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Hamling KR, Harmon K, Kimura Y, Higashijima SI, Schoppik D. The vestibulospinal nucleus is a locus of balance development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.06.570482. [PMID: 38105966 PMCID: PMC10723429 DOI: 10.1101/2023.12.06.570482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Mature vertebrates maintain posture using vestibulospinal neurons that transform sensed instability into reflexive commands to spinal motor circuits. Postural stability improves across development. However, due to the complexity of terrestrial locomotion, vestibulospinal contributions to postural refinement in early life remain unexplored. Here we leveraged the relative simplicity of underwater locomotion to quantify the postural consequences of losing vestibulospinal neurons during development in larval zebrafish of undifferentiated sex. By comparing posture at two timepoints, we discovered that later lesions of vestibulospinal neurons led to greater instability. Analysis of thousands of individual swim bouts revealed that lesions disrupted movement timing and corrective reflexes without impacting swim kinematics, and that this effect was particularly strong in older larvae. Using a generative model of swimming, we showed how these disruptions could account for the increased postural variability at both timepoints. Finally, late lesions disrupted the fin/trunk coordination observed in older larvae, linking vestibulospinal neurons to postural control schemes used to navigate in depth. Since later lesions were considerably more disruptive to postural stability, we conclude that vestibulospinal contributions to balance increase as larvae mature. Vestibulospinal neurons are highly conserved across vertebrates; we therefore propose that they are a substrate for developmental improvements to postural control.
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Affiliation(s)
- Kyla R Hamling
- Departments of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, New York University Grossman School of Medicine
| | - Katherine Harmon
- Departments of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, New York University Grossman School of Medicine
| | - Yukiko Kimura
- National Institutes of Natural Sciences, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institute for Basic Biology, Okazaki 444-8787, Aichi, Japan
| | - Shin-Ichi Higashijima
- National Institutes of Natural Sciences, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institute for Basic Biology, Okazaki 444-8787, Aichi, Japan
| | - David Schoppik
- Departments of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, New York University Grossman School of Medicine
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Rejc E, Bowersock C, Pisolkar T, Omofuma I, Luna T, Khan M, Santamaria V, Ugiliweneza B, Angeli CA, Forrest GF, Stein J, Agrawal S, Harkema SJ. Robotic Postural Training With Epidural Stimulation for the Recovery of Upright Postural Control in Individuals With Motor Complete Spinal Cord Injury: A Pilot Study. Neurotrauma Rep 2024; 5:277-292. [PMID: 38515546 PMCID: PMC10956531 DOI: 10.1089/neur.2024.0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024] Open
Abstract
Activity-based training and lumbosacral spinal cord epidural stimulation (scES) have the potential to restore standing and walking with self-balance assistance after motor complete spinal cord injury (SCI). However, improvements in upright postural control have not previously been addressed in this population. Here, we implemented a novel robotic postural training with scES, performed with free hands, to restore upright postural control in individuals with chronic, cervical (n = 5) or high-thoracic (n = 1) motor complete SCI, who had previously undergone stand training with scES using a walker or a standing frame for self-balance assistance. Robotic postural training re-enabled and/or largely improved the participants' ability to control steady standing, self-initiated trunk movements and upper limb reaching movements while standing with free hands, receiving only external assistance for pelvic control. These improvements were associated with neuromuscular activation pattern adaptations above and below the lesion. These findings suggest that the human spinal cord below the level of injury can generate meaningful postural responses when its excitability is modulated by scES, and can learn to improve these responses. Upright postural control improvements can enhance functional motor recovery promoted by scES after severe SCI.
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Affiliation(s)
- Enrico Rejc
- Tim and Caroline Reynolds Center for Spinal Stimulation, Kessler Foundation, West Orange, New Jersey, USA
- Department of Medicine, University of Udine, Udine, Italy
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
| | - Collin Bowersock
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Mechanical Engineering, Northern Arizona University, Flagstaff, Arizona, USA
| | - Tanvi Pisolkar
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
| | - Isirame Omofuma
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Tatiana Luna
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Moiz Khan
- Department of Radiology at BWH, Harvard Medical School, Boston, Massachusetts, USA
| | - Victor Santamaria
- Department of Physical Therapy, New York Medical College, Valhalla, New York, USA
| | - Beatrice Ugiliweneza
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
| | - Claudia A Angeli
- Tim and Caroline Reynolds Center for Spinal Stimulation, Kessler Foundation, West Orange, New Jersey, USA
| | - Gail F Forrest
- Tim and Caroline Reynolds Center for Spinal Stimulation, Kessler Foundation, West Orange, New Jersey, USA
- Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Joel Stein
- Department of Rehabilitation and Regenerative Medicine, Columbia University, New York, New York, USA
| | - Sunil Agrawal
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
- Department of Rehabilitation and Regenerative Medicine, Columbia University, New York, New York, USA
| | - Susan J Harkema
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
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Nakanowatari T, Hoshi M, Sone T, Kamide N, Sakamoto M, Shiba Y. Detecting differences in limb load asymmetry during walking between older adult fallers and non-fallers using in-shoe sensors. Gait Posture 2024; 107:312-316. [PMID: 37919177 DOI: 10.1016/j.gaitpost.2023.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 09/06/2023] [Accepted: 10/26/2023] [Indexed: 11/04/2023]
Abstract
BACKGROUND Previous studies have reported that clinical walk tests could not detect differences between fallers and non-fallers in older adults. With advancements in wearable technology, it may be possible to assess differences in loading parameters in clinical settings using portable data collection methods. RESEARCH QUESTION The purpose of this study was to determine if wearable sensors (loadsol®) are reliable for assessing asymmetry of contact time, peak force, loading rate (LR), and impulse in older adults and determine if the insole can detect differences in these parameters between fallers and non-fallers during walking. METHODS Fifty-five older adults (74.1 ± 6.1 years) walked at their maximum speed on a flat floor. Force data were collected from insoles (100 Hz) during a 10-m walk test. To assess reliability, an intraclass correlation coefficient [ICC(2,k)] was generated for each asymmetry variable. To determine differences between fallers and non-fallers, analysis of covariance (ANCOVA; covariate: body mass index) was completed for each variable. RESULTS The ICC of peak force asymmetry (PFA) was 0.942, but other ICCs were less than 0.75. The ANCOVA results indicate that the loadsol® can detect differences in PFA between fallers and non-fallers. The PFA was significantly greater in fallers than in non-fallers. SIGNIFICANCE The ability to collect force data while walking using loadsol® has the potential to broaden the research questions investigated, explore clinical applications, and increase generalizability.
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Affiliation(s)
- Tatsuya Nakanowatari
- Department of Physical Therapy, School of Health Sciences, Fukushima Medical University, Japan.
| | - Masayuki Hoshi
- Department of Physical Therapy, School of Health Sciences, Fukushima Medical University, Japan
| | - Toshimasa Sone
- Department of Occupational Therapy, School of Health Sciences, Fukushima Medical University, Japan
| | - Naoto Kamide
- School of Allied Health Sciences, Kitasato University, Japan
| | - Miki Sakamoto
- School of Allied Health Sciences, Kitasato University, Japan
| | - Yoshitaka Shiba
- Department of Physical Therapy, School of Health Sciences, Fukushima Medical University, Japan
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Bowersock CD, Pisolkar T, Omofuma I, Luna T, Khan M, Santamaria V, Stein J, Agrawal S, Harkema SJ, Rejc E. Robotic upright stand trainer (RobUST) and postural control in individuals with spinal cord injury. J Spinal Cord Med 2023; 46:889-899. [PMID: 35532324 PMCID: PMC10653750 DOI: 10.1080/10790268.2022.2069532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
CONTEXT/OBJECTIVE Assessed feasibility and potential effectiveness of using a novel robotic upright stand trainer (RobUST) to deliver postural perturbations or provide assistance-as-needed at the trunk while individuals with spinal cord injury (SCI) performed stable standing and self-initiated trunk movements. These tasks were assessed with research participants' hands on handlebars for self-balance assistance (hands on) and with hands off (free hands). DESIGN Proof of concept study. PARTICIPANTS Four individuals with motor complete (n = 3) or incomplete (n = 1) SCI who were not able to achieve independent standing and presented a neurological lesion level ranging from cervical 4 to thoracic 2. OUTCOME MEASURES Ground reaction forces, trunk displacement, and electromyography activity of trunk and lower limb muscles. RESULTS Research participants received continuous pelvic assistance via RobUST, and manual trainer assistance at the knees to maintain standing. Participants were able to attempt all tasks. Free hands trunk perturbations resulted in greater load bearing-related sensory information (73% ipsilateral vertical loading), trunk displacement (57%), and muscle activation compared to hands on. Similarly, free hands stable standing with RobUST assistance-as-needed resulted in 8.5% larger bodyweight bearing, 112% larger trunk movement velocity, and higher trunk muscles activation compared to standing with hands on. Self-initiated trunk movements controlled by hands on showed 116% greater trunk displacement, 10% greater vertical ground reaction force, and greater ankle muscle activation compared to free hands. CONCLUSION RobUST established a safe and challenging standing environment for individuals with SCI and has the potential to improve training paradigms and assessments of standing postural control.
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Affiliation(s)
- Collin D. Bowersock
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
| | - Tanvi Pisolkar
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
| | - Isirame Omofuma
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Tatiana Luna
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Moiz Khan
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Victor Santamaria
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
| | - Joel Stein
- Department of Rehabilitation and Regenerative Medicine, Columbia University, New York, New York, USA
| | - Sunil Agrawal
- Department of Mechanical Engineering, Columbia University, New York, New York, USA
- Department of Rehabilitation and Regenerative Medicine, Columbia University, New York, New York, USA
| | - Susan J. Harkema
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
- Frazier Rehabilitation Institute, University of Louisville Health, Louisville, Kentucky, USA
- Department of Bioengineering, University of Louisville, Louisville, Kentucky, USA
| | - Enrico Rejc
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, USA
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Kalinina DS, Lyakhovetskii VA, Gorskii OV, Shkorbatova PY, Pavlova NV, Bazhenova EY, Sysoev YI, Gainetdinov RR, Musienko PE. Alteration of Postural Reactions in Rats with Different Levels of Dopamine Depletion. Biomedicines 2023; 11:1958. [PMID: 37509596 PMCID: PMC10377029 DOI: 10.3390/biomedicines11071958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/19/2023] [Accepted: 06/28/2023] [Indexed: 07/30/2023] Open
Abstract
Dopamine (DA) is the critical neurotransmitter involved in the unconscious control of muscle tone and body posture. We evaluated the general motor capacities and muscle responses to postural disturbance in three conditions: normal DA level (wild-type rats, WT), mild DA deficiency (WT after administration of α-methyl-p-tyrosine-AMPT, that blocks DA synthesis), and severe DA depletion (DAT-KO rats after AMPT). The horizontal displacements in WT rats elicited a multi-component EMG corrective response in the flexor and extensor muscles. Similar to the gradual progression of DA-related diseases, we observed different degrees of bradykinesia, rigidity, and postural instability after AMPT. The mild DA deficiency impaired the initiation pattern of corrective responses, specifically delaying the extensor muscles' activity ipsilaterally to displacement direction and earlier extensor activity from the opposite side. DA depletion in DAT-KO rats after AMPT elicited tremors, general stiffness, and akinesia, and caused earlier response to horizontal displacements in the coactivated flexor and extensor muscles bilaterally. The data obtained show the specific role of DA in postural reactions and suggest that this experimental approach can be used to investigate sensorimotor control in different dopamine-deficient states and to model DA-related diseases.
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Affiliation(s)
- Daria S Kalinina
- Institute of Translational Biomedicine, St. Petersburg State University Hospital, St. Petersburg State University, 199034 St. Petersburg, Russia
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 St. Petersburg, Russia
- Department of Neuroscience, Sirius University of Science and Technology, 354340 Sirius, Russia
| | | | - Oleg V Gorskii
- Institute of Translational Biomedicine, St. Petersburg State University Hospital, St. Petersburg State University, 199034 St. Petersburg, Russia
- Pavlov Institute of Physiology, Russian Academy of Sciences, 199034 St. Petersburg, Russia
- Center for Biomedical Engineering, National University of Science and Technology "MISIS", 119049 Moscow, Russia
| | - Polina Yu Shkorbatova
- Institute of Translational Biomedicine, St. Petersburg State University Hospital, St. Petersburg State University, 199034 St. Petersburg, Russia
- Department of Neuroscience, Sirius University of Science and Technology, 354340 Sirius, Russia
- Pavlov Institute of Physiology, Russian Academy of Sciences, 199034 St. Petersburg, Russia
| | - Natalia V Pavlova
- Institute of Translational Biomedicine, St. Petersburg State University Hospital, St. Petersburg State University, 199034 St. Petersburg, Russia
- Pavlov Institute of Physiology, Russian Academy of Sciences, 199034 St. Petersburg, Russia
| | - Elena Yu Bazhenova
- Institute of Translational Biomedicine, St. Petersburg State University Hospital, St. Petersburg State University, 199034 St. Petersburg, Russia
- Pavlov Institute of Physiology, Russian Academy of Sciences, 199034 St. Petersburg, Russia
| | - Yurii I Sysoev
- Institute of Translational Biomedicine, St. Petersburg State University Hospital, St. Petersburg State University, 199034 St. Petersburg, Russia
- Department of Neuroscience, Sirius University of Science and Technology, 354340 Sirius, Russia
- Pavlov Institute of Physiology, Russian Academy of Sciences, 199034 St. Petersburg, Russia
- Department of Pharmacology and Clinical Pharmacology, Saint Petersburg State Chemical and Pharmaceutical University, 197022 St. Petersburg, Russia
| | - Raul R Gainetdinov
- Institute of Translational Biomedicine, St. Petersburg State University Hospital, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Pavel E Musienko
- Institute of Translational Biomedicine, St. Petersburg State University Hospital, St. Petersburg State University, 199034 St. Petersburg, Russia
- Pavlov Institute of Physiology, Russian Academy of Sciences, 199034 St. Petersburg, Russia
- Life Improvement by Future Technologies Center "LIFT", 143025 Moscow, Russia
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Zelenin PV, Lyalka VF, Deliagina TG. Changes in operation of postural networks in rabbits with postural functions recovered after lateral hemisection of the spinal cord. J Physiol 2023; 601:307-334. [PMID: 36463517 PMCID: PMC9840688 DOI: 10.1113/jp283458] [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: 08/19/2022] [Accepted: 11/30/2022] [Indexed: 12/07/2022] Open
Abstract
Acute lateral hemisection of the spinal cord (LHS) severely impairs postural functions, which recover over time. Here, to reveal changes in the operation of postural networks underlying the recovery, male rabbits with recovered postural functions after LHS at T12 (R-rabbits) were used. After decerebration, we characterized the responses of individual spinal interneurons from L5 along with hindlimb EMG responses to stimulation causing postural limb reflexes (PLRs) that substantially contribute to postural corrections in intact animals. The data were compared with those obtained in our previous studies of rabbits with the intact spinal cord and rabbits after acute LHS. Although, in R-rabbits, the EMG responses to postural disturbances both ipsilateral and contralateral to the LHS (ipsi-LHS and co-LHS) were only slightly distorted, PLRs on the co-LHS side (unaffected by acute LHS) were distorted substantially and PLRs on the ipsi-LHS side (abolished by acute LHS) were close to control. Thus, in R-rabbits, plastic changes develop in postural networks both affected and unaffected by acute LHS. PLRs on the ipsi-LHS side recover mainly as a result of changes at brainstem-cerebellum-spinal levels, whereas the forebrain is substantially involved in the generation of PLRs on the co-LHS side. We found that, in areas of grey matter in which the activity of spinal neurons of the postural network was significantly decreased after acute LHS, it recovered to the control level, whereas, in areas unaffected by acute LHS, it was significantly changed. These changes underlie the recovery and distortion of PLRs on the ipsi-LHS and co-LHS sides, respectively. KEY POINTS: After lateral hemisection of the spinal cord (LHS), postural functions recover over time. The underlying changes in the operation of postural networks are unknown. We compared the responses of individual spinal neurons and hindlimb muscles to stimulation causing postural limb reflexes (PLRs) in recovered LHS-rabbits with those obtained in rabbits with the intact spinal cord and rabbits after acute LHS. We demonstrated that changes underlying the recovery of postural functions take place not only in postural networks that are severely impaired, but also in those that are almost unaffected by acute LHS. PLRs on the LHS side recover mainly as a result of changes at brainstem-cerebellum-spinal levels, whereas the forebrain is substantially involved in the generation of PLRs contralateral to the LHS.
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Affiliation(s)
- Pavel V. Zelenin
- Department of Neuroscience Karolinska Institute Stockholm Sweden
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Ohno Y, Horikoshi A, Imamura K. Reaching Task in Rats: Quantitative Evaluation and Effects of 6-OHDA into the Striatum. J Mot Behav 2022; 54:648-655. [PMID: 35392775 DOI: 10.1080/00222895.2022.2061410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In this study, we developed an evaluation method using image analysis for reaching tasks. Using this method, we studied forearm function during the reaching task in rats that received a unilateral injection of 6-OHDA into the striatum. The success ratio of the reaching task reduced to 40.5% seven days after the injection. In addition, significant changes were observed in the pronation angle of the forearm, posture control, and targeting (i.e., the distance between all fingertips and the center of the target pellet). Thus, unilateral injection of 6-OHDA reduces dopaminergic function in the brain and causes deterioration of forearm function and posture control in the reaching task.
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Affiliation(s)
- Yoichi Ohno
- Department of Physical Therapy, Faculty of Health Care, Takasaki Univ. Health and Welfare, Takasaki City, Gunma, Japan.,Department of System Life Engineering, Maebashi Institute of Technology, Maebashi City, Gunma, Japan
| | - Akinori Horikoshi
- Department of System Life Engineering, Maebashi Institute of Technology, Maebashi City, Gunma, Japan
| | - Kazuyuki Imamura
- Department of System Life Engineering, Maebashi Institute of Technology, Maebashi City, Gunma, Japan
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Popov A, Lyakhovetskii V, Bazhenova E, Gorskii O, Kalinina D, Merkulyeva N, Musienko P. The role of load-dependent sensory input in the control of balance during gait in rats. J Exp Biol 2021; 224:271196. [PMID: 34350950 DOI: 10.1242/jeb.242138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 06/23/2021] [Indexed: 11/20/2022]
Abstract
Locomotor activity requires fine balance control that strongly depends on the afferent input from the load receptors. Following hindlimb unloading (HU), the kinematic and EMG activity of the hindlimbs is known to change significantly. However, the effects of HU on the integrative control mechanisms of posture and locomotion are not clear. The goal of the present study was to evaluate the center of mass (CoM) dynamic stabilization and associated adaptive changes in the trunk and hindlimb muscle activity during locomotion after 7 days of HU. The EMG signals from the muscles of the low lumbar trunk [m. longissimus dorsi (VERT)] and the hind limb [m. tibialis anterior (TA), m. semitendinosus (ST), m. soleus (SOL)] were recorded together with the hindquarter kinematics during locomotion on a treadmill in six rats before and after HU. The CoM lateral shift in the step cycle significantly increased after HU and coincided with the enhanced activity of the VERT. The mean EMG of the TA and the ST flexor activity increased significantly with reduction of their burst duration. These data demonstrate the disturbances of body balance after HU that can influence the basic parameters of locomotor activity. The load-dependent mechanisms resulted in compensatory adjustments of flexor activity toward a faster gait strategy, such as a trot or gallop, which presumably have supraspinal origin. The neuronal underpinnings of these integrative posture and locomotion mechanisms and their possible reorganization after HU are discussed.
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Affiliation(s)
- Alexander Popov
- Institute of Translational Biomedicine, Saint-Petersburg State University, 7-9 Universitetskaya emb., 199034 Saint-Petersburg, Russia.,Pavlov Institute of Physiology RAS, 6 Makarov emb., 199034 Saint-Petersburg, Russia
| | | | - Elena Bazhenova
- Institute of Translational Biomedicine, Saint-Petersburg State University, 7-9 Universitetskaya emb., 199034 Saint-Petersburg, Russia
| | - Oleg Gorskii
- Institute of Translational Biomedicine, Saint-Petersburg State University, 7-9 Universitetskaya emb., 199034 Saint-Petersburg, Russia.,Pavlov Institute of Physiology RAS, 6 Makarov emb., 199034 Saint-Petersburg, Russia
| | - Daria Kalinina
- Institute of Translational Biomedicine, Saint-Petersburg State University, 7-9 Universitetskaya emb., 199034 Saint-Petersburg, Russia
| | - Natalia Merkulyeva
- Institute of Translational Biomedicine, Saint-Petersburg State University, 7-9 Universitetskaya emb., 199034 Saint-Petersburg, Russia.,Pavlov Institute of Physiology RAS, 6 Makarov emb., 199034 Saint-Petersburg, Russia
| | - Pavel Musienko
- Institute of Translational Biomedicine, Saint-Petersburg State University, 7-9 Universitetskaya emb., 199034 Saint-Petersburg, Russia.,Pavlov Institute of Physiology RAS, 6 Makarov emb., 199034 Saint-Petersburg, Russia.,Sirius National Technical University, Neuroscience Program, 1 Olympic pr., 354340 Sochi, Russia
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Nandakumar B, Blumenthal GH, Pauzin FP, Moxon KA. Hindlimb Somatosensory Information Influences Trunk Sensory and Motor Cortices to Support Trunk Stabilization. Cereb Cortex 2021; 31:5165-5187. [PMID: 34165153 DOI: 10.1093/cercor/bhab150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/10/2021] [Accepted: 04/27/2021] [Indexed: 11/14/2022] Open
Abstract
Sensorimotor integration in the trunk system is poorly understood despite its importance for functional recovery after neurological injury. To address this, a series of mapping studies were performed in the rat. First, the receptive fields (RFs) of cells recorded from thoracic dorsal root ganglia were identified. Second, the RFs of cells recorded from trunk primary sensory cortex (S1) were used to assess the extent and internal organization of trunk S1. Finally, the trunk motor cortex (M1) was mapped using intracortical microstimulation to assess coactivation of trunk muscles with hindlimb and forelimb muscles, and integration with S1. Projections from trunk S1 to trunk M1 were not anatomically organized, with relatively weak sensorimotor integration between trunk S1 and M1 compared to extensive integration between hindlimb S1/M1 and trunk M1. Assessment of response latency and anatomical tracing suggest that trunk M1 is abundantly guided by hindlimb somatosensory information that is derived primarily from the thalamus. Finally, neural recordings from awake animals during unexpected postural perturbations support sensorimotor integration between hindlimb S1 and trunk M1, providing insight into the role of the trunk system in postural control that is useful when studying recovery after injury.
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Affiliation(s)
- Bharadwaj Nandakumar
- Department of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, 19104 PA, USA.,Department of Biomedical Engineering, University of California, Davis, 95616 CA, USA
| | - Gary H Blumenthal
- Department of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, 19104 PA, USA.,Department of Biomedical Engineering, University of California, Davis, 95616 CA, USA
| | | | - Karen A Moxon
- Department of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, 19104 PA, USA.,Department of Biomedical Engineering, University of California, Davis, 95616 CA, USA.,Center for Neuroscience, Davis, 95618 CA, USA
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10
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Differential Contribution of V0 Interneurons to Execution of Rhythmic and Nonrhythmic Motor Behaviors. J Neurosci 2021; 41:3432-3445. [PMID: 33637562 DOI: 10.1523/jneurosci.1979-20.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 11/21/2022] Open
Abstract
Locomotion, scratching, and stabilization of the body orientation in space are basic motor functions which are critically important for animal survival. Their execution requires coordinated activity of muscles located in the left and right halves of the body. Commissural interneurons (CINs) are critical elements of the neuronal networks underlying the left-right motor coordination. V0 interneurons (characterized by the early expression of the transcription factor Dbx1) contain a major class of CINs in the spinal cord (excitatory, V0V; inhibitory, V0D), and a small subpopulation of excitatory ipsilaterally projecting interneurons. The role of V0 CINs in left-right coordination during forward locomotion was demonstrated earlier. Here, to reveal the role of glutamatergic V0 and other V0 subpopulations in control of backward locomotion, scratching, righting behavior, and postural corrections, kinematics of these movements performed by wild-type mice and knock-out mice with glutamatergic V0 or all V0 interneurons ablated were compared. Our results suggest that the functional effect of excitatory V0 neurons during backward locomotion and scratching is inhibitory, and that the execution of scratching involves active inhibition of the contralateral scratching central pattern generator mediated by excitatory V0 neurons. By contrast, other V0 subpopulations are elements of spinal networks generating postural corrections. Finally, all V0 subpopulations contribute to the generation of righting behavior. We found that different V0 subpopulations determine left-right coordination in the anterior and posterior parts of the body during a particular behavior. Our study shows a differential contribution of V0 subpopulations to diverse motor acts that provides new insight to organization of motor circuits.SIGNIFICANCE STATEMENT Commissural interneurons with their axons crossing the midline of the nervous system are critical elements of the neuronal networks underlying the left-right motor coordination. For the majority of motor behaviors, the neuronal mechanisms underlying left-right coordination are unknown. Here, we demonstrate the functional role of excitatory V0 neurons and other subpopulations of V0 interneurons in control of a number of basic motor behaviors-backward locomotion, scratching, righting behavior, and postural corrections-which are critically important for animal survival. We have shown that different subpopulations of V0 neurons determine left-right coordination in the context of different behaviors as well as in the anterior and posterior parts of the body during a particular behavior.
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Zelenin PV, Lyalka VF, Orlovsky GN, Deliagina TG. Changes in Activity of Spinal Postural Networks at Different Time Points After Spinalization. Front Cell Neurosci 2019; 13:387. [PMID: 31496938 PMCID: PMC6712497 DOI: 10.3389/fncel.2019.00387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/06/2019] [Indexed: 11/25/2022] Open
Abstract
Postural limb reflexes (PLRs) are an essential component of postural corrections. Spinalization leads to disappearance of postural functions (including PLRs). After spinalization, spastic, incorrectly phased motor responses to postural perturbations containing oscillatory EMG bursting gradually develop, suggesting plastic changes in the spinal postural networks. Here, to reveal these plastic changes, rabbits at 3, 7, and 30 days after spinalization at T12 were decerebrated, and responses of spinal interneurons from L5 along with hindlimb muscles EMG responses to postural sensory stimuli, causing PLRs in subjects with intact spinal cord (control), were characterized. Like in control and after acute spinalization, at each of three studied time points after spinalization, neurons responding to postural sensory stimuli were found. Proportion of such neurons during 1st month after spinalization did not reach the control level, and was similar to that observed after acute spinalization. In contrast, their activity (which was significantly decreased after acute spinalization) reached the control value at 3 days after spinalization and remained close to this level during the following month. However, the processing of postural sensory signals, which was severely distorted after acute spinalization, did not recover by 30 days after injury. In addition, we found a significant enhancement of the oscillatory activity in a proportion of the examined neurons, which could contribute to generation of oscillatory EMG bursting. Motor responses to postural stimuli (which were almost absent after acute spinalization) re-appeared at 3 days after spinalization, although they were very weak, irregular, and a half of them was incorrectly phased in relation to postural stimuli. Proportion of correct and incorrect motor responses remained almost the same during the following month, but their amplitude gradually increased. Thus, spinalization triggers two processes of plastic changes in the spinal postural networks: rapid (taking days) restoration of normal activity level in spinal interneurons, and slow (taking months) recovery of motoneuronal excitability. Most likely, recovery of interneuronal activity underlies re-appearance of motor responses to postural stimuli. However, absence of recovery of normal processing of postural sensory signals and enhancement of oscillatory activity of neurons result in abnormal PLRs and loss of postural functions.
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12
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Zelenin PV, Lyalka VF, Orlovsky GN, Deliagina TG. Effect of acute lateral hemisection of the spinal cord on spinal neurons of postural networks. Neuroscience 2016; 339:235-253. [PMID: 27702647 PMCID: PMC5118056 DOI: 10.1016/j.neuroscience.2016.09.043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 08/10/2016] [Accepted: 09/25/2016] [Indexed: 01/24/2023]
Abstract
In quadrupeds, acute lateral hemisection of the spinal cord (LHS) severely impairs postural functions, which recover over time. Postural limb reflexes (PLRs) represent a substantial component of postural corrections in intact animals. The aim of the present study was to characterize the effects of acute LHS on two populations of spinal neurons (F and E) mediating PLRs. For this purpose, in decerebrate rabbits, responses of individual neurons from L5 to stimulation causing PLRs were recorded before and during reversible LHS (caused by temporal cold block of signal transmission in lateral spinal pathways at L1), as well as after acute surgical LHS at L1. Results obtained after Sur-LHS were compared to control data obtained in our previous study. We found that acute LHS caused disappearance of PLRs on the affected side. It also changed a proportion of different types of neurons on that side. A significant decrease and increase in the proportion of F- and non-modulated neurons, respectively, was found. LHS caused a significant decrease in most parameters of activity in F-neurons located in the ventral horn on the lesioned side and in E-neurons of the dorsal horn on both sides. These changes were caused by a significant decrease in the efficacy of posture-related sensory input from the ipsilateral limb to F-neurons, and from the contralateral limb to both F- and E-neurons. These distortions in operation of postural networks underlie the impairment of postural control after acute LHS, and represent a starting point for the subsequent recovery of postural functions.
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Affiliation(s)
- P V Zelenin
- Department of Neuroscience, Karolinska Institute, SE-17177 Stockholm, Sweden
| | - V F Lyalka
- Department of Neuroscience, Karolinska Institute, SE-17177 Stockholm, Sweden
| | - G N Orlovsky
- Department of Neuroscience, Karolinska Institute, SE-17177 Stockholm, Sweden
| | - T G Deliagina
- Department of Neuroscience, Karolinska Institute, SE-17177 Stockholm, Sweden.
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13
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Lavrov I, Gerasimenko Y, Burdick J, Zhong H, Roy RR, Edgerton VR. Integrating multiple sensory systems to modulate neural networks controlling posture. J Neurophysiol 2015; 114:3306-14. [PMID: 26445868 DOI: 10.1152/jn.00583.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 10/05/2015] [Indexed: 01/03/2023] Open
Abstract
In this study we investigated the ability of sensory input to produce tonic responses in hindlimb muscles to facilitate standing in adult spinal rats and tested two hypotheses: 1) whether the spinal neural networks below a complete spinal cord transection can produce tonic reactions by activating different sensory inputs and 2) whether facilitation of tonic and rhythmic responses via activation of afferents and with spinal cord stimulation could engage similar neuronal mechanisms. We used a dynamically controlled platform to generate vibration during weight bearing, epidural stimulation (at spinal cord level S1), and/or tail pinching to determine the postural control responses that can be generated by the lumbosacral spinal cord. We observed that a combination of platform displacement, epidural stimulation, and tail pinching produces a cumulative effect that progressively enhances tonic responses in the hindlimbs. Tonic responses produced by epidural stimulation alone during standing were represented mainly by monosynaptic responses, whereas the combination of epidural stimulation and tail pinching during standing or epidural stimulation during stepping on a treadmill facilitated bilaterally both monosynaptic and polysynaptic responses. The results demonstrate that tonic muscle activity after complete spinal cord injury can be facilitated by activation of specific combinations of afferent inputs associated with load-bearing proprioception and cutaneous input in the presence of epidural stimulation and indicate that whether activation of tonic or rhythmic responses is generated depends on the specific combinations of sources and types of afferents activated in the hindlimb muscles.
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Affiliation(s)
- I Lavrov
- Departments of Integrative Biology and Physiology and Neurobiology, University of California, Los Angeles, California; Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia; and
| | - Y Gerasimenko
- Departments of Integrative Biology and Physiology and Neurobiology, University of California, Los Angeles, California; Pavlov Institute of Physiology, St. Petersburg, Russia; Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia; and
| | - J Burdick
- Bioengineering, California Institute of Technology, Pasadena, California
| | - H Zhong
- Departments of Integrative Biology and Physiology and Neurobiology, University of California, Los Angeles, California; Brain Research Institute, University of California, Los Angeles, California
| | - R R Roy
- Departments of Integrative Biology and Physiology and Neurobiology, University of California, Los Angeles, California; Brain Research Institute, University of California, Los Angeles, California
| | - V R Edgerton
- Departments of Integrative Biology and Physiology and Neurobiology, University of California, Los Angeles, California; Brain Research Institute, University of California, Los Angeles, California
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14
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Zelenin PV, Hsu LJ, Lyalka VF, Orlovsky GN, Deliagina TG. Putative spinal interneurons mediating postural limb reflexes provide a basis for postural control in different planes. Eur J Neurosci 2015; 41:168-81. [PMID: 25370349 PMCID: PMC4300251 DOI: 10.1111/ejn.12780] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 10/01/2014] [Accepted: 10/08/2014] [Indexed: 11/27/2022]
Abstract
The dorsal-side-up trunk orientation in standing quadrupeds is maintained by the postural system driven mainly by somatosensory inputs from the limbs. Postural limb reflexes (PLRs) represent a substantial component of this system. Earlier we described spinal neurons presumably contributing to the generation of PLRs. The first aim of the present study was to reveal trends in the distribution of neurons with different parameters of PLR-related activity across the gray matter of the spinal cord. The second aim was to estimate the contribution of PLR-related neurons with different patterns of convergence of sensory inputs from the limbs to stabilization of body orientation in different planes. For this purpose, the head and vertebral column of the decerebrate rabbit were fixed and the hindlimbs were positioned on a platform. Activity of individual neurons from L5 to L6 was recorded during PLRs evoked by lateral tilts of the platform. In addition, the neurons were tested by tilts of the platform under only the ipsilateral or only the contralateral limb, as well as during in-phase tilts of the platforms under both limbs. We found that, across the spinal gray matter, strength of PLR-related neuronal activity and sensory input from the ipsilateral limb decreased in the dorsoventral direction, while strength of the input from the contralateral limb increased. A near linear summation of tilt-related sensory inputs from different limbs was found. Functional roles were proposed for individual neurons. The obtained data present the first characterization of posture-related spinal neurons, forming a basis for studies of postural networks impaired by injury.
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Affiliation(s)
- Pavel V Zelenin
- Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden
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15
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Deliagina TG, Beloozerova IN, Orlovsky GN, Zelenin PV. Contribution of supraspinal systems to generation of automatic postural responses. Front Integr Neurosci 2014; 8:76. [PMID: 25324741 PMCID: PMC4181245 DOI: 10.3389/fnint.2014.00076] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 09/14/2014] [Indexed: 11/13/2022] Open
Abstract
Different species maintain a particular body orientation in space due to activity of the closed-loop postural control system. In this review we discuss the role of neurons of descending pathways in operation of this system as revealed in animal models of differing complexity: lower vertebrate (lamprey) and higher vertebrates (rabbit and cat). In the lamprey and quadruped mammals, the role of spinal and supraspinal mechanisms in the control of posture is different. In the lamprey, the system contains one closed-loop mechanism consisting of supraspino-spinal networks. Reticulospinal (RS) neurons play a key role in generation of postural corrections. Due to vestibular input, any deviation from the stabilized body orientation leads to activation of a specific population of RS neurons. Each of the neurons activates a specific motor synergy. Collectively, these neurons evoke the motor output necessary for the postural correction. In contrast to lampreys, postural corrections in quadrupeds are primarily based not on the vestibular input but on the somatosensory input from limb mechanoreceptors. The system contains two closed-loop mechanisms - spinal and spino-supraspinal networks, which supplement each other. Spinal networks receive somatosensory input from the limb signaling postural perturbations, and generate spinal postural limb reflexes. These reflexes are relatively weak, but in intact animals they are enhanced due to both tonic supraspinal drive and phasic supraspinal commands. Recent studies of these supraspinal influences are considered in this review. A hypothesis suggesting common principles of operation of the postural systems stabilizing body orientation in a particular plane in the lamprey and quadrupeds, that is interaction of antagonistic postural reflexes, is discussed.
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Affiliation(s)
| | | | | | - Pavel V. Zelenin
- Department of Neuroscience, Karolinska InstituteStockholm, Sweden
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16
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Farrell BJ, Bulgakova MA, Beloozerova IN, Sirota MG, Prilutsky BI. Body stability and muscle and motor cortex activity during walking with wide stance. J Neurophysiol 2014; 112:504-24. [PMID: 24790167 PMCID: PMC4122701 DOI: 10.1152/jn.00064.2014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 04/23/2014] [Indexed: 11/22/2022] Open
Abstract
Biomechanical and neural mechanisms of balance control during walking are still poorly understood. In this study, we examined the body dynamic stability, activity of limb muscles, and activity of motor cortex neurons [primarily pyramidal tract neurons (PTNs)] in the cat during unconstrained walking and walking with a wide base of support (wide-stance walking). By recording three-dimensional full-body kinematics we found for the first time that during unconstrained walking the cat is dynamically unstable in the forward direction during stride phases when only two diagonal limbs support the body. In contrast to standing, an increased lateral between-paw distance during walking dramatically decreased the cat's body dynamic stability in double-support phases and prompted the cat to spend more time in three-legged support phases. Muscles contributing to abduction-adduction actions had higher activity during stance, while flexor muscles had higher activity during swing of wide-stance walking. The overwhelming majority of neurons in layer V of the motor cortex, 82% and 83% in the forelimb and hindlimb representation areas, respectively, were active differently during wide-stance walking compared with unconstrained condition, most often by having a different depth of stride-related frequency modulation along with a different mean discharge rate and/or preferred activity phase. Upon transition from unconstrained to wide-stance walking, proximal limb-related neuronal groups subtly but statistically significantly shifted their activity toward the swing phase, the stride phase where most of body instability occurs during this task. The data suggest that the motor cortex participates in maintenance of body dynamic stability during locomotion.
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Affiliation(s)
- Brad J Farrell
- School of Applied Physiology, Center for Human Movement Studies, Georgia Institute of Technology, Atlanta, Georgia; and
| | - Margarita A Bulgakova
- School of Applied Physiology, Center for Human Movement Studies, Georgia Institute of Technology, Atlanta, Georgia; and Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Irina N Beloozerova
- Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Mikhail G Sirota
- Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Boris I Prilutsky
- School of Applied Physiology, Center for Human Movement Studies, Georgia Institute of Technology, Atlanta, Georgia; and
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17
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Abstract
Postural limb reflexes (PLRs) represent a substantial component of the postural system responsible for stabilization of dorsal-side-up trunk orientation in quadrupeds. Spinalization causes spinal shock, that is a dramatic reduction of extensor tone and spinal reflexes, including PLRs. The goal of our study was to determine changes in activity of spinal interneurons, in particular those mediating PLRs, that is caused by spinalization. For this purpose, in decerebrate rabbits, activity of individual interneurons from L5 was recorded during stimulation causing PLRs under two conditions: (1) when neurons received supraspinal influences and (2) when these influences were temporarily abolished by a cold block of spike propagation in spinal pathways at T12 ("reversible spinalization"; RS). The effect of RS, that is a dramatic reduction of PLRs, was similar to the effect of surgical spinalization. In the examined population of interneurons (n = 199), activity of 84% of them correlated with PLRs, suggesting that they contribute to PLR generation. RS affected differently individual neurons: the mean frequency decreased in 67% of neurons, increased in 15%, and did not change in 18%. Neurons with different RS effects were differently distributed across the spinal cord: 80% of inactivated neurons were located in the intermediate area and ventral horn, whereas 50% of nonaffected neurons were located in the dorsal horn. We found a group of neurons that were coactivated with extensors during PLRs before RS and exhibited a dramatic (>80%) decrease in their activity during RS. We suggest that these neurons are responsible for reduction of extensor tone and postural reflexes during spinal shock.
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18
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Hsu LJ, Zelenin PV, Orlovsky GN, Deliagina TG. Effects of galvanic vestibular stimulation on postural limb reflexes and neurons of spinal postural network. J Neurophysiol 2012; 108:300-13. [PMID: 22514291 DOI: 10.1152/jn.00041.2012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Quadrupeds maintain the dorsal side up body orientation due to the activity of the postural control system driven by limb mechanoreceptors. Binaural galvanic vestibular stimulation (GVS) causes a lateral body sway toward the anode. Previously, we have shown that this new position is actively stabilized, suggesting that GVS changes a set point in the reflex mechanisms controlling body posture. The aim of the present study was to reveal the underlying neuronal mechanisms. Experiments were performed on decerebrate rabbits. The vertebral column was rigidly fixed, whereas hindlimbs were positioned on a platform. Periodic lateral tilts of the platform caused postural limb reflexes (PLRs): activation of extensors in the loaded and flexing limb and a decrease in extensor activity in the opposite (unloaded and extending) limb. Putative spinal interneurons were recorded in segments L4-L5 during PLRs, with and without GVS. We have found that GVS enhanced PLRs on the cathode side and reduced them on the anode side. This asymmetry in PLRs can account for changes in the stabilized body orientation observed in normal rabbits subjected to continuous GVS. Responses to platform tilts (frequency modulation) were observed in 106 spinal neurons, suggesting that they can contribute to PLR generation. Two neuron groups were active in opposite phases of the tilt cycle of the ipsi-limb: F-neurons in the flexion phase, and E-neurons in the extension phase. Neurons were driven mainly by afferent input from the ipsi-limb. If one supposes that F- and E-neurons contribute, respectively, to excitation and inhibition of extensor motoneurons, one can expect that the pattern of response to GVS in F-neurons will be similar to that in extensor muscles, whereas E-neurons will have an opposite pattern. We have found that ~40% of all modulated neurons meet this condition, suggesting that they contribute to the generation of PLRs and to the GVS-caused changes in PLRs.
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Affiliation(s)
- L-J Hsu
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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19
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Musienko P, Courtine G, Tibbs JE, Kilimnik V, Savochin A, Garfinkel A, Roy RR, Edgerton VR, Gerasimenko Y. Somatosensory control of balance during locomotion in decerebrated cat. J Neurophysiol 2012; 107:2072-82. [PMID: 22236709 PMCID: PMC3331606 DOI: 10.1152/jn.00730.2011] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 01/04/2012] [Indexed: 01/24/2023] Open
Abstract
Postmammillary decerebrated cats can generate stepping on a moving treadmill belt when the brain stem or spinal cord is stimulated tonically and the hindquarters are supported both vertically and laterally. While adequate propulsion seems to be generated by the hindlimbs under these conditions, the ability to sustain equilibrium during locomotion has not been examined extensively. We found that tonic epidural spinal cord stimulation (5 Hz at L5) of decerebrated cats initiated and sustained unrestrained weight-bearing hindlimb stepping for extended periods. Detailed analyses of the relationships among hindlimb muscle EMG activity and trunk and limb kinematics and kinetics indicated that the motor circuitries in decerebrated cats actively maintain equilibrium during walking, similar to that observed in intact animals. Because of the suppression of vestibular, visual, and head-neck-trunk sensory input, balance-related adjustments relied entirely on the integration of somatosensory information arising from the moving hindquarters. In addition to dynamic balance control during unperturbed locomotion, sustained stepping could be reestablished rapidly after a collapse or stumble when the hindquarters switched from a restrained to an unrestrained condition. Deflecting the body by pulling the tail laterally induced adaptive modulations in the EMG activity, step cycle features, and left-right ground reaction forces that were sufficient to maintain lateral stability. Thus the brain stem-spinal cord circuitry of decerebrated cats in response to tonic spinal cord stimulation can control dynamic balance during locomotion using only somatosensory input.
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20
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Physiological and circuit mechanisms of postural control. Curr Opin Neurobiol 2012; 22:646-52. [PMID: 22446009 DOI: 10.1016/j.conb.2012.03.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 02/27/2012] [Accepted: 03/05/2012] [Indexed: 11/21/2022]
Abstract
The postural system maintains a specific body orientation and equilibrium during standing and during locomotion in the presence of many destabilizing factors (external and internal). Numerous studies in humans have revealed essential features of the functional organization of this system. Recent studies on different animal models have significantly supplemented human studies. They have greatly expanded our knowledge of how the control system operates, how the postural functions are distributed within different parts of CNS, and how these parts interact with each other to produce postural corrections and adjustments. This review outlines recent advances in the studies of postural control in quadrupeds, with special attention given the neuronal postural mechanisms.
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21
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Zelenin PV, Hsu LJ, Orlovsky GN, Deliagina TG. Use of galvanic vestibular feedback to control postural orientation in decerebrate rabbits. J Neurophysiol 2012; 107:3020-6. [PMID: 22402660 DOI: 10.1152/jn.00042.2012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In quadrupeds, the dorsal-side-up body orientation during standing is maintained due to a postural system that is driven by feedback signals coming mainly from limb mechanoreceptors. In caudally decerebrated (postmammillary) rabbits, the efficacy of this system is considerably reduced. In this paper, we report that the efficacy of postural control in these animals can be restored with galvanic vestibular stimulation (GVS) applied transcutaneously to the labyrinths. In standing intact rabbits, GVS causes a lateral body sway towards the positive electrode. We used this GVS-caused sway to counteract the lateral body sway resulting from a mechanical perturbation of posture. Experiments were performed on postmammillary rabbits that stood on the tilting platform with their hindlimbs. To make the GVS value dependent on the postural perturbation (i.e., on the lateral body sway caused by tilt of the platform), an artificial feedback loop was formed in the following ways: 1) Information about the body sway was provided by a mechanical sensor; 2) The GVS current was applied when the sway exceeded a threshold value; the polarity of the current was determined by the sway direction. This simple algorithm allowed the "hybrid" postural system to maintain the dorsal-side-up orientation of the hindquarters when the platform was tilted by ± 20°. Thus, an important postural function, i.e., securing lateral stability during standing, can be restored in decerebrate rabbits with the GVS-based artificial feedback. We suggest that such a control system can compensate for the loss of lateral stability of various etiologies, and can be used for restoration of balance control in patients with impaired postural functions.
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Affiliation(s)
- P V Zelenin
- Dept. of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden
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22
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Musienko PE, Zelenin PV, Orlovsky GN, Deliagina TG. Facilitation of postural limb reflexes with epidural stimulation in spinal rabbits. J Neurophysiol 2010; 103:1080-92. [PMID: 20018835 PMCID: PMC2822695 DOI: 10.1152/jn.00575.2009] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 12/16/2009] [Indexed: 11/22/2022] Open
Abstract
It is known that after spinalization animals lose their ability to maintain lateral stability when standing or walking. A likely reason for this is a reduction of the postural limb reflexes (PLRs) driven by stretch and load receptors of the limbs. The aim of this study was to clarify whether spinal networks contribute to the generation of PLRs. For this purpose, first, PLRs were recorded in decerebrated rabbits before and after spinalization at T12. Second, the effects of epidural electrical stimulation (EES) at L7 on the limb reflexes were studied after spinalization. To evoke PLRs, the vertebrate column of the rabbit was fixed, whereas the hindlimbs were positioned on the platform. Periodic lateral tilts of the platform caused antiphase flexion-extension limbs movements, similar to those observed in intact animals keeping balance on the tilting platform. Before spinalization, these movements evoked PLRs: augmentation of extensor EMGs and increase of contact force during limb flexion, suggesting their stabilizing postural effects. Spinalization resulted in almost complete disappearance of PLRs. After EES, however, the PLRs reappeared and persisted for up to several minutes, although their values were reduced. The post-EES effects could be magnified by intrathecal application of quipazine (5-HT agonist) at L4-L6. Results of this study suggest that the spinal cord contains the neuronal networks underlying PLRs; they can contribute to the maintenance of lateral stability in intact subjects. In acute spinal animals, these networks can be activated by EES, suggesting that they are normally activated by a tonic supraspinal drive.
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Affiliation(s)
- P. E. Musienko
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden; and
- Pavlov Institute of Physiology, St. Petersburg, Russia
| | - P. V. Zelenin
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden; and
| | - G. N. Orlovsky
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden; and
| | - T. G. Deliagina
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden; and
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23
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Karayannidou A, Beloozerova IN, Zelenin PV, Stout EE, Sirota MG, Orlovsky GN, Deliagina TG. Activity of pyramidal tract neurons in the cat during standing and walking on an inclined plane. J Physiol 2009; 587:3795-811. [PMID: 19491244 DOI: 10.1113/jphysiol.2009.170183] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
To keep balance when standing or walking on a surface inclined in the roll plane, the cat modifies its body configuration so that the functional length of its right and left limbs becomes different. The aim of the present study was to assess the motor cortex participation in the generation of this left/right asymmetry. We recorded the activity of fore- and hindlimb-related pyramidal tract neurons (PTNs) during standing and walking on a treadmill. A difference in PTN activity at two tilted positions of the treadmill (+/- 15 deg) was considered a positional response to surface inclination. During standing, 47% of PTNs exhibited a positional response, increasing their activity with either the contra-tilt (20%) or the ipsi-tilt (27%). During walking, PTNs were modulated in the rhythm of stepping, and tilts of the supporting surface evoked positional responses in the form of changes to the magnitude of modulation in 58% of PTNs. The contra-tilt increased activity in 28% of PTNs, and ipsi-tilt increased activity in 30% of PTNs. We suggest that PTNs with positional responses contribute to the modifications of limb configuration that are necessary for adaptation to the inclined surface. By comparing the responses to tilts in individual PTNs during standing and walking, four groups of PTNs were revealed: responding in both tasks (30%); responding only during standing (16%); responding only during walking (30%); responding in none of the tasks (24%). This diversity suggests that common and separate cortical mechanisms are used for postural adaptation to tilts during standing and walking.
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Affiliation(s)
- A Karayannidou
- Department of Neuroscience, Karolinska Institute, SE-17177 Stockholm, Sweden
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24
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Lyalka VF, Orlovsky GN, Deliagina TG. Impairment of postural control in rabbits with extensive spinal lesions. J Neurophysiol 2009; 101:1932-40. [PMID: 19164112 PMCID: PMC2695648 DOI: 10.1152/jn.00009.2008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Accepted: 01/15/2009] [Indexed: 11/22/2022] Open
Abstract
Our previous studies on rabbits demonstrated that the ventral spinal pathways are of primary importance for postural control in the hindquarters. After ventral hemisection, postural control did not recover, whereas after dorsal or lateral hemisection it did. The aim of this study was to examine postural capacity of rabbits after more extensive lesion (3/4 section of the spinal cord at T(12) level), that is, with only one ventral quadrant spared (VQ animals). They were tested before (control) and after lesion on the platform periodically tilted in the frontal plane. In control animals, tilts of the platform regularly elicited coordinated electromyographic (EMG) responses in the hindlimbs, which resulted in generation of postural corrections and in maintenance of balance. In VQ rabbits, the EMG responses appeared only in a part of tilt cycles, and they could be either correctly or incorrectly phased in relation to tilts. Because of a reduced value and incorrect phasing of EMG responses on both sides, this muscle activity did not cause postural corrective movements in the majority of rabbits, and the body swayed together with the platform. In these rabbits, the ability to perform postural corrections did not recover during the whole period of observation (< or =30 days). Low probability of correct EMG responses to tilts in most rabbits as well as an appearance of incorrect responses to tilts suggest that the spinal reflex chains, necessary for postural control, have not been specifically selected by a reduced supraspinal drive transmitted via a single ventral quadrant.
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Affiliation(s)
- V. F. Lyalka
- Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden
| | - G. N. Orlovsky
- Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden
| | - T. G. Deliagina
- Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden
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Deliagina TG, Beloozerova IN, Zelenin PV, Orlovsky GN. Spinal and supraspinal postural networks. BRAIN RESEARCH REVIEWS 2008; 57:212-21. [PMID: 17822773 PMCID: PMC2204048 DOI: 10.1016/j.brainresrev.2007.06.017] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 06/18/2007] [Indexed: 11/18/2022]
Abstract
Different species maintain a particular body orientation in space (upright in humans, dorsal-side-up in quadrupeds, fish and lamprey) due to the activity of a closed-loop postural control system. We will discuss operation of spinal and supraspinal postural networks studied in a lower vertebrate (lamprey) and in two mammals (rabbit and cat). In the lamprey, the postural control system is driven by vestibular input. The key role in the postural network belongs to the reticulospinal (RS) neurons. Due to vestibular input, deviation from the stabilized body orientation in any (roll, pitch, yaw) plane leads to generation of RS commands, which are sent to the spinal cord and cause postural correction. For each of the planes, there are two groups of RS neurons responding to rotation in the opposite directions; they cause a turn opposite to the initial one. The command transmitted by an individual RS neuron causes the motor response, which contributes to the correction of posture. In each plane, the postural system stabilizes the orientation at which the antagonistic vestibular reflexes compensate for each other. Thus, in lamprey the supraspinal networks play a crucial role in stabilization of body orientation, and the function of the spinal networks is transformation of supraspinal commands into the motor pattern of postural corrections. In terrestrial quadrupeds, the postural system stabilizing the trunk orientation in the transversal plane was analyzed. It consists of two relatively independent sub-systems stabilizing orientation of the anterior and posterior parts of the trunk. They are driven by somatosensory input from limb mechanoreceptors. Each sub-system consists of two closed-loop mechanisms - spinal and spino-supraspinal. Operation of the supraspinal networks was studied by recording the posture-related activity of corticospinal neurons. The postural capacity of spinal networks was evaluated in animals with lesions to the spinal cord. Relative contribution of spinal and supraspinal mechanisms to the stabilization of trunk orientation is discussed.
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Affiliation(s)
- T G Deliagina
- Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden.
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Karayannidou A, Deliagina TG, Tamarova ZA, Sirota MG, Zelenin PV, Orlovsky GN, Beloozerova IN. Influences of sensory input from the limbs on feline corticospinal neurons during postural responses. J Physiol 2007; 586:247-63. [PMID: 17974591 DOI: 10.1113/jphysiol.2007.144840] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The dorsal-side-up body posture of standing quadrupeds is maintained by coordinated activity of all limbs. Somatosensory input from the limbs evokes postural responses when the supporting surface is perturbed. The aim of this study was to reveal the contribution of sensory inputs from individual limbs to the posture-related modulation of pyramidal tract neurons (PTNs) arising in the primary motor cortex. We recorded the activity of PTNs from the limb representation of motor cortex in the cat maintaining balance on a platform periodically tilted in the frontal plane. Each PTN was recorded during standing on four limbs, and when two or three limbs were lifted from the platform and thus did not signal its displacement to motor cortex. By comparing PTN responses to tilts in different tests we found that the amplitude and the phase of the response in the majority of them were determined primarily by the sensory input from the corresponding contralateral limb. In a portion of PTNs, this input originated from afferents of the peripheral receptive field. Sensory input from the ipsilateral limb, as well as input from limbs of the other girdle made a much smaller contribution to the PTN modulation. These results show that, during postural activity, a key role of PTNs is the feedback control of the corresponding contralateral limb and, to a lesser extent, the coordination of posture within a girdle and between the two girdles.
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Abstract
This paper briefly summarizes the studies of nervous mechanisms controlling the body posture, which were performed in the Department of Neuroscience of the Karolinska Institute during the last decade. Postural mechanisms were investigated in "animal models" of different complexity--the mollusk, lamprey, rabbit, and cat. The following problems were addressed: (1) functional organization of the postural system; (2) localization of postural functions in the mammalian CNS; (3) postural networks; (4) impairment of postural control caused by vestibular deficit. These studies have significantly expanded our knowledge of how the postural control system operates, how the stabilized body orientation can be changed, and how the postural functions are distributed within different parts of the CNS. For simpler animal models (mollusk, lamprey), the neuronal networks responsible for the control of body posture have been analyzed in considerable detail, with identification of the main cell types and their interactions. Also, alterations in the activity of postural mechanisms caused by the vestibular deficit were investigated to better understand the process of recovery of postural function.
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Affiliation(s)
- Tatiana G Deliagina
- Karolinska Institutet, The Nobel Institute for Neurophysiology, Department of Neuroscience, S-17177, Stockholm, Sweden.
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Raptis HA, Dannenbaum E, Paquet N, Feldman AG. Vestibular system may provide equivalent motor actions regardless of the number of body segments involved in the task. J Neurophysiol 2007; 97:4069-78. [PMID: 17428903 DOI: 10.1152/jn.00909.2006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The vestibulospinal system likely plays an essential role in motor equivalence--the ability to reach the desired motor goal despite intentional or imposed changes in the number of body segments involved in the task. To test this hypothesis, we compared the ability of healthy subjects and patients with unilateral vestibular lesions (surgical acoustic neuroma resection 0.6 to 6.7 yr before the study) to maintain either the same hand position or the same trajectory of within arm reach movements while flexing the trunk, in the absence of vision. In randomly selected trials, the trunk motion was prevented by an electromagnetic device. Healthy subjects were able to preserve the hand position or trajectory by modifying the elbow and shoulder joint rotations in a condition-dependent way, at a minimal latency of about 60 ms after the trunk movement onset. In contrast, six of seven patients showed deficits in the compensatory angular modifications at least in one of two tasks so that 30-100% of the trunk displacement was not compensated and thus influenced the hand position or trajectory. Results suggest that vestibular influences evoked by the head motion during trunk flexion play a major role in maintaining the consistency of arm motor actions in external space despite changes in the number of body segments involved. Our findings also suggest that despite long-term plasticity in the vestibular system and related neural structures, unilateral vestibular lesion may reduce the capacity of the nervous system to achieve motor equivalence.
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Affiliation(s)
- H A Raptis
- Neurological Science Research Center, Department of Physiology, University of Montreal and Center for Multidisciplinary Research in Rehabilitation (CRIR), Rehabilitation Institute of Montreal, Montreal., Quebec, Canada
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Deliagina TG, Orlovsky GN, Zelenin PV, Beloozerova IN. Neural bases of postural control. Physiology (Bethesda) 2007; 21:216-25. [PMID: 16714480 DOI: 10.1152/physiol.00001.2006] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The body posture during standing and walking is maintained due to the activity of a closed-loop control system. In the review, we consider different aspects of postural control: its functional organization, the distribution of postural functions in different parts of the central nervous system, and the activity of neuronal networks controlling posture.
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Deliagina TG, Sirota MG, Zelenin PV, Orlovsky GN, Beloozerova IN. Interlimb postural coordination in the standing cat. J Physiol 2006; 573:211-24. [PMID: 16527856 PMCID: PMC1779703 DOI: 10.1113/jphysiol.2006.104893] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The dorsal-side-up body posture in standing quadrupeds is maintained by coordinated activity of four limbs. We studied this coordination in the cat standing on the platform periodically tilted in the frontal plane. By suspending different body parts, we unloaded one, two, or three limbs. The activity of selected extensor muscles and the contact forces under the limbs were recorded. With all four limbs on the platform, extensors of the fore- and hindlimbs increased their activity in parallel during ipsilateral downward tilt. With two forelimbs on the platform, this muscular pattern persisted in the forelimbs and in the suspended hindlimbs. With two hindlimbs on the platform, the muscular pattern persisted only in the hindlimbs, but not in the suspended forelimbs. These results suggest that coordination between the two girdles is based primarily on the influences of the forelimbs upon the hindlimbs. However, these influences do not necessarily determine the responses to tilt in the hindlimbs. This was demonstrated by antiphase tilting of the fore- and hindquarters. Under these conditions, the extensors of the fore- and hindlimbs appeared uncoupled and modulated in antiphase, suggesting an independent control of posture in the fore- and hindquarters. With only one limb supporting the shoulder or hip girdle, a muscular pattern with normal phasing was observed in both limbs of that girdle. This finding suggests that reflex mechanisms of an individual limb generate only a part of postural corrections; another part is produced on the basis of crossed influences.
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Affiliation(s)
- Tatiana G Deliagina
- The Nobel Institute for Neurophysiology, Department of Neuroscience, Karolinska Institute, SE-17177, Stockholm, Sweden.
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Beloozerova IN, Sirota MG, Orlovsky GN, Deliagina TG. Comparison of activity of individual pyramidal tract neurons during balancing, locomotion, and scratching. Behav Brain Res 2006; 169:98-110. [PMID: 16445992 DOI: 10.1016/j.bbr.2005.12.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2005] [Revised: 12/16/2005] [Accepted: 12/23/2005] [Indexed: 11/23/2022]
Abstract
Neuronal mechanisms of the spinal cord, brainstem, and cerebellum play a key role in the control of complex automatic motor behaviors-postural corrections, stepping, and scratching, whereas the role of the motor cortex is less clear. To assess this role, we recorded fore and hind limb-related pyramidal tract neurons (PTNs) in the cat during postural corrections and during locomotion; hind limb PTNs were also tested during scratching. The activity of nearly all PTNs was modulated in the rhythm of each of these motor patterns. The discharge frequency, averaged over the PTN population, was similar in different motor tasks, whereas the degree of frequency modulation was larger during locomotion. In individual PTNs, a correlation between analogous discharge characteristics (frequency or its modulation) in different tasks was very low, suggesting that input signals to PTNs in these tasks have a substantially different origin. In about a half of PTNs, their activity in different tasks was timed to the analogous (flexor/extensor) parts of the cycle, suggesting that these PTNs perform similar functions in these tasks (e.g., control of the value of muscle activity). In another half of PTNs, their activity was timed to opposite parts of the cycle in different tasks. These PTNs seem to perform different motor functions in different tasks, or their targets are active in different parts of the cycle in these tasks, or their effects are not directly related to the control of motor output (e.g., they modulate transmission of afferent signals).
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Lyalka VF, Zelenin PV, Karayannidou A, Orlovsky GN, Grillner S, Deliagina TG. Impairment and recovery of postural control in rabbits with spinal cord lesions. J Neurophysiol 2005; 94:3677-90. [PMID: 16049143 DOI: 10.1152/jn.00538.2005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to characterize impairment and subsequent recovery of postural control after spinal cord injuries. Experiments were carried out on rabbits with three types of lesion--a dorsal (D), lateral (L), or ventral (V) hemisection (HS) at T(12) level. The animals were maintaining equilibrium on a platform periodically tilted in the frontal plane. We assessed the postural limb/trunk configuration from video recordings and postural reflexes in the hindquarters from kinematical and electromyographic (EMG) recordings. We found that for a few days after DHS or LHS, the animals were not able to maintain the dorsal-side-up position of their hindquarters. This ability was then gradually restored, and the dynamic postural reflexes reached the prelesion value within 2-3 wk. By contrast, a VHS almost completely abolished postural reflexes, and they did not recover for > or =7 wk. The DHS, LHS, and VHS caused immediate and slowly compensated changes in the postural limb/trunk configuration as well as gradually developing changes. After DHS, both hind limbs were placed in an abnormal rostral and medial position. After LHS, the limb on the undamaged side was turned inward and occurred at the abnormal medial position; LHS also caused a gradually developing twisting of the caudal trunk. VHS caused gradually developing extension of the ankle and knee joints. These findings show that ventral spinal pathways are of crucial importance for postural control. When a part of these pathways is spared, postural reflexes can be restored rapidly, but not the postural limb/trunk configuration. Spinal and supraspinal mechanisms responsible for postural deficits and their compensation are discussed.
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Affiliation(s)
- V F Lyalka
- The Nobel Institute for Neurophysiology, Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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Beloozerova IN, Sirota MG, Orlovsky GN, Deliagina TG. Activity of Pyramidal Tract Neurons in the Cat During Postural Corrections. J Neurophysiol 2005; 93:1831-44. [PMID: 15525811 DOI: 10.1152/jn.00577.2004] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The dorsal side-up body orientation in quadrupeds is maintained by a postural control system. We investigated participation of the motor cortex in this system by recording activity of pyramidal tract neurons (PTNs) from limb representations of the motor cortex during postural corrections. The cat was standing on the platform periodically tilting in the frontal plane, and maintained equilibrium at different body configurations: with the head directed forward (symmetrically alternating loading of the left and right fore limbs), or with the head voluntary turned to the right or to the left (asymmetrical loading). We found that postural corrective responses to tilts included an increase of the contact forces and activity of limb extensors on the side moving down, and their decrease on the opposite side. The activity of PTNs was strongly modulated in relation to the tilt cycle. Phases of activity of individual PTNs were distributed over the cycle. Thus the cortical output mediated by PTNs appeared closely related to a highly automatic motor activity, the maintenance of the body posture. An asymmetrical loading of limbs, caused by head turns, resulted in the corresponding changes of motor responses to tilts. These voluntary postural modifications were also well reflected in the PTNs' activity. The activity of a part of PTNs correlated well with contact forces, in some others with the limb muscle activity; in still others no correlation with these variables was observed. This heterogeneity of the PTNs population suggests a different functional role of individual PTNs.
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Beloozerova IN, Zelenin PV, Popova LB, Orlovsky GN, Grillner S, Deliagina TG. Postural control in the rabbit maintaining balance on the tilting platform. J Neurophysiol 2003; 90:3783-93. [PMID: 12930819 DOI: 10.1152/jn.00590.2003] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A deviation from the dorsal-side-up body posture in quadrupeds activates the mechanisms for postural corrections. Operation of these mechanisms was studied in the rabbit maintaining balance on a platform periodically tilted in the frontal plane. First, we characterized the kinematics and electromyographic (EMG) patterns of postural responses to tilts. It was found that a reaction to tilt includes an extension of the limbs on the side moving down and flexion on the opposite side. These limb movements are primarily due to a modulation of the activity of extensor muscles. Second, it was found that rabbits can effectively maintain the dorsal-side-up body posture when complex postural stimuli are applied, i.e., asynchronous tilts of the platforms supporting the anterior and posterior parts of the body. These data suggest that the nervous mechanisms controlling positions of these parts of the body can operate independently of each other. Third, we found that normally the somatosensory input plays a predominant role for the generation of postural responses. However, when the postural response appears insufficient to maintain balance, the vestibular input contributes considerably to activation of postural mechanisms. We also found that an asymmetry in the tonic vestibular input, caused by galvanic stimulation of the labyrinths, can affect the stabilized body orientation while the magnitude of postural responses to tilts remains unchanged. Fourth, we found that the mechanisms for postural corrections respond only to tilts that exceed a certain (threshold) value.
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Affiliation(s)
- I N Beloozerova
- The Nobel Institute for Neurophysiology, Department of Neuroscience, Karolinska Institute, SE-17177 Stockholm, Sweden
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Abstract
The dorsal side-up body orientation in quadrupeds is maintained by a postural system that is driven by sensory feedback signals. The spinal cord, brainstem, and cerebellum play essential roles in postural control, whereas the role of the forebrain is unclear. In the present study we investigated whether the motor cortex is involved in maintenance of the dorsal side-up body orientation. We recorded activity of neurons in the motor cortex in awake rabbits while animals maintained balance on a platform periodically tilting in the frontal plane. The tilts evoked postural corrections, i.e., extension of the limbs on the side moving down and flexion on the opposite side. Because of these limb movements, rabbits maintained body orientation close to the dorsal side up. Four classes of efferent neurons were studied: descending corticofugal neurons of layer V (CF5s), those of layer VI (CF6s), corticocortical neurons with ipsilateral projection (CCIs), and those with contralateral projection (CCCs). One class of inhibitory interneurons [suspected inhibitory neurons (SINs)] was also investigated. CF5 neurons and SINs were strongly active during postural corrections. In most of these neurons, a clear-cut modulation of discharge in the rhythm of tilting was observed. This finding suggests that the motor cortex is involved in postural control. In contrast to CF5 neurons, other classes of efferent neurons (CCI, CCC, CF6) were much less active during postural corrections. This suggests that corticocortical interactions, both within a hemisphere (mediated by CCIs) and between hemispheres (mediated by CCCs), as well as corticothalamic interactions via CF6 neurons are not essential for motor coordination during postural corrections.
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Abstract
In recent years, studies of nervous mechanisms for the control of body posture have been performed on animal models of different complexity - cat, rabbit, lamprey and the mollusc Clione. These studies have greatly expanded our knowledge of how the control system operates, how the system can change the stabilized body orientation and how the postural functions are distributed within different parts of the CNS. For simpler animal models, the postural network has been analyzed in considerable detail and main cell types and their interactions have been identified.
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Affiliation(s)
- Tatiana G Deliagina
- Department of Neuroscience, Karolinska Institute, SE-171 77 Stockholm, Sweden.
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