation is achieved remains obscure. Previous studies have shown that group Ib afferent feedback from Golgi tendon organs that signal force is one of the major regulators of the strength of muscle activity during walking in cats and humans. In contrast, the contribution of group Ia/II afferent feedback from muscle spindle stretch receptors that signal angular displacement of leg joints is unclear. Some studies indicate that group II afferent feedback may be important for amplitude regulation in humans, but the role of muscle spindle feedback in regulation of muscle activity strength in quadrupedal animals is very poorly understood. To examine the role of feedback from muscle spindles, we combined in vivo electrophysiology and motion analysis with mouse genetics and gene delivery with adeno-associated virus. We provide evidence that proprioceptive sensory feedback from muscle spindles is important for the regulation of the muscle activity strength and speed-dependent amplitude modulation. Furthermore, our data suggest that feedback from the muscle spindles of the ankle extensor muscles, the triceps surae, is the main source for this mechanism. In contrast, muscle spindle feedback from the knee extensor muscles, the quadriceps femoris, has no influence on speed-dependent amplitude modulation. We provide evidence that proprioceptive feedback from ankle extensor muscles is critical for regulating muscle activity strength as gait speed increases. NEW & NOTEWORTHY Animals upregulate the activity of extensor muscles to increase their walking speed, but the mechanism behind this is not known. We show that this speed-dependent amplitude modulation requires proprioceptive sensory feedback from muscle spindles of ankle extensor muscle. In the absence of muscle spindle feedback, animals cannot walk at higher speeds as they can when muscle spindle feedback is present.
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Affiliation(s)
- William P Mayer
- Atlantic Mobility Action Project, Brain Repair Center, Department of Medical Neuroscience, Dalhousie University , Halifax, Nova Scotia , Canada.,Department of Morphology, Federal University of Espirito Santo , Vitoria , Brazil
| | - Andrew J Murray
- Sainsbury Wellcome Center for Neural Circuits and Behaviour, University College London , London , United Kingdom
| | - Susan Brenner-Morton
- Howard Hughes Medical Institute, Department of Neuroscience, Columbia University , New York, New York
| | - Thomas M Jessell
- Howard Hughes Medical Institute, Department of Neuroscience, Columbia University , New York, New York
| | - Warren G Tourtellotte
- Department of Pathology and Laboratory Medicine, Cedar Sinai Medical Center, West Hollywood, California
| | - Turgay Akay
- Atlantic Mobility Action Project, Brain Repair Center, Department of Medical Neuroscience, Dalhousie University , Halifax, Nova Scotia , Canada
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Müller R, Abaid N, Boreyko JB, Fowlkes C, Goel AK, Grimm C, Jung S, Kennedy B, Murphy C, Cushing ND, Han JP. Biodiversifying bioinspiration. BIOINSPIRATION & BIOMIMETICS 2018; 13:053001. [PMID: 29855430 DOI: 10.1088/1748-3190/aac96a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Bioinspiration-using insights into the function of biological systems for the development of new engineering concepts-is already a successful and rapidly growing field. However, only a small portion of the world's biodiversity has thus far been considered as a potential source for engineering inspiration. This means that vast numbers of biological systems of potentially high value to engineering have likely gone unnoticed. Even more important, insights into form and function that reside in the evolutionary relationships across the tree of life have not yet received attention by engineers. These insights could soon become accessible through recent developments in disparate areas of research; in particular, advancements in digitization of museum specimens, methods to describe and analyze complex biological shapes, quantitative prediction of biological function from form, and analysis of large digital data sets. Taken together, these emerging capabilities should make it possible to mine the world's known biodiversity as a natural resource for knowledge relevant to engineering. This transformation of bioinspiration would be very timely in the development of engineering, because it could yield exactly the kind of insights that are needed to make technology more autonomous, adaptive, and capable of operation in complex environments.
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Affiliation(s)
- Rolf Müller
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, United States of America
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Côté MP, Murray LM, Knikou M. Spinal Control of Locomotion: Individual Neurons, Their Circuits and Functions. Front Physiol 2018; 9:784. [PMID: 29988534 PMCID: PMC6026662 DOI: 10.3389/fphys.2018.00784] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 06/05/2018] [Indexed: 12/31/2022] Open
Abstract
Systematic research on the physiological and anatomical characteristics of spinal cord interneurons along with their functional output has evolved for more than one century. Despite significant progress in our understanding of these networks and their role in generating and modulating movement, it has remained a challenge to elucidate the properties of the locomotor rhythm across species. Neurophysiological experimental evidence indicates similarities in the function of interneurons mediating afferent information regarding muscle stretch and loading, being affected by motor axon collaterals and those mediating presynaptic inhibition in animals and humans when their function is assessed at rest. However, significantly different muscle activation profiles are observed during locomotion across species. This difference may potentially be driven by a modified distribution of muscle afferents at multiple segmental levels in humans, resulting in an altered interaction between different classes of spinal interneurons. Further, different classes of spinal interneurons are likely activated or silent to some extent simultaneously in all species. Regardless of these limitations, continuous efforts on the function of spinal interneuronal circuits during mammalian locomotion will assist in delineating the neural mechanisms underlying locomotor control, and help develop novel targeted rehabilitation strategies in cases of impaired bipedal gait in humans. These rehabilitation strategies will include activity-based therapies and targeted neuromodulation of spinal interneuronal circuits via repetitive stimulation delivered to the brain and/or spinal cord.
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Affiliation(s)
- Marie-Pascale Côté
- CÔTÉ Lab, Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Lynda M. Murray
- Motor Control and NeuroRecovery Research Laboratory (Klab4Recovery), Department of Physical Therapy, College of Staten Island, City University of New York, New York, NY, United States
- Graduate Center, Ph.D. Program in Biology, City University of New York, New York, NY, United States
| | - Maria Knikou
- Motor Control and NeuroRecovery Research Laboratory (Klab4Recovery), Department of Physical Therapy, College of Staten Island, City University of New York, New York, NY, United States
- Graduate Center, Ph.D. Program in Biology, City University of New York, New York, NY, United States
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Vanden Hole C, Goyens J, Prims S, Fransen E, Ayuso Hernando M, Van Cruchten S, Aerts P, Van Ginneken C. How innate is locomotion in precocial animals? A study on the early development of spatio-temporal gait variables and gait symmetry in piglets. ACTA ACUST UNITED AC 2018; 220:2706-2716. [PMID: 28768747 DOI: 10.1242/jeb.157693] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Accepted: 05/17/2017] [Indexed: 01/17/2023]
Abstract
Locomotion is one of the most important ecological functions in animals. Precocial animals, such as pigs, are capable of independent locomotion shortly after birth. This raises the question whether coordinated movement patterns and the underlying muscular control in these animals is fully innate or whether there still exists a rapid maturation. We addressed this question by studying gait development in neonatal pigs through the analysis of spatio-temporal gait characteristics during locomotion at self-selected speed. To this end, we made video recordings of piglets walking along a corridor at several time points (from 0 h to 96 h). After digitization of the footfalls, we analysed self-selected speed and spatio-temporal characteristics (e.g. stride and step lengths, stride frequency and duty factor) to study dynamic similarity, intralimb coordination and interlimb coordination. To assess the variability of the gait pattern, left-right asymmetry was studied. To distinguish neuromotor maturation from effects caused by growth, both absolute and normalized data (according to the dynamic similarity concept) were included in the analysis. All normalized spatio-temporal variables reached stable values within 4 h of birth, with most of them showing little change after the age of 2 h. Most asymmetry indices showed stable values, hovering around 10%, within 8 h of birth. These results indicate that coordinated movement patterns are not entirely innate, but that a rapid neuromotor maturation, potentially also the result of the rearrangement or recombination of existing motor modules, takes place in these precocial animals.
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Affiliation(s)
- Charlotte Vanden Hole
- Laboratory of Applied Veterinary Morphology, Department of Veterinary Sciences, Faculty of Biomedical, Pharmaceutical and Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Jana Goyens
- Laboratory of Functional Morphology, Department of Biology, Faculty of Sciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Sara Prims
- Laboratory of Applied Veterinary Morphology, Department of Veterinary Sciences, Faculty of Biomedical, Pharmaceutical and Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Erik Fransen
- StatUa Center for Statistics, University of Antwerp, 2000 Antwerp, Belgium
| | - Miriam Ayuso Hernando
- Laboratory of Applied Veterinary Morphology, Department of Veterinary Sciences, Faculty of Biomedical, Pharmaceutical and Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Steven Van Cruchten
- Laboratory of Applied Veterinary Morphology, Department of Veterinary Sciences, Faculty of Biomedical, Pharmaceutical and Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Peter Aerts
- Laboratory of Functional Morphology, Department of Biology, Faculty of Sciences, University of Antwerp, 2610 Wilrijk, Belgium
| | - Chris Van Ginneken
- Laboratory of Applied Veterinary Morphology, Department of Veterinary Sciences, Faculty of Biomedical, Pharmaceutical and Veterinary Sciences, University of Antwerp, 2610 Wilrijk, Belgium
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Herbin M, Hommet E, Hanotin-Dossot V, Perret M, Hackert R. Treadmill locomotion of the mouse lemur (Microcebus murinus); kinematic parameters during symmetrical and asymmetrical gaits. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2018; 204:537-547. [PMID: 29610933 DOI: 10.1007/s00359-018-1256-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 03/16/2018] [Accepted: 03/16/2018] [Indexed: 10/17/2022]
Abstract
The gaits of the adult grey mouse lemur Microcebus murinus were studied during treadmill locomotion over a large range of velocities. The locomotion sequences were analysed to determine the gait and the various spatiotemporal gait parameters of the limbs. We found that velocity adjustments are accounted for differently by stride frequency and stride length depending on whether the animal showed a symmetrical or an asymmetrical gait. When using symmetrical gaits the increase in velocity is associated with a constant contribution of the stride length and stride frequency; the increase of the stride frequency being always lower. When using asymmetrical gaits, the increase in velocity is mainly assured by an increase in the stride length which tends to decrease with increasing velocity. A reduction in both stance time and swing time contributed to the increase in stride frequency for both gaits, though with a major contribution from the decrease in stance time. The pattern of locomotion obtained in a normal young adult mouse lemurs can be used as a template for studying locomotor control deficits during aging or in different environments such as arboreal ones which likely modify the kinematics of locomotion.
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Affiliation(s)
- Marc Herbin
- Department Adaptations du Vivant, UMR MECADEV 7179 Sorbonne Universités-MNHN-UPMC-CNRS-IRD, Muséum National d'Histoire Naturelle, CP55 57 rue Cuvier, 75231, Paris Cedex05, France.
| | - Eva Hommet
- Department Adaptations du Vivant, UMR MECADEV 7179 Sorbonne Universités-MNHN-UPMC-CNRS-IRD, Muséum National d'Histoire Naturelle, CP55 57 rue Cuvier, 75231, Paris Cedex05, France
| | - Vicky Hanotin-Dossot
- Department Adaptations du Vivant, UMR MECADEV 7179 Sorbonne Universités-MNHN-UPMC-CNRS-IRD, Muséum National d'Histoire Naturelle, CP55 57 rue Cuvier, 75231, Paris Cedex05, France
| | - Martine Perret
- Department Adaptations du Vivant, UMR MECADEV 7179 Sorbonne Universités-MNHN-UPMC-CNRS-IRD, Muséum National d'Histoire Naturelle, CP55 57 rue Cuvier, 75231, Paris Cedex05, France
| | - Rémi Hackert
- Department Adaptations du Vivant, UMR MECADEV 7179 Sorbonne Universités-MNHN-UPMC-CNRS-IRD, Muséum National d'Histoire Naturelle, CP55 57 rue Cuvier, 75231, Paris Cedex05, France
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Sobinov A, Yakovenko S. Model of a bilateral Brown-type central pattern generator for symmetric and asymmetric locomotion. J Neurophysiol 2018; 119:1071-1083. [PMID: 29187551 PMCID: PMC5899308 DOI: 10.1152/jn.00443.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 11/22/2017] [Accepted: 11/23/2017] [Indexed: 11/22/2022] Open
Abstract
The coordinated activity of muscles is produced in part by spinal rhythmogenic neural circuits, termed central pattern generators (CPGs). A classical CPG model is a system of coupled oscillators that transform locomotor drive into coordinated and gait-specific patterns of muscle recruitment. The network properties of this conceptual model can be simulated by a system of ordinary differential equations with a physiologically inspired coupling locus of interactions capturing the timing relationship for bilateral coordination of limbs in locomotion. Whereas most similar models are solved numerically, it is intriguing to have a full analytical description of this plausible CPG architecture to illuminate the functionality within this structure and to expand it to include steering control. Here, we provided a closed-form analytical solution contrasted against the previous numerical method. The evaluation time of the analytical solution was decreased by an order of magnitude when compared with the numerical approach (relative errors, <0.01%). The analytical solution tested and supported the previous finding that the input to the model can be expressed in units of the desired limb locomotor speed. Furthermore, we performed parametric sensitivity analysis in the context of controlling steering and documented two possible mechanisms associated with either an external drive or intrinsic CPG parameters. The results identify specific propriospinal pathways that may be associated with adaptations within the CPG structure. The model offered several network configurations that may generate the same behavioral outcomes. NEW & NOTEWORTHY Using a simple process of leaky integration, we developed an analytical solution to a robust model of spinal pattern generation. We analyzed the ability of this neural element to exert locomotor control of the signal associated with limb speeds and tested the ability of this simple structure to embed steering control using the velocity signal in the model's inputs or within the internal connectivity of its elements.
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Affiliation(s)
- Anton Sobinov
- Centers for Neuroscience, School of Medicine, West Virginia University , Morgantown, West Virginia
| | - Sergiy Yakovenko
- Centers for Neuroscience, School of Medicine, West Virginia University , Morgantown, West Virginia
- Division of Exercise Physiology, Department of Human Performance, School of Medicine, West Virginia University , Morgantown, West Virginia
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Jean-Xavier C, Perreault MC. Influence of Brain Stem on Axial and Hindlimb Spinal Locomotor Rhythm Generating Circuits of the Neonatal Mouse. Front Neurosci 2018; 12:53. [PMID: 29479302 PMCID: PMC5811543 DOI: 10.3389/fnins.2018.00053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 01/23/2018] [Indexed: 12/18/2022] Open
Abstract
The trunk plays a pivotal role in limbed locomotion. Yet, little is known about how the brain stem controls trunk activity during walking. In this study, we assessed the spatiotemporal activity patterns of axial and hindlimb motoneurons (MNs) during drug-induced fictive locomotor-like activity (LLA) in an isolated brain stem-spinal cord preparation of the neonatal mouse. We also evaluated the extent to which these activity patterns are affected by removal of brain stem. Recordings were made in the segments T7, L2, and L5 using calcium imaging from individual axial MNs in the medial motor column (MMC) and hindlimb MNs in lateral motor column (LMC). The MN activities were analyzed during both the rhythmic and the tonic components of LLA, the tonic component being used as a readout of generalized increase in excitability in spinal locomotor networks. The most salient effect of brain stem removal was an increase in locomotor rhythm frequency and a concomitant reduction in burst durations in both MMC and LMC MNs. The lack of effect on the tonic component of LLA indicated specificity of action during the rhythmic component. Cooling-induced silencing of the brain stem reproduced the increase in rhythm frequency and accompanying decrease in burst durations in L2 MMC and LMC, suggesting a dependency on brain stem neuron activity. The work supports the idea that the brain stem locomotor circuits are operational already at birth and further suggests an important role in modulating trunk activity. The brain stem may influence the axial and hindlimb spinal locomotor rhythm generating circuits by extending their range of operation. This may represent a critical step of locomotor development when learning how to walk in different conditions and environments is a major endeavor.
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Affiliation(s)
| | - Marie-Claude Perreault
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
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Reversible silencing of lumbar spinal interneurons unmasks a task-specific network for securing hindlimb alternation. Nat Commun 2017; 8:1963. [PMID: 29213073 PMCID: PMC5719045 DOI: 10.1038/s41467-017-02033-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 11/02/2017] [Indexed: 12/05/2022] Open
Abstract
Neural circuitry in the lumbar spinal cord governs two principal features of locomotion, rhythm and pattern, which reflect intra- and interlimb movement. These features are functionally organized into a hierarchy that precisely controls stepping in a stereotypic, speed-dependent fashion. Here, we show that a specific component of the locomotor pattern can be independently manipulated. Silencing spinal L2 interneurons that project to L5 selectively disrupts hindlimb alternation allowing a continuum of walking to hopping to emerge from the otherwise intact network. This perturbation, which is independent of speed and occurs spontaneously with each step, does not disrupt multi-joint movements or forelimb alternation, nor does it translate to a non-weight-bearing locomotor activity. Both the underlying rhythm and the usual relationship between speed and spatiotemporal characteristics of stepping persist. These data illustrate that hindlimb alternation can be manipulated independently from other core features of stepping, revealing a striking freedom in an otherwise precisely controlled system. Intra- and interlimb coordination during locomotion is governed by hierarchically organized lumbar spinal networks. Here, the authors show that reversible silencing of spinal L2–L5 interneurons specifically disrupts hindlimb alternation leading to a continuum of walking to hopping.
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Postural perturbation does not reset stepping rhythm in humans, but brief intermission does. Exp Brain Res 2017; 235:3561-3572. [DOI: 10.1007/s00221-017-5084-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 09/03/2017] [Indexed: 10/18/2022]
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50
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Ziskind-Conhaim L, Hochman S. Diversity of molecularly defined spinal interneurons engaged in mammalian locomotor pattern generation. J Neurophysiol 2017; 118:2956-2974. [PMID: 28855288 DOI: 10.1152/jn.00322.2017] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 08/29/2017] [Accepted: 08/30/2017] [Indexed: 01/18/2023] Open
Abstract
Mapping the expression of transcription factors in the mouse spinal cord has identified ten progenitor domains, four of which are cardinal classes of molecularly defined, ventrally located interneurons that are integrated in the locomotor circuitry. This review focuses on the properties of these interneuronal populations and their contribution to hindlimb locomotor central pattern generation. Interneuronal populations are categorized based on their excitatory or inhibitory functions and their axonal projections as predictors of their role in locomotor rhythm generation and coordination. The synaptic connectivity and functions of these interneurons in the locomotor central pattern generators (CPGs) have been assessed by correlating their activity patterns with motor output responses to rhythmogenic neurochemicals and sensory and descending fibers stimulations as well as analyzing kinematic gait patterns in adult mice. The observed complex organization of interneurons in the locomotor CPG circuitry, some with seemingly similar physiological functions, reflects the intricate repertoire associated with mammalian motor control and is consistent with high transcriptional heterogeneity arising from cardinal interneuronal classes. This review discusses insights derived from recent studies to describe innovative approaches and limitations in experimental model systems and to identify missing links in current investigational enterprise.
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Affiliation(s)
- Lea Ziskind-Conhaim
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin; and
| | - Shawn Hochman
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
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