1
|
Hüche Larsen H, Justiniano MD, Frisk RF, Lundbye-Jensen J, Farmer SF, Nielsen JB. Task difficulty of visually guided gait modifications involves differences in central drive to spinal motor neurons. J Neurophysiol 2024; 132:1126-1141. [PMID: 39196679 DOI: 10.1152/jn.00466.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 08/16/2024] [Accepted: 08/21/2024] [Indexed: 08/30/2024] Open
Abstract
Walking in natural environments requires visually guided modifications, which can be more challenging when involving sideways steps rather than longer steps. This exploratory study investigated whether these two types of modifications involve different changes in the central drive to spinal motor neurons of leg muscles. Fifteen adults [age: 36 ± 6 (SD) years] walked on a treadmill (4 km/h) while observing a screen displaying the real-time position of their toes. At the beginning of the swing phase, a visual target appeared in front (forward) or medial-lateral (sideways) of the ground contact in random step cycles (approximately every third step). We measured three-dimensional kinematics and electromyographic activity from leg muscles bilaterally. Intermuscular coherence was calculated in the alpha (5-15 Hz), beta (15-30 Hz), and gamma bands (30-45 Hz) approximately 230 ms before and after ground contact in control and target steps. Results showed that adjustments toward sideways targets were associated with significantly higher error, lower foot lift, and higher cocontraction between antagonist ankle muscles. Movements toward sideways targets were associated with larger beta-band soleus (SOL): medial gastrocnemius (MG) coherence and a more narrow and larger peak of synchronization in the cumulant density before ground contact. In contrast, movements toward forward targets showed no significant differences in coherence or synchronization compared with control steps. Larger SOL:MG beta-band coherence and short-term synchronization were observed during sideways, but not forward, gait modifications. This suggests that visually guided gait modifications may involve differences in the central drive to spinal ankle motor neurons dependent on the level of task difficulty.NEW & NOTEWORTHY This exploratory study suggests a specific and temporally restricted increase of central (likely corticospinal) drive to ankle muscles in relation to visually guided gait modifications. The findings indicate that a high level of visual attention to control the position of the ankle joint precisely before ground contact may involve increased central drive to ankle muscles. These findings are important for understanding the neural mechanisms underlying visually guided gait and may help develop rehabilitation interventions.
Collapse
Affiliation(s)
- Helle Hüche Larsen
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
- Elsass Foundation, Charlottenlund, Denmark
| | | | - Rasmus Feld Frisk
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
- Elsass Foundation, Charlottenlund, Denmark
| | - Jesper Lundbye-Jensen
- Movement and Neuroscience, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Simon Francis Farmer
- Department of Clinical and Movement Neuroscience, Institute of Neurology, University College London, London, United Kingdom
- Department of Clinical Neurology, National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Jens Bo Nielsen
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
- Elsass Foundation, Charlottenlund, Denmark
| |
Collapse
|
2
|
Zipser-Mohammadzada F, Scheffers MF, Conway BA, Halliday DM, Zipser CM, Curt A, Schubert M. Intramuscular coherence enables robust assessment of modulated supra-spinal input in human gait: an inter-dependence study of visual task and walking speed. Exp Brain Res 2023; 241:1675-1689. [PMID: 37199775 DOI: 10.1007/s00221-023-06635-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 05/11/2023] [Indexed: 05/19/2023]
Abstract
Intramuscular high-frequency coherence is increased during visually guided treadmill walking as a consequence of increased supra-spinal input. The influence of walking speed on intramuscular coherence and its inter-trial reproducibility need to be established before adoption as a functional gait assessment tool in clinical settings. Here, fifteen healthy controls performed a normal and a target walking task on a treadmill at various speeds (0.3 m/s, 0.5 m/s, 0.9 m/s, and preferred) during two sessions. Intramuscular coherence was calculated between two surface EMG recordings sites of the Tibialis anterior muscle during the swing phase of walking. The results were averaged across low-frequency (5-14 Hz) and high-frequency (15-55 Hz) bands. The effect of speed, task, and time on mean coherence was assessed using three-way repeated measures ANOVA. Reliability and agreement were calculated with the intra-class correlation coefficient and Bland-Altman method, respectively. Intramuscular coherence during target walking was significantly higher than during normal walking across all walking speeds in the high-frequency band as obtained by the three-way repeated measures ANOVA. Interaction effects between task and speed were found for the low- and high-frequency bands, suggesting that task-dependent differences increase at higher walking speeds. Reliability of intramuscular coherence was moderate to excellent for most normal and target walking tasks in all frequency bands. This study confirms previous reports of increased intramuscular coherence during target walking, while providing first evidence for reproducibility and robustness of this measure as a requirement to investigate supra-spinal input.Trial registration Registry number/ClinicalTrials.gov Identifier: NCT03343132, date of registration 2017/11/17.
Collapse
Affiliation(s)
| | - Marjelle Fredie Scheffers
- Department of Neurophysiology, Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- Faculty of Medicine, Utrecht University, Utrecht, The Netherlands
| | - Bernard A Conway
- Biomedical Engineering, University of Strathclyde, Glasgow, G4 0NW, UK
| | - David M Halliday
- School of Physics, Engineering and Technology, University of York, York, YO10 5DD, UK
- York Biomedical Research Institute, University of York, York, UK
| | - Carl Moritz Zipser
- Department of Neurophysiology, Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Armin Curt
- Department of Neurophysiology, Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Martin Schubert
- Department of Neurophysiology, Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| |
Collapse
|
3
|
Rasman BG, Forbes PA, Peters RM, Ortiz O, Franks I, Inglis JT, Chua R, Blouin JS. Learning to stand with unexpected sensorimotor delays. eLife 2021; 10:65085. [PMID: 34374648 PMCID: PMC8480973 DOI: 10.7554/elife.65085] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 08/04/2021] [Indexed: 11/23/2022] Open
Abstract
Human standing balance relies on self-motion estimates that are used by the nervous system to detect unexpected movements and enable corrective responses and adaptations in control. These estimates must accommodate for inherent delays in sensory and motor pathways. Here, we used a robotic system to simulate human standing about the ankles in the anteroposterior direction and impose sensorimotor delays into the control of balance. Imposed delays destabilized standing, but through training, participants adapted and re-learned to balance with the delays. Before training, imposed delays attenuated vestibular contributions to balance and triggered perceptions of unexpected standing motion, suggesting increased uncertainty in the internal self-motion estimates. After training, vestibular contributions partially returned to baseline levels and larger delays were needed to evoke perceptions of unexpected standing motion. Through learning, the nervous system accommodates balance sensorimotor delays by causally linking whole-body sensory feedback (initially interpreted as imposed motion) to self-generated balance motor commands. When standing, neurons in the brain send signals to skeletal muscles so we can adjust our movements to stay upright based on the requirements from the surrounding environment. The long nerves needed to connect our brain, muscles and sensors lead to considerable time delays (up to 160 milliseconds) between sensing the environment and the generation of balance-correcting motor signals. Such delays must be accounted for by the brain so it can adjust how it regulates balance and compensates for unexpected movements. Aging and neurological disorders can lead to lengthened neural delays, which may result in poorer balance. Computer modeling suggests that we cannot maintain upright balance if delays are longer than 300-340 milliseconds. Directly assessing the destabilizing effects of increased delays in human volunteers can reveal how capable the brain is at adapting to this neurological change. Using a custom-designed robotic balance simulator, Rasman et al. tested whether healthy volunteers could learn to balance with delays longer than the predicted 300-340 millisecond limit. In a series of experiments, 46 healthy participants stood on the balance simulator which recreates the physical sensations and neural signals for balancing upright based on a computer-driven virtual reality. This unique device enabled Rasman et al. to artificially impose delays by increasing the time between the generation of motor signals and resulting whole-body motion. The experiments showed that lengthening the delay between motor signals and whole-body motion destabilized upright standing, decreased sensory contributions to balance and led to perceptions of unexpected movements. Over five days of training on the robotic balance simulator, participants regained their ability to balance, which was accompanied by recovered sensory contributions and perceptions of expected standing, despite the imposed delays. When a subset of participants was tested three months later, they were still able to compensate for the increased delay. The experiments show that the human brain can learn to overcome delays up to 560 milliseconds in the control of balance. This discovery may have important implications for people who develop balance problems because of older age or neurologic diseases like multiple sclerosis. It is possible that robot-assisted training therapies, like the one in this study, could help people overcome their balance impairments.
Collapse
Affiliation(s)
- Brandon G Rasman
- School of Physical Education, Sport, and Exercise Sciences, University of Otago, Dunedin, New Zealand
| | - Patrick A Forbes
- Department of Neuroscience, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - Ryan M Peters
- Faculty of Kinesiology, University of Calgary, Calgary, Canada
| | - Oscar Ortiz
- Faculty of Kinesiology, University of New Brunswick, Fredericton, Canada
| | - Ian Franks
- School of Kinesiology, University of British Columbia, Vancouver, Canada
| | - J Timothy Inglis
- School of Kinesiology, University of British Columbia, Vancouver, Canada
| | - Romeo Chua
- School of Kinesiology, University of British Columbia, Vancouver, Canada
| | | |
Collapse
|
4
|
Motoneurone synchronization for intercostal and abdominal muscles: interneurone influences in two different species. Exp Brain Res 2020; 239:95-115. [PMID: 33106893 PMCID: PMC7884307 DOI: 10.1007/s00221-020-05924-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/07/2020] [Indexed: 11/12/2022]
Abstract
The contribution of branched-axon monosynaptic inputs in the generation of short-term synchronization of motoneurones remains uncertain. Here, synchronization was measured for intercostal and abdominal motoneurones supplying the lower thorax and upper abdomen, mostly showing expiratory discharges. Synchronization in the anaesthetized cat, where the motoneurones receive a strong direct descending drive, is compared with that in anaesthetized or decerebrate rats, where the direct descending drive is much weaker. In the cat, some examples could be explained by branched-axon monosynaptic inputs, but many others could not, by virtue of peaks in cross-correlation histograms whose widths (relatively wide) and timing indicated common inputs with more complex linkages, e.g., disynaptic excitatory. In contrast, in the rat, correlations for pairs of internal intercostal nerves were dominated by very narrow peaks, indicative of branched-axon monosynaptic inputs. However, the presence of activity in both inspiration and expiration in many of the nerves allowed additional synchronization measurements between internal and external intercostal nerves. Time courses of synchronization for these often consisted of combinations of peaks and troughs, which have never been previously described for motoneurone synchronization and which we interpret as indicating combinations of inputs, excitation of one group of motoneurones being common with either excitation or inhibition of the other. Significant species differences in the circuits controlling the motoneurones are indicated, but in both cases, the roles of spinal interneurones are emphasised. The results demonstrate the potential of motoneurone synchronization for investigating inhibition and have important general implications for the interpretation of neural connectivity measurements by cross-correlation.
Collapse
|
5
|
Lorentzen J, Willerslev-Olsen M, Hüche Larsen H, Farmer SF, Nielsen JB. Maturation of feedforward toe walking motor program is impaired in children with cerebral palsy. Brain 2020; 142:526-541. [PMID: 30726881 DOI: 10.1093/brain/awz002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 11/02/2018] [Accepted: 11/26/2018] [Indexed: 11/13/2022] Open
Abstract
Voluntary toe walking in adults is characterized by feedforward control of ankle muscles in order to ensure optimal stability of the ankle joint at ground impact. Toe walking is frequently observed in children with cerebral palsy, but the mechanisms involved have not been clarified. Here, we investigated maturation of voluntary toe walking in typically-developing children and typically-developed adults and compared it to involuntary toe walking in children with cerebral palsy. Twenty-eight children with cerebral palsy (age 3-14 years), 24 typically-developing children (age 2-14 years) and 15 adults (mean age 30.7 years) participated in the study. EMG activity was measured from the tibialis anterior and soleus muscles together with knee and ankle joint position during treadmill walking. In typically-developed adults, low step-to-step variability of the drop of the heel after ground impact was correlated with low tibialis anterior and high soleus EMG with no significant coupling between the antagonist muscle EMGs. Typically-developing children showed a significant age-related decline in EMG amplitude reaching an adult level at 10-12 years of age. The youngest typically-developing children showed a broad peak EMG-EMG synchronization (>100 ms) associated with large 5-15 Hz coherence between antagonist muscle activities. EMG coherence declined with age and at the age of 10-12 years no correlation was observed similar to adults. This reduction in coherence was closely related to improved step-to-step stability of the ankle joint position. Children with cerebral palsy generally showed lower EMG levels than typically-developing children and larger step-to-step variability in ankle joint position. In contrast to typically-developing children, children with cerebral palsy showed no age-related decline in tibialis anterior EMG amplitude. Motor unit synchronization and 5-15 Hz coherence between antagonist EMGs was observed more frequently in children with cerebral palsy when compared to typically-developing children and in contrast to typically-developing participants there was no age-related decline. We conclude that typically-developing children develop mature feedforward control of ankle muscle activity as they age, such that at age 10-12 years there is little agonist-antagonist muscle co-contraction around the time of foot-ground contact during toe walking. Children with cerebral palsy, in contrast, continue to co-contract agonist and antagonist ankle muscles when toe walking. We speculate that children with cerebral palsy maintain a co-contraction activation pattern when toe walking due to weak muscles and insufficient motor and sensory signalling necessary for optimization of feedforward motor programs. These findings are important for understanding of the pathophysiology and treatment of toe walking.
Collapse
Affiliation(s)
- Jakob Lorentzen
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Elsass Institute, Charlottenlund, Denmark
| | - Maria Willerslev-Olsen
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Elsass Institute, Charlottenlund, Denmark
| | | | - Simon Francis Farmer
- Department of Clinical and Movement Neuroscience, Institute of Neurology, University College London, London, UK.,Department of Clinical Neurology, National Hospital for Neurology and Neurosurgery, UK
| | - Jens Bo Nielsen
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Elsass Institute, Charlottenlund, Denmark
| |
Collapse
|
6
|
Thompson CK, Johnson MD, Negro F, Mcpherson LM, Farina D, Heckman CJ. Exogenous neuromodulation of spinal neurons induces beta-band coherence during self-sustained discharge of hind limb motor unit populations. J Appl Physiol (1985) 2019; 127:1034-1041. [PMID: 31318619 PMCID: PMC6850985 DOI: 10.1152/japplphysiol.00110.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The spontaneous or self-sustained discharge of spinal motoneurons can be observed in both animals and humans. Although the origins of this self-sustained discharge are not fully known, it can be generated by activation of persistent inward currents intrinsic to the motoneuron. If self-sustained discharge is generated exclusively through this intrinsic mechanism, the discharge of individual motor units will be relatively independent of one another. Alternatively, if increased activation of premotor circuits underlies this prolonged discharge of spinal motoneurons, we would expect correlated activity among motoneurons. Our aim is to assess potential synaptic drive by quantifying coherence during self-sustained discharge of spinal motoneurons. Electromyographic activity was collected from 20 decerebrate animals using a 64-channel electrode grid placed on the isolated soleus muscle before and following intrathecal administration of methoxamine, a selective α1-noradrenergic agonist. Sustained muscle activity was recorded and decomposed into the discharge times of ~10-30 concurrently active individual motor units. Consistent with previous reports, the self-sustained discharge of motor units occurred at low mean discharge rates with low-interspike variability. Before methoxamine administration, significant low-frequency coherence (<2 Hz) was observed, while minimal coherence was observed within higher frequency bands. Following intrathecal administration of methoxamine, increases in motor unit discharge rates and strong coherence in both the low-frequency and 15- to 30-Hz beta bands were observed. These data demonstrate beta-band coherence among motor units can be observed through noncortical mechanisms and that neuromodulation of spinal/brainstem neurons greatly influences coherent discharge within spinal motor pools.NEW & NOTEWORTHY The correlated discharge of spinal motoneurons is often used to describe the input to the motor pool. We demonstrate spinal/brainstem neurons devoid of cortical input can generate correlated motor unit discharge in the 15- to 30-Hz beta band, which is amplified through neuromodulation. Activity in the beta band is often ascribed to cortical drive in humans; however, these data demonstrate the capability of the mammalian segmental motor system to generate and modulate this coherent state of motor unit discharge.
Collapse
Affiliation(s)
| | | | - Francesco Negro
- 3Department of Clinical and Experimental Sciences, Research Centre for Neuromuscular Function and Adapted Physical Activity “Teresa Camplani,” Università degli Studi di Brescia, Bescia, Italy
| | | | - Dario Farina
- 5Department of Bioengineering, Imperial College London, London, United Kingdom
| | | |
Collapse
|
7
|
Radosevic M, Willumsen A, Petersen PC, Lindén H, Vestergaard M, Berg RW. Decoupling of timescales reveals sparse convergent CPG network in the adult spinal cord. Nat Commun 2019; 10:2937. [PMID: 31270315 PMCID: PMC6610135 DOI: 10.1038/s41467-019-10822-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 06/04/2019] [Indexed: 12/12/2022] Open
Abstract
During the generation of rhythmic movements, most spinal neurons receive an oscillatory synaptic drive. The neuronal architecture underlying this drive is unknown, and the corresponding network size and sparseness have not yet been addressed. If the input originates from a small central pattern generator (CPG) with dense divergent connectivity, it will induce correlated input to all receiving neurons, while sparse convergent wiring will induce a weak correlation, if any. Here, we use pairwise recordings of spinal neurons to measure synaptic correlations and thus infer the wiring architecture qualitatively. A strong correlation on a slow timescale implies functional relatedness and a common source, which will also cause correlation on fast timescale due to shared synaptic connections. However, we consistently find marginal coupling between slow and fast correlations regardless of neuronal identity. This suggests either sparse convergent connectivity or a CPG network with recurrent inhibition that actively decorrelates common input.
Collapse
Affiliation(s)
- Marija Radosevic
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Alex Willumsen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Peter C Petersen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
- Neuroscience Institute, New York University, New York, NY, 10016, USA
| | - Henrik Lindén
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Mikkel Vestergaard
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
- Department of Neuroscience, Max Delbrück Center for Molecular Medicine (MDC), 13125, Berlin-Buch, Germany
| | - Rune W Berg
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark.
| |
Collapse
|
8
|
Bhattacharya S, Ma Y, Dunn AR, Bradner JM, Scimemi A, Miller GW, Traynelis SF, Wichmann T. NMDA receptor blockade ameliorates abnormalities of spike firing of subthalamic nucleus neurons in a parkinsonian nonhuman primate. J Neurosci Res 2018; 96:1324-1335. [PMID: 29577359 PMCID: PMC5980712 DOI: 10.1002/jnr.24230] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 01/25/2018] [Accepted: 02/08/2018] [Indexed: 12/21/2022]
Abstract
N-methyl-D-aspartate receptors (NMDARs) are ion channels comprising tetrameric assemblies of GluN1 and GluN2 receptor subunits that mediate excitatory neurotransmission in the central nervous system. Of the four different GluN2 subunits, the GluN2D subunit-containing NMDARs have been suggested as a target for antiparkinsonian therapy because of their expression pattern in some of the basal ganglia nuclei that show abnormal firing patterns in the parkinsonian state, specifically the subthalamic nucleus (STN). In this study, we demonstrate that blockade of NMDARs altered spike firing in the STN in a male nonhuman primate that had been rendered parkinsonian by treatment with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. In accompanying experiments in male rodents, we found that GluN2D-NMDAR expression in the STN was reduced in acutely or chronically dopamine-depleted animals. Taken together, our data suggest that blockade of NMDARs in the STN may be a viable antiparkinsonian strategy, but that the ultimate success of this approach may be complicated by parkinsonism-associated changes in NMDAR expression in the STN.
Collapse
Affiliation(s)
| | - Yuxian Ma
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia
| | - Amy R Dunn
- Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Joshua M Bradner
- Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Annalisa Scimemi
- Department of Biology, State University of New York at Albany, Albany, New York
| | - Gary W Miller
- Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia
| | - Thomas Wichmann
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia
- Morris K. Udall Center of Excellence for Parkinson's Disease Research at Emory University, Atlanta, Georgia
| |
Collapse
|
9
|
Jensen P, Jensen NJ, Terkildsen CU, Choi JT, Nielsen JB, Geertsen SS. Increased central common drive to ankle plantar flexor and dorsiflexor muscles during visually guided gait. Physiol Rep 2018; 6:e13598. [PMID: 29405634 PMCID: PMC5800295 DOI: 10.14814/phy2.13598] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 01/07/2018] [Indexed: 11/24/2022] Open
Abstract
When we walk in a challenging environment, we use visual information to modify our gait and place our feet carefully on the ground. Here, we explored how central common drive to ankle muscles changes in relation to visually guided foot placement. Sixteen healthy adults aged 23 ± 5 years participated in the study. Electromyography (EMG) from the Soleus (Sol), medial Gastrocnemius (MG), and the distal and proximal ends of the Tibialis anterior (TA) muscles and electroencephalography (EEG) from Cz were recorded while subjects walked on a motorized treadmill. A visually guided walking task, where subjects received visual feedback of their foot placement on a screen in real-time and were required to place their feet within narrow preset target areas, was compared to normal walking. There was a significant increase in the central common drive estimated by TA-TA and Sol-MG EMG-EMG coherence in beta and gamma frequencies during the visually guided walking compared to normal walking. EEG-TA EMG coherence also increased, but the group average did not reach statistical significance. The results indicate that the corticospinal tract is involved in modifying gait when visually guided placement of the foot is required. These findings are important for our basic understanding of the central control of human bipedal gait and for the design of rehabilitation interventions for gait function following central motor lesions.
Collapse
Affiliation(s)
- Peter Jensen
- Department of Nutrition, Exercise and SportsUniversity of CopenhagenCopenhagenDenmark
| | | | | | - Julia T. Choi
- Department of KinesiologyUniversity of MassachusettsAmherstMassachusetts
| | - Jens Bo Nielsen
- Department of NeuroscienceUniversity of CopenhagenCopenhagenDenmark
- Elsass InstituteCharlottenlundDenmark
| | - Svend Sparre Geertsen
- Department of Nutrition, Exercise and SportsUniversity of CopenhagenCopenhagenDenmark
- Department of NeuroscienceUniversity of CopenhagenCopenhagenDenmark
| |
Collapse
|
10
|
Bravo-Esteban E, Taylor J, Aleixandre M, Simón-Martínez C, Torricelli D, Pons JL, Avila-Martín G, Galán-Arriero I, Gómez-Soriano J. Longitudinal estimation of intramuscular Tibialis Anterior coherence during subacute spinal cord injury: relationship with neurophysiological, functional and clinical outcome measures. J Neuroeng Rehabil 2017; 14:58. [PMID: 28619087 PMCID: PMC5472888 DOI: 10.1186/s12984-017-0271-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 06/05/2017] [Indexed: 12/11/2022] Open
Abstract
Background Estimation of surface intramuscular coherence has been used to indirectly assess pyramidal tract activity following spinal cord injury (SCI), especially within the 15-30 Hz bandwidth. However, change in higher frequency (>40 Hz) muscle coherence during SCI has not been characterised. Thus, the objective of this study was to identify change of high and low frequency intramuscular Tibialis Anterior (TA) coherence during incomplete subacute SCI. Methods Fifteen healthy subjects and 22 subjects with motor incomplete SCI (American Spinal Injury Association Impairment Scale, AIS, C or D grade) were recruited and tested during 4 sessions performed at 2-week intervals up to 8 months after SCI. Intramuscular TA coherence estimation was calculated within the 10–60 Hz bandwidth during controlled maximal isometric and isokinetic foot dorsiflexion. Maximal voluntary dorsiflexion torque, gait function measured with the WISCI II scale, and TA motor evoked potentials (MEP) were recorded. Results During subacute SCI, significant improvement in total lower limb manual muscle score, TA muscle strength and gait function were observed. No change in TA MEP amplitude was identified. Significant increase in TA coherence was detected in the 40–60 Hz, but not the 15–30 Hz bandwidth. The spasticity syndrome was associated with lower 15-30 Hz TA coherence during maximal isometric dorsiflexion and higher 10–60 Hz coherence during fast isokinetic movement (p < 0.05). Conclusions Longitudinal estimation of neurophysiological and clinical measures during subacute SCI suggest that estimation of TA muscle coherence during controlled movement provides indirect information regarding adaptive and maladaptive motor control mechanisms during neurorehabilitation.
Collapse
Affiliation(s)
- Elisabeth Bravo-Esteban
- Sensorimotor Function Group, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain.,Neurorehabilitation Group, Instituto Cajal, CSIC, Madrid, Spain.,Toledo Physiotherapy Research Group (GIFTO), Nursing and Physiotherapy Faculty, Universidad de Castilla la Mancha, Toledo, Spain
| | - Julian Taylor
- Sensorimotor Function Group, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain. .,Stoke Mandeville Spinal Research, National Spinal Injuries Centre, Buckinghamshire Healthcare Trust, NHS, Aylesbury, UK. .,Harris Manchester College, University of Oxford, Oxford, UK.
| | | | | | | | - Jose Luis Pons
- Neurorehabilitation Group, Instituto Cajal, CSIC, Madrid, Spain
| | - Gerardo Avila-Martín
- Sensorimotor Function Group, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain
| | - Iriana Galán-Arriero
- Sensorimotor Function Group, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain
| | - Julio Gómez-Soriano
- Sensorimotor Function Group, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain.,Toledo Physiotherapy Research Group (GIFTO), Nursing and Physiotherapy Faculty, Universidad de Castilla la Mancha, Toledo, Spain
| |
Collapse
|
11
|
Kammermeier S, Pittard D, Hamada I, Wichmann T. Effects of high-frequency stimulation of the internal pallidal segment on neuronal activity in the thalamus in parkinsonian monkeys. J Neurophysiol 2016; 116:2869-2881. [PMID: 27683881 DOI: 10.1152/jn.00104.2016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 09/22/2016] [Indexed: 01/28/2023] Open
Abstract
Deep brain stimulation of the internal globus pallidus (GPi) is a major treatment for advanced Parkinson's disease. The effects of this intervention on electrical activity patterns in targets of GPi output, specifically in the thalamus, are poorly understood. The experiments described here examined these effects using electrophysiological recordings in two Rhesus monkeys rendered moderately parkinsonian through treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), after sampling control data in the same animals. Analysis of spontaneous spiking activity of neurons in the basal ganglia-receiving areas of the ventral thalamus showed that MPTP-induced parkinsonism is associated with a reduction of firing rates of segments of the data that contained neither bursts nor decelerations, and with increased burst firing. Spectral analyses revealed an increase of power in the 3- to 13-Hz band and a reduction in the γ-range in the spiking activity of these neurons. Electrical stimulation of the ventrolateral motor territory of GPi with macroelectrodes, mimicking deep brain stimulation in parkinsonian patients (bipolar electrodes, 0.5 mm intercontact distance, biphasic stimuli, 120 Hz, 100 μs/phase, 200 μA), had antiparkinsonian effects. The stimulation markedly reduced oscillations in thalamic firing in the 13- to 30-Hz range and uncoupled the spiking activity of recorded neurons from simultaneously recorded local field potential (LFP) activity. These results confirm that oscillatory and nonoscillatory characteristics of spontaneous activity in the basal ganglia receiving ventral thalamus are altered in MPTP-induced parkinsonism. Electrical stimulation of GPi did not entrain thalamic activity but changed oscillatory activity in the ventral thalamus and altered the relationship between spikes and simultaneously recorded LFPs.
Collapse
Affiliation(s)
- Stefan Kammermeier
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia.,Udall Center of Excellence in Parkinson's Disease Research, Emory University, Atlanta, Georgia
| | - Damien Pittard
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia.,Udall Center of Excellence in Parkinson's Disease Research, Emory University, Atlanta, Georgia
| | - Ikuma Hamada
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia.,Udall Center of Excellence in Parkinson's Disease Research, Emory University, Atlanta, Georgia
| | - Thomas Wichmann
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia; .,School of Medicine, Department of Neurology, Emory University, Atlanta, Georgia; and.,Udall Center of Excellence in Parkinson's Disease Research, Emory University, Atlanta, Georgia
| |
Collapse
|
12
|
Devergnas A, Chen E, Ma Y, Hamada I, Pittard D, Kammermeier S, Mullin AP, Faundez V, Lindsley CW, Jones C, Smith Y, Wichmann T. Anatomical localization of Cav3.1 calcium channels and electrophysiological effects of T-type calcium channel blockade in the motor thalamus of MPTP-treated monkeys. J Neurophysiol 2015; 115:470-85. [PMID: 26538609 DOI: 10.1152/jn.00858.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 11/03/2015] [Indexed: 12/28/2022] Open
Abstract
Conventional anti-Parkinsonian dopamine replacement therapy is often complicated by side effects that limit the use of these medications. There is a continuing need to develop nondopaminergic approaches to treat Parkinsonism. One such approach is to use medications that normalize dopamine depletion-related firing abnormalities in the basal ganglia-thalamocortical circuitry. In this study, we assessed the potential of a specific T-type calcium channel blocker (ML218) to eliminate pathologic burst patterns of firing in the basal ganglia-receiving territory of the motor thalamus in Parkinsonian monkeys. We also carried out an anatomical study, demonstrating that the immunoreactivity for T-type calcium channels is strongly expressed in the motor thalamus in normal and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys. At the electron microscopic level, dendrites accounted for >90% of all tissue elements that were immunoreactive for voltage-gated calcium channel, type 3.2-containing T-type calcium channels in normal and Parkinsonian monkeys. Subsequent in vivo electrophysiologic studies in awake MPTP-treated Parkinsonian monkeys demonstrated that intrathalamic microinjections of ML218 (0.5 μl of a 2.5-mM solution, injected at 0.1-0.2 μl/min) partially normalized the thalamic activity by reducing the proportion of rebound bursts and increasing the proportion of spikes in non-rebound bursts. The drug also attenuated oscillatory activity in the 3-13-Hz frequency range and increased gamma frequency oscillations. However, ML218 did not normalize Parkinsonism-related changes in firing rates and oscillatory activity in the beta frequency range. Whereas the described changes are promising, a more complete assessment of the cellular and behavioral effects of ML218 (or similar drugs) is needed for a full appraisal of their anti-Parkinsonian potential.
Collapse
Affiliation(s)
- Annaelle Devergnas
- Yerkes National Primate Research Center, Atlanta, Georgia; Udall Center of Excellence for Parkinson's Disease Research at Emory University, Atlanta, Georgia;
| | - Erdong Chen
- Yerkes National Primate Research Center, Atlanta, Georgia; Udall Center of Excellence for Parkinson's Disease Research at Emory University, Atlanta, Georgia
| | - Yuxian Ma
- Yerkes National Primate Research Center, Atlanta, Georgia; Udall Center of Excellence for Parkinson's Disease Research at Emory University, Atlanta, Georgia
| | - Ikuma Hamada
- Yerkes National Primate Research Center, Atlanta, Georgia; Udall Center of Excellence for Parkinson's Disease Research at Emory University, Atlanta, Georgia
| | - Damien Pittard
- Yerkes National Primate Research Center, Atlanta, Georgia; Udall Center of Excellence for Parkinson's Disease Research at Emory University, Atlanta, Georgia
| | - Stefan Kammermeier
- Yerkes National Primate Research Center, Atlanta, Georgia; Udall Center of Excellence for Parkinson's Disease Research at Emory University, Atlanta, Georgia; Klinikum der Universität München, Neurologische Klinik und Poliklinik, München, Germany
| | - Ariana P Mullin
- Department of Cell Biology, Emory University, Atlanta, Georgia
| | - Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, Georgia; Center for Social Translational Neuroscience, Emory University, Atlanta, Georgia
| | - Craig W Lindsley
- Department of Pharmacology and Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | - Carrie Jones
- Department of Pharmacology and Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee; and
| | - Yoland Smith
- Yerkes National Primate Research Center, Atlanta, Georgia; Udall Center of Excellence for Parkinson's Disease Research at Emory University, Atlanta, Georgia; Department of Neurology, School of Medicine, Emory University, Atlanta, Georgia
| | - Thomas Wichmann
- Yerkes National Primate Research Center, Atlanta, Georgia; Udall Center of Excellence for Parkinson's Disease Research at Emory University, Atlanta, Georgia; Department of Neurology, School of Medicine, Emory University, Atlanta, Georgia
| |
Collapse
|
13
|
Petzold A, Valencia M, Pál B, Mena-Segovia J. Decoding brain state transitions in the pedunculopontine nucleus: cooperative phasic and tonic mechanisms. Front Neural Circuits 2015; 9:68. [PMID: 26582977 PMCID: PMC4628121 DOI: 10.3389/fncir.2015.00068] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 10/15/2015] [Indexed: 02/03/2023] Open
Abstract
Cholinergic neurons of the pedunculopontine nucleus (PPN) are most active during the waking state. Their activation is deemed to cause a switch in the global brain activity from sleep to wakefulness, while their sustained discharge may contribute to upholding the waking state and enhancing arousal. Similarly, non-cholinergic PPN neurons are responsive to brain state transitions and their activation may influence some of the same targets of cholinergic neurons, suggesting that they operate in coordination. Yet, it is not clear how the discharge of distinct classes of PPN neurons organize during brain states. Here, we monitored the in vivo network activity of PPN neurons in the anesthetized rat across two distinct levels of cortical dynamics and their transitions. We identified a highly structured configuration in PPN network activity during slow-wave activity that was replaced by decorrelated activity during the activated state (AS). During the transition, neurons were predominantly excited (phasically or tonically), but some were inhibited. Identified cholinergic neurons displayed phasic and short latency responses to sensory stimulation, whereas the majority of non-cholinergic showed tonic responses and remained at high discharge rates beyond the state transition. In vitro recordings demonstrate that cholinergic neurons exhibit fast adaptation that prevents them from discharging at high rates over prolonged time periods. Our data shows that PPN neurons have distinct but complementary roles during brain state transitions, where cholinergic neurons provide a fast and transient response to sensory events that drive state transitions, whereas non-cholinergic neurons maintain an elevated firing rate during global activation.
Collapse
Affiliation(s)
- Anne Petzold
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford Oxford, UK
| | - Miguel Valencia
- Neurosciences Area, CIMA, Universidad de Navarra Pamplona, Spain ; IdiSNA, Navarra Institute for Health Research Pamplona, Spain
| | - Balázs Pál
- Department of Physiology, Faculty of Medicine University of Debrecen Debrecen, Hungary
| | - Juan Mena-Segovia
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford Oxford, UK ; Center for Molecular and Behavioral Neuroscience, Rutgers University Newark, NJ, USA
| |
Collapse
|
14
|
Galvan A, Hu X, Rommelfanger KS, Pare JF, Khan ZU, Smith Y, Wichmann T. Localization and function of dopamine receptors in the subthalamic nucleus of normal and parkinsonian monkeys. J Neurophysiol 2014; 112:467-79. [PMID: 24760789 DOI: 10.1152/jn.00849.2013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The subthalamic nucleus (STN) receives a dopaminergic innervation from the substantia nigra pars compacta, but the role of this projection remains poorly understood, particularly in primates. To address this issue, we used immuno-electron microscopy to localize D1, D2, and D5 dopamine receptors in the STN of rhesus macaques and studied the electrophysiological effects of activating D1-like or D2-like receptors in normal and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated parkinsonian monkeys. Labeling of D1 and D2 receptors was primarily found presynaptically, on preterminal axons and putative glutamatergic and GABAergic terminals, while D5 receptors were more significantly expressed postsynaptically, on dendritic shafts of STN neurons. The electrical spiking activity of STN neurons, recorded with standard extracellular recording methods, was studied before, during, and after intra-STN administration of the dopamine D1-like receptor agonist SKF82958, the D2-like receptor agonist quinpirole, or artificial cerebrospinal fluid (control injections). In normal animals, administration of SKF82958 significantly reduced the spontaneous firing but increased the rate of intraburst firing and the proportion of pause-burst sequences of firing. Quinpirole only increased the proportion of such pause-burst sequences in STN neurons of normal monkeys. In MPTP-treated monkeys, the D1-like receptor agonist also reduced the firing rate and increased the proportion of pause-burst sequences, while the D2-like receptor agonist did not change any of the chosen descriptors of the firing pattern of STN neurons. Our data suggest that dopamine receptor activation can directly modulate the electrical activity of STN neurons by pre- and postsynaptic mechanisms in both normal and parkinsonian states, predominantly via activation of D1 receptors.
Collapse
Affiliation(s)
- Adriana Galvan
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia; Department of Neurology, School of Medicine, Emory University, Atlanta, Georgia; Udall Center of Excellence for Parkinson's Disease Research, Emory University, Atlanta, Georgia;
| | - Xing Hu
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia
| | - Karen S Rommelfanger
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia; Department of Neurology, School of Medicine, Emory University, Atlanta, Georgia
| | - Jean-Francois Pare
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia
| | - Zafar U Khan
- Laboratory of Neurobiology at CIMES, Faculty of Medicine, University of Malaga, Malaga, Spain; Department of Medicine, Faculty of Medicine, University of Malaga, Malaga, Spain; and CIBERNED, Institute of Health Carlos III, Madrid, Spain
| | - Yoland Smith
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia; Department of Neurology, School of Medicine, Emory University, Atlanta, Georgia; Udall Center of Excellence for Parkinson's Disease Research, Emory University, Atlanta, Georgia
| | - Thomas Wichmann
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia; Department of Neurology, School of Medicine, Emory University, Atlanta, Georgia; Udall Center of Excellence for Parkinson's Disease Research, Emory University, Atlanta, Georgia
| |
Collapse
|
15
|
Bogenpohl J, Galvan A, Hu X, Wichmann T, Smith Y. Metabotropic glutamate receptor 4 in the basal ganglia of parkinsonian monkeys: ultrastructural localization and electrophysiological effects of activation in the striatopallidal complex. Neuropharmacology 2013; 66:242-52. [PMID: 22634360 PMCID: PMC3490034 DOI: 10.1016/j.neuropharm.2012.05.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 03/14/2012] [Accepted: 05/13/2012] [Indexed: 11/23/2022]
Abstract
Group III metabotropic glutamate receptors (mGluR4,7,8) are widely distributed in the basal ganglia. Injection of group III mGluR agonists into the striatopallidal complex alleviates parkinsonian symptoms in 6-hydroxydopamine-treated rats. In vitro rodent studies have suggested that this may be partly due to modulation of synaptic transmission at striatopallidal and corticostriatal synapses through mGluR4 activation. However, the in vivo electrophysiological effects of group III mGluRs activation upon basal ganglia neurons activity in nonhuman primates remain unknown. Thus, in order to examine the anatomical substrates and physiological effects of group III mGluRs activation upon striatal and pallidal neurons in monkeys, we used electron microscopy immunohistochemistry to localize mGluR4, combined with local administration of the group III mGluR agonist L-AP4, or the mGluR4 positive allosteric modulator VU0155041, to assess the effects of group III mGluR activation on the firing rate and pattern of striatal and pallidal neurons in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated parkinsonian monkeys. At the ultrastructural level, striatal mGluR4 immunoreactivity was localized in pre- (60%) and post-synaptic (30%) elements, while in the GPe, mGluR4 was mainly expressed pre-synaptically (90%). In the putamen, terminals expressing mGluR4 were evenly split between putative excitatory and inhibitory terminals, while in the GPe, most labeled terminals displayed the ultrastructural features of striatal-like inhibitory terminals, though putative excitatory boutons were also labeled. No significant difference was found between normal and parkinsonian monkeys. Extracellular recordings in awake MPTP-treated monkeys revealed that local microinjections of small volumes of L-AP4 resulted in increased firing rates in one half of striatal cells and one third of pallidal cells, while a significant number of neurons in both structures showed either opposite effects, or did not display any significant rate changes following L-AP4 application. VU0155041 administration had little effect on firing rates. Both compounds also had subtle effects on bursting and oscillatory properties, acting to increase the irregularity of firing. The occurrence of pauses in firing was reduced in the majority (80%) of GPe neurons after L-AP4 injection. Our findings indicate that glutamate can mediate multifarious physiological effects upon striatal and pallidal neurons through activation of pre-synaptic group III mGluRs at inhibitory and excitatory synapses in parkinsonian monkeys. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
Collapse
Affiliation(s)
- James Bogenpohl
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329 USA
- NIH UDALL Center of Excellence for Parkinson’s Disease Research, Emory University, Atlanta, GA 30322 USA
| | - Adriana Galvan
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329 USA
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia 30322 USA
- NIH UDALL Center of Excellence for Parkinson’s Disease Research, Emory University, Atlanta, GA 30322 USA
| | - Xing Hu
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329 USA
- NIH UDALL Center of Excellence for Parkinson’s Disease Research, Emory University, Atlanta, GA 30322 USA
| | - Thomas Wichmann
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329 USA
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia 30322 USA
- NIH UDALL Center of Excellence for Parkinson’s Disease Research, Emory University, Atlanta, GA 30322 USA
| | - Yoland Smith
- Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329 USA
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia 30322 USA
- NIH UDALL Center of Excellence for Parkinson’s Disease Research, Emory University, Atlanta, GA 30322 USA
| |
Collapse
|
16
|
Dependence of Transformation of Intrinsic Rhythmic Impulse Activity of Neurons on Spatio-Temporal Organization of Synaptic Actions on Dendrites: A Simulation Study. NEUROPHYSIOLOGY+ 2012. [DOI: 10.1007/s11062-012-9246-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
17
|
Markin SN, Lemay MA, Prilutsky BI, Rybak IA. Motoneuronal and muscle synergies involved in cat hindlimb control during fictive and real locomotion: a comparison study. J Neurophysiol 2011; 107:2057-71. [PMID: 22190626 DOI: 10.1152/jn.00865.2011] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We compared the activity profiles and synergies of spinal motoneurons recorded during fictive locomotion evoked in immobilized decerebrate cat preparations by midbrain stimulation to the activity profiles and synergies of the corresponding hindlimb muscles obtained during forward level walking in cats. The fictive locomotion data were collected in the Spinal Cord Research Centre, University of Manitoba, and provided by Dr. David McCrea; the real locomotion data were obtained in the laboratories of M. A. Lemay and B. I. Prilutsky. Scatterplot representation and minimum spanning tree clustering algorithm were used to identify the possible motoneuronal and muscle synergies operating during both fictive and real locomotion. We found a close similarity between the activity profiles and synergies of motoneurons innervating one-joint muscles during fictive locomotion and the profiles and synergies of the corresponding muscles during real locomotion. However, the activity patterns of proximal nerves controlling two-joint muscles, such as posterior biceps and semitendinosus (PBSt) and rectus femoris (RF), were not uniform in fictive locomotion preparations and differed from the activity profiles of the corresponding two-joint muscles recorded during forward level walking. Moreover, the activity profiles of these nerves and the corresponding muscles were unique and could not be included in the synergies identified in fictive and real locomotion. We suggest that afferent feedback is involved in the regulation of locomotion via motoneuronal synergies controlled by the spinal central pattern generator (CPG) but may also directly affect the activity of motoneuronal pools serving two-joint muscles (e.g., PBSt and RF). These findings provide important insights into the organization of the spinal CPG in mammals, the motoneuronal and muscle synergies engaged during locomotion, and their afferent control.
Collapse
Affiliation(s)
- Sergey N Markin
- Dept. of Neurobiology and Anatomy, Drexel Univ. College of Medicine, Philadelphia, PA 19129, USA
| | | | | | | |
Collapse
|
18
|
Whitford M, Kukulka CG. Task-related variations in the surface EMG of the human first dorsal interosseous muscle. Exp Brain Res 2011; 215:101-13. [PMID: 21964867 DOI: 10.1007/s00221-011-2875-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 09/09/2011] [Indexed: 11/30/2022]
Abstract
Evidence from human and animal studies suggests that motor neuron pool organization is not uniform for all motor tasks. Groupings of motor units within a muscle may be recruited differentially for a given task based on principles beyond anatomical or architectural features of the muscle alone. This study aimed to determine whether: (1) there was differential activation across locations of the first dorsal interosseous (FDI) muscle during a given task, (2) the differential activation was related to directional requirements and/or end goal of the task, and (3) there was an anatomical pattern to the differential activation. Twenty-six healthy right-handed participants carried out isometric finger/hand contractions in sitting while surface EMG was collected from 4 bipolar sites on the FDI muscle simultaneously. The tasks included: abduction, flexion, diagonal, 30% abduction + 30% flexion, 30% flexion + 30% abduction, key pinch, and power grasp. Mean peak integrated EMG for each task was normalized to site and task specific mean M waves. Differential activation was evident across FDI sites based on movement direction, order of directional components within a combination condition, and end goal of the task. There was greatest activation in the distal ulnar site for all tasks. Additionally there was a trend toward an ordering effect in the amount of activation at each site: distal ulnar > distal radial > proximal radial > proximal ulnar.
Collapse
Affiliation(s)
- Maureen Whitford
- National Rehabilitation Hospital, Neuroscience Research Center, 102 Irving Street NW, Washington, DC, 20010, USA.
| | | |
Collapse
|
19
|
Galvan A, Hu X, Smith Y, Wichmann T. Localization and pharmacological modulation of GABA-B receptors in the globus pallidus of parkinsonian monkeys. Exp Neurol 2011; 229:429-39. [PMID: 21419765 DOI: 10.1016/j.expneurol.2011.03.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 03/10/2011] [Accepted: 03/11/2011] [Indexed: 01/11/2023]
Abstract
Changes in GABAergic transmission in the external and internal segments of the globus pallidus (GPe and GPi) contribute to the pathophysiology of the basal ganglia network in Parkinson's disease. Because GABA-B receptors are involved in the modulation of GABAergic transmission in GPe and GPi, it is possible that changes in the functions or localization of these receptors contribute to the changes in GABAergic transmission. To further examine this question, we investigated the anatomical localization of GABA-B receptors and the electrophysiologic effects of microinjections of GABA-B receptor ligands in GPe and GPi of MPTP-treated (parkinsonian) monkeys. We found that the pattern of cellular and ultrastructural localization of the GABA-BR1 subunit of the GABA-B receptor in GPe and GPi was not significantly altered in parkinsonian monkeys. However, the magnitude of reduction in firing rate of GPe and GPi neurons produced by microinjections of the GABA-B receptor agonist baclofen was larger in MPTP-treated animals than in normal monkeys. Injections of the GABA-B receptor antagonist CGP55845A were more effective in reducing the firing rate of GPi neurons in parkinsonian monkeys than in normal animals. In addition, the injections of baclofen in GPe and GPi, or of CGP55845A in GPi lead to a significant increase in the proportion of spikes in rebound bursts in parkinsonian animals, but not in normal monkeys. Thus, despite the lack of changes in the localization of GABA-BR1 subunits in the pallidum, GABA-B receptor-mediated effects are altered in the GPe and GPi of parkinsonian monkeys. These changes in GABA-B receptor function may contribute to bursting activities in the parkinsonian state.
Collapse
Affiliation(s)
- Adriana Galvan
- Yerkes National Primate Research Center, 954 Gatewood Road NE, Emory University Atlanta, GA 30329, USA.
| | | | | | | |
Collapse
|
20
|
Barthélemy D, Grey MJ, Nielsen JB, Bouyer L. Involvement of the corticospinal tract in the control of human gait. PROGRESS IN BRAIN RESEARCH 2011; 192:181-97. [PMID: 21763526 DOI: 10.1016/b978-0-444-53355-5.00012-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Given the inherent mechanical complexity of human bipedal locomotion, and that complete spinal cord lesions in human leads to paralysis with no recovery of gait, it is often suggested that the corticospinal tract (CST) has a more predominant role in the control of walking in humans than in other animals. However, what do we actually know about the contribution of the CST to the control of gait? This chapter will provide an overview of this topic based on the premise that a better understanding of the role of the CST in gait will be essential for the design of evidence-based approaches to rehabilitation therapy, which will enhance gait ability and recovery in patients with lesions to the central nervous system (CNS). We review evidence for the involvement of the primary motor cortex and the CST during normal and perturbed walking and during gait adaptation. We will also discuss knowledge on the CST that has been gained from studies involving CNS lesions, with a particular focus on recent data acquired in people with spinal cord injury.
Collapse
Affiliation(s)
- Dorothy Barthélemy
- School of Rehabilitation, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada.
| | | | | | | |
Collapse
|
21
|
Nielsen J, Brittain JS, Halliday D, Marchand-Pauvert V, Mazevet D, Conway B. Reduction of common motoneuronal drive on the affected side during walking in hemiplegic stroke patients. Clin Neurophysiol 2008; 119:2813-8. [DOI: 10.1016/j.clinph.2008.07.283] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Revised: 07/23/2008] [Accepted: 07/26/2008] [Indexed: 11/17/2022]
|
22
|
Brittain JS, Halliday DM, Conway BA, Nielsen JB. Single-trial multiwavelet coherence in application to neurophysiological time series. IEEE Trans Biomed Eng 2007; 54:854-62. [PMID: 17518282 DOI: 10.1109/tbme.2006.889185] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A method of single-trial coherence analysis is presented, through the application of continuous multiwavelets. Multiwavelets allow the construction of spectra and bivariate statistics such as coherence within single trials. Spectral estimates are made consistent through optimal time-frequency localization and smoothing. The use of multiwavelets is considered along with an alternative single-trial method prevalent in the literature, with the focus being on statistical, interpretive and computational aspects. The multiwavelet approach is shown to possess many desirable properties, including optimal conditioning, statistical descriptions and computational efficiency. The methods are then applied to bivariate surrogate and neurophysiological data for calibration and comparative study. Neurophysiological data were recorded intracellularly from two spinal motoneurones innervating the posterior biceps muscle during fictive locomotion in the decerebrated cat.
Collapse
|
23
|
Perreault MC, Pastor-Bernier A, Renaud JS, Roux S, Glover JC. C fragment of tetanus toxin hybrid proteins evaluated for muscle-specific transsynaptic mapping of spinal motor circuitry in the newborn mouse. Neuroscience 2006; 141:803-816. [PMID: 16713105 DOI: 10.1016/j.neuroscience.2006.04.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Revised: 03/08/2006] [Accepted: 04/02/2006] [Indexed: 11/17/2022]
Abstract
We investigated whether the non-toxic C fragment of tetanus toxin (TTC) fused to either beta-galactosidase or green fluorescent protein could be utilized to transsynaptically trace muscle-specific spinal circuitry in the neonatal mouse after i.m. injection into a single hindlimb muscle. We found that even with careful low volume injection (0.2-1.0 microl) into a single muscle (medial gastrocnemius), the TTC hybrid proteins spread rapidly to many other hindlimb muscles and to trunk musculature such that retrograde labeling of motoneurons could not be constrained to a single motoneuron pool. Retrogradely labeled motoneurons in the lower lumbar segments harboring the medial gastrocnemius motoneuron pool were first observed two hours after the medial gastrocnemius injection. Within the next 10 h, additional lumbar and lower thoracic motoneurons became labeled, and punctate labeling in the neuropil surrounding the motoneurons appeared. Many of the TTC hybrid protein-labeled puncta in the neuropil co-localized synaptotagmin, indicating that they represent presynaptic axon terminals onto motoneurons. Although this is consistent with retrograde transsynaptic passage, we found no evidence that the TTC hybrid proteins were transported further along premotor axons to label interneuron somata. The i.m. TTC injection procedure described here therefore provides an important tool for the study of presynaptic terminals onto motoneurons. However, additional technical modifications will be required to utilize TTC tracers for transsynaptic mapping of muscle-specific spinal motor circuitry in the neonatal mouse. We provide here a set of criteria for assessing the i.m. delivery of TTC tracers as a basis for future improvements in this technique.
Collapse
Affiliation(s)
- M-C Perreault
- Department of Physiology, University of Oslo, Domus Medica, Sognsvannsveien 9, POB 1103 Blindern, N-0317 Oslo, Norway.
| | - A Pastor-Bernier
- Department of Physiology, University of Oslo, Domus Medica, Sognsvannsveien 9, POB 1103 Blindern, N-0317 Oslo, Norway
| | - J-S Renaud
- Department of Physiology, University of Oslo, Domus Medica, Sognsvannsveien 9, POB 1103 Blindern, N-0317 Oslo, Norway
| | - S Roux
- Unité d'Embryologie Moléculaire, Institut Pasteur, Unités de Recherche Associées 2578, Centre National de la Recherche Scientifique, 25 rue du Dr roux, 75724 Paris, France
| | - J C Glover
- Department of Physiology, University of Oslo, Domus Medica, Sognsvannsveien 9, POB 1103 Blindern, N-0317 Oslo, Norway
| |
Collapse
|