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Inoue K, Asaka M, Lee S, Ishikawa K, Yanagihara D. Gait disorders induced by photothrombotic cerebellar stroke in mice. Sci Rep 2023; 13:15805. [PMID: 37737224 PMCID: PMC10516889 DOI: 10.1038/s41598-023-42817-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 09/14/2023] [Indexed: 09/23/2023] Open
Abstract
Patients with cerebellar stroke display relatively mild ataxic gaits. These motor deficits often improve dramatically; however, the neural mechanisms of this improvement have yet to be elucidated. Previous studies in mouse models of gait ataxia, such as ho15J mice and cbln1-null mice, have shown that they have a dysfunction of parallel fiber-Purkinje cell synapses in the cerebellum. However, the effects of cerebellar stroke on the locomotor kinematics of wild-type mice are currently unknown. Here, we performed a kinematic analysis of gait ataxia caused by a photothrombotic stroke in the medial, vermal, and intermediate regions of the cerebellum of wild-type mice. We used the data and observations from this analysis to develop a model that will allow locomotive prognosis and indicate potential treatment regimens following a cerebellar stroke. Our analysis showed that mice performed poorly in a ladder rung test after a stroke. During walking on a treadmill, the mice with induced cerebellar stroke had an increased duty ratio of the hindlimb caused by shortened duration of the swing phase. Overall, our findings suggest that photothrombotic cerebellar infarction and kinematic gait analyses will provide a useful model for quantification of different types of acute management of cerebellar stroke in rodents.
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Affiliation(s)
- Keisuke Inoue
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
- Department of Rehabilitation, JA Toride Medical Center, Toride, Japan
| | - Meiko Asaka
- Cognition and Behavior Joint Research Laboratory, RIKEN center for Brain Science, Wako, Japan
| | - Sachiko Lee
- Department of Rehabilitation Sciences, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Kinya Ishikawa
- The Center for Personalized Medicine for Healthy Aging, Tokyo Medical and Dental University, Tokyo, Japan
- Department of Neurology and Neurological Science, Graduate School of Medical and Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Dai Yanagihara
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
- Cognition and Behavior Joint Research Laboratory, RIKEN center for Brain Science, Wako, Japan.
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2
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Van Malderen S, Hehl M, Verstraelen S, Swinnen SP, Cuypers K. Dual-site TMS as a tool to probe effective interactions within the motor network: a review. Rev Neurosci 2023; 34:129-221. [PMID: 36065080 DOI: 10.1515/revneuro-2022-0020] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 07/02/2022] [Indexed: 02/07/2023]
Abstract
Dual-site transcranial magnetic stimulation (ds-TMS) is well suited to investigate the causal effect of distant brain regions on the primary motor cortex, both at rest and during motor performance and learning. However, given the broad set of stimulation parameters, clarity about which parameters are most effective for identifying particular interactions is lacking. Here, evidence describing inter- and intra-hemispheric interactions during rest and in the context of motor tasks is reviewed. Our aims are threefold: (1) provide a detailed overview of ds-TMS literature regarding inter- and intra-hemispheric connectivity; (2) describe the applicability and contributions of these interactions to motor control, and; (3) discuss the practical implications and future directions. Of the 3659 studies screened, 109 were included and discussed. Overall, there is remarkable variability in the experimental context for assessing ds-TMS interactions, as well as in the use and reporting of stimulation parameters, hindering a quantitative comparison of results across studies. Further studies examining ds-TMS interactions in a systematic manner, and in which all critical parameters are carefully reported, are needed.
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Affiliation(s)
- Shanti Van Malderen
- Department of Movement Sciences, Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Heverlee 3001, Belgium.,Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek 3590, Belgium
| | - Melina Hehl
- Department of Movement Sciences, Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Heverlee 3001, Belgium.,Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek 3590, Belgium
| | - Stefanie Verstraelen
- Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek 3590, Belgium
| | - Stephan P Swinnen
- Department of Movement Sciences, Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Heverlee 3001, Belgium.,KU Leuven, Leuven Brain Institute (LBI), Leuven, Belgium
| | - Koen Cuypers
- Department of Movement Sciences, Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Heverlee 3001, Belgium.,Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek 3590, Belgium
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3
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Sado T, Nielsen J, Glaister B, Takahashi KZ, Malcolm P, Mukherjee M. A passive exoskeleton can assist split-belt adaptation. Exp Brain Res 2022; 240:1159-1176. [PMID: 35165776 PMCID: PMC9103932 DOI: 10.1007/s00221-022-06314-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 01/25/2022] [Indexed: 11/04/2022]
Abstract
An exoskeletal device can assist walking in those with gait deficits. A passive exoskeleton can be a favorable choice for local or home rehabilitation settings because it is affordable, light weight, and less complex to utilize. While there is research that investigates the effects of exoskeleton on gait research examining the effects of such devices on gait adaptation, is rare. This is important because in diseases like stroke, the ability to flexibly adapt is affected, such that functional recovery becomes difficult. The purpose of this study was to characterize gait adaptation patterns that result from exoskeleton usage during a split-belt adaptation task. Healthy young participants were randomly assigned to a unilateral exoskeleton or a no-exoskeleton group. Each participant performed the specific split-belt adaptation tasks on the treadmill, where the speed of each belt could be controlled independently. Symmetry indices of spatiotemporal variables were calculated to quantify gait adaptation. To analyze the adaptation, trials were divided into early and late adaptation. We also analyzed degree of adaptation, and transfer effects. We also measured the symmetry of the positive power generated by the individual legs during the split-belt task to determine if using exoskeleton assistance reduced power in the exoskeleton group versus the no-exoskeleton group. Use of a passive exoskeleton device altered gait adaptation during a split-belt treadmill task in comparison to the control group. Such adaptation was found to be largely restricted to the temporal domain. Changes in the gait coordination patterns consisted of both early and late adaptive changes, especially in intra-limb patterns like stance time rather than inter-limb patterns like step time. Although the symmetry of the positive power generated during the split-belt task was found to be reduced for the exoskeleton-assistance group, it was shown that this was primarily the result of increased positive power generated by the side not receiving exoskeletal assistance. An unpowered assistive device can provide a unique solution for coordinating the lower limbs during different gait tasks. Such a solution could reduce the neural burden of adaptation consequently resulting in a reduction of the mechanical burden of walking during the bilateral gait coordination task. This may be useful for accelerating gait rehabilitation in different patient populations. However, balance control is important to consider during unilateral exoskeletal assistance.
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Affiliation(s)
- Takashi Sado
- Department of Biomechanics, University of Nebraska at Omaha, BRB#210, Biomechanics Research Building, 6160, University Drive, Omaha, NE, 68182-0860, USA
| | - James Nielsen
- Department of Biomechanics, University of Nebraska at Omaha, BRB#210, Biomechanics Research Building, 6160, University Drive, Omaha, NE, 68182-0860, USA
| | | | - Kota Z Takahashi
- Department of Biomechanics, University of Nebraska at Omaha, BRB#210, Biomechanics Research Building, 6160, University Drive, Omaha, NE, 68182-0860, USA
| | - Philippe Malcolm
- Department of Biomechanics, University of Nebraska at Omaha, BRB#210, Biomechanics Research Building, 6160, University Drive, Omaha, NE, 68182-0860, USA
| | - Mukul Mukherjee
- Department of Biomechanics, University of Nebraska at Omaha, BRB#210, Biomechanics Research Building, 6160, University Drive, Omaha, NE, 68182-0860, USA.
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4
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Albergaria C, Silva NT, Darmohray DM, Carey MR. Cannabinoids modulate associative cerebellar learning via alterations in behavioral state. eLife 2020; 9:61821. [PMID: 33077026 PMCID: PMC7575324 DOI: 10.7554/elife.61821] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/01/2020] [Indexed: 02/06/2023] Open
Abstract
Cannabinoids are notorious and profound modulators of behavioral state. In the brain, endocannabinoids act via Type 1-cannabinoid receptors (CB1) to modulate synaptic transmission and mediate multiple forms of synaptic plasticity. CB1 knockout (CB1KO) mice display a range of behavioral phenotypes, in particular hypoactivity and various deficits in learning and memory, including cerebellum-dependent delay eyeblink conditioning. Here we find that the apparent effects of CB1 deletion on cerebellar learning are not due to direct effects on CB1-dependent plasticity, but rather, arise as a secondary consequence of altered behavioral state. Hypoactivity of CB1KO mice accounts for their impaired eyeblink conditioning across both animals and trials. Moreover, learning in these mutants is rescued by walking on a motorized treadmill during training. Finally, cerebellar granule-cell-specific CB1KOs exhibit normal eyeblink conditioning, and both global and granule-cell-specific CB1KOs display normal cerebellum-dependent locomotor coordination and learning. These findings highlight the modulation of behavioral state as a powerful independent means through which individual genes contribute to complex behaviors.
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Affiliation(s)
- Catarina Albergaria
- Champalimaud Neuroscience Program, Champalimaud Center for the Unknown, Lisbon, Portugal
| | - N Tatiana Silva
- Champalimaud Neuroscience Program, Champalimaud Center for the Unknown, Lisbon, Portugal
| | - Dana M Darmohray
- Champalimaud Neuroscience Program, Champalimaud Center for the Unknown, Lisbon, Portugal
| | - Megan R Carey
- Champalimaud Neuroscience Program, Champalimaud Center for the Unknown, Lisbon, Portugal
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5
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Auta J, Gatta E, Davis JM, Zhang H, Pandey SC, Guidotti A. Essential role for neuronal nitric oxide synthase in acute ethanol-induced motor impairment. Nitric Oxide 2020; 100-101:50-56. [PMID: 32278831 PMCID: PMC7428855 DOI: 10.1016/j.niox.2020.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 04/02/2020] [Accepted: 04/06/2020] [Indexed: 11/18/2022]
Abstract
The cerebellum is widely known as a motor structure because it regulates and controls motor learning, coordination, and balance. However, it is also critical for non-motor functions such as cognitive processing, sensory discrimination, addictive behaviors and mental disorders. The cerebellum has the highest relative abundance of neuronal nitric oxide synthase (nNos) and is sensitive to ethanol. Although it has been demonstrated that the interaction of γ-aminobutyric acid (GABA) and nitric oxide (NO) might play an important role in the regulation of ethanol-induced cerebellar ataxia, the molecular mechanisms through which ethanol regulates nNos function to elicit this behavioral effect have not been studied extensively. Here, we investigated the dose-dependent effects of acute ethanol treatment on motor impairment using the rotarod behavioral paradigm and the alterations of nNos mRNA expression in cerebellum, frontal cortex (FC), hippocampus and striatum. We also examined the link between acute ethanol-induced motor impairment and nNos by pharmacological manipulation of nNos function. We found that acute ethanol induced a dose-dependent elevation of ethanol blood levels which was associated with the impairment of motor coordination performance and decreased expression of cerebellar nNos. In contrast, acute ethanol increased nNos expression in FC but did not to change the expression for this enzyme in striatum and hippocampus. The effects of acute ethanol were attenuated by l-arginine, a precursor for NO and potentiated by 7-nitroindazole (7-NI), a selective inhibitor of nNos. Our data suggests that differential regulation of nNos mRNA expression in cerebellum and frontal cortex might be involved in acute ethanol-induced motor impairment.
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Affiliation(s)
- James Auta
- Center for Alcohol Research in Epigenetics, Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, USA.
| | - Eleonora Gatta
- Center for Alcohol Research in Epigenetics, Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, USA
| | - John M Davis
- Department of Psychiatry, College of Medicine, University of Illinois at Chicago, USA
| | - Huaibo Zhang
- Center for Alcohol Research in Epigenetics, Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, USA
| | - Subhash C Pandey
- Center for Alcohol Research in Epigenetics, Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, USA; Jesse Brown VA Medical Center, Chicago, IL, USA
| | - Alessandro Guidotti
- Center for Alcohol Research in Epigenetics, Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, USA
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6
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Kumari N, Taylor D, Rashid U, Vandal AC, Smith PF, Signal N. Cerebellar transcranial direct current stimulation for learning a novel split-belt treadmill task: a randomised controlled trial. Sci Rep 2020; 10:11853. [PMID: 32678285 PMCID: PMC7366632 DOI: 10.1038/s41598-020-68825-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 06/30/2020] [Indexed: 11/09/2022] Open
Abstract
This study aimed to examine the effect of repeated anodal cerebellar transcranial direct current stimulation (ctDCS) on learning a split-belt treadmill task. Thirty healthy individuals randomly received three consecutive sessions of active or sham anodal ctDCS during split-belt treadmill training. Motor performance and strides to steady-state performance were evaluated before (baseline), during (adaptation), and after (de-adaptation) the intervention. The outcomes were measured one week later to assess absolute learning and during the intervention to evaluate cumulative, consecutive, and session-specific effects. Data were analysed using linear mixed-effects regression models. During adaptation, there was no significant difference in absolute learning between the groups (p > 0.05). During de-adaptation, a significant difference in absolute learning between the groups (p = 0.03) indicated slower de-adaptation with anodal ctDCS. Pre-planned secondary analysis revealed that anodal ctDCS significantly reduced the cumulative (p = 0.01) and consecutive-session effect (p = 0.01) on immediate adaptation. There were significant cumulative (p = 0.02) and session-specific effects (p = 0.003) on immediate de-adaptation. Repeated anodal ctDCS does not enhance motor learning measured during adaptation to a split-belt treadmill task. However, it influences the maintenance of learnt walking patterns, suggesting that it may be beneficial in maintaining therapeutic effects.
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Affiliation(s)
- Nitika Kumari
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand.
| | - Denise Taylor
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand.,Brain Research New Zealand, Auckland, New Zealand
| | - Usman Rashid
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Alain C Vandal
- Department of Statistics, University of Auckland, Auckland, New Zealand
| | - Paul F Smith
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand, Auckland, New Zealand
| | - Nada Signal
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
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7
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Molinari M, Masciullo M. The Implementation of Predictions During Sequencing. Front Cell Neurosci 2019; 13:439. [PMID: 31649509 PMCID: PMC6794410 DOI: 10.3389/fncel.2019.00439] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 09/17/2019] [Indexed: 12/13/2022] Open
Abstract
Optimal control mechanisms require prediction capabilities. If one cannot predict the consequences of a motor act or behavior, one will continually collide with walls or become a social pariah. "Looking into the future" is thus one of the most important prerequisites for smooth movements and social interactions. To achieve this goal, the brain must constantly predict future events. This principle applies to all domains of information processing, including motor and cognitive control, as well as the development of decision-making skills, theory of mind, and virtually all cognitive processes. Sequencing is suggested to support the predictive capacity of the brain. To recognize that events are related, the brain must discover links among them in the spatiotemporal domain. To achieve this, the brain must often hold one event in working memory and compare it to a second one, and the characteristics of the two must be compared and correctly placed in space and time. Among the different brain structures involved in sequencing, the cerebellum has been proposed to have a central function. We have suggested that the operational mode of the cerebellum is based on "sequence detection" and that this process is crucial for prediction. Patterns of temporally or spatially structured events are conveyed to the cerebellum via the pontine nuclei and compared with actual ones conveyed through the climbing fibers olivary inputs. Through this interaction, data on previously encountered sequences can be obtained and used to generate internal models from which predictions can be made. This mechanism would allow the cerebellum not only to recognize sequences but also to detect sequence violations. Cerebellar pattern detection and prediction would thus be a means to allow feedforward control based on anticipation. We will argue that cerebellar sequencing allows implementation of prediction by setting the correct excitatory levels in defined brain areas to implement the adaptive response for a given pattern of stimuli that embeds sufficient information to be recognized as a previously encountered template. Here, we will discuss results from human and animal studies and correlate them with the present understanding of cerebellar function in cognition and behavior.
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8
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Spatial and Temporal Locomotor Learning in Mouse Cerebellum. Neuron 2019; 102:217-231.e4. [DOI: 10.1016/j.neuron.2019.01.038] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 11/16/2018] [Accepted: 01/17/2019] [Indexed: 12/11/2022]
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9
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Fujiki S, Aoi S, Funato T, Sato Y, Tsuchiya K, Yanagihara D. Adaptive hindlimb split-belt treadmill walking in rats by controlling basic muscle activation patterns via phase resetting. Sci Rep 2018; 8:17341. [PMID: 30478405 PMCID: PMC6255885 DOI: 10.1038/s41598-018-35714-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 11/09/2018] [Indexed: 12/31/2022] Open
Abstract
To investigate the adaptive locomotion mechanism in animals, a split-belt treadmill has been used, which has two parallel belts to produce left–right symmetric and asymmetric environments for walking. Spinal cats walking on the treadmill have suggested the contribution of the spinal cord and associated peripheral nervous system to the adaptive locomotion. Physiological studies have shown that phase resetting of locomotor commands involving a phase shift occurs depending on the types of sensory nerves and stimulation timing, and that muscle activation patterns during walking are represented by a linear combination of a few numbers of basic temporal patterns despite the complexity of the activation patterns. Our working hypothesis was that resetting the onset timings of basic temporal patterns based on the sensory information from the leg, especially extension of hip flexors, contributes to adaptive locomotion on the split-belt treadmill. Our hypothesis was examined by conducting forward dynamic simulations using a neuromusculoskeletal model of a rat walking on a split-belt treadmill with its hindlimbs and by comparing the simulated motions with the measured motions of rats.
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Affiliation(s)
- Soichiro Fujiki
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan.
| | - Shinya Aoi
- Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto University, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto, 615-8540, Japan
| | - Tetsuro Funato
- Department of Mechanical Engineering and Intelligent Systems, Graduate School of Informatics and Engineering, The University of Electro-communications, 1-5-1 Chofugaoka, Chofu-shi, Tokyo, 182-8585, Japan
| | - Yota Sato
- Department of Mechanical Engineering and Intelligent Systems, Graduate School of Informatics and Engineering, The University of Electro-communications, 1-5-1 Chofugaoka, Chofu-shi, Tokyo, 182-8585, Japan
| | - Kazuo Tsuchiya
- Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto University, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto, 615-8540, Japan
| | - Dai Yanagihara
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan
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10
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The Impact of Stimulation Intensity and Coil Type on Reliability and Tolerability of Cerebellar Brain Inhibition (CBI) via Dual-Coil TMS. THE CEREBELLUM 2018; 17:540-549. [PMID: 29730789 DOI: 10.1007/s12311-018-0942-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cerebellar brain inhibition (CBI) describes the inhibitory tone the cerebellum exerts on the primary motor cortex (M1). CBI can be indexed via a dual-coil transcranial magnetic stimulation protocol, whereby a conditioning stimulus (CS) is delivered to the cerebellum in advance of a test stimulus (TS) to M1. The CS is typically delivered at intensities over 60% maximum stimulus output (MSO) via a double-cone coil. This is reportedly uncomfortable for participants, reducing the reliability and validity of outcomes. This feasibility study investigates the reliability and tolerability of eliciting CBI across a range of CS intensities using both a double-cone and high-powered figure-of-8 coil, the D702. It was expected that the double-cone coil would elicit CBI at intensities upwards of 60%MSO. The range for the D702 coil was exploratory. The double-cone coil was expected to be less tolerable than the D702 coil. CBI was assessed in 13 participants (25.92 ± 5.42 years, six female) using each coil (randomized) over intensities 40, 50, 60, 70, 80%MSO. Tolerability was assessed via visual analog scales. Comparisons across intensities and tolerability were assessed non-parametrically and via a linear model. The double-cone coil elicited CBI at intensities 60, 70, and 80%MSO (p < .05), with suppression elicited at 60%MSO not significantly different to that at higher intensities. CBI was not reliably elicited by the D702 coil at any intensity. The double-cone coil was significantly less tolerable than the D702. A CS of 60%MSO with a double-cone coil provides a balance between the reliability and tolerability of CBI.
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11
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Muzzu T, Mitolo S, Gava GP, Schultz SR. Encoding of locomotion kinematics in the mouse cerebellum. PLoS One 2018; 13:e0203900. [PMID: 30212563 PMCID: PMC6136788 DOI: 10.1371/journal.pone.0203900] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 08/29/2018] [Indexed: 01/23/2023] Open
Abstract
The cerebellum is involved in coordinating motor behaviour, but how the cerebellar network regulates locomotion is still not well understood. We characterised the activity of putative cerebellar Purkinje cells, Golgi cells and mossy fibres in awake mice engaged in an active locomotion task, using high-density silicon electrode arrays. Analysis of the activity of over 300 neurons in response to locomotion revealed that the majority of cells (53%) were significantly modulated by phase of the stepping cycle. However, in contrast to studies involving passive locomotion on a treadmill, we found that a high proportion of cells (45%) were tuned to the speed of locomotion, and 19% were tuned to yaw movements. The activity of neurons in the cerebellar vermis provided more information about future speed of locomotion than about past or present speed, suggesting a motor, rather than purely sensory, role. We were able to accurately decode the speed of locomotion with a simple linear algorithm, with only a relatively small number of well-chosen cells needed, irrespective of cell class. Our observations suggest that behavioural state modulates cerebellar sensorimotor integration, and advocate a role for the cerebellar vermis in control of high-level locomotor kinematic parameters such as speed and yaw.
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Affiliation(s)
- Tomaso Muzzu
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Susanna Mitolo
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Giuseppe P. Gava
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Simon R. Schultz
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, United Kingdom
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12
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Yokoyama H, Sato K, Ogawa T, Yamamoto SI, Nakazawa K, Kawashima N. Characteristics of the gait adaptation process due to split-belt treadmill walking under a wide range of right-left speed ratios in humans. PLoS One 2018; 13:e0194875. [PMID: 29694404 PMCID: PMC5918641 DOI: 10.1371/journal.pone.0194875] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 03/12/2018] [Indexed: 11/18/2022] Open
Abstract
The adaptability of human bipedal locomotion has been studied using split-belt treadmill walking. Most of previous studies utilized experimental protocol under remarkably different split ratios (e.g. 1:2, 1:3, or 1:4). While, there is limited research with regard to adaptive process under the small speed ratios. It is important to know the nature of adaptive process under ratio smaller than 1:2, because systematic evaluation of the gait adaptation under small to moderate split ratios would enable us to examine relative contribution of two forms of adaptation (reactive feedback and predictive feedforward control) on gait adaptation. We therefore examined a gait behavior due to on split-belt treadmill adaptation under five belt speed difference conditions (from 1:1.2 to 1:2). Gait parameters related to reactive control (stance time) showed quick adjustments immediately after imposing the split-belt walking in all five speed ratios. Meanwhile, parameters related to predictive control (step length and anterior force) showed a clear pattern of adaptation and subsequent aftereffects except for the 1:1.2 adaptation. Additionally, the 1:1.2 ratio was distinguished from other ratios by cluster analysis based on the relationship between the size of adaptation and the aftereffect. Our findings indicate that the reactive feedback control was involved in all the speed ratios tested and that the extent of reaction was proportionally dependent on the speed ratio of the split-belt. On the contrary, predictive feedforward control was necessary when the ratio of the split-belt was greater. These results enable us to consider how a given split-belt training condition would affect the relative contribution of the two strategies on gait adaptation, which must be considered when developing rehabilitation interventions for stroke patients.
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Affiliation(s)
- Hikaru Yokoyama
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Meguro, Tokyo, Japan.,Department of Rehabilitation for the Movement Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan.,Japan Society for the Promotion of Science, Chiyoda, Tokyo, Japan
| | - Koji Sato
- Department of Rehabilitation for the Movement Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan.,Department of Bioscience and Engineering, Graduate School of Engineering and Science, Shibaura Institute of Technology, Minuma, Saitama, Japan
| | - Tetsuya Ogawa
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Meguro, Tokyo, Japan
| | - Shin-Ichiro Yamamoto
- Department of Bioscience and Engineering, Graduate School of Engineering and Science, Shibaura Institute of Technology, Minuma, Saitama, Japan
| | - Kimitaka Nakazawa
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Meguro, Tokyo, Japan
| | - Noritaka Kawashima
- Department of Rehabilitation for the Movement Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
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13
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Velocity-dependent transfer of adaptation in human running as revealed by split-belt treadmill adaptation. Exp Brain Res 2018; 236:1019-1029. [PMID: 29411081 DOI: 10.1007/s00221-018-5195-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 02/02/2018] [Indexed: 10/18/2022]
Abstract
Animal studies demonstrate that the neural mechanisms underlying locomotion are specific to the modes and/or speeds of locomotion. In line with animal results, human locomotor adaptation studies, particularly those focusing on walking, have revealed limited transfers of adaptation among movement contexts including different locomotion speeds. Running is another common gait that humans utilize in their daily lives and is distinct from walking in terms of the underlying neural mechanisms. The present study employed an adaptation paradigm on a split-belt treadmill to examine the possible independence of neural mechanisms mediating different running speeds. The adaptations learned with split-belt running resulted in aftereffects with magnitudes that varied in a speed-dependent matter. In the two components of the ground reaction force investigated, the anterior braking and posterior propulsive components exhibited different trends. The anterior braking component tended to show larger aftereffect under speeds near the slower side speed of the previously experienced split-belt in contrast to the posterior propulsive component in which the aftereffect size tended to be the largest at a speed that corresponded to the faster side speed of the split-belt. These results show that the neural mechanisms underlying different running speeds in humans may be independent, just as in human walking and animal studies.
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Fernandez L, Major BP, Teo WP, Byrne LK, Enticott PG. Assessing cerebellar brain inhibition (CBI) via transcranial magnetic stimulation (TMS): A systematic review. Neurosci Biobehav Rev 2017; 86:176-206. [PMID: 29208533 DOI: 10.1016/j.neubiorev.2017.11.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/10/2017] [Accepted: 11/25/2017] [Indexed: 12/24/2022]
Abstract
The inhibitory tone that the cerebellum exerts on the primary motor cortex (M1) is known as cerebellar brain inhibition (CBI). Studies show CBI to be relevant to several motor functions, including adaptive motor learning and muscle control. CBI can be assessed noninvasively via transcranial magnetic stimulation (TMS) using a double-coil protocol. Variability in parameter choice and controversy surrounding the protocol's ability to isolate the cerebellothalamocortical pathway casts doubt over its validity in neuroscience research. This justifies a systematic review of both the protocol, and its application. The following review examines studies using the double-coil protocol to assess CBI in healthy adults. Parameters and CBI in relation to task-based studies, other non-invasive protocols, over different muscles, and in clinical samples are reviewed. Of the 1398 studies identified, 24 met selection criteria. It was found that methodological design and selection of parameters in several studies may have reduced the validity of outcomes. Further systematic testing of CBI protocols is warranted, both from a parameter and task-based perspective.
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Affiliation(s)
- Lara Fernandez
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Victoria, 3220, Australia.
| | - Brendan P Major
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Victoria, 3220, Australia
| | - Wei-Peng Teo
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, 3220, Australia
| | - Linda K Byrne
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Victoria, 3220, Australia
| | - Peter G Enticott
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Victoria, 3220, Australia; Deakin Child Study Centre, School of Psychology, Deakin University, Geelong, Victoria, 3220, Australia
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Aoi S, Manoonpong P, Ambe Y, Matsuno F, Wörgötter F. Adaptive Control Strategies for Interlimb Coordination in Legged Robots: A Review. Front Neurorobot 2017; 11:39. [PMID: 28878645 PMCID: PMC5572352 DOI: 10.3389/fnbot.2017.00039] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 07/31/2017] [Indexed: 12/02/2022] Open
Abstract
Walking animals produce adaptive interlimb coordination during locomotion in accordance with their situation. Interlimb coordination is generated through the dynamic interactions of the neural system, the musculoskeletal system, and the environment, although the underlying mechanisms remain unclear. Recently, investigations of the adaptation mechanisms of living beings have attracted attention, and bio-inspired control systems based on neurophysiological findings regarding sensorimotor interactions are being developed for legged robots. In this review, we introduce adaptive interlimb coordination for legged robots induced by various factors (locomotion speed, environmental situation, body properties, and task). In addition, we show characteristic properties of adaptive interlimb coordination, such as gait hysteresis and different time-scale adaptations. We also discuss the underlying mechanisms and control strategies to achieve adaptive interlimb coordination and the design principle for the control system of legged robots.
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Affiliation(s)
- Shinya Aoi
- Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto UniversityKyoto, Japan
| | - Poramate Manoonpong
- Embodied AI & Neurorobotics Lab, Centre for Biorobotics, Mærsk Mc-Kinney Møller Institute, University of Southern DenmarkOdense, Denmark
| | - Yuichi Ambe
- Department of Applied Information Sciences, Graduate School of Information Sciences, Tohoku UniversityAoba-ku, Japan
| | - Fumitoshi Matsuno
- Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto UniversityKyoto, Japan
| | - Florentin Wörgötter
- Bernstein Center for Computational Neuroscience, Third Institute of Physics, Georg-August-Universität GöttingenGöttingen, Germany
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Kuczynski V, Telonio A, Thibaudier Y, Hurteau MF, Dambreville C, Desrochers E, Doelman A, Ross D, Frigon A. Lack of adaptation during prolonged split-belt locomotion in the intact and spinal cat. J Physiol 2017. [PMID: 28643899 DOI: 10.1113/jp274518] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
KEY POINTS During split-belt locomotion in humans where one leg steps faster than the other, the symmetry of step lengths and double support periods of the slow and fast legs is gradually restored. When returning to tied-belt locomotion, there is an after-effect, with a reversal in the asymmetry observed in the early split-belt period, indicating that the new pattern was stored within the central nervous system. In this study, we investigated if intact and spinal-transected cats show a similar pattern of adaptation to split-belt locomotion by measuring kinematic variables and electromyography before, during and after 10 min of split-belt locomotion. The results show that cats do not adapt to prolonged split-belt locomotion. Our results suggest an important physiological difference in how cats and humans respond to prolonged asymmetric locomotion. ABSTRACT In humans, gait adapts to prolonged walking on a split-belt treadmill, where one leg steps faster than the other, by gradually restoring the symmetry of interlimb kinematic variables, such as double support periods and step lengths, and by reducing muscle activity (EMG, electromyography). The adaptation is also characterized by reversing the asymmetry of interlimb variables observed during the early split-belt period when returning to tied-belt locomotion, termed an after-effect. To determine if cats adapt to prolonged split-belt locomotion and to assess if spinal locomotor circuits participate in the adaptation, we measured interlimb variables and EMG in intact and spinal-transected cats before, during and after 10 min of split-belt locomotion. In spinal cats, only the hindlimbs performed stepping with the forelimbs stationary. In intact and spinal cats, step lengths and double support periods were, on average, symmetric, during tied-belt locomotion. They became asymmetric during split-belt locomotion and remained asymmetric throughout the split-belt period. Upon returning to tied-belt locomotion, symmetry was immediately restored. In intact cats, the mean EMG amplitude of hindlimb extensors increased during split-belt locomotion and remained increased throughout the split-belt period, whereas in spinal cats, EMG amplitude did not change. Therefore, the results indicate that the locomotor pattern of cats does not adapt to prolonged split-belt locomotion, suggesting an important physiological difference in the control of locomotion between cats and humans. We propose that restoring left-right symmetry is not required to maintain balance during prolonged asymmetric locomotion in the cat, a quadruped, as opposed to human bipedal locomotion.
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Affiliation(s)
- Victoria Kuczynski
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada, J1H 5N4
| | - Alessandro Telonio
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada, J1H 5N4
| | - Yann Thibaudier
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada, J1H 5N4
| | - Marie-France Hurteau
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada, J1H 5N4
| | - Charline Dambreville
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada, J1H 5N4
| | - Etienne Desrochers
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada, J1H 5N4
| | - Adam Doelman
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada, J1H 5N4
| | - Declan Ross
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada, J1H 5N4
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada, J1H 5N4
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Abstract
The cerebellum is important for movement control and plays a particularly crucial role in balance and locomotion. As such, one of the most characteristic signs of cerebellar damage is walking ataxia. It is not known how the cerebellum normally contributes to walking, although recent work suggests that it plays a role in the generation of appropriate patterns of limb movements, dynamic regulation of balance, and adaptation of posture and locomotion through practice. The purpose of this review is to examine mechanisms of cerebellar control of balance and locomotion, emphasizing studies of humans and other animals. Implications for rehabilitation are also considered.
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Affiliation(s)
- Susanne M Morton
- Kennedy Krieger Institute and Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Choi JT, Jensen P, Nielsen JB, Bouyer LJ. Error signals driving locomotor adaptation: cutaneous feedback from the foot is used to adapt movement during perturbed walking. J Physiol 2016; 594:5673-84. [PMID: 27218896 DOI: 10.1113/jp271996] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 05/02/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Sensory input from peripheral receptors are important for the regulation of walking patterns. Cutaneous input mediates muscle responses to deal with immediate external perturbations. In this study we focused on the role of cutaneous feedback in locomotor adaptation that takes place over minutes of training. We show that interfering with cutaneous feedback reduced adaptation to ankle perturbations during walking. These results help us understand the neural mechanisms underlying walking adaptation, and have clinical implications for treating walking impairments after neurological injuries. ABSTRACT Locomotor patterns must be adapted to external forces encountered during daily activities. The contribution of different sensory inputs to detecting perturbations and adapting movements during walking is unclear. In the present study, we examined the role of cutaneous feedback in adapting walking patterns to force perturbations. Forces were applied to the ankle joint during the early swing phase using an electrohydraulic ankle-foot orthosis. Repetitive 80 Hz electrical stimulation was applied to disrupt cutaneous feedback from the superficial peroneal nerve (foot dorsum) and medial plantar nerve (foot sole) during walking (Choi et al. 2013). Sensory tests were performed to measure the cutaneous touch threshold and perceptual threshold of force perturbations. Ankle movement were measured when the subjects walked on the treadmill over three periods: baseline (1 min), adaptation (1 min) and post-adaptation (3 min). Subjects (n = 10) showed increased touch thresholds measured with Von Frey monofilaments and increased force perception thresholds with stimulation. Stimulation reduced the magnitude of walking adaptation to force perturbation. In addition, we compared the effects of interrupting cutaneous feedback using anaesthesia (n = 5) instead of repetitive nerve stimulation. Foot anaesthesia reduced ankle adaptation to external force perturbations during walking. The results of the present study suggest that cutaneous input plays a role in force perception, and may contribute to the 'error' signal involved in driving walking adaptation when there is a mismatch between expected and actual force.
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Affiliation(s)
- Julia T Choi
- Department of Kinesiology, University of Massachusetts, Amherst, MA, USA. .,Neural Control of Movement Research Group, Department of Neuroscience and Pharmacology & Department of Nutrition, Exercise and Sport, University of Copenhagen, Copenhagen, Denmark.
| | - Peter Jensen
- Neural Control of Movement Research Group, Department of Neuroscience and Pharmacology & Department of Nutrition, Exercise and Sport, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bo Nielsen
- Neural Control of Movement Research Group, Department of Neuroscience and Pharmacology & Department of Nutrition, Exercise and Sport, University of Copenhagen, Copenhagen, Denmark
| | - Laurent J Bouyer
- Department of Rehabilitation, Université Laval & Centre for Interdisciplinary Research in Rehabilitation and Social Integration, Québec City, Canada
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Fujiki S, Aoi S, Funato T, Tomita N, Senda K, Tsuchiya K. Adaptation mechanism of interlimb coordination in human split-belt treadmill walking through learning of foot contact timing: a robotics study. J R Soc Interface 2016; 12:0542. [PMID: 26289658 PMCID: PMC4614464 DOI: 10.1098/rsif.2015.0542] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Human walking behaviour adaptation strategies have previously been examined using split-belt treadmills, which have two parallel independently controlled belts. In such human split-belt treadmill walking, two types of adaptations have been identified: early and late. Early-type adaptations appear as rapid changes in interlimb and intralimb coordination activities when the belt speeds of the treadmill change between tied (same speed for both belts) and split-belt (different speeds for each belt) configurations. By contrast, late-type adaptations occur after the early-type adaptations as a gradual change and only involve interlimb coordination. Furthermore, interlimb coordination shows after-effects that are related to these adaptations. It has been suggested that these adaptations are governed primarily by the spinal cord and cerebellum, but the underlying mechanism remains unclear. Because various physiological findings suggest that foot contact timing is crucial to adaptive locomotion, this paper reports on the development of a two-layered control model for walking composed of spinal and cerebellar models, and on its use as the focus of our control model. The spinal model generates rhythmic motor commands using an oscillator network based on a central pattern generator and modulates the commands formulated in immediate response to foot contact, while the cerebellar model modifies motor commands through learning based on error information related to differences between the predicted and actual foot contact timings of each leg. We investigated adaptive behaviour and its mechanism by split-belt treadmill walking experiments using both computer simulations and an experimental bipedal robot. Our results showed that the robot exhibited rapid changes in interlimb and intralimb coordination that were similar to the early-type adaptations observed in humans. In addition, despite the lack of direct interlimb coordination control, gradual changes and after-effects in the interlimb coordination appeared in a manner that was similar to the late-type adaptations and after-effects observed in humans. The adaptation results of the robot were then evaluated in comparison with human split-belt treadmill walking, and the adaptation mechanism was clarified from a dynamic viewpoint.
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Affiliation(s)
- Soichiro Fujiki
- Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto University, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Shinya Aoi
- Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto University, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan JST, CREST, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075, Japan
| | - Tetsuro Funato
- Department Mechanical Engineering and Intelligent Systems, Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Choufugaoka, Choufu-shi, Tokyo 182-8585, Japan JST, CREST, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075, Japan
| | - Nozomi Tomita
- Department of Mathematics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan JST, CREST, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075, Japan
| | - Kei Senda
- Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto University, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Kazuo Tsuchiya
- Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto University, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan JST, CREST, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075, Japan
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Fujiki S, Aoi S, Yanagihara D, Funato T, Sato Y, Senda K, Tsuchiya K. Investigation of adaptive split-belt treadmill walking by the hindlimbs of rats. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:6756-9. [PMID: 26737844 DOI: 10.1109/embc.2015.7319944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In this study, we investigated the adaptive behavior during hindlimb locomotion of rats on a split-belt treadmill. We measured and analyzed the movement of intact rats walking by the hindlimbs on the splitbelt treadmill with two conditions: symmetric and asymmetric belt speed. In addition, we conducted the dynamic simulation of a neuromusculoskeletal model of rat's hindlimb walking on a split-belt treadmill. We investigated the immediate modulations of the duty factors and relative phase between the right and left limbs depending on the conditions of the treadmill. The results of the simulation were qualitatively similar to those of the measurement experiment. Furthermore, these results were qualitatively similar to the measurement data of the humans and cats in the previous studies. This suggests that our model have the essential aspects to produce the adaptive split-belt treadmill walking in dynamics viewpoints.
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Understanding and modulating motor learning with cerebellar stimulation. THE CEREBELLUM 2015; 14:171-4. [PMID: 25283180 DOI: 10.1007/s12311-014-0607-y] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Non-invasive brain stimulation techniques are a powerful approach to investigate the physiology and function of the central nervous system. Recent years have seen numerous investigations delivering transcranial magnetic stimulation (TMS) and or transcranial direct current stimulation (tDCS) to the cerebellum to determine its role in motor, cognitive and emotional behaviours. Early studies have shown that it is possible to assess cerebellar-motor cortex (CB-M1) connectivity using a paired-pulse TMS paradigm called cerebellar inhibition (CBI), and indirectly infer the state of cerebellar excitability. Thus, it has been shown that CBI changes proportionally to the magnitude of locomotor learning and in association with reaching adaption tasks. In addition, CBI has been used to demonstrate at a physiological level the effects of applying TMS or tDCS to modulate, up or down, the excitability of cerebellar-M1 connectivity. These studies became the fundamental substrate to newer investigations showing that we can affect motor, cognitive and emotional behaviour when targeting the cerebellum with TMS or tDCS in the context of performance. Furthermore, newer investigations are starting to report the effects of cerebellar non-invasive stimulation to treat symptoms associated with neurological conditions such as stroke and dystonia. Altogether, given the scarcity of current effective therapeutic options, non-invasive cerebellar stimulation can potentially become a game changer for the management of conditions that affect the cerebellum. This brief manuscript presents some of the current evidence demonstrating the effects of cerebellar stimulation to modulate motor behaviour and its use to assess physiological processes underlying motor learning.
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22
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Ogawa T, Kawashima N, Obata H, Kanosue K, Nakazawa K. Distinct motor strategies underlying split-belt adaptation in human walking and running. PLoS One 2015; 10:e0121951. [PMID: 25775426 PMCID: PMC4361606 DOI: 10.1371/journal.pone.0121951] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 02/05/2015] [Indexed: 12/03/2022] Open
Abstract
The aim of the present study was to elucidate the adaptive and de-adaptive nature of human running on a split-belt treadmill. The degree of adaptation and de-adaptation was compared with those in walking by calculating the antero-posterior component of the ground reaction force (GRF). Adaptation to walking and running on a split-belt resulted in a prominent asymmetry in the movement pattern upon return to the normal belt condition, while the two components of the GRF showed different behaviors depending on the gaits. The anterior braking component showed prominent adaptive and de-adaptive behaviors in both gaits. The posterior propulsive component, on the other hand, exhibited such behavior only in running, while that in walking showed only short-term aftereffect (lasting less than 10 seconds) accompanied by largely reactive responses. These results demonstrate a possible difference in motor strategies (that is, the use of reactive feedback and adaptive feedforward control) by the central nervous system (CNS) for split-belt locomotor adaptation between walking and running. The present results provide basic knowledge on neural control of human walking and running as well as possible strategies for gait training in athletic and rehabilitation scenes.
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Affiliation(s)
- Tetsuya Ogawa
- Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, Japan
- Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda, Tokyo, Japan
- Department of Rehabilitation for the Movement Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, 4-1, Namiki, Tokorozawa, Saitama, Japan
- * E-mail:
| | - Noritaka Kawashima
- Department of Rehabilitation for the Movement Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, 4-1, Namiki, Tokorozawa, Saitama, Japan
| | - Hiroki Obata
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1, Komaba, Meguro, Tokyo, Japan
| | - Kazuyuki Kanosue
- Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, Japan
| | - Kimitaka Nakazawa
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1, Komaba, Meguro, Tokyo, Japan
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Possible interaction of hippocampal nitric oxide and calcium/calmodulin-dependent protein kinase II on reversal of spatial memory impairment induced by morphine. Eur J Pharmacol 2015; 751:99-111. [DOI: 10.1016/j.ejphar.2015.01.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 01/19/2015] [Accepted: 01/21/2015] [Indexed: 01/24/2023]
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Abstract
Cerebellar climbing fiber activity encodes performance errors during many motor learning tasks, but the role of these error signals in learning has been controversial. We compared two motor learning paradigms that elicited equally robust putative error signals in the same climbing fibers: learned increases and decreases in the gain of the vestibulo-ocular reflex (VOR). During VOR-increase training, climbing fiber activity on one trial predicted changes in cerebellar output on the next trial, and optogenetic activation of climbing fibers to mimic their encoding of performance errors was sufficient to implant a motor memory. In contrast, during VOR-decrease training, there was no trial-by-trial correlation between climbing fiber activity and changes in cerebellar output, and climbing fiber activation did not induce VOR-decrease learning. Our data suggest that the ability of climbing fibers to induce plasticity can be dynamically gated in vivo, even under conditions where climbing fibers are robustly activated by performance errors. DOI:http://dx.doi.org/10.7554/eLife.02076.001 The cerebellum (or ‘little brain’) is located underneath the cerebral hemispheres. Despite comprising around 10% of the brain’s volume, the cerebellum contains roughly half of the brain’s neurons. Many of the functions of the cerebellum are related to the control and fine-tuning of movement, and people whose cerebellum has been damaged have problems with balance and coordination, and with learning new motor skills. One of the roles of the cerebellum is to control a reflex known as the vestibulo-ocular reflex, which enables us to keep our gaze fixed on an object as we turn our heads. The cerebellum relays information about head movements to the muscles that control the eyes, instructing the eyes to move in the opposite direction to the head. This keeps the image of the object we are looking at stable on the retina. The vestibulo-ocular reflex is controlled by a circuit that includes Purkinje cells (which are the main output cells of the cerebellum) and climbing fibres (which originate in the brainstem). Any failure of the vestibulo-ocular reflex to fully compensate for head movements generates an error signal that activates the climbing fibres. These in turn modify the output of Purkinje cells, leading ultimately to adjustments in eye movements. However, Kimpo et al. have now obtained evidence that Purkinje cells can modulate their response to the instructions they receive from climbing fibres. Monkeys sat in a rotating chair while a visual object they were trained to track with their eyes was moved to induce errors in the vestibulo-ocular reflex. When the object was moved so that a bigger reflexive eye movement was required to stabilize the image, the activation of the climbing fibres in response to the error led to a change in the response of the Purkinje cells, as expected. However, when a smaller reflexive eye movement was needed, the error-driven responses of the climbing fibres did not alter the responses of Purkinje cells. Similar results were obtained using pulses of light to artificially activate climbing fibres and thus simulate error signals. The work of Kimpo et al. indicates that the cerebellum does not blindly follow the instructions it receives from the brainstem, but can instead modulate its responses to incoming information about performance errors. Further work is now required to identify factors that influence the responsiveness of the cerebellum: such information could ultimately be used to improve learning of motor skills and recovery from injury. DOI:http://dx.doi.org/10.7554/eLife.02076.002
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Affiliation(s)
- Rhea R Kimpo
- Department of Neurobiology, Stanford University, Stanford, United States
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25
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Singh S, Trigun S. Low grade cirrhosis induces cognitive impairment and motor dysfunction in rats: Could be a model for minimal hepatic encephalopathy. Neurosci Lett 2014; 559:136-40. [DOI: 10.1016/j.neulet.2013.11.058] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 11/27/2013] [Accepted: 11/30/2013] [Indexed: 01/16/2023]
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Yamaura H, Hirai H, Yanagihara D. Postural dysfunction in a transgenic mouse model of spinocerebellar ataxia type 3. Neuroscience 2013; 243:126-35. [DOI: 10.1016/j.neuroscience.2013.03.044] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 03/07/2013] [Accepted: 03/24/2013] [Indexed: 12/23/2022]
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27
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Mawase F, Haizler T, Bar-Haim S, Karniel A. Kinetic adaptation during locomotion on a split-belt treadmill. J Neurophysiol 2013; 109:2216-27. [DOI: 10.1152/jn.00938.2012] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It has been suggested that a feedforward control mechanism drives the adaptation of the spatial and temporal interlimb locomotion variables. However, the internal representation of limb kinetics during split-belt locomotion has not yet been studied. In hand movements, it has been suggested that kinetic and kinematic parameters are controlled by separate neural processes; therefore, it is possible that separate neural processes are responsible for kinetic and kinematic locomotion parameters. In the present study, we assessed the adaptation of the limb kinetics by analyzing the ground reaction forces (GRFs) as well as the center of pressure (COP) during adaptation to speed perturbation, using a split-belt treadmill with an integrated force plate. We found that both the GRF of each leg at initial contact and the COP changed gradually and showed motor aftereffects during early postadaptation, suggesting the use of a feedforward predictive mechanism. However, the GRF of each leg in the single-support period used a feedback control mechanism. It changed rapidly during the adaptation phase and showed no motor aftereffect when the speed perturbation was removed. Finally, we found that the motor adaptation of the GRF and the COP are mediated by a dual-rate process. Our results suggest two important contributions to neural control of locomotion. First, different control mechanisms are responsible for forces at single- and double-support periods, as previously reported for kinematic variables. Second, our results suggest that motor adaptation during split-belt locomotion is mediated by fast and slow adaptation processes.
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Affiliation(s)
- Firas Mawase
- Department of Biomedical Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Tamar Haizler
- Department of Biomedical Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Simona Bar-Haim
- Department of Physiotherapy, Ben-Gurion University of the Negev, Beer-Sheva, Israel; and
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Amir Karniel
- Department of Biomedical Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Fujiki S, Aoi S, Yamashita T, Funato T, Tomita N, Senda K, Tsuchiya K. Adaptive splitbelt treadmill walking of a biped robot using nonlinear oscillators with phase resetting. Auton Robots 2013. [DOI: 10.1007/s10514-013-9331-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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29
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Aoi S, Katayama D, Fujiki S, Tomita N, Funato T, Yamashita T, Senda K, Tsuchiya K. A stability-based mechanism for hysteresis in the walk-trot transition in quadruped locomotion. J R Soc Interface 2013; 10:20120908. [PMID: 23389894 PMCID: PMC3627097 DOI: 10.1098/rsif.2012.0908] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 01/11/2013] [Indexed: 11/12/2022] Open
Abstract
Quadrupeds vary their gaits in accordance with their locomotion speed. Such gait transitions exhibit hysteresis. However, the underlying mechanism for this hysteresis remains largely unclear. It has been suggested that gaits correspond to attractors in their dynamics and that gait transitions are non-equilibrium phase transitions that are accompanied by a loss in stability. In the present study, we used a robotic platform to investigate the dynamic stability of gaits and to clarify the hysteresis mechanism in the walk-trot transition of quadrupeds. Specifically, we used a quadruped robot as the body mechanical model and an oscillator network for the nervous system model to emulate dynamic locomotion of a quadruped. Experiments using this robot revealed that dynamic interactions among the robot mechanical system, the oscillator network, and the environment generate walk and trot gaits depending on the locomotion speed. In addition, a walk-trot transition that exhibited hysteresis was observed when the locomotion speed was changed. We evaluated the gait changes of the robot by measuring the locomotion of dogs. Furthermore, we investigated the stability structure during the gait transition of the robot by constructing a potential function from the return map of the relative phase of the legs and clarified the physical characteristics inherent to the gait transition in terms of the dynamics.
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Affiliation(s)
- Shinya Aoi
- Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 6068501, Japan.
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30
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Aoi S, Kondo T, Hayashi N, Yanagihara D, Aoki S, Yamaura H, Ogihara N, Funato T, Tomita N, Senda K, Tsuchiya K. Contributions of phase resetting and interlimb coordination to the adaptive control of hindlimb obstacle avoidance during locomotion in rats: a simulation study. BIOLOGICAL CYBERNETICS 2013; 107:201-216. [PMID: 23430278 DOI: 10.1007/s00422-013-0546-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 01/09/2013] [Indexed: 06/01/2023]
Abstract
Obstacle avoidance during locomotion is essential for safe, smooth locomotion. Physiological studies regarding muscle synergy have shown that the combination of a small number of basic patterns produces the large part of muscle activities during locomotion and the addition of another pattern explains muscle activities for obstacle avoidance. Furthermore, central pattern generators in the spinal cord are thought to manage the timing to produce such basic patterns. In the present study, we investigated sensory-motor coordination for obstacle avoidance by the hindlimbs of the rat using a neuromusculoskeletal model. We constructed the musculoskeletal part of the model based on empirical anatomical data of the rat and the nervous system model based on the aforementioned physiological findings of central pattern generators and muscle synergy. To verify the dynamic simulation by the constructed model, we compared the simulation results with kinematic and electromyographic data measured during actual locomotion in rats. In addition, we incorporated sensory regulation models based on physiological evidence of phase resetting and interlimb coordination and examined their functional roles in stepping over an obstacle during locomotion. Our results show that the phase regulation based on interlimb coordination contributes to stepping over a higher obstacle and that based on phase resetting contributes to quick recovery after stepping over the obstacle. These results suggest the importance of sensory regulation in generating successful obstacle avoidance during locomotion.
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Affiliation(s)
- Shinya Aoi
- Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
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31
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Ogawa T, Kawashima N, Ogata T, Nakazawa K. Limited transfer of newly acquired movement patterns across walking and running in humans. PLoS One 2012; 7:e46349. [PMID: 23029490 PMCID: PMC3459930 DOI: 10.1371/journal.pone.0046349] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 08/31/2012] [Indexed: 11/18/2022] Open
Abstract
The two major modes of locomotion in humans, walking and running, may be regarded as a function of different speed (walking as slower and running as faster). Recent results using motor learning tasks in humans, as well as more direct evidence from animal models, advocate for independence in the neural control mechanisms underlying different locomotion tasks. In the current study, we investigated the possible independence of the neural mechanisms underlying human walking and running. Subjects were tested on a split-belt treadmill and adapted to walking or running on an asymmetrically driven treadmill surface. Despite the acquisition of asymmetrical movement patterns in the respective modes, the emergence of asymmetrical movement patterns in the subsequent trials was evident only within the same modes (walking after learning to walk and running after learning to run) and only partial in the opposite modes (walking after learning to run and running after learning to walk) (thus transferred only limitedly across the modes). Further, the storage of the acquired movement pattern in each mode was maintained independently of the opposite mode. Combined, these results provide indirect evidence for independence in the neural control mechanisms underlying the two locomotive modes.
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Affiliation(s)
- Tetsuya Ogawa
- Department of Rehabilitation for the Movement Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Namiki, Tokorozawa, Saitama, Japan.
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32
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Stubbs PW, Gervasio S. Motor adaptation following split-belt treadmill walking. J Neurophysiol 2012; 108:1225-7. [DOI: 10.1152/jn.01197.2011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Malone L, Vasudevan E, and Bastian A ( J Neurosci 31: 15136–15143, 2011) investigated the effects of different training paradigms on the day-by-day retention of learned motor patterns. In this Neuro Forum, a description and assessment of the methods used will be presented. The interpretation of the findings will be extended and the possible implications will be discussed. Finally, alternative explanations of the possible regions involved in motor pattern relearning will be provided.
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Affiliation(s)
- Peter W. Stubbs
- Hammel Neurorehabilitation Hospital and Research Centre, Aarhus University, Hammel, Denmark; and
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Sabata Gervasio
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
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33
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Correlation between hippocampal levels of neural, epithelial and inducible NOS and spatial learning skills in rats. Behav Brain Res 2012; 235:326-33. [PMID: 22909987 DOI: 10.1016/j.bbr.2012.08.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 06/27/2012] [Accepted: 08/06/2012] [Indexed: 11/23/2022]
Abstract
In the present study, to better understand the role of different nitric oxide synthase (NOS) isoforms in hippocampus-dependent forms of learning, we examined the expression of neural, endothelial, and inducible NOS in the hippocampus of young-adult rats classified as "poor" and "good" learners on the basis of their performance in the partially baited 12-arm radial maze. Taking into consideration strain-dependent differences in learning skills and NOS expression, experiments were performed on two different lines of laboratory rats: the inbred Wistar (W) and the outcrossed Wistar/Spraque-Dawley (W/S) line. The hippocampal levels of NOS proteins were assessed by Western Blotting. In the present study, genetically more homogenous W rats showed a slower rate of learning compared to the genetically less homogenous outcrossed W/S rats. The deficient performance in the W rat group compared to outcrossed W/S rats, and in "poor" learners of both groups compared to "good" learners was due to a higher percentage of reference memory errors. The overall NOS levels were significantly higher in W group compared to outcrossed W/S rats. In both rat lines, the rate of learning positively correlated with hippocampal levels of nNOS and negatively correlated with iNOS levels. Hippocampal eNOS levels correlated negatively with animals' performance but only in the W rats. These results suggest that all 3 NOS isoforms are implemented but play different roles in neural signaling.
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Malone LA, Bastian AJ, Torres-Oviedo G. How does the motor system correct for errors in time and space during locomotor adaptation? J Neurophysiol 2012; 108:672-83. [PMID: 22514294 DOI: 10.1152/jn.00391.2011] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Walking is a complex behavior for which the healthy nervous system favors a smooth, symmetric pattern. However, people often adopt an asymmetric walking pattern after neural or biomechanical damage (i.e., they limp). To better understand this aberrant motor pattern and how to change it, we studied walking adaptation to a split-belt perturbation where one leg is driven to move faster than the other. Initially, healthy adult subjects take asymmetric steps on the split-belt treadmill, but within 10-15 min people adapt to reestablish walking symmetry. Which of the many walking parameters does the nervous system change to restore symmetry during this complex act (i.e., what motor mappings are adapted to restore symmetric walking in this asymmetric environment)? Here we found two parameters that met our criteria for adaptive learning: a temporal motor output consisting of the duration between heel-strikes of the two legs (i.e., "when" the feet land) and a spatial motor output related to the landing position of each foot relative to one another (i.e., "where" the feet land). We found that when subjects walk in an asymmetric environment they smoothly change their temporal and spatial motor outputs to restore temporal and spatial symmetry in the interlimb coordination of their gait. These changes in motor outputs are stored and have to be actively deadapted. Importantly, the adaptation of temporal and spatial motor outputs is dissociable since subjects were able to adapt their temporal motor output without adapting the spatial output. Taken together, our results suggest that temporal and spatial control for symmetric gait can be adapted separately, and therefore we could potentially develop interventions targeting either temporal or spatial walking deficits.
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Affiliation(s)
- Laura A Malone
- Department of Biomedical Engineering, The Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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35
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Zarrindast MR, Piri M, Nasehi M, Ebrahimi-Ghiri M. Nitric oxide in the nucleus accumbens is involved in retrieval of inhibitory avoidance memory by nicotine. Pharmacol Biochem Behav 2012; 101:166-73. [DOI: 10.1016/j.pbb.2011.11.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 11/09/2011] [Accepted: 11/15/2011] [Indexed: 12/22/2022]
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Savin DN, Tseng SC, Whitall J, Morton SM. Poststroke hemiparesis impairs the rate but not magnitude of adaptation of spatial and temporal locomotor features. Neurorehabil Neural Repair 2012; 27:24-34. [PMID: 22367915 DOI: 10.1177/1545968311434552] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Persons with stroke and hemiparesis walk with a characteristic pattern of spatial and temporal asymmetry that is resistant to most traditional interventions. It was recently shown in nondisabled persons that the degree of walking symmetry can be readily altered via locomotor adaptation. However, it is unclear whether stroke-related brain damage affects the ability to adapt spatial or temporal gait symmetry. OBJECTIVE Determine whether locomotor adaptation to a novel swing phase perturbation is impaired in persons with chronic stroke and hemiparesis. METHODS Participants with ischemic stroke (14) and nondisabled controls (12) walked on a treadmill before, during, and after adaptation to a unilateral perturbing weight that resisted forward leg movement. Leg kinematics were measured bilaterally, including step length and single-limb support (SLS) time symmetry, limb angle center of oscillation, and interlimb phasing, and magnitude of "initial" and "late" locomotor adaptation rates were determined. RESULTS All participants had similar magnitudes of adaptation and similar initial adaptation rates both spatially and temporally. All 14 participants with stroke and baseline asymmetry temporarily walked with improved SLS time symmetry after adaptation. However, late adaptation rates poststroke were decreased (took more strides to achieve adaptation) compared with controls. CONCLUSIONS Mild to moderate hemiparesis does not interfere with the initial acquisition of novel symmetrical gait patterns in both the spatial and temporal domains, though it does disrupt the rate at which "late" adaptive changes are produced. Impairment of the late, slow phase of learning may be an important rehabilitation consideration in this patient population.
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G-substrate: the cerebellum and beyond. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 106:381-416. [PMID: 22340725 DOI: 10.1016/b978-0-12-396456-4.00004-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The discovery of nitric oxide (NO) as an activator of soluble guanylate cyclase (sGC) has stimulated extensive research on the NO-sGC-3':5'-cyclic guanosine monophosphate (cGMP)-cGMP-dependent protein kinase (PKG) pathway. However, the restricted localization of pathway components and the lack of information on PKG substrates have hindered research seeking to examine the physiological roles of the NO-sGC-cGMP-PKG pathway. An excellent substrate for PKG is the G-substrate, which was originally discovered in the cerebellum. The role of G-substrate in the cerebellum and other brain structures has been revealed in recent years. This review discusses the relationship between the G-substrate and other components of the NO-sGC-cGMP-PKG pathway and describes the characteristics of the G-substrate gene and protein related to diseases. Finally, we discuss the physiological role of G-substrate in the cerebellum, where it regulates cerebellum-dependent long-term memory, and its role in the ventral tegmental area and retina, where it acts as an effective neuroprotectant.
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38
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Houldin A, Luttin K, Lam T. Locomotor adaptations and aftereffects to resistance during walking in individuals with spinal cord injury. J Neurophysiol 2011; 106:247-58. [PMID: 21543755 DOI: 10.1152/jn.00753.2010] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Muscle activity during the swing phase of walking is influenced by proprioceptive feedback pathways. Previous studies have shown that feedback and anticipatory motor commands contribute to locomotor adaptive strategies to prolonged exposure to a resistance against leg movements during walking. The purpose of this study was to determine whether people with motor-incomplete spinal cord injuries (SCI) modulate flexor muscle activity in response to different levels of resistance in a similar way as uninjured controls. A second purpose was to determine whether people with motor-incomplete SCI have the capacity to form anticipatory motor commands following exposure to resistance. Subjects walked on a treadmill with the Lokomat robotic gait orthosis. The Lokomat applied different levels of a velocity-dependent resistance, normalized to each subject's maximum voluntary contraction of the hip flexors. Each condition consisted of 20 steps against resistance followed by 20 steps without. Electromyography and kinematics of the lower limb were recorded. Although both groups responded to the resistance with an overall increase in rectus femoris activity during swing, the SCI group showed weak modulation of muscle activity to different levels of resistance. Following removal of the resistance, both groups showed aftereffects, but they were manifested differently. Controls responded to the removal of resistance with a high step, whereas the SCI subjects exhibited increased step length. The size of the aftereffect was related to the amount of added resistance. In addition, the SCI group showed a negative relationship between the size of the aftereffect and locomotor function.
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Affiliation(s)
- Adina Houldin
- School of Human Kinetics, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
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39
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Musselman KE, Patrick SK, Vasudevan EVL, Bastian AJ, Yang JF. Unique characteristics of motor adaptation during walking in young children. J Neurophysiol 2011; 105:2195-203. [PMID: 21368001 DOI: 10.1152/jn.01002.2010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Children show precocious ability in the learning of languages; is this the case with motor learning? We used split-belt walking to probe motor adaptation (a form of motor learning) in children. Data from 27 children (ages 8-36 mo) were compared with those from 10 adults. Children walked with the treadmill belts at the same speed (tied belt), followed by walking with the belts moving at different speeds (split belt) for 8-10 min, followed again by tied-belt walking (postsplit). Initial asymmetries in temporal coordination (i.e., double support time) induced by split-belt walking were slowly reduced, with most children showing an aftereffect (i.e., asymmetry in the opposite direction to the initial) in the early postsplit period, indicative of learning. In contrast, asymmetries in spatial coordination (i.e., center of oscillation) persisted during split-belt walking and no aftereffect was seen. Step length, a measure of both spatial and temporal coordination, showed intermediate effects. The time course of learning in double support and step length was slower in children than in adults. Moreover, there was a significant negative correlation between the size of the initial asymmetry during early split-belt walking (called error) and the aftereffect for step length. Hence, children may have more difficulty learning when the errors are large. The findings further suggest that the mechanisms controlling temporal and spatial adaptation are different and mature at different times.
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Affiliation(s)
- Kristin E Musselman
- Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada
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40
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Jayaram G, Galea JM, Bastian AJ, Celnik P. Human locomotor adaptive learning is proportional to depression of cerebellar excitability. ACTA ACUST UNITED AC 2011; 21:1901-9. [PMID: 21239392 DOI: 10.1093/cercor/bhq263] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Human locomotor adaptive learning is thought to involve the cerebellum, but the neurophysiological mechanisms underlying this process are not known. While animal research has pointed to depressive modulation of cerebellar outputs, a direct correlation between adaptive learning and cerebellar depression has never been demonstrated. Here, we used transcranial magnetic stimulation to assess excitability changes occurring in the cerebellum and primary motor cortex (M1) after individuals learned a new locomotor pattern on a split-belt treadmill. To control for potential changes associated to task performance complexity, the same group of subjects was also assessed after performing 2 other locomotor tasks that did not elicit learning. We found that only adaptive learning resulted in reduction of cerebellar inhibition. This effect was strongly correlated with the magnitude of learning (r = 0.78). In contrast, M1 excitability changes were not specific to learning but rather occurred in association with task complexity performance. Our results demonstrate that locomotor adaptive learning in humans is proportional to cerebellar excitability depression. This finding supports the theory that adaptive learning is mediated, at least in part, by long-term depression in Purkinje cells. This knowledge opens the opportunity to target cerebellar processes with noninvasive brain stimulation to enhance motor learning.
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Affiliation(s)
- Gowri Jayaram
- The Kennedy Krieger Institute, Baltimore, MD 21205, USA
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41
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Currás-Collazo MC. Nitric oxide signaling as a common target of organohalogens and other neuroendocrine disruptors. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2011; 14:495-536. [PMID: 21790323 DOI: 10.1080/10937404.2011.578564] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Organohalogen compounds such as polychlorinated biphenyls (PCB) and polybrominated diphenyl ethers (PBDE) are global environmental pollutants and highly persistent, bioaccumulative chemicals that produce adverse effects in humans and wildlife. Because of the widespread use of these organohalogens in household items and consumer products, indoor contamination is a significant source of human exposure, especially for children. One significant concern with regard to health effects associated with exposure to organohalogens is endocrine disruption. Toxicological studies on organohalogen pollutants primarily focused on sex steroid and thyroid hormone actions, and findings have largely shaped the way one envisions their disruptive effects occurring. Organohalogens exert additional effects on other systems including other complex endocrine systems that may be disregulated at various levels of organization. Over the last 20 years evidence has mounted in favor of a critical role of nitric oxide (NO) in numerous functions ranging from neuroendocrine functions to learning and memory. With its participation in multiple systems and action at several levels of integration, NO signaling has a pervasive influence on nervous and endocrine functions. Like blockers of NO synthesis, PCBs and PBDEs produce multifaceted effects on physiological systems. Based on this unique set of converging information it is proposed that organohalogen actions occur, in part, by hijacking processes associated with this ubiquitous bioactive molecule. The current review examines the emerging evidence for NO involvement in selected organohalogen actions and includes recent progress from our laboratory that adds to our current understanding of the actions of organohalogens within hypothalamic neuroendocrine circuits. The thyroid, vasopressin, and reproductive systems as well as processes associated with long-term potentiation were selected as sample targets of organohalogens that rely on regulation by NO. Information is provided about other toxicants with demonstrated interference of NO signaling. Our focus on the convergence between NO system and organohalogen toxicity offers a novel approach to understanding endocrine and neuroendocrine disruption that is particularly problematic for developing organisms. This new working model is proposed as a way to encourage future study in elucidating common mechanisms of action that are selected with a better operational understanding of the systems affected.
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Affiliation(s)
- Margarita C Currás-Collazo
- Department of Cell Biology and Neuroscience, University of California, Riverside, Riverside, California 92521, USA.
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42
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Savin DN, Tseng SC, Morton SM. Bilateral adaptation during locomotion following a unilaterally applied resistance to swing in nondisabled adults. J Neurophysiol 2010; 104:3600-11. [PMID: 20943942 DOI: 10.1152/jn.00633.2010] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Human walking must be flexible enough to accommodate many contexts and goals. One form of this flexibility is locomotor adaptation: a practice-dependent alteration to walking occurring in response to some novel perturbing stimulus. Although studies have examined locomotor adaptation and its storage by the CNS in humans, it remains unclear whether altered movements occurring in the leg contralateral to a perturbation are caused by true practice-dependent adaptation or whether they are generated via feedback corrective mechanisms. To test this, we recorded leg kinematics and electromyography (EMG) from nondisabled adults as they walked on a treadmill before, during, and after a novel force was applied to one leg, which resisted its forward movement during swing phase. The perturbation produced kinematic changes to numerous walking parameters, including swing phase durations, step lengths, and hip angular excursions. Nearly all occurred bilaterally. Importantly, kinematic changes were gradually adjusted over a period of exposure to the perturbation and were associated with negative aftereffects on its removal, suggesting they were adjusted through a true motor adaptation process. In addition, increases in the EMG of both legs persisted even after the perturbation was removed, providing further evidence that the CNS made and stored changes to feedforward motor commands controlling each leg. Our results show evidence for a feedforward adaptation of walking involving the leg opposite a perturbation. This result may help support the application of locomotor adaptation paradigms in clinical rehabilitation interventions targeting recovery of symmetric walking patterns in a variety of patient populations.
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Affiliation(s)
- Douglas N Savin
- University of Maryland Baltimore, School of Medicine, Department of Physical Therapy and Rehabilitation Science, Baltimore, Maryland, USA
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43
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Gordon KE, Wu M, Kahn JH, Schmit BD. Feedback and feedforward locomotor adaptations to ankle-foot load in people with incomplete spinal cord injury. J Neurophysiol 2010; 104:1325-38. [PMID: 20573970 DOI: 10.1152/jn.00604.2009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Humans with spinal cord injury (SCI) modulate locomotor output in response to limb load. Understanding the neural control mechanisms responsible for locomotor adaptation could provide a framework for selecting effective interventions. We quantified feedback and feedforward locomotor adaptations to limb load modulations in people with incomplete SCI. While subjects airstepped (stepping performed with kinematic assistance and 100% bodyweight support), a powered-orthosis created a dorisflexor torque during the "stance phase" of select steps producing highly controlled ankle-load perturbations. When given repetitive, stance phase ankle-load, the increase in hip extension work, 0.27 J/kg above baseline (no ankle-load airstepping), was greater than the response to ankle-load applied during a single step, 0.14 J/kg (P = 0.029). This finding suggests that, at the hip, subjects produced both feedforward and feedback locomotor modulations. We estimate that, at the hip, the locomotor response to repetitive ankle-load was modulated almost equally by ongoing feedback and feedforward adaptations. The majority of subjects also showed after-effects in hip kinetic patterns that lasted 3 min in response to repetitive loading, providing additional evidence of feedforward locomotor adaptations. The magnitude of the after-effect was proportional to the response to repetitive ankle-foot load (R(2) = 0.92). In contrast, increases in soleus EMG amplitude were not different during repetitive and single-step ankle-load exposure, suggesting that ankle locomotor modulations were predominately feedback-based. Although subjects made both feedback and feedforward locomotor adaptations to changes in ankle-load, between-subject variations suggest that walking function may be related to the ability to make feedforward adaptations.
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Affiliation(s)
- Keith E Gordon
- Sensory Motor Performance Program, Rehabilitation Inst. of Chicago, 345 E. Superior St., Rm. 1406, Chicago, IL 60611, USA.
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44
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Kim SH, Banala SK, Brackbill EA, Agrawal SK, Krishnamoorthy V, Scholz JP. Robot-assisted modifications of gait in healthy individuals. Exp Brain Res 2010; 202:809-24. [PMID: 20186402 DOI: 10.1007/s00221-010-2187-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2008] [Accepted: 02/04/2010] [Indexed: 01/14/2023]
Abstract
This study investigated whether short-term modifications of gait could be induced in healthy adults and whether a combination of kinetic (a compliant force resisting deviation of the foot from the prescribed footpath) and visual guidance was superior to either kinetic guidance or visual guidance alone in producing this modification. Thirty-nine healthy adults, 20-33 years old, were randomly assigned to the three groups receiving six 10-min blocks of treadmill training requiring them to modify their footpath to match a scaled-down path. Changes of the footpath, specific joint events and joint moments were analyzed. Persons receiving combined kinetic and visual guidance showed larger modifications of their gait patterns that were maintained longer, persisting up to 2 h after intervening over-ground activities, than did persons receiving training with primarily kinetic guidance or with visual guidance alone. The results emphasize the short-term plasticity of locomotor circuits and provide a possible basis for persons learning to achieve more functional gait patterns following a stroke or other neurological disorders.
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Affiliation(s)
- Seok Hun Kim
- School of Physical Therapy and Rehabilitation Sciences, University of South Florida, Tampa, FL 33612, USA.
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45
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Neurophysiologic and rehabilitation insights from the split-belt and other locomotor adaptation paradigms. Phys Ther 2010; 90:187-95. [PMID: 20023001 PMCID: PMC2816031 DOI: 10.2522/ptj.20090073] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Locomotion is incredibly flexible. Humans are able to stay upright and navigate long distances in the face of ever-changing environments and varied task demands, such as walking while carrying a heavy object or in thick mud. The focus of this review is a behavior that is critical for this flexibility: motor adaptation. Adaptation is defined here as the process of adjusting a movement to new demands through trial-and-error practice. A key feature of adaptation is that more practice without the new demand is required to return the movement to its original state. Thus, motor adaptation is a short-term motor learning process. Several studies have been undertaken to determine how humans adapt walking to novel circumstances. Many of these studies have examined locomotor adaptation using a split-belt treadmill. The results of these studies of people who were healthy and people with neurologic damage suggest that the cerebellum is required for normal adaptation of walking and that the role of cerebral structures may be less critical. They also suggest that intersegmental and interlimb coordination is critical but readily adaptable to accommodate changes in the environment. Locomotor adaptation also can be used to determine the walking potential of people with specific neurologic deficits. For instance, split-belt and limb-weighting locomotor adaptation studies show that adults with chronic stroke are capable of improving weight-bearing and spatiotemporal symmetry, at least temporarily. Our challenge as rehabilitation specialists is to intervene in ways that maximize this capacity.
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Vasudevan EVL, Bastian AJ. Split-belt treadmill adaptation shows different functional networks for fast and slow human walking. J Neurophysiol 2009; 103:183-91. [PMID: 19889853 DOI: 10.1152/jn.00501.2009] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
New walking patterns can be learned over short time scales (i.e., adapted in minutes) using a split-belt treadmill that controls the speed of each leg independently. This leads to storage of a modified motor pattern that is expressed as an aftereffect in regular walking conditions and must be de-adapted to return to normal. Here we asked whether the nervous system adapts a general walking pattern that is used across many speeds or a specific pattern affecting only the two speeds experienced during split-belt training. In experiment 1, we tested three groups of healthy adult subjects walking at different split-belt speed combinations and then assessed aftereffects at a range of speeds. We found that aftereffects were largest at the slower speed that was used in split-belt training in all three groups, and it decayed gradually for all other speeds. Thus adaptation appeared to be more strongly linked to the slow walking speed. This result suggests a separation in the functional networks used for fast and slow walking. We tested this in experiment 2 by adapting walking to split belts and then determining how much fast regular walking washed out the slow aftereffect and vice versa. We found that 23-38% of the aftereffect remained regardless of which speed was washed out first. This demonstrates that there is only partial overlap in the functional networks coordinating different walking speeds. Taken together, our results suggest that there are some neural networks for controlling locomotion that are recruited specifically for fast versus slow walking in humans, similar to recent findings in other vertebrates.
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Affiliation(s)
- Erin V L Vasudevan
- Motion Analysis Laboratory, Kennedy Krieger Institute, 707 N. Broadway, Baltimore, MD 21205, USA
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Reisman DS, Wityk R, Silver K, Bastian AJ. Split-belt treadmill adaptation transfers to overground walking in persons poststroke. Neurorehabil Neural Repair 2009; 23:735-44. [PMID: 19307434 DOI: 10.1177/1545968309332880] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND OBJECTIVE Following stroke, subjects retain the ability to adapt interlimb symmetry on the split-belt treadmill. Critical to advancing our understanding of locomotor adaptation and its usefulness in rehabilitation is discerning whether adaptive effects observed on a treadmill transfer to walking over ground. We examined whether aftereffects following split-belt treadmill adaptation transfer to overground walking in healthy persons and those poststroke. METHODS Eleven poststroke and 11 age-matched and gender-matched healthy subjects walked over ground before and after walking on a split-belt treadmill. Adaptation and aftereffects in step length and double support time were calculated. RESULTS Both groups demonstrated partial transfer of the aftereffects observed on the treadmill (P<.001) to overground walking (P<.05), but the transfer was more robust in the subjects poststroke (P<.05). The subjects with baseline asymmetry after stroke improved in asymmetry of step length and double limb support (P=.06). CONCLUSIONS The partial transfer of aftereffects to overground walking suggests that some shared neural circuits that control locomotion for different environmental contexts are adapted during split-belt treadmill walking. The larger adaptation transfer from the treadmill to overground walking in the stroke survivors may be due to difficulty adjusting their walking pattern to changing environmental demands. Such difficulties with context switching have been considered detrimental to function poststroke. However, we propose that the persistence of improved symmetry when changing context to overground walking could be used to advantage in poststroke rehabilitation.
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Affiliation(s)
- Darcy S Reisman
- Department of Physical Therapy, University of Delaware, Newark, Delaware 19716, USA.
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Dual involvement of G-substrate in motor learning revealed by gene deletion. Proc Natl Acad Sci U S A 2009; 106:3525-30. [PMID: 19218432 DOI: 10.1073/pnas.0813341106] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this study, we generated mice lacking the gene for G-substrate, a specific substrate for cGMP-dependent protein kinase uniquely located in cerebellar Purkinje cells, and explored their specific functional deficits. G-substrate-deficient Purkinje cells in slices obtained at postnatal weeks (PWs) 10-15 maintained electrophysiological properties essentially similar to those from WT littermates. Conjunction of parallel fiber stimulation and depolarizing pulses induced long-term depression (LTD) normally. At younger ages, however, LTD attenuated temporarily at PW6 and recovered thereafter. In parallel with LTD, short-term (1 h) adaptation of optokinetic eye movement response (OKR) temporarily diminished at PW6. Young adult G-substrate knockout mice tested at PW12 exhibited no significant differences from their WT littermates in terms of brain structure, general behavior, locomotor behavior on a rotor rod or treadmill, eyeblink conditioning, dynamic characteristics of OKR, or short-term OKR adaptation. One unique change detected was a modest but significant attenuation in the long-term (5 days) adaptation of OKR. The present results support the concept that LTD is causal to short-term adaptation and reveal the dual functional involvement of G-substrate in neuronal mechanisms of the cerebellum for both short-term and long-term adaptation.
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Choopani S, Moosavi M, Naghdi N. Involvement of nitric oxide in insulin induced memory improvement. Peptides 2008; 29:898-903. [PMID: 18295375 DOI: 10.1016/j.peptides.2008.01.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Revised: 01/09/2008] [Accepted: 01/11/2008] [Indexed: 12/14/2022]
Abstract
Although brain was considered as an insulin-insensitive organ, recently it has appeared that insulin has some interesting effects on some brain regions like hippocampus. It has been known that intra-hippocampally administered insulin can improve learning and memory. Knowing that insulin can stimulate nitric oxide (NO) synthesis via eNOS activation and also that NO synthase (NOS) inhibitors can affect learning and memory, the aim of this study was to assess if NO is involved in insulin induced memory improvement. Wistar male rats were intra-CA1 cannulated and the effect of post-training and pre-probe trial intra-hippocampal administration of N-nitro-L-arginine methyl ester (L-NAME) (5, 10, 30 microg), insulin+L-NAME+/-L-arginine were assessed in a single-day testing version of Morris water maze (MWM) task. Our results show that, l-NAME can prevent insulin induced memory improvement. This drug had no effect on escape latency of a non-spatial visual discrimination task. Therefore, it seems that endogenous nitric oxide has a role in spatial learning and memory improvement caused by insulin.
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Affiliation(s)
- S Choopani
- Department of Physiology, Pasteur Institute of Iran, Tehran, Iran
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Choi JT, Bastian AJ. Adaptation reveals independent control networks for human walking. Nat Neurosci 2007; 10:1055-62. [PMID: 17603479 DOI: 10.1038/nn1930] [Citation(s) in RCA: 235] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Accepted: 05/21/2007] [Indexed: 11/08/2022]
Abstract
Human walking is remarkably adaptable on short and long timescales. We can immediately transition between directions and gait patterns, and we can adaptively learn accurate calibrations for different walking contexts. Here we studied the degree to which different motor patterns can adapt independently. We used a split-belt treadmill to adapt the right and left legs to different speeds and in different directions (forward versus backward). To our surprise, adults could easily walk with their legs moving in opposite directions. Analysis of aftereffects showed that walking adaptations are stored independently for each leg and do not transfer across directions. Thus, there are separate functional networks controlling forward and backward walking in humans, and the circuits controlling the right and left legs can be trained individually. Such training could provide a new therapeutic approach for correcting various walking asymmetries.
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Affiliation(s)
- Julia T Choi
- The Kennedy Krieger Institute, 707 North Broadway, Baltimore, Maryland 21205, USA.
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